National Library of Energy BETA

Sample records for hydrates system dynamics

  1. Oil & Natural Gas Technology Temporal Characterization of Hydrates System Dynamics beneath Seafloor

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Oil & Natural Gas Technology Temporal Characterization of Hydrates System Dynamics beneath Seafloor Mounds: Integrating Time-Lapse Electrical Resistivity Methods and In Situ Observations of Multiple Oceanographic Parameters Final Technical Report Project Period: October 1, 2012 - January 31, 2015 Submitted by: Carol Blanton Lutken, Leonardo Macelloni, Marco D'Emidio, John Dunbar, Paul Higley August, 2015 DOE Award No.: DE- FE0010141 The University of Mississippi Mississippi Mineral Resources

  2. Gas hydrate cool storage system

    DOE Patents [OSTI]

    Ternes, M.P.; Kedl, R.J.

    1984-09-12

    The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)

  3. Temporal Characterization of Hydrates System Dynamics beneath Seafloor Mounds. Integrating Time-Lapse Electrical Resistivity Methods and In Situ Observations of Multiple Oceanographic Parameters

    SciTech Connect (OSTI)

    Lutken, Carol; Macelloni, Leonardo; D'Emidio, Marco; Dunbar, John; Higley, Paul

    2015-01-31

    This study was designed to investigate temporal variations in hydrate system dynamics by measuring changes in volumes of hydrate beneath hydrate-bearing mounds on the continental slope of the northern Gulf of Mexico, the landward extreme of hydrate occurrence in this region. Direct Current Resistivity (DCR) measurements were made contemporaneously with measurements of oceanographic parameters at Woolsey Mound, a carbonate-hydrate complex on the mid-continental slope, where formation and dissociation of hydrates are most vulnerable to variations in oceanographic parameters affected by climate change, and where changes in hydrate stability can readily translate to loss of seafloor stability, impacts to benthic ecosystems, and venting of greenhouse gases to the water-column, and eventually, the atmosphere. We focused our study on hydrate within seafloor mounds because the structurally-focused methane flux at these sites likely causes hydrate formation and dissociation processes to occur at higher rates than at sites where the methane flux is less concentrated and we wanted to maximize our chances of witnessing association/dissociation of hydrates. We selected a particularly well-studied hydrate-bearing seafloor mound near the landward extent of the hydrate stability zone, Woolsey Mound (MC118). This mid-slope site has been studied extensively and the project was able to leverage considerable resources from the team’s research experience at MC118. The site exhibits seafloor features associated with gas expulsion, hydrates have been documented at the seafloor, and changes in the outcropping hydrates have been documented, photographically, to have occurred over a period of months. We conducted observatory-based, in situ measurements to 1) characterize, geophysically, the sub-bottom distribution of hydrate and its temporal variability, and 2) contemporaneously record relevant environmental parameters (temperature, pressure, salinity, turbidity, bottom currents) to detect short-term changes within the hydrates system, identify relationships/impacts of local oceanographic parameters on the hydrates system, and improve our understanding of how seafloor instability is affected by hydrates-driven changes. A 2009 DCR survey of MC118 demonstrated that we could image resistivity anomalies to a depth of 75m below the seafloor in water depths of 1km. We reconfigured this system to operate autonomously on the seafloor in a pre-programmed mode, for periods of months. We designed and built a novel seafloor lander and deployment capability that would allow us to investigate the seafloor at potential deployment sites and deploy instruments only when conditions met our criteria. This lander held the DCR system, controlling computers, and battery power supply, as well as instruments to record oceanographic parameters. During the first of two cruises to the study site, we conducted resistivity surveying, selected a monitoring site, and deployed the instrumented lander and DCR, centered on what appeared to be the most active locations within the site, programmed to collect a DCR profile, weekly. After a 4.5-month residence on the seafloor, the team recovered all equipment. Unfortunately, several equipment failures occurred prior to recovery of the instrument packages. Prior to the failures, however, two resistivity profiles were collected together with oceanographic data. Results show, unequivocally, that significant changes can occur in both hydrate volume and distribution during time periods as brief as one week. Occurrences appear to be controlled by both deep and near-surface structure. Results have been integrated with seismic data from the area and show correspondence in space of hydrate and structures, including faults and gas chimneys.

  4. Hydration water dynamics and instigation of protein structuralrelaxation

    SciTech Connect (OSTI)

    Russo, Daniela; Hura, Greg; Head-Gordon, Teresa

    2003-09-01

    Until a critical hydration level is reached, proteins do not function. This critical level of hydration is analogous to a similar lack of protein function observed for temperatures below a dynamical temperature range of 180-220K that also is connected to the dynamics of protein surface water. Restoration of some enzymatic activity is observed in partially hydrated protein powders, sometimes corresponding to less than a single hydration layer on the protein surface, which indicates that the dynamical and structural properties of the surface water is intimately connected to protein stability and function. Many elegant studies using both experiment and simulation have contributed important information about protein hydration structure and timescales. The molecular mechanism of the solvent motion that is required to instigate the protein structural relaxation above a critical hydration level or transition temperature has yet to be determined. In this work we use experimental quasi-elastic neutron scattering (QENS) and molecular dynamics simulation to investigate hydration water dynamics near a greatly simplified protein system. We consider the hydration water dynamics near the completely deuterated N-acetyl-leucine-methylamide (NALMA) solute, a hydrophobic amino acid side chain attached to a polar blocked polypeptide backbone, as a function of concentration between 0.5M-2.0M under ambient conditions. We note that roughly 50-60% of a folded protein's surface is equally distributed between hydrophobic and hydrophilic domains, domains whose lengths are on the order of a few water diameters, that justify our study of hydration dynamics of this simple model protein system. The QENS experiment was performed at the NIST Center for Neutron Research, using the disk chopper time of flight spectrometer (DCS). In order to separate the translational and rotational components in the spectra, two sets of experiments were carried out using different incident neutron wavelengths of 7.5{angstrom} and 5.5{angstrom} to give two different time resolutions. All the spectra have been measure at room temperature. The spectra were corrected for the sample holder contribution and normalized using the vanadium standard. The resulting data were analyzed with DAVE programs (http://www.ncnr.nist.gov/dave/). The AMBER force field and SPCE water model were used for modeling the NALMA solute and water, respectively. For the analysis of the water dynamics in the NALMA aqueous solutions, we performed simulations of a dispersed solute configuration consistent with our previous structural analysis, where we had primarily focused on the structural organization of these peptide solutions and their connection to protein folding. Further details of the QENS experiment and molecular dynamics simulations are reported elsewhere.

  5. Nucleation Rate Analysis of Methane Hydrate from Molecular Dynamics Simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yuhara, Daisuke; Barnes, Brian C.; Suh, Donguk; Knott, Brandon C.; Beckham, Gregg T.; Yasuoka, Kenji; Wu, David T.; Amadeu K. Sum

    2015-01-06

    Clathrate hydrates are solid crystalline structures most commonly formed from solutions that have nucleated to form a mixed solid composed of water and gas. Understanding the mechanism of clathrate hydrate nucleation is essential to grasp the fundamental chemistry of these complex structures and their applications. Molecular dynamics (MD) simulation is an ideal method to study nucleation at the molecular level because the size of the critical nucleus and formation rate occur on the nano scale. Moreover, various analysis methods for nucleation have been developed through MD to analyze nucleation. In particular, the mean first-passage time (MFPT) and survival probability (SP)more » methods have proven to be effective in procuring the nucleation rate and critical nucleus size for monatomic systems. This study assesses the MFPT and SP methods, previously used for monatomic systems, when applied to analyzing clathrate hydrate nucleation. Because clathrate hydrate nucleation is relatively difficult to observe in MD simulations (due to its high free energy barrier), these methods have yet to be applied to clathrate hydrate systems. In this study, we have analyzed the nucleation rate and critical nucleus size of methane hydrate using MFPT and SP methods from data generated by MD simulations at 255 K and 50 MPa. MFPT was modified for clathrate hydrate from the original version by adding the maximum likelihood estimate and growth effect term. The nucleation rates were calculated by MFPT and SP methods and are within 5%; the critical nucleus size estimated by the MFPT method was 50% higher, than values obtained through other more rigorous but computationally expensive estimates. These methods can also be extended to the analysis of other clathrate hydrates.« less

  6. Time-dependent water dynamics in hydrated uranyl fluoride

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miskowiec, Andrew J.; Anderson, Brian B.; Herwig, Kenneth W.; Huq, Ashfia; Mamontov, Eugene; Rondinone, Adam; Trowbridge, Lee D.

    2015-09-15

    In this study, uranyl fluoride is a three-layer, hexagonal structure with significant stacking disorder in the c-direction. It supports a range of unsolved ‘thermodynamic’ hydrates with 0–2.5 water molecules per uranium atom, and perhaps more. However, the relationship between water, hydrate crystal structures, and thermodynamic results, collectively representing the chemical pathway through these hydrate structures, has not been sufficiently elucidated. We used high-resolution quasielastic neutron scattering to study the dynamics of water in partially hydrated uranyl fluoride powder over the course of 4 weeks under closed conditions. The spectra are composed of two quasielastic components: one is associated with translationalmore » diffusive motion of water that is approximately five to six times slower than bulk water, and the other is a slow (on the order of 2–300 ps), spatially bounded water motion. The translational component represents water diffusing between the weakly bonded layers in the crystal, while the bounded component may represent water trapped in subnanometre ‘pockets’ formed by the space between uranium-centred polymerisation units. Complementary neutron diffraction measurements do not show any significant structural changes, suggesting that a chemical conversion of the material does not occur in the thermodynamically isolated system on this timescale.« less

  7. Time-dependent water dynamics in hydrated uranyl fluoride

    SciTech Connect (OSTI)

    Miskowiec, Andrew J.; Anderson, Brian B.; Herwig, Kenneth W.; Huq, Ashfia; Mamontov, Eugene; Rondinone, Adam; Trowbridge, Lee D.

    2015-09-15

    In this study, uranyl fluoride is a three-layer, hexagonal structure with significant stacking disorder in the c-direction. It supports a range of unsolved ‘thermodynamic’ hydrates with 0–2.5 water molecules per uranium atom, and perhaps more. However, the relationship between water, hydrate crystal structures, and thermodynamic results, collectively representing the chemical pathway through these hydrate structures, has not been sufficiently elucidated. We used high-resolution quasielastic neutron scattering to study the dynamics of water in partially hydrated uranyl fluoride powder over the course of 4 weeks under closed conditions. The spectra are composed of two quasielastic components: one is associated with translational diffusive motion of water that is approximately five to six times slower than bulk water, and the other is a slow (on the order of 2–300 ps), spatially bounded water motion. The translational component represents water diffusing between the weakly bonded layers in the crystal, while the bounded component may represent water trapped in subnanometre ‘pockets’ formed by the space between uranium-centred polymerisation units. Complementary neutron diffraction measurements do not show any significant structural changes, suggesting that a chemical conversion of the material does not occur in the thermodynamically isolated system on this timescale.

  8. Gas hydrate cool storage system

    DOE Patents [OSTI]

    Ternes, Mark P. (Knoxville, TN); Kedl, Robert J. (Oak Ridge, TN)

    1985-01-01

    This invention is a process for formation of a gas hydrate to be used as a cool storage medium using a refrigerant in water. Mixing of the immiscible refrigerant and water is effected by addition of a surfactant and agitation. The difficult problem of subcooling during the process is overcome by using the surfactant and agitation and performance of the process significantly improves and approaches ideal.

  9. Dynamics of lysozyme and its hydration water under electric field

    SciTech Connect (OSTI)

    Favi, Pelagie M; Zhang, Qiu; O'Neill, Hugh Michael; Mamontov, Eugene; Omar Diallo, Souleymane; Palmer, Jeremy

    2014-01-01

    The effects of static electric field on the dynamics of lysozyme and its hydration water have been investigated by means of incoherent quasi-elastic neutron scattering (QENS). Measurements were performed on lysozyme samples, hydrated respectively with heavy water (D2O) to capture the protein dynamics, and with light water (H2O), to probe the dynamics of the hydration shell, in the temperature range from 210 < T < 260 K. The hydration fraction in both cases was about 0.38 gram of water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm ( 2 106 V/m) for the protein hydrated with D2O and 0 kV and 1 kV/mm for the H2O-hydrated counterpart. While the overall internal protons dynamics of the protein appears to be unaffected by the application of electric field up to 2 kV/mm, likely due to the stronger intra-molecular interactions, there is also no appreciable quantitative enhancement of the diffusive dynamics of the hydration water, as would be anticipated based on our recent observations in water confined in silica pores under field values of 2.5 kV/mm. This may be due to the difference in surface interactions between water and the two adsorption hosts (silica and protein), or to the existence of a critical threshold field value Ec 2 3 kV/mm for increased molecular diffusion, for which electrical breakdown is a limitation for our sample.

  10. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle D.

    1995-01-01

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member and/or six member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone.

  11. Ion mixing, hydration, and transport in aqueous ionic systems

    SciTech Connect (OSTI)

    Tse, Ying-Lung Steve; Voth, Gregory A.; Witten, Thomas A.

    2015-05-14

    The enhancement effect on the ion mobility of fluoride (and that of chloride) in a polycationic system, as the chloride content increases, is shown to also exist in other more simple ionic systems with cations such as the cesium ion and an organic ammonium ion. As the chloride content increases, in addition to the finding that there is more unbound water associated with the cation, we also observe that the average lifetime of a hydrogen bond decreases. This change to the hydrogen bonds is correlated to significant changes to both the structural and dynamical properties of water. The more disordered water structure and faster water dynamics are hypothesized to be also responsible for the enhanced ion mobilities. Furthermore, when either the chloride content or hydration level is changed, the self-diffusion constant of each co-ion changes by almost the same factor, implying the existence of a single universal transport mechanism that determines ion mobilities.

  12. Tricalcium aluminate hydration in additivated systems. A crystallographic

    Office of Scientific and Technical Information (OSTI)

    study by SR-XRPD (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Tricalcium aluminate hydration in additivated systems. A crystallographic study by SR-XRPD Citation Details In-Document Search Title: Tricalcium aluminate hydration in additivated systems. A crystallographic study by SR-XRPD Synchrotron radiation X-ray powder diffraction has been used to monitor the evolution of ettringite in C3A-gypsum synthetic mixture and in commercial cement systems

  13. Metal halogen battery system with multiple outlet nozzle for hydrate

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K.

    1983-06-21

    A metal halogen battery system, including at least one cell having a positive electrode and a negative electrode contacted by aqueous electrolyte containing the material of said metal and halogen, store means whereby halogen hydrate is formed and stored as part of an aqueous material, means for circulating electrolyte through the cell and to the store means, and conduit means for transmitting halogen gas formed in the cell to a hydrate former whereby the hydrate is formed in association with the store means, said store means being constructed in the form of a container which includes a filter means, said filter means being inoperative to separate the hydrate formed from the electrolyte, said system having, a hydrate former pump means associated with the store means and being operative to intermix halogen gas with aqueous electrolyte to form halogen hydrate, said hydrate former means including, multiple outlet nozzle means connected with the outlet side of said pump means and being operative to minimize plugging, said nozzle means being comprised of at least one divider means which is generally perpendicular to the rotational axes of gears within the pump means, said divider means acting to divide the flow from the pump means into multiple outlet flow paths.

  14. Molecular dynamics simulations of methane hydrate using polarizable force fields

    SciTech Connect (OSTI)

    Jiang, H.N.; Jordan, K.D.; Taylor, C.E.

    2007-03-01

    Molecular dynamics simulations of methane hydrate have been carried out using the AMOEBA and COS/G2 polarizable force fields. Properties examined include the temperature dependence of the lattice constant, the OC and OO radial distribution functions and the vibrational spectra. Both the AMOEBA and COS/G2 models are found to successfully account for the available experimental data, with overall slightly better agreement with experiment being found for the AMOEBA model. Several properties calculated using the AMOEBA and COS/G2 models differ appreciable from the corresponding results obtained previously using the polarizable TIP4P-FQ model. This appears to be due to the inadequacy of the treatment of polarization, especially, the restriction of polarization to in-plane only, in the TIP4P-FQ model.

  15. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, E.D. Jr.

    1995-07-11

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.

  16. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle D.

    1995-01-01

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.

  17. {sup 1}H nuclear magnetic resonance study of hydrated water dynamics in perfluorosulfonic acid ionomer Nafion

    SciTech Connect (OSTI)

    Han, Jun Hee; Lee, Kyu Won; Jeon, G. W.; Lee, Cheol Eui; Park, W. K.; Choi, E. H.

    2015-01-12

    We have studied the dynamics of hydrated water molecules in the proton exchange membrane of Nafion by means of high-resolution {sup 1}H nuclear magnetic resonance (NMR) measurements. “Bound” and “free” states of hydrated water clusters as well as the exchange protons were identified from the NMR chemical shift measurements, and their activation energies were obtained from the temperature-dependent laboratory- and rotating-frame spin-lattice relaxation measurements. Besides, a peculiar motional transition in the ultralow frequency region was observed at 373 K for the “free” hydrated water from the rotating-frame NMR spin-lattice relaxation time measurements.

  18. Inter-cage dynamics in structure I, II, and H fluoromethane hydrates as studied by NMR and molecular dynamics simulations

    SciTech Connect (OSTI)

    Trueba, Alondra Torres; Kroon, Maaike C.; Peters, Cor J.; Moudrakovski, Igor L.; Ratcliffe, Christopher I.; Ripmeester, John A.; Alavi, Saman

    2014-06-07

    Prospective industrial applications of clathrate hydrates as materials for gas separation require further knowledge of cavity distortion, cavity selectivity, and defects induction by guest-host interactions. The results presented in this contribution show that under certain temperature conditions the guest combination of CH{sub 3}F and a large polar molecule induces defects on the clathrate hydrate framework that allow intercage guest dynamics. {sup 13}C NMR chemical shifts of a CH{sub 3}F/CH{sub 4}/TBME sH hydrate and a temperature analysis of the {sup 2}H NMR powder lineshapes of a CD{sub 3}F/THF sII and CD{sub 3}F/TBME sH hydrate, displayed evidence that the populations of CH{sub 4} and CH{sub 3}F in the D and D{sup ?} cages were in a state of rapid exchange. A hydrogen bonding analysis using molecular dynamics simulations on the TBME/CH{sub 3}F and TBME/CH{sub 4} sH hydrates showed that the presence of CH{sub 3}F enhances the hydrogen bonding probability of the TBME molecule with the water molecules of the cavity. Similar results were obtained for THF/CH{sub 3}F and THF/CH{sub 4} sII hydrates. The enhanced hydrogen bond formation leads to the formation of defects in the water hydrogen bonding lattice and this can enhance the migration of CH{sub 3}F molecules between adjacent small cages.

  19. Dynamics of a globular protein and its hydration water studied by neutron scattering and MD simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Sow-Hsin; Lagi, Marco; Chu, Xiang-qiang; Zhang, Yang; Kim, Chansoo; Faraone, Antonio; Fratini, Emiliano; Baglioni, Piero

    2010-01-01

    This review article describes our neutron scattering experiments made in the past four years for the understanding of the single-particle (hydrogen atom) dynamics of a protein and its hydration water and the strong coupling between them. We found that the key to this strong coupling is the existence of a fragile-to-strong dynamic crossover (FSC) phenomenon occurring at around T L = 225±5 K in the hydration water. On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the high density form (HDL), a more fluid state, to predominantly the low density formmore » (LDL), a less fluid state, derived from the existence of a liquid–liquid critical point at an elevated pressure. We show experimentally that this sudden switch in the mobility of hydration water on Lysozyme, B-DNA and RNA triggers the dynamic transition, at a temperature T D = 220 K, for these biopolymers. In the glassy state, below T D , the biopolymers lose their vital conformational flexibility resulting in a substantial diminishing of their biological functions. We also performed molecular dynamics (MD) simulations on a realistic model of hydrated lysozyme powder, which confirms the existence of the FSC and the hydration level dependence of the FSC temperature. Furthermore, we show a striking feature in the short time relaxation ( β -relaxation) of protein dynamics, which is the logarithmic decay spanning 3 decades (from ps to ns). The long time α -relaxation shows instead a diffusive behavior, which supports the liquid-like motions of protein constituents. We then discuss our recent high-resolution X-ray inelastic scattering studies of globular proteins, Lysozyme and Bovine Serum Albumin. We were able to measure the dispersion relations of collective, intra-protein phonon-like excitations in these proteins for the first time. We found that the phonon energies show a marked softening and at the same time their population increases substantially in a certain wave vector range when temperature crosses over the T D . Thus the increase of biological activities above T D has positive correlation with activation of slower and large amplitude collective motions of a protein.« less

  20. Water around fullerene shape amphiphiles: A molecular dynamics simulation study of hydrophobic hydration

    SciTech Connect (OSTI)

    Varanasi, S. R. E-mail: guskova@ipfdd.de; John, A.; Guskova, O. A. E-mail: guskova@ipfdd.de; Sommer, J.-U.

    2015-06-14

    Fullerene C{sub 60} sub-colloidal particle with diameter ?1 nm represents a boundary case between small and large hydrophobic solutes on the length scale of hydrophobic hydration. In the present paper, a molecular dynamics simulation is performed to investigate this complex phenomenon for bare C{sub 60} fullerene and its amphiphilic/charged derivatives, so called shape amphiphiles. Since most of the unique properties of water originate from the pattern of hydrogen bond network and its dynamics, spatial, and orientational aspects of water in solvation shells around the solute surface having hydrophilic and hydrophobic regions are analyzed. Dynamical properties such as translational-rotational mobility, reorientational correlation and occupation time correlation functions of water molecules, and diffusion coefficients are also calculated. Slower dynamics of solvent moleculeswater retardationin the vicinity of the solutes is observed. Both the topological properties of hydrogen bond pattern and the dangling OH groups that represent surface defects in water network are monitored. The fraction of such defect structures is increased near the hydrophobic cap of fullerenes. Some dry regions of C{sub 60} are observed which can be considered as signatures of surface dewetting. In an effort to provide molecular level insight into the thermodynamics of hydration, the free energy of solvation is determined for a family of fullerene particles using thermodynamic integration technique.

  1. Additives and method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle Dendy; Christiansen, Richard Lee; Lederhos, Joseph P.; Long, Jin Ping; Panchalingam, Vaithilingam; Du, Yahe; Sum, Amadeu Kun Wan

    1997-01-01

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  2. Additives and method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, E.D. Jr.; Christiansen, R.L.; Lederhos, J.P.; Long, J.P.; Panchalingam, V.; Du, Y.; Sum, A.K.W.

    1997-06-17

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hindrance and/or charge repulsion. Also, polymers having an amide on which a C{sub 1}-C{sub 4} group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  3. Hydrate detection

    SciTech Connect (OSTI)

    Dillon, W.P.; Ahlbrandt, T.S.

    1992-06-01

    Project objectives were: (1) to create methods of analyzing gas hydrates in natural sea-floor sediments, using available data, (2) to make estimates of the amount of gas hydrates in marine sediments, (3) to map the distribution of hydrates, (4) to relate concentrations of gas hydrates to natural processes and infer the factors that control hydrate concentration or that result in loss of hydrate from the sea floor. (VC)

  4. Hydrate detection

    SciTech Connect (OSTI)

    Dillon, W.P.; Ahlbrandt, T.S.

    1992-01-01

    Project objectives were: (1) to create methods of analyzing gas hydrates in natural sea-floor sediments, using available data, (2) to make estimates of the amount of gas hydrates in marine sediments, (3) to map the distribution of hydrates, (4) to relate concentrations of gas hydrates to natural processes and infer the factors that control hydrate concentration or that result in loss of hydrate from the sea floor. (VC)

  5. Some thermodynamical aspects of protein hydration water

    SciTech Connect (OSTI)

    Mallamace, Francesco; Corsaro, Carmelo; Mallamace, Domenico; Vasi, Sebastiano; Vasi, Cirino; Stanley, H. Eugene; Chen, Sow-Hsin

    2015-06-07

    We study by means of nuclear magnetic resonance the self-diffusion of protein hydration water at different hydration levels across a large temperature range that includes the deeply supercooled regime. Starting with a single hydration shell (h = 0.3), we consider different hydrations up to h = 0.65. Our experimental evidence indicates that two phenomena play a significant role in the dynamics of protein hydration water: (i) the measured fragile-to-strong dynamic crossover temperature is unaffected by the hydration level and (ii) the first hydration shell remains liquid at all hydrations, even at the lowest temperature.

  6. System Dynamics Model | NISAC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NISACSystem Dynamics Model

  7. The HD molecule in small and medium cages of clathrate hydrates: Quantum dynamics studied by neutron scattering measurements and computation

    SciTech Connect (OSTI)

    Colognesi, Daniele; Celli, Milva; Ulivi, Lorenzo; Powers, Anna; Xu, Minzhong; Bačić, Zlatko

    2014-10-07

    We report inelastic neutron scattering (INS) measurements on molecular hydrogen deuteride (HD) trapped in binary cubic (sII) and hexagonal (sH) clathrate hydrates, performed at low temperature using two different neutron spectrometers in order to probe both energy and momentum transfer. The INS spectra of binary clathrate samples exhibit a rich structure containing sharp bands arising from both the rotational transitions and the rattling modes of the guest molecule. For the clathrates with sII structure, there is a very good agreement with the rigorous fully quantum simulations which account for the subtle effects of the anisotropy, angular and radial, of the host cage on the HD microscopic dynamics. The sH clathrate sample presents a much greater challenge, due to the uncertainties regarding the crystal structure, which is known only for similar crystals with different promoter, but nor for HD (or H{sub 2}) plus methyl tert-butyl ether (MTBE-d12)

  8. Dynamic Information Architecture System

    Energy Science and Technology Software Center (OSTI)

    1997-02-12

    The Dynamic Information System (DIAS) is a flexible object-based software framework for concurrent, multidiscplinary modeling of arbitrary (but related) processes. These processes are modeled as interrelated actions caused by and affecting the collection of diverse real-world objects represented in a simulation. The DIAS architecture allows independent process models to work together harmoniously in the same frame of reference and provides a wide range of data ingestion and output capabilities, including Geographic Information System (GIS) typemore » map-based displays and photorealistic visualization of simulations in progress. In the DIAS implementation of the object-based approach, software objects carry within them not only the data which describe their static characteristics, but also the methods, or functions, which describe their dynamic behaviors. There are two categories of objects: (1) Entity objects which have real-world counterparts and are the actors in a simulation, and (2) Software infrastructure objects which make it possible to carry out the simulations. The Entity objects contain lists of Aspect objects, each of which addresses a single aspect of the Entity''s behavior. For example, a DIAS Stream Entity representing a section of a river can have many aspects correspondimg to its behavior in terms of hydrology (as a drainage system component), navigation (as a link in a waterborne transportation system), meteorology (in terms of moisture, heat, and momentum exchange with the atmospheric boundary layer), and visualization (for photorealistic visualization or map type displays), etc. This makes it possible for each real-world object to exhibit any or all of its unique behaviors within the context of a single simulation.« less

  9. CONTENTS Gas Hydrate-Bearing Sand

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CONTENTS Gas Hydrate-Bearing Sand Reservoir Systems in the Offshore of India: Results of the India National Gas Hydrate Program Expedition 02 ..............1 The Potential for Abiotic Methane in Arctic Gas Hydrates .................9 Coupled Thermo-Hydro-Chemo- Mechanical (THCM) Models for Hydrate-Bearing Sediments ....13 Emerging Issues in the Development of Geologic Models for Gas Hydrate Numerical Simulation ................19 Announcements ...................... 23 * DOE/NETL FY2016 Methane

  10. Entanglement dynamics in chaotic systems

    SciTech Connect (OSTI)

    Ghose, Shohini [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada); Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Sanders, Barry C. [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada); Centre for Quantum Computer Technology, Macquarie University, Sydney, New South Wales (Australia)

    2004-12-01

    We study quantum chaos for systems with more than one degree of freedom, for which we present an analysis of the dynamics of entanglement. Our analysis explains the main features of entanglement dynamics and identifies entanglement-based signatures of quantum chaos. We discuss entanglement dynamics for a feasible experiment involving an atom in a magneto-optical trap and compare the results with entanglement dynamics for the well-studied quantum kicked top.

  11. CONTENTS Preliminary Results of China's Third Gas Hydrate Drilling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Preliminary Results of China's Third Gas Hydrate Drilling Expedition: A Critical Step From Discovery to Development in the South China Sea ............................1 Gas Hydrate Occurrences in the Black Sea - New Observations from the German SUGAR Project ...............................................6 Methane Hydrate Dynamics on the Northern US Atlantic Margin ............................................ 10 Gas Hydrate, Carbonate Crusts, and Chemosynthetic Organisms on A Vestnesa Ridge

  12. Hydrate decomposition conditions in the system hydrogen sulfide-methane, and propane

    SciTech Connect (OSTI)

    Schroeter, J.P.; Kobayashi, R.; Hildebrand, H.A.

    1982-12-01

    Experimental hydrate decomposition conditions are presented for 3 different H/sub 2/S-containing mixtures in the temperature region 0 C to 30 C. The 3 mixtures investigated were 4% H/sub 2/S, 7% propane, 89% methane; 12% H/sub 2/S, 7% propane, 81% methane; and 30% H/sub 2/S, 7% propane, 63% methane. Hydrate decomposition pressures and temperatures were obtained for each of these mixtures by observation of the pressure-temperature hysteresis curves associated with formation and decomposition of the hydrate crystals. A repeatable decomposition point was observed in every case, and this was identified as the hydrate point. The results for the 4% H/sub 2/S mixture were used to adjust parameters in a computer model based on the Parrish and Prausnitz statistical thermodynamics method, coupled with the BWRS equation of state. After the parameter adjustment, the computer model predicted the behavior of the 12% H/sub 2/S and the 30% H/sub 2/S mixtures to within 2 C. Experimental data for the 3 mixtures are given.

  13. Dynamic granularity of imaging systems

    SciTech Connect (OSTI)

    Geissel, Matthias; Smith, Ian C.; Shores, Jonathon E.; Porter, John L.

    2015-11-04

    Imaging systems that include a specific source, imaging concept, geometry, and detector have unique properties such as signal-to-noise ratio, dynamic range, spatial resolution, distortions, and contrast. Some of these properties are inherently connected, particularly dynamic range and spatial resolution. It must be emphasized that spatial resolution is not a single number but must be seen in the context of dynamic range and consequently is better described by a function or distribution. We introduce the dynamic granularity Gdyn as a standardized, objective relation between a detectors spatial resolution (granularity) and dynamic range for complex imaging systems in a given environment rather than the widely found characterization of detectors such as cameras or films by themselves. We found that this relation can partly be explained through consideration of the signals photon statistics, background noise, and detector sensitivity, but a comprehensive description including some unpredictable data such as dust, damages, or an unknown spectral distribution will ultimately have to be based on measurements. Measured dynamic granularities can be objectively used to assess the limits of an imaging systems performance including all contributing noise sources and to qualify the influence of alternative components within an imaging system. Our article explains the construction criteria to formulate a dynamic granularity and compares measured dynamic granularities for different detectors used in the X-ray backlighting scheme employed at Sandias Z-Backlighter facility.

  14. Dynamic granularity of imaging systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Geissel, Matthias; Smith, Ian C.; Shores, Jonathon E.; Porter, John L.

    2015-11-04

    Imaging systems that include a specific source, imaging concept, geometry, and detector have unique properties such as signal-to-noise ratio, dynamic range, spatial resolution, distortions, and contrast. Some of these properties are inherently connected, particularly dynamic range and spatial resolution. It must be emphasized that spatial resolution is not a single number but must be seen in the context of dynamic range and consequently is better described by a function or distribution. We introduce the “dynamic granularity” Gdyn as a standardized, objective relation between a detector’s spatial resolution (granularity) and dynamic range for complex imaging systems in a given environment rathermore » than the widely found characterization of detectors such as cameras or films by themselves. We found that this relation can partly be explained through consideration of the signal’s photon statistics, background noise, and detector sensitivity, but a comprehensive description including some unpredictable data such as dust, damages, or an unknown spectral distribution will ultimately have to be based on measurements. Measured dynamic granularities can be objectively used to assess the limits of an imaging system’s performance including all contributing noise sources and to qualify the influence of alternative components within an imaging system. Our article explains the construction criteria to formulate a dynamic granularity and compares measured dynamic granularities for different detectors used in the X-ray backlighting scheme employed at Sandia’s Z-Backlighter facility.« less

  15. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Rack, Frank; Bohrmann, Gerhard; Trehu, Anne; Storms, Michael; Schroeder, Derryl

    2002-09-30

    The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the deployment of tools and measurement systems on ODP Leg 204 to study hydrate deposits on Hydrate Ridge, offshore Oregon from July through September, 2002. During Leg 204, we cored and logged 9 sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of hydrates in situ. A 3D seismic survey conducted in 2000 provided images of potential subsurface fluid conduits and indicated the position of the GHSZ throughout the survey region. After coring the first site, we acquired Logging-While-Drilling (LWD) data at all but one site to provide an overview of downhole physical properties. The LWD data confirmed the general position of key seismic stratigraphic horizons and yielded an initial estimate of hydrate concentration through the proxy of in situ electrical resistivity. These records proved to be of great value in planning subsequent coring. The second new hydrate proxy to be tested was infrared thermal imaging of cores on the catwalk as rapidly as possible after retrieval. The thermal images were used to identify hydrate samples and to map estimate the distribution and texture of hydrate within the cores. Geochemical analyses of interstitial waters and of headspace and void gases provide additional information on the distribution and concentration of hydrate within the stability zone, the origin and pathway of fluids into and through the GHSZ, and the rates at which the process of gas hydrate formation is occurring. Bio- and lithostratigraphic description of cores, measurement of physical properties, and in situ pressure core sampling and thermal measurements complement the data set, providing ground-truth tests of inferred physical and sedimentological properties. Among the most interesting preliminary results are: (1) the discovery that gas hydrates are distributed through a broad depth range within the GHSZ and that different physical and chemical proxies for hydrate distribution and concentration give generally consistent results; (2) evidence for the importance of sediment properties for controlling the migration of fluids in the accretionary complex; (3) geochemical indications that the gas hydrate system at Hydrate Ridge contains significant concentrations of higher order hydrocarbons and that fractionation and mixing signals will provide important constraints on gas hydrate dynamics; and (4) the discovery of very high chlorinity values that extend for at least 10 mbsf near the summit, indicating that hydrate formation here must be very rapid.

  16. Dynamical systems probabilistic risk assessment.

    SciTech Connect (OSTI)

    Denman, Matthew R.; Ames, Arlo Leroy

    2014-03-01

    Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.

  17. Simulation and sequential dynamical systems

    SciTech Connect (OSTI)

    Mortveit, H.S.; Reidys, C.M.

    1999-06-01

    Computer simulations have a generic structure. Motivated by this the authors present a new class of discrete dynamical systems that captures this structure in a mathematically precise way. This class of systems consists of (1) a loopfree graph {Upsilon} with vertex set {l_brace}1,2,{hor_ellipsis},n{r_brace} where each vertex has a binary state, (2) a vertex labeled set of functions (F{sub i,{Upsilon}}:F{sub 2}{sup n} {yields} F{sub 2}{sup n}){sub i} and (3) a permutation {pi} {element_of} S{sub n}. The function F{sub i,{Upsilon}} updates the state of vertex i as a function of the states of vertex i and its {Upsilon}-neighbors and leaves the states of all other vertices fixed. The permutation {pi} represents the update ordering, i.e., the order in which the functions F{sub i,{Upsilon}} are applied. By composing the functions F{sub i,{Upsilon}} in the order given by {pi} one obtains the dynamical system (equation given in paper), which the authors refer to as a sequential dynamical system, or SDS for short. The authors will present bounds for the number of functionally different systems and for the number of nonisomorphic digraphs {Gamma}[F{sub {Upsilon}},{pi}] that can be obtained by varying the update order and applications of these to specific graphs and graph classes.

  18. Multiple stage multiple filter hydrate store

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K.

    1983-05-31

    An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means or separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means.

  19. Multiple stage multiple filter hydrate store

    DOE Patents [OSTI]

    Bjorkman, H.K. Jr.

    1983-05-31

    An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means for separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means. 7 figs.

  20. CONTENTS Concentrated Gas Hydrate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Concentrated Gas Hydrate Deposits in the Kumano Forearc Basin, Nankai Trough, Japan .....1 Recent Advances in NETL's Laboratory Studies of Hydrate- Bearing Sediments .......................5 Initial Interpretation of Results from the Iġnik Sikumi Gas Hydrate Exchange Field Trial .. 10 A Fresh Look at the Mediterranean and Black Sea Basins: Potential for High-Quality Hydrate Reservoirs .....................15 Announcements .......................19 * United Nations Hydrate Report Published

  1. Videos of Experiments from ORNL Gas Hydrate Research

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Gas hydrate research performed by the Environmental Sciences Division utilizes the ORNL Seafloor Process Simulator, the Parr Vessel, the Sapphire Cell, a fiber optic distributed sensing system, and Raman spectroscopy. The group studies carbon sequestration in the ocean, desalination, gas hydrates in the solar system, and nucleation and dissociation kinetics. The videos available at the gas hydrates website are very short clips from experiments.

  2. Methane Hydrate Program

    Energy Savers [EERE]

    Fiscal Year 2013 Methane Hydrate Program Report to Congress October 2014 United States Department of Energy Washington, DC 20585 Department of Energy | October 2014 Fiscal Year 2013 Methane Hydrate Program Report to Congress | Page ii Message from the Secretary The Department of Energy is required 1 to submit to Congress an annual report on the actions taken to carry out methane hydrate research. I am pleased to submit the enclosed Report to Congress, Fiscal Year 2013 Methane Hydrate Program.

  3. The effect of reservoir heterogeneity on gas production from hydrate accumulations in the permafrost

    SciTech Connect (OSTI)

    Reagan, M. T.; Kowalsky, M B.; Moridis, G. J.; Silpngarmlert, S.

    2010-05-01

    The quantity of hydrocarbon gases trapped in natural hydrate accumulations is enormous, leading to significant interest in the evaluation of their potential as an energy source. Large volumes of gas can be readily produced at high rates for long times from methane hydrate accumulations in the permafrost by means of depressurization-induced dissociation combined with conventional technologies and horizontal or vertical well configurations. Initial studies on the possibility of natural gas production from permafrost hydrates assumed homogeneity in intrinsic reservoir properties and in the initial condition of the hydrate-bearing layers (either due to the coarseness of the model or due to simplifications in the definition of the system). These results showed great promise for gas recovery from Class 1, 2, and 3 systems in the permafrost. This work examines the consequences of inevitable heterogeneity in intrinsic properties, such as in the porosity of the hydrate-bearing formation, or heterogeneity in the initial state of hydrate saturation. Heterogeneous configurations are generated through multiple methods: (1) through defining heterogeneous layers via existing well-log data, (2) through randomized initialization of reservoir properties and initial conditions, and (3) through the use of geostatistical methods to create heterogeneous fields that extrapolate from the limited data available from cores and well-log data. These extrapolations use available information and established geophysical methods to capture a range of deposit properties and hydrate configurations. The results show that some forms of heterogeneity, such as horizontal stratification, can assist in production of hydrate-derived gas. However, more heterogeneous structures can lead to complex physical behavior within the deposit and near the wellbore that may obstruct the flow of fluids to the well, necessitating revised production strategies. The need for fine discretization is crucial in all cases to capture dynamic behavior during production.

  4. Methane Hydrate Field Program

    SciTech Connect (OSTI)

    2013-12-31

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report. • Historical Methane Hydrate Project Review Report • Methane Hydrate Workshop Report • Topical Report: Marine Methane Hydrate Field Research Plan • Final Scientific/Technical Report

  5. CONTENTS Gas Hydrate Assessment in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Gas Hydrate Assessment in the Northern Gulf of Mexico: Preliminary Results Reveal New Prospects .........................................1 A Global Review of Gas Hydrate Resource Potential ........................5 Prospecting for Gas Hydrate Resources .........................................9 Announcements ...................... 14 * AGU Technical Sessions on Methane Hydrates * Ninth International Methane Hydrate Workshop in Hyderabad, India * Gulf of Mexico JIP Leg II Well Logs Available

  6. Methane Hydrate Program

    Energy Savers [EERE]

    FY 2011 Methane Hydrate Program Report to Congress July 2012 United States Department of Energy Washington, DC 20585 Department of Energy | July 2012 FY 2011 Methane Hydrate Program Report to Congress | Page ii Message from the Secretary Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of methane hydrate research. I am pleased to submit the enclosed report entitled U.S. Department of Energy FY 2011 Methane

  7. Methane Hydrate Program

    Energy Savers [EERE]

    Fiscal Year 2012 Methane Hydrate Program Report to Congress August 2013 United States Department of Energy Washington, DC 20585 Department of Energy | August 2013 Fiscal Year 2012 Methane Hydrate Program Report to Congress | Page ii Message from the Secretary Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the actions taken to carry out methane hydrate research. I am pleased to submit the enclosed report, entitled U.S.

  8. Methane Hydrate Program

    Office of Environmental Management (EM)

    from the Secretary Section 968 of the Energy Policy Act of 2005 requires the Department of ... implications of the potentially vast occurrence of gas hydrate in nature. ...

  9. Gas Hydrate Storage of Natural Gas

    SciTech Connect (OSTI)

    Rudy Rogers; John Etheridge

    2006-03-31

    Environmental and economic benefits could accrue from a safe, above-ground, natural-gas storage process allowing electric power plants to utilize natural gas for peak load demands; numerous other applications of a gas storage process exist. A laboratory study conducted in 1999 to determine the feasibility of a gas-hydrates storage process looked promising. The subsequent scale-up of the process was designed to preserve important features of the laboratory apparatus: (1) symmetry of hydrate accumulation, (2) favorable surface area to volume ratio, (3) heat exchanger surfaces serving as hydrate adsorption surfaces, (4) refrigeration system to remove heat liberated from bulk hydrate formation, (5) rapid hydrate formation in a non-stirred system, (6) hydrate self-packing, and (7) heat-exchanger/adsorption plates serving dual purposes to add or extract energy for hydrate formation or decomposition. The hydrate formation/storage/decomposition Proof-of-Concept (POC) pressure vessel and supporting equipment were designed, constructed, and tested. This final report details the design of the scaled POC gas-hydrate storage process, some comments on its fabrication and installation, checkout of the equipment, procedures for conducting the experimental tests, and the test results. The design, construction, and installation of the equipment were on budget target, as was the tests that were subsequently conducted. The budget proposed was met. The primary goal of storing 5000-scf of natural gas in the gas hydrates was exceeded in the final test, as 5289-scf of gas storage was achieved in 54.33 hours. After this 54.33-hour period, as pressure in the formation vessel declined, additional gas went into the hydrates until equilibrium pressure/temperature was reached, so that ultimately more than the 5289-scf storage was achieved. The time required to store the 5000-scf (48.1 hours of operating time) was longer than designed. The lower gas hydrate formation rate is attributed to a lower heat transfer rate in the internal heat exchanger than was designed. It is believed that the fins on the heat-exchanger tubes did not make proper contact with the tubes transporting the chilled glycol, and pairs of fins were too close for interior areas of fins to serve as hydrate collection sites. A correction of the fabrication fault in the heat exchanger fin attachments could be easily made to provide faster formation rates. The storage success with the POC process provides valuable information for making the process an economically viable process for safe, aboveground natural-gas storage.

  10. SIAM conference on applications of dynamical systems

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    A conference (Oct.15--19, 1992, Snowbird, Utah; sponsored by SIAM (Society for Industrial and Applied Mathematics) Activity Group on Dynamical Systems) was held that highlighted recent developments in applied dynamical systems. The main lectures and minisymposia covered theory about chaotic motion, applications in high energy physics and heart fibrillations, turbulent motion, Henon map and attractor, integrable problems in classical physics, pattern formation in chemical reactions, etc. The conference fostered an exchange between mathematicians working on theoretical issues of modern dynamical systems and applied scientists. This two-part document contains abstracts, conference program, and an author index.

  11. Parallel Implementation of Power System Dynamic Simulation

    SciTech Connect (OSTI)

    Jin, Shuangshuang; Huang, Zhenyu; Diao, Ruisheng; Wu, Di; Chen, Yousu

    2013-07-21

    Dynamic simulation of power system transient stability is important for planning, monitoring, operation, and control of electrical power systems. However, modeling the system dynamics and network involves the computationally intensive time-domain solution of numerous differential and algebraic equations (DAE). This results in a transient stability implementation that may not maintain the real-time constraints of an online security assessment. This paper presents a parallel implementation of the dynamic simulation on a high-performance computing (HPC) platform using parallel simulation algorithms and computation architectures. It enables the simulation to run even faster than real time, enabling the look-ahead capability of upcoming stability problems in the power grid.

  12. Dynamics of micelle-nanoparticle systems undergoing shear: a...

    Office of Scientific and Technical Information (OSTI)

    Dynamics of micelle-nanoparticle systems undergoing shear: a coarse-grained molecular dynamics approach Citation Details In-Document Search Title: Dynamics of micelle-nanoparticle ...

  13. TOUGH-Fx/Hydrate

    Energy Science and Technology Software Center (OSTI)

    2005-02-01

    TOUGH-Fx/HYORATL can model the non-isothermal gas release. phase behavior and flow of fluids and heat in complex geologic media. The code can simulate production from natural gas hydrate deposits in the subsurtace (i.e., in the permafrost and in deep ocean sediments), as well as laboratory experiments of hydrate dissociation/formation in porous/fractured media. T006H-Fx/HYDRATE vi .0 includes both an equilibrium and a kinetic model of hydrate Ibmiation and dissociation. The model accounts for heat and upmore » to four mass components-- i.e., water, CH4, hydrate, and water-soluble inhibitors such as salts or alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice phase and hydrate phase). Hydrate dIssociation or formation, phase changes, and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects, and inhibItor-Induced effects.« less

  14. Detection and Production of Methane Hydrate

    SciTech Connect (OSTI)

    George Hirasaki; Walter Chapman; Gerald Dickens; Colin Zelt; Brandon Dugan; Kishore Mohanty; Priyank Jaiswal

    2011-12-31

    This project seeks to understand regional differences in gas hydrate systems from the perspective of as an energy resource, geohazard, and long-term climate influence. Specifically, the effort will: (1) collect data and conceptual models that targets causes of gas hydrate variance, (2) construct numerical models that explain and predict regional-scale gas hydrate differences in 2-dimensions with minimal 'free parameters', (3) simulate hydrocarbon production from various gas hydrate systems to establish promising resource characteristics, (4) perturb different gas hydrate systems to assess potential impacts of hot fluids on seafloor stability and well stability, and (5) develop geophysical approaches that enable remote quantification of gas hydrate heterogeneities so that they can be characterized with minimal costly drilling. Our integrated program takes advantage of the fact that we have a close working team comprised of experts in distinct disciplines. The expected outcomes of this project are improved exploration and production technology for production of natural gas from methane hydrates and improved safety through understanding of seafloor and well bore stability in the presence of hydrates. The scope of this project was to more fully characterize, understand, and appreciate fundamental differences in the amount and distribution of gas hydrate and how this would affect the production potential of a hydrate accumulation in the marine environment. The effort combines existing information from locations in the ocean that are dominated by low permeability sediments with small amounts of high permeability sediments, one permafrost location where extensive hydrates exist in reservoir quality rocks and other locations deemed by mutual agreement of DOE and Rice to be appropriate. The initial ocean locations were Blake Ridge, Hydrate Ridge, Peru Margin and GOM. The permafrost location was Mallik. Although the ultimate goal of the project was to understand processes that control production potential of hydrates in marine settings, Mallik was included because of the extensive data collected in a producible hydrate accumulation. To date, such a location had not been studied in the oceanic environment. The project worked closely with ongoing projects (e.g. GOM JIP and offshore India) that are actively investigating potentially economic hydrate accumulations in marine settings. The overall approach was fivefold: (1) collect key data concerning hydrocarbon fluxes which is currently missing at all locations to be included in the study, (2) use this and existing data to build numerical models that can explain gas hydrate variance at all four locations, (3) simulate how natural gas could be produced from each location with different production strategies, (4) collect new sediment property data at these locations that are required for constraining fluxes, production simulations and assessing sediment stability, and (5) develop a method for remotely quantifying heterogeneities in gas hydrate and free gas distributions. While we generally restricted our efforts to the locations where key parameters can be measured or constrained, our ultimate aim was to make our efforts universally applicable to any hydrate accumulation.

  15. Comparison and analysis of zinc and cobalt-based systems as catalytic entities for the hydration of carbon dioxide

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lau, E. Y.; Wong, S. E.; Baker, S. E.; Bearinger, J. P.; Koziol, L.; Valdez, C. A.; Satcher, J. H.; Aines, R. D.; Lightstone, F. C.

    2013-06-20

    In nature, the zinc metalloenzyme carbonic anhydrase II (CAII) efficiently catalyzes the conversion of carbon dioxide (CO 2) to bicarbonate under physiological conditions. Efforts have been directed towards the development of small molecule mimetics that can facilitate this process and thus have a beneficial environmental impact, but these efforts have met very limited success. Herein, we undertook quantum mechanical calculations of four mimetics, 1,5,9-triazacyclododedacane, 1,4,7,10-tetraazacyclododedacane, tris(4,5-dimethyl-2-imidazolyl)phosphine, and tris(2-benzimidazolylmethyl)amine, in their complexed form either with the Zn 2+ or the Co 2+ ion and studied their reaction coordinate for CO 2 hydration. These calculations demonstrated that the ability of the complexmore » to maintain a tetrahedral geometry and bind bicarbonate in a unidentate manner were vital for the hydration reaction to proceed favorably. Moreover, these calculations show that the catalytic activity of the examined zinc complexes was insensitive to coordination states for zinc, while coordination states above four were found to have an unfavorable effect on product release for the cobalt counterparts.« less

  16. Reaction dynamics in polyatomic molecular systems

    SciTech Connect (OSTI)

    Miller, W.H.

    1993-12-01

    The goal of this program is the development of theoretical methods and models for describing the dynamics of chemical reactions, with specific interest for application to polyatomic molecular systems of special interest and relevance. There is interest in developing the most rigorous possible theoretical approaches and also in more approximate treatments that are more readily applicable to complex systems.

  17. TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of...

    Office of Scientific and Technical Information (OSTI)

    System Behavior in Hydrate-Bearing Geologic Media Citation Details In-Document Search Title: TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of System Behavior in ...

  18. Very Large System Dynamics Models - Lessons Learned

    SciTech Connect (OSTI)

    Jacob J. Jacobson; Leonard Malczynski

    2008-10-01

    This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

  19. Effect of under-inhibition with methanol and ethylene glycol on the hydrate control process

    SciTech Connect (OSTI)

    Yousif, M.H.

    1996-12-31

    Hydrate control can be achieved by chemical injection. Currently, methanol and ethylene glycol are the most widely used inhibitors in offshore hydrate control operations. To achieve effective hydrate inhibition, a sufficient amount of inhibitor must be injected to shift the thermodynamic equilibrium condition for hydrate formation outside the pipeline operating pressure and temperature. Recently published field experiments showed that hydrate blockages form more readily in under-inhibited systems than in systems completely without inhibitor. A laboratory study is conducted to determine the effect of low concentration (1--5wt%) methanol and ethylene glycol on the hydrate formation process. The results show that, although these chemicals are effective hydrate inhibitors when added in sufficient quantities, they actually enhance the rate of hydrate formation when added at low concentrations to the water. Furthermore, the presence of these chemicals seems to affect the size of the forming hydrate particles.

  20. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting Minutes May 15, 2014 Washington, DC...

  1. International Cooperation in Methane Hydrates | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Oil & Gas Methane Hydrate International Cooperation in Methane Hydrates International Cooperation in Methane Hydrates In 1982 the multi-national Deep Sea Drilling Program ...

  2. Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments [Part 1 of 2

    SciTech Connect (OSTI)

    Bryant, Steven; Juanes, Ruben

    2011-12-31

    In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate saturations. Large volumes (of order one pore volume) of gaseous and aqueous phases must be transported into the gas hydrate stability zone. The driver for this transport is the pressure sink induced by a reduction in occupied pore volume that accompanies the formation of hydrate from gas and water. Pore-scale imbibition models and bed-scale multiphase flow models indicate that the rate-limiting step in converting gas to hydrate is the supply of water to the hydrate stability zone. Moreover, the water supply rate is controlled by capillarity-driven flux for conditions typical of the Alaska North Slope. A meter-scale laboratory experiment confirms that significant volumes of fluid phases move into the hydrate stability zone and that capillarity is essential for the water flux. The model shows that without capillarity-driven flux, large saturations of hydrate cannot form. The observations of thick zones of large saturation at Mallik and Mt Elbert thus suggest that the primary control on these systems is the rate of transport of gaseous and aqueous phases, driven by the pressure sink at the base of the gas hydrate stability zone. A key finding of our project is the elucidation of ?capillary fracturing? as a dominant gas transport mechanism in low-permeability media. We initially investigate this phenomenon by means of grain-scale simulations in which we extended a discrete element mechanics code (PFC, by Itasca) to incorporate the dynamics of first single-phase and then multiphase flow. A reductionist model on a square lattice allows us to determine some of the fundamental dependencies of the mode of gas invasion (capillary fingering, viscous fingering, and fracturing) on the parameters of the system. We then show that the morphology of the gas-invaded region exerts a fundamental control on the fabric of methane hydrate formation, and on the overpressures caused by methane hydrate dissociation. We demonstrate the existence of the different invasion regimes by means of controlled laboratory experiments in a radial cell. We collapse the behavior in the form of a phase diagram fully characterized by two dimensionless groups: a modified capillary number and a ?fracturing number? that reflects the balance between the pressure forces that act to open conduits in the granular pack, and frictional forces that resist it. We use all this small-scale knowledge to propose simple mechanistic models of gas migration and hydrate formation at the geologic bed scale. We propose that methane transport in lake and oceanic sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other methane-rich sediment systems, and to assess its climate feedbacks.

  3. Final Report Computational Analysis of Dynamical Systems

    SciTech Connect (OSTI)

    Guckenheimer, John

    2012-05-08

    This is the final report for DOE Grant DE-FG02-93ER25164, initiated in 1993. This grant supported research of John Guckenheimer on computational analysis of dynamical systems. During that period, seventeen individuals received PhD degrees under the supervision of Guckenheimer and over fifty publications related to the grant were produced. This document contains copies of these publications.

  4. Induced topological pressure for topological dynamical systems

    SciTech Connect (OSTI)

    Xing, Zhitao; Chen, Ercai

    2015-02-15

    In this paper, inspired by the article [J. Jaerisch et al., Stochastics Dyn. 14, 1350016, pp. 1-30 (2014)], we introduce the induced topological pressure for a topological dynamical system. In particular, we prove a variational principle for the induced topological pressure.

  5. Design tools for complex dynamic security systems.

    SciTech Connect (OSTI)

    Byrne, Raymond Harry; Rigdon, James Brian; Rohrer, Brandon Robinson; Laguna, Glenn A.; Robinett, Rush D. III; Groom, Kenneth Neal; Wilson, David Gerald; Bickerstaff, Robert J.; Harrington, John J.

    2007-01-01

    The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systems are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle.

  6. A dynamically reconfigurable data stream processing system

    SciTech Connect (OSTI)

    Nogiec, J.M.; Trombly-Freytag, K.; /Fermilab

    2004-11-01

    This paper describes a component-based framework for data stream processing that allows for configuration, tailoring, and runtime system reconfiguration. The system's architecture is based on a pipes and filters pattern, where data is passed through routes between components. A network of pipes and filters can be dynamically reconfigured in response to a preplanned sequence of processing steps, operator intervention, or a change in one or more data streams. This framework provides several mechanisms supporting dynamic reconfiguration and can be used to build static data stream processing applications such as monitoring or data acquisition systems, as well as self-adjusting systems that can adapt their processing algorithm, presentation layer, or data persistency layer in response to changes in input data streams.

  7. On sequential dynamical systems and simulation

    SciTech Connect (OSTI)

    Barrett, C.L.; Mortveit, H.S.; Reidys, C.M.

    1999-06-01

    The generic structure of computer simulations motivates a new class of discrete dynamical systems that captures this structure in a mathematically precise way. This class of systems consists of (1) a loopfree graph {Upsilon} with vertex set {l_brace}1,2,{hor_ellipsis},n{r_brace} where each vertex has a binary state, (2) a vertex labeled set of functions (F{sub i,{Upsilon}}:F{sub 2}{sup n} {r_arrow} F{sub 2}{sup n}){sub i} and (3) a permutation {pi} {element_of} S{sub n}. The function F{sub i,{Upsilon}} updates the state of vertex i as a function of the states of vertex i and its {Upsilon}-neighbors and leaves the states of all other vertices fixed. The permutation {pi} represents the update ordering, i.e., the order in which the functions F{sub i,{Upsilon}} are applied. By composing the functions F{sub i,{Upsilon}} in the order given by {pi} one obtains the dynamical system (equation given in paper) which the authors refer to as a sequential dynamical system, or SDS for short. The authors will present bounds for the number of functionally different systems and for the number of nonisomorphic digraphs {Gamma}[F{sub {Upsilon}},{pi}] that can be obtained by varying the update order and applications of these to specific graphs and graph classes. This will be done using both combinatorial/algebraic techniques and probabilistic techniques. Finally the authors give results on dynamical system properties for some special systems.

  8. Dynamic graph system for a semantic database

    DOE Patents [OSTI]

    Mizell, David

    2016-04-12

    A method and system in a computer system for dynamically providing a graphical representation of a data store of entries via a matrix interface is disclosed. A dynamic graph system provides a matrix interface that exposes to an application program a graphical representation of data stored in a data store such as a semantic database storing triples. To the application program, the matrix interface represents the graph as a sparse adjacency matrix that is stored in compressed form. Each entry of the data store is considered to represent a link between nodes of the graph. Each entry has a first field and a second field identifying the nodes connected by the link and a third field with a value for the link that connects the identified nodes. The first, second, and third fields represent the rows, column, and elements of the adjacency matrix.

  9. Dynamic graph system for a semantic database

    DOE Patents [OSTI]

    Mizell, David

    2015-01-27

    A method and system in a computer system for dynamically providing a graphical representation of a data store of entries via a matrix interface is disclosed. A dynamic graph system provides a matrix interface that exposes to an application program a graphical representation of data stored in a data store such as a semantic database storing triples. To the application program, the matrix interface represents the graph as a sparse adjacency matrix that is stored in compressed form. Each entry of the data store is considered to represent a link between nodes of the graph. Each entry has a first field and a second field identifying the nodes connected by the link and a third field with a value for the link that connects the identified nodes. The first, second, and third fields represent the rows, column, and elements of the adjacency matrix.

  10. TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of...

    Office of Scientific and Technical Information (OSTI)

    User's Manual: A Code for the Simulation of System Behavior in Hydrate-Bearing Geologic Media Citation Details In-Document Search Title: TOUGH+Hydrate v1.0 User's Manual: A Code ...

  11. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

    Jones, Daniel O.; Walsh, Michael M.

    2003-01-01

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  12. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

    Jones, Daniel O.; Walsh, Michael M.

    1999-01-01

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  13. Methane Hydrate | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane hydrate is a cage-like lattice of ice inside of which are trapped molecules of methane, the chief constituent of natural gas. If methane hydrate is either warmed or ...

  14. Methane Hydrates and Climate Change

    Broader source: Energy.gov [DOE]

    Methane hydrates store huge volumes of methane formed by the bacterial decay of organic matter or leaked from underlying oil and natural gas deposits. The active formation of methane hydrates in...

  15. Methane Hydrate Program Reports | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Program Reports Methane Hydrate Program Reports PDF icon Secretary of Energy Advisory Board Task Force Report on Methane Hydrate PDF icon FY14 Methane Hydrate Report to Congress PDF icon FY13 Methane Hydrate Report to Congress PDF icon FY12 Methane Hydrate Report to Congress More Documents & Publications Methane Hydrate Annual Reports Report of the Task Force on Methane Hydrates Presentations from the March 27th - 28th Methane Hydrates Advisory Committee

  16. Structure And Dynamics of the Hydrated Palladium(II) Ion in Aqueous Solution a QMCF MD Simulation And EXAFS Spectroscopic Study

    SciTech Connect (OSTI)

    Hofer, T.S.; Randolf, B.R.; Shah, S.Adnan Ali; Rode, B.M.; Persson, I.

    2009-06-01

    The pharmacologically and industrially important palladium(II) ion is usually characterised as square-planar structure in aqueous solution, similar to the platinum(II) ion. Our investigations by means of the most modern experimental and theoretical methods give clear indications, however, that the hydrated palladium(II) ion is hexa-coordinated, with four ligands arranged in a plane at 2.0 {angstrom} plus two additional ligands in axial positions showing an elongated bond distance of 2.7-2.8 A. The second shell consists in average of 8.0 ligands at a mean distance of 4.4 {angstrom}. This structure provides a new basis for the interpretation of the kinetic properties of palladium(II) complexes.

  17. Obstacle penetrating dynamic radar imaging system

    DOE Patents [OSTI]

    Romero, Carlos E.; Zumstein, James E.; Chang, John T.; Leach, Jr.. Richard R.

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  18. Dynamic Analysis of Nuclear Energy System Strategies

    Energy Science and Technology Software Center (OSTI)

    2004-06-17

    DANESS is an integrated process model for nuclear energy systems allowing the simulation of multiple reactors and fuel cycles in a continuously changing nuclear reactor park configuration. The model is energy demand driven and simulates all nuclear fuel cycle facilites, up to 10 reactors and fuels. Reactor and fuel cycle facility history are traced and the cost of generating energy is calculated per reactor and for total nuclear energy system. The DANESS model aims atmore » performing dynamic systems analysis of nuclear energy development used for integrated analysis of development paths for nuclear energy, parameter scoping for new nuclear energy systems, economic analysis of nuclear energy, government role analysis, and education.« less

  19. Dynamically stable magnetic suspension/bearing system

    DOE Patents [OSTI]

    Post, Richard F.

    1996-01-01

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw's Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements.

  20. Dynamically stable magnetic suspension/bearing system

    DOE Patents [OSTI]

    Post, R.F.

    1996-02-27

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw`s Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements. 32 figs.

  1. Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments [Part 2 of 2

    SciTech Connect (OSTI)

    Bryant, Steven; Juanes, Ruben

    2011-12-31

    In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate saturations. Large volumes (of order one pore volume) of gaseous and aqueous phases must be transported into the gas hydrate stability zone. The driver for this transport is the pressure sink induced by a reduction in occupied pore volume that accompanies the formation of hydrate from gas and water. Pore-scale imbibition models and bed-scale multiphase flow models indicate that the rate-limiting step in converting gas to hydrate is the supply of water to the hydrate stability zone. Moreover, the water supply rate is controlled by capillarity-driven flux for conditions typical of the Alaska North Slope. A meter-scale laboratory experiment confirms that significant volumes of fluid phases move into the hydrate stability zone and that capillarity is essential for the water flux. The model shows that without capillarity-driven flux, large saturations of hydrate cannot form. The observations of thick zones of large saturation at Mallik and Mt Elbert thus suggest that the primary control on these systems is the rate of transport of gaseous and aqueous phases, driven by the pressure sink at the base of the gas hydrate stability zone. A key finding of our project is the elucidation of ?capillary fracturing? as a dominant gas transport mechanism in low-permeability media. We initially investigate this phenomenon by means of grain-scale simulations in which we extended a discrete element mechanics code (PFC, by Itasca) to incorporate the dynamics of first singlephase and then multiphase flow. A reductionist model on a square lattice allows us to determine some of the fundamental dependencies of the mode of gas invasion (capillary fingering, viscous fingering, and fracturing) on the parameters of the system. We then show that the morphology of the gas-invaded region exerts a fundamental control on the fabric of methane hydrate formation, and on the overpressures caused by methane hydrate dissociation. We demonstrate the existence of the different invasion regimes by means of controlled laboratory experiments in a radial cell. We collapse the behavior in the form of a phase dia

  2. Quantitative Adaptation Analytics for Assessing Dynamic Systems of Systems.

    SciTech Connect (OSTI)

    Gauthier, John H.; Miner, Nadine E.; Wilson, Michael L.; Le, Hai D.; Kao, Gio K; Melander, Darryl J.; Longsine, Dennis Earl; Vander Meer, Robert Charles,

    2015-01-01

    Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combining the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.

  3. Extensions to Dynamic System Simulation of Fissile Solution Systems

    SciTech Connect (OSTI)

    Klein, Steven Karl; Bernardin, John David; Kimpland, Robert Herbert; Spernjak, Dusan

    2015-08-24

    Previous reports have documented the results of applying dynamic system simulation (DSS) techniques to model a variety of fissile solution systems. The SUPO (Super Power) aqueous homogeneous reactor (AHR) was chosen as the benchmark for comparison of model results to experimental data for steadystate operation.1 Subsequently, DSS was applied to additional AHR to verify results obtained for SUPO and extend modeling to prompt critical excursions, ramp reactivity insertions of various magnitudes and rate, and boiling operations in SILENE and KEWB (Kinetic Experiment Water Boiler).2 Additional models for pressurized cores (HRE: Homogeneous Reactor Experiment), annular core geometries, and accelerator-driven subcritical systems (ADAHR) were developed and results reported.3 The focus of each of these models is core dynamics; neutron kinetics, thermal hydraulics, radiolytic gas generation and transport are coupled to examine the time-based evolution of these systems from start-up through transition to steady-state. A common characteristic of these models is the assumption that (a) core cooling system inlet temperature and flow and (b) plenum gas inlet pressure and flow are held constant; no external (to core) component operations that may result in dynamic change to these parameters are considered. This report discusses extension of models to include explicit reference to cooling structures and radiolytic gas handling. The accelerator-driven subcritical generic system model described in References 3 and 4 is used as a basis for this extension.

  4. Dynamic data filtering system and method

    DOE Patents [OSTI]

    Bickford, Randall L; Palnitkar, Rahul M

    2014-04-29

    A computer-implemented dynamic data filtering system and method for selectively choosing operating data of a monitored asset that modifies or expands a learned scope of an empirical model of normal operation of the monitored asset while simultaneously rejecting operating data of the monitored asset that is indicative of excessive degradation or impending failure of the monitored asset, and utilizing the selectively chosen data for adaptively recalibrating the empirical model to more accurately monitor asset aging changes or operating condition changes of the monitored asset.

  5. Investigating the Metastability of Clathrate Hydrates for Energy Storage

    SciTech Connect (OSTI)

    Koh, Carolyn Ann

    2014-11-18

    Important breakthrough discoveries have been achieved from the DOE award on the key processes controlling the synthesis and structure-property relations of clathrate hydrates, which are critical to the development of clathrate hydrates as energy storage materials. Key achievements include: (i) the discovery of key clathrate hydrate building blocks (stable and metastable) leading to clathrate hydrate nucleation and growth; (ii) development of a rapid clathrate hydrate synthesis route via a seeding mechanism; (iii) synthesis-structure relations of H2 + CH4/CO2 binary hydrates to control thermodynamic requirements for energy storage and sequestration applications; (iv) discovery of a new metastable phase present during clathrate hydrate structural transitions. The success of our research to-date is demonstrated by the significant papers we have published in high impact journals, including Science, Angewandte Chemie, J. Am. Chem. Soc. Intellectual Merits of Project Accomplishments: The intellectual merits of the project accomplishments are significant and transformative, in which the fundamental coupled computational and experimental program has provided new and critical understanding on the key processes controlling the nucleation, growth, and thermodynamics of clathrate hydrates containing hydrogen, methane, carbon dioxide, and other guest molecules for energy storage. Key examples of the intellectual merits of the accomplishments include: the first discovery of the nucleation pathways and dominant stable and metastable structures leading to clathrate hydrate formation; the discovery and experimental confirmation of new metastable clathrate hydrate structures; the development of new synthesis methods for controlling clathrate hydrate formation and enclathration of molecular hydrogen. Broader Impacts of Project Accomplishments: The molecular investigations performed in this project on the synthesis (nucleation & growth)-structure-stability relations of clathrate hydrate systems are pivotal in the fundamental understanding of crystalline clathrate hydrates and the discovery of new clathrate hydrate properties and novel materials for a broad spectrum of energy applications, including: energy storage (hydrogen, natural gas); carbon dioxide sequestration; controlling hydrate formation in oil/gas transportation in subsea pipelines. The Project has also enabled the training of undergraduate, graduate and postdoctoral students in computational methods, molecular spectroscopy and diffraction, and measurement methods at extreme conditions of high pressure and low temperature.

  6. Site Selection for DOE/JIP Gas Hydrate Drilling in the Northern Gulf of Mexico

    SciTech Connect (OSTI)

    Collett, T.S.; Riedel, M.; Cochran, J.R.; Boswell, R.M.; Kumar, Pushpendra; Sathe, A.V.

    2008-07-01

    Studies of geologic and geophysical data from the offshore of India have revealed two geologically distinct areas with inferred gas hydrate occurrences: the passive continental margins of the Indian Peninsula and along the Andaman convergent margin. The Indian National Gas Hydrate Program (NGHP) Expedition 01 was designed to study the occurrence of gas hydrate off the Indian Peninsula and along the Andaman convergent margin with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. NGHP Expedition 01 established the presence of gas hydrates in Krishna- Godavari, Mahanadi and Andaman basins. The expedition discovered one of the richest gas hydrate accumulations yet documented (Site 10 in the Krishna-Godavari Basin), documented the thickest and deepest gas hydrate stability zone yet known (Site 17 in Andaman Sea), and established the existence of a fully-developed gas hydrate system in the Mahanadi Basin (Site 19).

  7. Rapid gas hydrate formation process

    DOE Patents [OSTI]

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  8. Methods and systems for combustion dynamics reduction

    DOE Patents [OSTI]

    Kraemer, Gilbert Otto; Varatharajan, Balachandar; Srinivasan, Shiva; Lynch, John Joseph; Yilmaz, Ertan; Kim, Kwanwoo; Lacy, Benjamin; Crothers, Sarah; Singh, Kapil Kumar

    2009-08-25

    Methods and systems for combustion dynamics reduction are provided. A combustion chamber may include a first premixer and a second premixer. Each premixer may include at least one fuel injector, at least one air inlet duct, and at least one vane pack for at least partially mixing the air from the air inlet duct or ducts and fuel from the fuel injector or injectors. Each vane pack may include a plurality of fuel orifices through which at least a portion of the fuel and at least a portion of the air may pass. The vane pack or packs of the first premixer may be positioned at a first axial position and the vane pack or packs of the second premixer may be positioned at a second axial position axially staggered with respect to the first axial position.

  9. Methane Hydrate Advisory Committee | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Hydrate Advisory Committee Methane Hydrate Advisory Committee The Methane Hydrate Advisory Committee was created in response to provisions of the Methane Hydrate Research and Development Act of 2000 and reauthorized by the Energy Policy Act of 2005. The Committee is to advise the Secretary of Energy on potential applications of methane hydrate; assist in developing recommendations and priorities for the methane hydrate research and development program; and submit to Congress one or more

  10. Methane Hydrate Annual Reports | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Annual Reports Methane Hydrate Annual Reports Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of Methane Hydrate research. Listed are the Annual Reports per Fiscal Year. PDF icon FY 13 Methane Hydrates Annual Report to Congress PDF icon FY 12 Methane Hydrates Annual Report to Congress PDF icon FY 11 Methane Hydrates Annual Report to Congress PDF icon FY 10 Methane Hydrates Annual Report to Congress More

  11. Methane Hydrate Reservoir Simulator Code Comparison Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Annual Reports Methane Hydrate Annual Reports Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of Methane Hydrate research. Listed are the Annual Reports per Fiscal Year. PDF icon FY 13 Methane Hydrates Annual Report to Congress PDF icon FY 12 Methane Hydrates Annual Report to Congress PDF icon FY 11 Methane Hydrates Annual Report to Congress PDF icon FY 10 Methane Hydrates Annual Report to Congress More

  12. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2012 Houston, TX PDF icon July 26, 2012 Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting...

  13. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Office of Environmental Management (EM)

    Washington, DC PDF icon July 16, 2013 Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting...

  14. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Energy Savers [EERE]

    DC PDF icon March 27-28, 2014, Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane Hydrate Advisory...

  15. methane_hydrates | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane Hydrates Special Report: Frozen Heat: A Global Outlook on Methane Hydrates The United Nations Environmental Programme released this new, two-volume report in March 2015....

  16. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Broader source: Energy.gov (indexed) [DOE]

    June 6th - 7th, 2013 Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, June 6th-7th, 2013 Methane Hydrate Advisory Committee Meeting...

  17. Methane Hydrate Production Feasibility | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    forms hydrate in the presence of water, low temperatures and high pressures. Alternatively, when the temperature is increased or the pressure decreased so that hydrates are outside ...

  18. Dynamic Object Oriented Requirements System (DOORS) System Test Plan

    SciTech Connect (OSTI)

    JOHNSON, A.L.

    2000-04-01

    The U. S. Department of Energy, Office of River Protection (ORP) will use the Dynamic Object Oriented Requirements System (DOORS) as a tool to assist in identifying, capturing, and maintaining the necessary and sufficient set of requirements for accomplishing the ORP mission. By managing requirements as one integrated set, the ORP will be able to carry out its mission more efficiently and effectively. DOORS is a Commercial-Off-The-Shelf (COTS) requirements management tool. The tool has not been customized for the use of the PIO, at this time.

  19. Dimensions of invariant measures for continuous random dynamical systems

    SciTech Connect (OSTI)

    Bielaczyc, Tomasz; Horbacz, Katarzyna

    2015-03-10

    We consider continuous random dynamical systems with jumps. We estimate the dimension of the invariant measures and apply the results to a model of stochastic gene expression.

  20. Wax and hydrate control with electrical power

    SciTech Connect (OSTI)

    1997-08-01

    Electrical heating of subsea flowlines is an effective way to prevent wax and hydrate information, especially for long transportation distances and in low-temperature deep water. Systems are available for use in conjunction with bundles, pipe-in-pipe, and wet-thermal-insulation systems. These systems provide environmentally friendly fluid-temperature control without chemicals or flaring for pipeline depressurizing. Enhanced production is achieved because no time is lost by unnecessary depressurizing, pigging, heating-medium circulation, or removal of hydrate and wax blockages. The seabed temperature at 100-m and greater water depths may range from 7 to {minus}1.5 C, causing a rapid cooling of the hot well streams being transported in subsea flowlines. Under these supercooling conditions, vulnerable crude oils and multiphase compositions will deposit wax and asphalts; also the gas/water phase may freeze solid with hydrate particles. The paper discusses thermal-insulated flowlines, heat-loss compensation with electrical power, electrical power consumption and operation, and subsea electrical-power distribution system.

  1. Methane Hydrate Advisory Committee Meeting

    Broader source: Energy.gov (indexed) [DOE]

    Methane Hydrate Advisory Committee Meeting May 15, 2014 11:00am - 12:30pm (EDT) Public Access U.S. Department of Energy Forrestal Building, Room 3G-043 1000 Independence Ave., SW...

  2. methane hydrates | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    methane hydrates methane-hydrates.jpg Maintaining a focused vision on what's next is one trait that makes NETL a lab of the future, and methane hydrates are one "cool" part of that vision. Found in Arctic and deep-water marine environments, methane hydrates are an untapped abundant source of natural gas. A hydrate comprises a crystal structure in which frozen water creates a cage that traps molecules of primarily methane (natural gas). NETL researchers are exploring and developing

  3. Response of oceanic hydrate-bearing sediments to thermalstresses

    SciTech Connect (OSTI)

    Moridis, G.J.; Kowalsky, M.B.

    2006-05-01

    In this study, we evaluate the response of oceanicsubsurface systems to thermal stresses caused by the flow of warm fluidsthrough noninsulated well systems crossing hydrate-bearing sediments.Heat transport from warm fluids, originating from deeper reservoirs underproduction, into the geologic media can cause dissociation of the gashydrates. The objective of this study is to determine whether gasevolution from hydrate dissociation can lead to excessive pressurebuildup, and possibly to fracturing of hydrate-bearing formations andtheir confining layers, with potentially adverse consequences on thestability of the suboceanic subsurface. This study also aims to determinewhether the loss of the hydrate--known to have a strong cementing effecton the porous media--in the vicinity of the well, coupled with thesignificant pressure increases, can undermine the structural stability ofthe well assembly.Scoping 1D simulations indicated that the formationintrinsic permeability, the pore compressibility, the temperature of theproduced fluids andthe initial hydrate saturation are the most importantfactors affecting the system response, while the thermal conductivity andporosity (above a certain level) appear to have a secondary effect.Large-scale simulations of realistic systems were also conducted,involving complex well designs and multilayered geologic media withnonuniform distribution of properties and initial hydrate saturationsthat are typical of those expected in natural oceanic systems. Theresults of the 2D study indicate that although the dissociation radiusremains rather limited even after long-term production, low intrinsicpermeability and/or high hydrate saturation can lead to the evolution ofhigh pressures that can threaten the formation and its boundaries withfracturing. Although lower maximum pressures are observed in the absenceof bottom confining layers and in deeper (and thus warmer and morepressurized) systems, the reduction is limited. Wellbore designs withgravel packs that allow gas venting and pressure relief result insubstantially lower pressures.

  4. Generic solar photovoltaic system dynamic simulation model specification.

    SciTech Connect (OSTI)

    Ellis, Abraham; Behnke, Michael Robert; Elliott, Ryan Thomas

    2013-10-01

    This document is intended to serve as a specification for generic solar photovoltaic (PV) system positive-sequence dynamic models to be implemented by software developers and approved by the WECC MVWG for use in bulk system dynamic simulations in accordance with NERC MOD standards. Two specific dynamic models are included in the scope of this document. The first, a Central Station PV System model, is intended to capture the most important dynamic characteristics of large scale (> 10 MW) PV systems with a central Point of Interconnection (POI) at the transmission level. The second, a Distributed PV System model, is intended to represent an aggregation of smaller, distribution-connected systems that comprise a portion of a composite load that might be modeled at a transmission load bus.

  5. Evaluation of the thermodynamic properties of hydrated metal oxide nanoparticles by INS techniques

    SciTech Connect (OSTI)

    Spencer, Elinor; Ross, Dr. Nancy; Parker, Stewart F.; Kolesnikov, Alexander I

    2013-01-01

    In this contribution we will present a detailed methodology for the elucidation of the following aspects of the thermodynamic properties of hydrated metal oxide nanoparticles from high-resolution, low-temperature inelastic neutron scattering (INS) data: (i) the isochoric heat capacity and entropy of the hydration layers both chemi- and physisorbed to the particle surface; (ii) the magnetic contribution to the heat capacity of the nanoparticles. This will include the calculation of the vibrational density of states (VDOS) from the raw INS spectra, and the subsequent extraction of the thermodynamic data from the VDOS. This technique will be described in terms of a worked example namely, cobalt oxide (Co3O4 and CoO). To complement this evaluation of the physical properties of metal oxide nanoparticle systems, we will emphasise the importance of high-resolution, high-energy INS for the determination of the structure and dynamics of the water species, namely molecular (H2O) and dissociated water (OH, hydroxyl), confined to the oxide surfaces. For this component of the chapter we will focus on INS investigations of hydrated isostructural rutile (a-TiO2) and cassiterite (SnO2) nanoparticles. We will complete this discussion of nanoparticle analysis by including an appraisal of the INS instrumentation employed in such studies with particular focus on TOSCA [ISIS, Rutherford Appleton Laboratory (RAL), U.K.] and the newly developed spectrometer SEQUOIA [SNS, Oak Ridge National Laboratory (ORNL), U.S.A].

  6. The structure of CO{sub 2} hydrate between 0.7 and 1.0 GPa

    SciTech Connect (OSTI)

    Tulk, C. A.; Molaison, J. J.; Machida, S.; Klug, D. D.; Lu, H.; Guthrie, M.

    2014-11-07

    A deuterated sample of CO{sub 2} structure I (sI) clathrate hydrate (CO{sub 2}8.3 D{sub 2}O) has been formed and neutron diffraction experiments up to 1.0 GPa at 240 K were performed. The sI CO{sub 2} hydrate transformed at 0.7 GPa into the high pressure phase that had been observed previously by Hirai et al. [J. Phys. Chem. 133, 124511 (2010)] and Bollengier et al. [Geochim. Cosmochim. Acta 119, 322 (2013)], but which had not been structurally identified. The current neutron diffraction data were successfully fitted to a filled ice structure with CO{sub 2} molecules filling the water channels. This CO{sub 2}+water system has also been investigated using classical molecular dynamics and density functional ab initio methods to provide additional characterization of the high pressure structure. Both models indicate the water network adapts a MH-III like filled ice structure with considerable disorder of the orientations of the CO{sub 2} molecule. Furthermore, the disorder appears to be a direct result of the level of proton disorder in the water network. In contrast to the conclusions of Bollengier et al., our neutron diffraction data show that the filled ice phase can be recovered to ambient pressure (0.1?MPa) at 96 K, and recrystallization to sI hydrate occurs upon subsequent heating to 150?K, possibly by first forming low density amorphous ice. Unlike other clathrate hydrate systems, which transform from the sI or sII structure to the hexagonal structure (sH) then to the filled ice structure, CO{sub 2} hydrate transforms directly from the sI form to the filled ice structure.

  7. May 15, 2014 Methane Hydrates Committee Meeting Agenda | Department...

    Office of Environmental Management (EM)

    May 15, 2014 Methane Hydrates Committee Meeting Agenda May 15, 2014 Methane Hydrates Committee Meeting Agenda May 15, 2014 Methane Hydrates Committee Meeting Agenda PDF icon...

  8. Methane Hydrate Advisory Committee Meeting Minutes, March 2010...

    Energy Savers [EERE]

    March 2010 Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane Hydrate Advisory Committee Meeting Minutes March 2010 Washington, DC PDF icon Methane Hydrate...

  9. Methane Hydrate Advisory Committee Meeting Minutes, June 6th...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Hydrate Advisory Committee Meeting Minutes, June 6th-7th, 2013 Methane Hydrate Advisory Committee Meeting Minutes, June 6th-7th, 2013 Methane Hydrate Advisory Committee...

  10. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    SciTech Connect (OSTI)

    Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswell, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.

    2010-11-01

    The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas hydrate petroleum system, to discuss advances, requirement and suggested practices in gas hydrate (GH) prospecting and GH deposit characterization, and to review the associated technical, economic and environmental challenges and uncertainties, including: the accurate assessment of producible fractions of the GH resource, the development of methodologies for identifying suitable production targets, the sampling of hydrate-bearing sediments and sample analysis, the analysis and interpretation of geophysical surveys of GH reservoirs, well testing methods and interpretation of the results, geomechanical and reservoir/well stability concerns, well design, operation and installation, field operations and extending production beyond sand-dominated GH reservoirs, monitoring production and geomechanical stability, laboratory investigations, fundamental knowledge of hydrate behavior, the economics of commercial gas production from hydrates, and the associated environmental concerns.

  11. Dynamic System Simulation of the KRUSTY Experiment (Technical Report) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect SciTech Connect Search Results Technical Report: Dynamic System Simulation of the KRUSTY Experiment Citation Details In-Document Search Title: Dynamic System Simulation of the KRUSTY Experiment The proposed KRUSTY experiment is a demonstration of a reactor operating at power. The planned experimental configuration includes a highly enriched uranium (HEU) reflected core, cooled by multiple heat pipes leading to Stirling engines for primary heat rejection. Operating power is

  12. Dynamic System Simulation of the KRUSTY Experiment (Technical Report) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Technical Report: Dynamic System Simulation of the KRUSTY Experiment Citation Details In-Document Search Title: Dynamic System Simulation of the KRUSTY Experiment × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of

  13. Approximate Bisimulation-Based Reduction of Power System Dynamic Models

    SciTech Connect (OSTI)

    Stankovic, AM; Dukic, SD; Saric, AT

    2015-05-01

    In this paper we propose approximate bisimulation relations and functions for reduction of power system dynamic models in differential- algebraic (descriptor) form. The full-size dynamic model is obtained by linearization of the nonlinear transient stability model. We generalize theoretical results on approximate bisimulation relations and bisimulation functions, originally derived for a class of constrained linear systems, to linear systems in descriptor form. An algorithm for transient stability assessment is proposed and used to determine whether the power system is able to maintain the synchronism after a large disturbance. Two benchmark power systems are used to illustrate the proposed algorithm and to evaluate the applicability of approximate bisimulation relations and bisimulation functions for reduction of the power system dynamic models.

  14. MethaneHydrateRD_FC.indd

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    FOSSIL ENERGY RESEARCH BENEFITS Methane Hydrate R&D "The (DOE) Program has supported and ... The Nati onal Academies 2010 One of these is methane hydrate - molecules of natural gas ...

  15. Natural Gas Hydrates Update 1998-2000

    Reports and Publications (EIA)

    2001-01-01

    Significant events have transpired on the natural gas hydrate research and development front since "Future Supply Potential of Natural Gas Hydrates" appeared in Natural Gas 1998 Issues and Trends and in the Potential Gas Committee's 1998 biennial report.

  16. METHANE HYDRATE ADVISORY COMMITTEE U.S. Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    METHANE HYDRATE ADVISORY COMMITTEE U.S. Department of Energy Advisory Committee Charter - - - - ---- ---- ------ 1. Committee's Official Designation. Methane Hydrate Advisory...

  17. Hydrates_Annual _FY13 Format

    Office of Scientific and Technical Information (OSTI)

    Natural Gas Hydrate Research Fiscal Year 2012, Quarter 2 Progress Report AR Carbon Capture Simulation Initiative (CCSI) January 1, 2012 - March 31, 2012 FWP Number 2012.04.02 Natural Gas Hydrate Research Natural Gas Hydrate Research Annual Report: Natural Gas Hydrate Research 30 September 2013 NETL Technical Report Series Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof,

  18. Natural Gas Hydrates Update 2000-2002

    Reports and Publications (EIA)

    2003-01-01

    Natural gas hydrates research and development (R&D) activity expanded significantly during the 2000-2002.

  19. Methane Hydrate Advisory Committee Charter | Department of Energy

    Energy Savers [EERE]

    Charter Methane Hydrate Advisory Committee Charter Methane Hydrate Advisory Committee Charter PDF icon Methane Hydrate Advisory Committee Charter More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane Hydrate Advisory Committee Meeting Minutes, January 2010 Methane Hydrate Advisory Committee Meeting Minutes, October 2011

  20. Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

    SciTech Connect (OSTI)

    McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.

    2007-09-01

    Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate

  1. Electrical Resistivity Investigation of Gas Hydrate Distribution in Mississippi Canyon Block 118, Gulf of Mexico

    SciTech Connect (OSTI)

    Dunbar, John

    2012-12-31

    Electrical methods offer a geophysical approach for determining the sub-bottom distribution of hydrate in deep marine environments. Methane hydrate is essentially non-conductive. Hence, sediments containing hydrate are more resistive than sediments without hydrates. To date, the controlled source electromagnetic (CSEM) method has been used in marine hydrates studies. This project evaluated an alternative electrical method, direct current resistivity (DCR), for detecting marine hydrates. DCR involves the injection of direct current between two source electrodes and the simultaneous measurement of the electric potential (voltage) between multiple receiver electrodes. The DCR method provides subsurface information comparable to that produced by the CSEM method, but with less sophisticated instrumentation. Because the receivers are simple electrodes, large numbers can be deployed to achieve higher spatial resolution. In this project a prototype seafloor DCR system was developed and used to conduct a reconnaissance survey at a site of known hydrate occurrence in Mississippi Canyon Block 118. The resulting images of sub-bottom resistivities indicate that high-concentration hydrates at the site occur only in the upper 50 m, where deep-seated faults intersect the seafloor. Overall, there was evidence for much less hydrate at the site than previously thought based on available seismic and CSEM data alone.

  2. Sources of biogenic methane to form marine gas hydrates: In situ production or upward migration?

    SciTech Connect (OSTI)

    Paull, C.K.; Ussler, W. III; Borowski, W.S.

    1993-09-01

    Potential sources of biogenic methane in the Carolina Continental Rise -- Blake Ridge sediments have been examined. Two models were used to estimate the potential for biogenic methane production: (1) construction of sedimentary organic carbon budgets, and (2) depth extrapolation of modern microbial production rates. While closed-system estimates predict some gas hydrate formation, it is unlikely that >3% of the sediment volume could be filled by hydrate from methane produced in situ. Formation of greater amounts requires migration of methane from the underlying continental rise sediment prism. Methane may be recycled from below the base of the gas hydrate stability zone by gas hydrate decomposition, upward migration of the methane gas, and recrystallization of gas hydrate within the overlying stability zone. Methane bubbles may also form in the sediment column below the depth of gas hydrate stability because the methane saturation concentration of the pore fluids decreases with increasing depth. Upward migration of methane bubbles from these deeper sediments can add methane to the hydrate stability zone. From these models it appears that recycling and upward migration of methane is essential in forming significant gas hydrate concentrations. In addition, the depth distribution profiles of methane hydrate will differ if the majority of the methane has migrated upward rather than having been produced in situ.

  3. Modeling mesoscopic phenomena in extended dynamical systems

    SciTech Connect (OSTI)

    Bishop, A.; Lomdahl, P.; Jensen, N.G.; Cai, D.S. [Los Alamos National Lab., NM (United States); Mertenz, F. [Bayreuth Univ. (Germany); Konno, Hidetoshi [Tsukuba Univ., Ibaraki (Japan); Salkola, M. [Stanford Univ., CA (United States)

    1997-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development project at the Los Alamos National Laboratory (LANL). We have obtained classes of nonlinear solutions on curved geometries that demonstrate a novel interplay between topology and geometric frustration relevant for nanoscale systems. We have analyzed the nature and stability of localized oscillatory nonlinear excitations (multi-phonon bound states) on discrete nonlinear chains, including demonstrations of successful perturbation theories, existence of quasiperiodic excitations, response to external statistical time-dependent fields and point impurities, robustness in the presence of quantum fluctuations, and effects of boundary conditions. We have demonstrated multi-timescale effects for nonlinear Schroedinger descriptions and shown the success of memory function approaches for going beyond these approximations. In addition we have developed a generalized rate-equation framework that allows analysis of the important creation/annihilation processes in driven nonlinear, nonequilibiium systems.

  4. Reaction dynamics and photochemistry of divalent systems

    SciTech Connect (OSTI)

    Davis, H.F.

    1992-05-01

    Results are presented of molecular beam studies of bimolecular and unimolecular reactions of Ba. Chapter 1 discusses the reaction Ba + NO{sub 2}. Formation of the dominant BaO({sup 1}{Sigma}) + NO products resulted primarily from decay of long-lived Ba{sup +}NO{sub 2}{sup {minus}} collision complexes. Secondary mechanisms led to formation of forward scattered, internally excited BaO, and BaNO + O. D{sub o}(Ba-NO) = 65{plus_minus}20 kcal/mol. Reactions of ground state and electronically excited Ba with water and alcohols are examined in Chapter 2. Reaction of Ba({sup 1}S) + H{sup 2}O led to BaO + H{sub 2}, whereas excited state Ba({sup 1}D) + H{sub 2}O reacted to form BaOH + H. Collisions between Ba and CH{sub 3}OH led to BaOCH{sub 3} + H. Radical channels involve H-atom migration and are promoted by excitation of the incident Ba atom. In Chapter 3, reactions of Ba({sup 1}S) with ClO{sub 2}2 and O{sub 3} are discussed. Again, direct and complex mechanisms were observed. Formation of BaCl + O{sub 2} from decomposition of Ba{sup +}ClO{sub 2}{sup {minus}} accounted for 10% of total reaction crass section. Although Ba + O{sub 3} {yields} BaO + 0{sub 2} occurs primarily by direct reaction mechanisms, the secondary channel Ba + 0{sub 3} {yields} BaO{sub 2} + 0 involved decay of long lived Ba{sup +}O{sub 3}{sup {minus}} intermediates. D{sub o}(Ba{minus}O{sub 2}) = 120 {plus_minus}20 kcal/mol. Photodissociation dynamics of NO{sub 3} is explored in chapter 4. Visible excitation leads to formation of NO + 0{sub 2} and NO{sub 2} + O. Wavelength dependence of branching ratios is investigated. D{sub o}(O-NO{sub 2}) = 48.55 kcal/mole ;and calculate {Delta}H{sub f}(NO{sub 3}) = 17.75 kcal/mole (298K). Chapter 5 discusses the photodissociation of OClO in a molecular beam. Although ClO({sup 2}II) + O({sup 3}P) is dominant, Cl({sup 2}P) + O{sub 2} also forms, with a max yield of 3.9{plus_minus}0.8% near 404nm.

  5. Real-Time Dynamics Monitoring System with Synchronized Phasor Measurements

    Energy Science and Technology Software Center (OSTI)

    2005-01-01

    The Real-Time Dynamics Monitoring System is designed to monitor the dynamics within the power grid and assess the system behavior during normal and disturbance conditions. The RTDMS application was built on the Grid-3P technology platform and takes real-time information collected by Synchronized Phasor Measurement Units (PMU5) or other collection devices and transmitted to a central Phasor Data Concentrator (PDC) for monitoring grid dynamics. The data is sampled 30 times per second and is time-synchronized. Thismore » data is processed to create graphical and geographical displays to provide visualization for frequency/frequency response, voltage magnitudes and angles, voltage angle differences across critical paths as well as real and reactive power-flows on a sub-second and second basis. Software allows for monitoring, tracking, historical data archiving and electric system troubleshooting for reliability management.« less

  6. Modeling pure methane hydrate dissociation using a numerical simulator from a novel combination of X-ray computed tomography and macroscopic data

    SciTech Connect (OSTI)

    Gupta, A.; Moridis, G.J.; Kneafsey, T.J.; Sloan, Jr., E.D.

    2009-08-15

    The numerical simulator TOUGH+HYDRATE (T+H) was used to predict the transient pure methane hydrate (no sediment) dissociation data. X-ray computed tomography (CT) was used to visualize the methane hydrate formation and dissociation processes. A methane hydrate sample was formed from granular ice in a cylindrical vessel, and slow depressurization combined with thermal stimulation was applied to dissociate the hydrate sample. CT images showed that the water produced from the hydrate dissociation accumulated at the bottom of the vessel and increased the hydrate dissociation rate there. CT images were obtained during hydrate dissociation to confirm the radial dissociation of the hydrate sample. This radial dissociation process has implications for dissociation of hydrates in pipelines, suggesting lower dissociation times than for longitudinal dissociation. These observations were also confirmed by the numerical simulator predictions, which were in good agreement with the measured thermal data during hydrate dissociation. System pressure and sample temperature measured at the sample center followed the CH{sub 4} hydrate L{sub w}+H+V equilibrium line during hydrate dissociation. The predicted cumulative methane gas production was within 5% of the measured data. Thus, this study validated our simulation approach and assumptions, which include stationary pure methane hydrate-skeleton, equilibrium hydrate-dissociation and heat- and mass-transfer in predicting hydrate dissociation in the absence of sediments. It should be noted that the application of T+H for the pure methane hydrate system (no sediment) is outside the general applicability limits of T+H.

  7. Integrated dynamic modeling and management system mission analysis

    SciTech Connect (OSTI)

    Lee, A.K.

    1994-12-28

    This document summarizes the mission analysis performed on the Integrated Dynamic Modeling and Management System (IDMMS). The IDMMS will be developed to provide the modeling and analysis capability required to understand the TWRS system behavior in terms of the identified TWRS performance measures. The IDMMS will be used to demonstrate in a verified and validated manner the satisfactory performance of the TWRS system configuration and assurance that the requirements have been satisfied.

  8. Handbook of gas hydrate properties and occurrence

    SciTech Connect (OSTI)

    Kuustraa, V.A.; Hammershaimb, E.C.

    1983-12-01

    This handbook provides data on the resource potential of naturally occurring hydrates, the properties that are needed to evaluate their recovery, and their production potential. The first two chapters give data on the naturally occurring hydrate potential by reviewing published resource estimates and the known and inferred occurrences. The third and fourth chapters review the physical and thermodynamic properties of hydrates, respectively. The thermodynamic properties of hydrates that are discussed include dissociation energies and a simplified method to calculate them; phase diagrams for simple and multi-component gases; the thermal conductivity; and the kinetics of hydrate dissociation. The final chapter evaluates the net energy balance of recovering hydrates and shows that a substantial positive energy balance can theoretically be achieved. The Appendices of the Handbook summarize physical and thermodynamic properties of gases, liquids and solids that can be used in designing and evaluating recovery processes of hydrates. 158 references, 67 figures, 47 tables.

  9. Protein structure and hydration probed by SANS and osmotic stress

    SciTech Connect (OSTI)

    Rau, Dr. Donald [National Institutes of Health

    2008-01-01

    Interactions governing protein folding, stability, recognition, and activity are mediated by hydration. Here, we use small-angle neutron scattering coupled with osmotic stress to investigate the hydration of two proteins, lysozyme and guanylate kinase (GK), in the presence of solutes. By taking advantage of the neutron contrast variation that occurs upon addition of these solutes, the number of protein-associated (solute-excluded) water molecules can be estimated from changes in both the zero-angle scattering intensity and the radius of gyration. Poly(ethylene glycol) exclusion varies with molecular weight. This sensitivity can be exploited to probe structural features such as the large internal GK cavity. For GK, small-angle neutron scattering is complemented by isothermal titration calorimetry with osmoticstress to also measure hydration changes accompanying ligand binding. These results provide a framework for studying other biomolecular systems and assemblies using neutron scattering together with osmotic stress.

  10. Comparison of kinetic and equilibrium reaction models insimulating gas hydrate behavior in porous media

    SciTech Connect (OSTI)

    Kowalsky, Michael B.; Moridis, George J.

    2006-11-29

    In this study we compare the use of kinetic and equilibriumreaction models in the simulation of gas (methane) hydrate behavior inporous media. Our objective is to evaluate through numerical simulationthe importance of employing kinetic versus equilibrium reaction modelsfor predicting the response of hydrate-bearing systems to externalstimuli, such as changes in pressure and temperature. Specifically, we(1) analyze and compare the responses simulated using both reactionmodels for natural gas production from hydrates in various settings andfor the case of depressurization in a hydrate-bearing core duringextraction; and (2) examine the sensitivity to factors such as initialhydrate saturation, hydrate reaction surface area, and numericaldiscretization. We find that for large-scale systems undergoing thermalstimulation and depressurization, the calculated responses for bothreaction models are remarkably similar, though some differences areobserved at early times. However, for modeling short-term processes, suchas the rapid recovery of a hydrate-bearing core, kinetic limitations canbe important, and neglecting them may lead to significantunder-prediction of recoverable hydrate. The use of the equilibriumreaction model often appears to be justified and preferred for simulatingthe behavior of gas hydrates, given that the computational demands forthe kinetic reaction model far exceed those for the equilibrium reactionmodel.

  11. HYDRATE v1.5 OPTION OF TOUGH+ v1.5

    Energy Science and Technology Software Center (OSTI)

    2015-08-27

    HYDRATE v1.5 is a numerical code that for the simulation of the behavior of hydrate-bearing geologic systems, and represents the third update of the code since its first release [Moridis et al., 2008]. It is an option of TOUGH+ v1.5 [Moridis and Pruess, 2014], a successor to the TOUGH2 [Pruess et al., 1999, 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. HYDRATE v1.5 needs themore » TOUGH+ v1.5 core code in order to compile and execute. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available. By solving the coupled equations of mass and heat balance, the fully operational TOUGH+HYDRATE code can model the non-isothermal gas release, phase behavior and flow of fluids and heat under conditions typical of common natural CH4-hydrate deposits (i.e., in the permafrost and in deep ocean sediments) in complex geological media at any scale (from laboratory to reservoir) at which Darcy’s law is valid. TOUGH+HYDRATE v1.5 includes both an equilibrium and a kinetic model of hydrate formation and dissociation. The model accounts for heat and up to four mass components, i.e., water, CH4, hydrate, and water-soluble inhibitors such as salts or alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice phase and hydrate phase). Hydrate dissociation or formation, phase changes and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects and inhibitor-induced effects.« less

  12. Basin scale assessment of gas hydrate dissociation in response to climate change

    SciTech Connect (OSTI)

    Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M.; Cameron-Smith, P.

    2011-07-01

    Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenarios, has only recently been investigated. Field investigations have discovered substantial methane gas plumes exiting the seafloor along the Arctic Ocean margin, and the plumes appear at depths corresponding to the upper limit of a receding gas hydrate stability zone. It has been suggested that these plumes may be the first visible signs of the dissociation of shallow hydrate deposits due to ongoing climate change in the arctic. We simulate the release of methane from oceanic deposits, including the effects of fully-coupled heat transfer, fluid flow, hydrate dissociation, and other thermodynamic processes, for systems representative of segments of the Arctic Ocean margins. The modeling encompasses a range of shallow hydrate deposits from the landward limit of the hydrate stability zone down to water depths beyond the expected range of century-scale temperature changes. We impose temperature changes corresponding to predicted rates of climate change-related ocean warming and examine the possibility of hydrate dissociation and the release of methane. The assessment is performed at local-, regional-, and basin-scales. The simulation results are consistent with the hypothesis that dissociating shallow hydrates alone can result in significant methane fluxes at the seafloor. However, the methane release is likely to be confined to a narrow region of high dissociation susceptibility, defined by depth and temperature, and that any release will be continuous and controlled, rather than explosive. This modeling also establishes the first realistic bounds for methane release along the arctic continental shelf for potential hydrate dissociation scenarios, and ongoing work may help confirm whether climate change is already impacting the stability of the vast oceanic hydrate reservoir.

  13. Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities

    SciTech Connect (OSTI)

    Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina

    2012-09-01

    The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.

  14. Network Randomization and Dynamic Defense for Critical Infrastructure Systems

    SciTech Connect (OSTI)

    Chavez, Adrian R.; Martin, Mitchell Tyler; Hamlet, Jason; Stout, William M.S.; Lee, Erik

    2015-04-01

    Critical Infrastructure control systems continue to foster predictable communication paths, static configurations, and unpatched systems that allow easy access to our nation's most critical assets. This makes them attractive targets for cyber intrusion. We seek to address these attack vectors by automatically randomizing network settings, randomizing applications on the end devices themselves, and dynamically defending these systems against active attacks. Applying these protective measures will convert control systems into moving targets that proactively defend themselves against attack. Sandia National Laboratories has led this effort by gathering operational and technical requirements from Tennessee Valley Authority (TVA) and performing research and development to create a proof-of-concept solution. Our proof-of-concept has been tested in a laboratory environment with over 300 nodes. The vision of this project is to enhance control system security by converting existing control systems into moving targets and building these security measures into future systems while meeting the unique constraints that control systems face.

  15. An Optimization Framework for Dynamic Hybrid Energy Systems

    SciTech Connect (OSTI)

    Wenbo Du; Humberto E Garcia; Christiaan J.J. Paredis

    2014-03-01

    A computational framework for the efficient analysis and optimization of dynamic hybrid energy systems (HES) is developed. A microgrid system with multiple inputs and multiple outputs (MIMO) is modeled using the Modelica language in the Dymola environment. The optimization loop is implemented in MATLAB, with the FMI Toolbox serving as the interface between the computational platforms. Two characteristic optimization problems are selected to demonstrate the methodology and gain insight into the system performance. The first is an unconstrained optimization problem that optimizes the dynamic properties of the battery, reactor and generator to minimize variability in the HES. The second problem takes operating and capital costs into consideration by imposing linear and nonlinear constraints on the design variables. The preliminary optimization results obtained in this study provide an essential step towards the development of a comprehensive framework for designing HES.

  16. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    SciTech Connect (OSTI)

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  17. Development of Alaskan gas hydrate resources

    SciTech Connect (OSTI)

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  18. Simulating the Dynamic Coupling of Market and Physical System Operations

    SciTech Connect (OSTI)

    Widergren, Steven E.; Roop, Joseph M.; Guttromson, Ross T.; Huang, Zhenyu

    2004-06-01

    Abstract-As energy trading products cover shorter time periods and demand response programs move toward real-time pricing, financial market-based activity impacts ever more directly the physical operation of the system. To begin to understand the complex interactions between the market-driven operation signals, the engineered controlled schemes, and the laws of physics, new system modeling and simulation techniques must be explored. This discussion describes requirements for new simulation tools to address such market transaction control interactions and an approach to capture the dynamic coupling between energy markets and the physical operation of the power system appropriate for dispatcher reaction time frames.

  19. A molecular dynamics study of polymer/graphene interfacial systems

    SciTech Connect (OSTI)

    Rissanou, Anastassia N.; Harmandaris, Vagelis

    2014-05-15

    Graphene based polymer nanocomposites are hybrid materials with a very broad range of technological applications. In this work, we study three hybrid polymer/graphene interfacial systems (polystyrene/graphene, poly(methyl methacrylate)/graphene and polyethylene/graphene) through detailed atomistic molecular dynamics (MD) simulations. Density profiles, structural characteristics and mobility aspects are being examined at the molecular level for all model systems. In addition, we compare the properties of the hybrid systems to the properties of the corresponding bulk ones, as well as to theoretical predictions.

  20. Methane Hydrate Program Annual Report to Congress

    Energy Savers [EERE]

    FY 2010 Methane Hydrate Program Annual Report to Congress September 2011 U.S. Department of ENERGY United States Department of Energy Washington, DC 20585 Department of Energy | September 2011 FY 2010 Methane Hydrate Program Annual Report to Congress | Page 2 Message from the Secretary Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of methane hydrate research. I am pleased to submit the enclosed report

  1. MethaneHydrateRD_FC.indd

    Energy Savers [EERE]

    Research and Development Act of 2000 Methane Hydrate Research and Development Act of 2000 Methane Hydrate Research and Development Act of 2000 PDF icon Methane Hydrate Research and Development Act of 2000 More Documents & Publications NATIONAL DEFENSE AUTHORIZATION ACT FOR FISCAL YEAR 2000 E:\PUBLAW\PUBL404.106 Intelligence Reform and Terrorism Prevention Act - December 17, 200

    gas is an important energy resource for the United States, providing nearly one-quarter of total energy use. The

  2. Methane Hydrate Field Studies | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Field Studies Methane Hydrate Field Studies Arctic/Alaska North Slope Field Studies Since 2001, DOE has conducted field trials of exploration and production technology in the Alaska North Slope. Although Alaska methane hydrate resources are smaller than marine deposits and currently lack outlets to commercial markets, Alaska provides an excellent laboratory to study E&P technology. The research also has implications for various Alaska resources, including potential gas hydrate resources for

  3. Methane Hydrates R&D Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... and recommendations for future offshore drilling campaigns. * The University of Texas, ... Gulf of Mexico. * The geophysical evaluation of gas hydrates is being advanced ...

  4. Methane Hydrate Advisory Committee (MHAC) Meeting

    Broader source: Energy.gov (indexed) [DOE]

    the U.S. Department of Energy (DOE) and Designated Federal Officer (DFO) for the Methane Hydrate Advisory Committee (MHAC). She thanked members for their continued...

  5. Physical Properties of Gas Hydrates: A Review

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gabitto, Jorge F.; Tsouris, Costas

    2010-01-01

    Memore » thane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately 10 16   m 3 of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detected by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed.« less

  6. Hydration of Kr(aq) in dilute and concentrated solutions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chaudhari, Mangesh I.; Sabo, Dubravko; Pratt, Lawrence R.; Rempe, Susan B.

    2014-10-13

    Molecular dynamics simulations of water with both multi-Kr and single Kr atomic solutes are carried out to implement quasi-chemical theory evaluation of the hydration free energy of Kr(aq). This approach obtains free energy differences reflecting Kr–Kr interactions at higher concentrations. Those differences are negative changes in hydration free energies with increasing concentrations at constant pressure. The changes are due to a slight reduction of packing contributions in the higher concentration case. The observed Kr–Kr distributions, analyzed with the extrapolation procedure of Krüger et al., yield a modestly attractive osmotic second virial coefficient, B2 ≈ -60 cm3/mol. Moreover, the thermodynamic analysismore » interconnecting these two approaches shows that they are closely consistent with each other, providing support for both approaches.« less

  7. Stochastic dynamics of a delayed bistable system with multiplicative noise

    SciTech Connect (OSTI)

    Dung, Nguyen Tien E-mail: dungnt@fpt.edu.vn

    2014-05-15

    In this paper we investigate the properties of a delayed bistable system under the effect of multiplicative noise. We first prove the existence and uniqueness of the positive solution and show that its moments are uniformly bounded. Then, we study stochastic dynamics of the solution in long time, the lower and upper bounds for the paths and an estimate for the average value are provided.

  8. Small Stirling dynamic isotope power system for robotic space missions

    SciTech Connect (OSTI)

    Bents, D.J.

    1992-08-01

    The design of a multihundred-watt Dynamic Isotope Power System (DIPS), based on the US Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE), is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. The incentive for any dynamic system is that it can save fuel and reduce costs and radiological hazard. Unlike DIPS based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Stirling conversion extends the competitive range for dynamic systems down to a few hundred watts--a power level not previously considered for dynamic systems. The challenge for Stirling conversion will be to demonstrate reliability and life similar to RTG experience. Since the competitive potential of FPSE as an isotope converter was first identified, work has focused on feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within acceptable operating limits. Based on these results, preliminary characterizations of multihundred-watt units have been established.

  9. New Methane Hydrate Research: Investing in Our Energy Future...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    New Methane Hydrate Research: Investing in Our Energy Future New Methane Hydrate Research: Investing in Our Energy Future August 31, 2012 - 1:37pm Addthis Methane hydrates are 3D ...

  10. The Structure and Transport of Water and Hydrated Ions Within Hydrophobic, Nanoscale Channels

    SciTech Connect (OSTI)

    Holt, J K; Herberg, J L; Wu, Y; Schwegler, E; Mehta, A

    2009-06-15

    The purpose of this project includes an experimental and modeling investigation into water and hydrated ion structure and transport at nanomaterials interfaces. This is a topic relevant to understanding the function of many biological systems such as aquaporins that efficiently shuttle water and ion channels that permit selective transport of specific ions across cell membranes. Carbon nanotubes (CNT) are model nanoscale, hydrophobic channels that can be functionalized, making them artificial analogs for these biological channels. This project investigates the microscopic properties of water such as water density distributions and dynamics within CNTs using Nuclear Magnetic Resonance (NMR) and the structure of hydrated ions at CNT interfaces via X-ray Absorption Spectroscopy (XAS). Another component of this work is molecular simulation, which can predict experimental measurables such as the proton relaxation times, chemical shifts, and can compute the electronic structure of CNTs. Some of the fundamental questions this work is addressing are: (1) what is the length scale below which nanoscale effects such as molecular ordering become important, (2) is there a relationship between molecular ordering and transport?, and (3) how do ions interact with CNT interfaces? These are questions of interest to the scientific community, but they also impact the future generation of sensors, filters, and other devices that operate on the nanometer length scale. To enable some of the proposed applications of CNTs as ion filtration media and electrolytic supercapacitors, a detailed knowledge of water and ion structure at CNT interfaces is critical.

  11. Multi-property characterization chamber for geophysical-hydrological investigations of hydrate bearing sediments

    SciTech Connect (OSTI)

    Seol, Yongkoo Choi, Jeong-Hoon; Dai, Sheng

    2014-08-01

    With the increase in the interest of producing natural gas from methane hydrates as well as potential risks of massive hydrate dissociation in the context of global warming, studies have recently shifted from pure hydrate crystals to hydrates in sediments. Such a research focus shift requires a series of innovative laboratory devices that are capable of investigating various properties of hydrate-bearing sediments (HBS). This study introduces a newly developed high pressure testing chamber, i.e., multi-property characterization chamber (MPCC), that allows simultaneous investigation of a series of fundamental properties of HBS, including small-strain stiffness (i.e., P- and S-waves), shear strength, large-strain deformation, stress-volume responses, and permeability. The peripheral coolant circulation system of the MPCC permits stable and accurate temperature control, while the core holder body, made of aluminum, enables X-ray computer tomography scanning to be easily employed for structural and morphological characterization of specimens. Samples of hydrate-bearing sediments are held within a rubber sleeve inside the chamber. The thick sleeve is more durable and versatile than thin membranes while also being much softer than oedometer-type chambers that are incapable of enabling flow tests. Bias introduced by the rubber sleeve during large deformation tests are also calibrated both theoretically and experimentally. This system provides insight into full characterization of hydrate-bearing sediments in the laboratory, as well as pressure core technology in the field.

  12. Dynamic Operations Wayfinding System (DOWS) for Nuclear Power Plants

    SciTech Connect (OSTI)

    Boring, Ronald Laurids; Ulrich, Thomas Anthony; Lew, Roger Thomas

    2015-08-01

    A novel software tool is proposed to aid reactor operators in respond- ing to upset plant conditions. The purpose of the Dynamic Operations Wayfind- ing System (DOWS) is to diagnose faults, prioritize those faults, identify paths to resolve those faults, and deconflict the optimal path for the operator to fol- low. The objective of DOWS is to take the guesswork out of the best way to combine procedures to resolve compound faults, mitigate low threshold events, or respond to severe accidents. DOWS represents a uniquely flexible and dy- namic computer-based procedure system for operators.

  13. Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint

    SciTech Connect (OSTI)

    Wayman, E. N.; Sclavounos, P. D.; Butterfield, S.; Jonkman, J.; Musial, W.

    2006-03-01

    This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of the two concepts was also performed. Key cost components included the material and construction costs of the buoy; material and installation costs of the tethers, mooring lines, and anchor technologies; costs of transporting and installing the system at the chosen site; and the cost of mounting the wind turbine to the platform. The two systems were evaluated based on their static and dynamic performance and the total system installed cost. Both systems demonstrated acceptable motions, and have estimated costs of $1.4-$1.8 million, not including the cost of the wind turbine, the power electronics, or the electrical transmission.

  14. Time lagged ordinal partition networks for capturing dynamics of continuous dynamical systems

    SciTech Connect (OSTI)

    McCullough, Michael; Iu, Herbert Ho-Ching; Small, Michael; Stemler, Thomas

    2015-05-15

    We investigate a generalised version of the recently proposed ordinal partition time series to network transformation algorithm. First, we introduce a fixed time lag for the elements of each partition that is selected using techniques from traditional time delay embedding. The resulting partitions define regions in the embedding phase space that are mapped to nodes in the network space. Edges are allocated between nodes based on temporal succession thus creating a Markov chain representation of the time series. We then apply this new transformation algorithm to time series generated by the Rssler system and find that periodic dynamics translate to ring structures whereas chaotic time series translate to band or tube-like structuresthereby indicating that our algorithm generates networks whose structure is sensitive to system dynamics. Furthermore, we demonstrate that simple network measures including the mean out degree and variance of out degrees can track changes in the dynamical behaviour in a manner comparable to the largest Lyapunov exponent. We also apply the same analysis to experimental time series generated by a diode resonator circuit and show that the network size, mean shortest path length, and network diameter are highly sensitive to the interior crisis captured in this particular data set.

  15. FROZEN HEAT A GLOBAL OUTLOOK ON METHANE GAS HYDRATES EXECUTIVE...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Gumusut- Kakap Taiwan Messoyahka New Zealand Cascadia Margin Japan Sea Mexico Costa Rica Peru Selected gas-hydrates study areas The types of gas hydrate deposits considered most ...

  16. Methane Hydrate Advisory Committee Meeting Minutes, October 2011...

    Office of Environmental Management (EM)

    October 2011 Methane Hydrate Advisory Committee Meeting Minutes, October 2011 Methane Hydrate Advisory Committee Meeting Minutes October 2011 Washington, DC PDF icon Advisory...

  17. Methane Hydrate Advisory Committee Meeting Minutes, January 2010...

    Broader source: Energy.gov (indexed) [DOE]

    0 Atlanta, GA Methane Hydrate Advisory Committee Meeting Minutes, January 2010 More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane...

  18. gas-hydrate-global-assessment | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    gas-hydrate-global-assessment Frozen Heat: A Global Outlook on Methane Hydrate cover of executive summary The United Nations Environmental Programme released this new, two-volume...

  19. Assessment of dynamic energy conversion systems for radioisotope heat sources

    SciTech Connect (OSTI)

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.

  20. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the revolutionary and new Arctic Drilling Platform in search of gas hydrate and free gas accumulations at depths of approximately 1200 to 2500 ft MD. A secondary objective was the gas-charged sands of the uppermost Campanian interval at approximately 3000 ft. Summary results of geophysical analysis of the well are presented in this report.

  1. Extended space expectation values in quantum dynamical system evolutions

    SciTech Connect (OSTI)

    Demiralp, Metin

    2014-10-06

    The time variant power series expansion for the expectation value of a given quantum dynamical operator is well-known and well-investigated issue in quantum dynamics. However, depending on the operator and Hamiltonian singularities this expansion either may not exist or may not converge for all time instances except the beginning of the evolution. This work focuses on this issue and seeks certain cures for the negativities. We work in the extended space obtained by adding all images of the initial wave function under the system Hamiltonians positive integer powers. This requires the introduction of certain appropriately defined weight operators. The resulting better convergence in the temporal power series urges us to call the new defined entities extended space expectation values even though they are constructed over certain weight operators and are somehow pseudo expectation values.

  2. System and method for reducing combustion dynamics in a combustor

    DOE Patents [OSTI]

    Uhm, Jong Ho; Johnson, Thomas Edward; Zuo, Baifang; York, William David

    2015-09-01

    A system for reducing combustion dynamics in a combustor includes an end cap having an upstream surface axially separated from a downstream surface, and tube bundles extend from the upstream surface through the downstream surface. A divider inside a tube bundle defines a diluent passage that extends axially through the downstream surface, and a diluent supply in fluid communication with the divider provides diluent flow to the diluent passage. A method for reducing combustion dynamics in a combustor includes flowing a fuel through tube bundles, flowing a diluent through a diluent passage inside a tube bundle, wherein the diluent passage extends axially through at least a portion of the end cap into a combustion chamber, and forming a diluent barrier in the combustion chamber between the tube bundle and at least one other adjacent tube bundle.

  3. System and method for reducing combustion dynamics in a combustor

    DOE Patents [OSTI]

    Uhm, Jong Ho; Johnson, Thomas Edward; Zuo, Baifang; York, William David

    2013-08-20

    A system for reducing combustion dynamics in a combustor includes an end cap having an upstream surface axially separated from a downstream surface, and tube bundles extend through the end cap. A diluent supply in fluid communication with the end cap provides diluent flow to the end cap. Diluent distributors circumferentially arranged inside at least one tube bundle extend downstream from the downstream surface and provide fluid communication for the diluent flow through the end cap. A method for reducing combustion dynamics in a combustor includes flowing fuel through tube bundles that extend axially through an end cap, flowing a diluent through diluent distributors into a combustion chamber, wherein the diluent distributors are circumferentially arranged inside at least one tube bundle and each diluent distributor extends downstream from the end cap, and forming a diluent barrier in the combustion chamber between at least one pair of adjacent tube bundles.

  4. Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics...

    Office of Scientific and Technical Information (OSTI)

    Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics Model Citation Details In-Document Search Title: Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics ...

  5. Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics...

    Office of Scientific and Technical Information (OSTI)

    Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics Model Earl D. Mattson; Larry Hull; Kara Cafferty 02 PETROLEUM Water Water A system dynamic model was construction...

  6. OTEC Cold Water Pipe-Platform Sub-System Dynamic Interaction...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    OTEC Cold Water Pipe-Platform Sub-System Dynamic Interaction Validation (OPPSDIV) OTEC Cold Water Pipe-Platform Sub-System Dynamic Interaction Validation (OPPSDIV) OTEC Cold Water ...

  7. Overview on Hydrate Coring, Handling and Analysis

    SciTech Connect (OSTI)

    Jon Burger; Deepak Gupta; Patrick Jacobs; John Shillinglaw

    2003-06-30

    Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Worldwide, gas hydrate is estimated to hold about 1016 kg of organic carbon in the form of methane (Kvenvolden et al., 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In June 2002, Westport Technology Center was requested by the Department of Energy (DOE) to prepare a ''Best Practices Manual on Gas Hydrate Coring, Handling and Analysis'' under Award No. DE-FC26-02NT41327. The scope of the task was specifically targeted for coring sediments with hydrates in Alaska, the Gulf of Mexico (GOM) and from the present Ocean Drilling Program (ODP) drillship. The specific subjects under this scope were defined in 3 stages as follows: Stage 1: Collect information on coring sediments with hydrates, core handling, core preservation, sample transportation, analysis of the core, and long term preservation. Stage 2: Provide copies of the first draft to a list of experts and stakeholders designated by DOE. Stage 3: Produce a second draft of the manual with benefit of input from external review for delivery. The manual provides an overview of existing information available in the published literature and reports on coring, analysis, preservation and transport of gas hydrates for laboratory analysis as of June 2003. The manual was delivered as draft version 3 to the DOE Project Manager for distribution in July 2003. This Final Report is provided for records purposes.

  8. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in the project reports.

  9. Methane Recovery from Hydrate-bearing Sediments

    SciTech Connect (OSTI)

    J. Carlos Santamarina; Costas Tsouris

    2011-04-30

    Gas hydrates are crystalline compounds made of gas and water molecules. Methane hydrates are found in marine sediments and permafrost regions; extensive amounts of methane are trapped in the form of hydrates. Methane hydrate can be an energy resource, contribute to global warming, or cause seafloor instability. This study placed emphasis on gas recovery from hydrate bearing sediments and related phenomena. The unique behavior of hydrate-bearing sediments required the development of special research tools, including new numerical algorithms (tube- and pore-network models) and experimental devices (high pressure chambers and micromodels). Therefore, the research methodology combined experimental studies, particle-scale numerical simulations, and macro-scale analyses of coupled processes. Research conducted as part of this project started with hydrate formation in sediment pores and extended to production methods and emergent phenomena. In particular, the scope of the work addressed: (1) hydrate formation and growth in pores, the assessment of formation rate, tensile/adhesive strength and their impact on sediment-scale properties, including volume change during hydrate formation and dissociation; (2) the effect of physical properties such as gas solubility, salinity, pore size, and mixed gas conditions on hydrate formation and dissociation, and it implications such as oscillatory transient hydrate formation, dissolution within the hydrate stability field, initial hydrate lens formation, and phase boundary changes in real field situations; (3) fluid conductivity in relation to pore size distribution and spatial correlation and the emergence of phenomena such as flow focusing; (4) mixed fluid flow, with special emphasis on differences between invading gas and nucleating gas, implications on relative gas conductivity for reservoir simulations, and gas recovery efficiency; (5) identification of advantages and limitations in different gas production strategies with emphasis; (6) detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2; (7) the relevance of fines in otherwise clean sand sediments on gas recovery and related phenomena such as fines migration and clogging, vuggy structure formation, and gas-driven fracture formation during gas production by depressurization.

  10. Dynamic Non-Hierarchical File Systems for Exascale Storage

    SciTech Connect (OSTI)

    Long, Darrell E.; Miller, Ethan L

    2015-02-24

    This constitutes the final report for “Dynamic Non-Hierarchical File Systems for Exascale Storage”. The ultimate goal of this project was to improve data management in scientific computing and high-end computing (HEC) applications, and to achieve this goal we proposed: to develop the first, HEC-targeted, file system featuring rich metadata and provenance collection, extreme scalability, and future storage hardware integration as core design goals, and to evaluate and develop a flexible non-hierarchical file system interface suitable for providing more powerful and intuitive data management interfaces to HEC and scientific computing users. Data management is swiftly becoming a serious problem in the scientific community – while copious amounts of data are good for obtaining results, finding the right data is often daunting and sometimes impossible. Scientists participating in a Department of Energy workshop noted that most of their time was spent “...finding, processing, organizing, and moving data and it’s going to get much worse”. Scientists should not be forced to become data mining experts in order to retrieve the data they want, nor should they be expected to remember the naming convention they used several years ago for a set of experiments they now wish to revisit. Ideally, locating the data you need would be as easy as browsing the web. Unfortunately, existing data management approaches are usually based on hierarchical naming, a 40 year-old technology designed to manage thousands of files, not exabytes of data. Today’s systems do not take advantage of the rich array of metadata that current high-end computing (HEC) file systems can gather, including content-based metadata and provenance1 information. As a result, current metadata search approaches are typically ad hoc and often work by providing a parallel management system to the “main” file system, as is done in Linux (the locate utility), personal computers, and enterprise search appliances. These search applications are often optimized for a single file system, making it difficult to move files and their metadata between file systems. Users have tried to solve this problem in several ways, including the use of separate databases to index file properties, the encoding of file properties into file names, and separately gathering and managing provenance data, but none of these approaches has worked well, either due to limited usefulness or scalability, or both. Our research addressed several key issues: • High-performance, real-time metadata harvesting: extracting important attributes from files dynami- cally and immediately updating indexes used to improve search. • Transparent, automatic, and secure provenance capture: recording the data inputs and processing steps used in the production of each file in the system. • Scalable indexing: indexes that are optimized for integration with the file system. • Dynamic file system structure: our approach provides dynamic directories similar to those in semantic file systems, but these are the native organization rather than a feature grafted onto a conventional system. In addition to these goals, our research effort will include evaluating the impact of new storage technolo- gies on the file system design and performance. In particular, the indexing and metadata harvesting functions can potentially benefit from the performance improvements promised by new storage class memories.

  11. Dynamic Systems Analysis Report for Nuclear Fuel Recycle

    SciTech Connect (OSTI)

    Brent Dixon; Sonny Kim; David Shropshire; Steven Piet; Gretchen Matthern; Bill Halsey

    2008-12-01

    This report examines the time-dependent dynamics of transitioning from the current United States (U.S.) nuclear fuel cycle where used nuclear fuel is disposed in a repository to a closed fuel cycle where the used fuel is recycled and only fission products and waste are disposed. The report is intended to help inform policy developers, decision makers, and program managers of system-level options and constraints as they guide the formulation and implementation of advanced fuel cycle development and demonstration efforts and move toward deployment of nuclear fuel recycling infrastructure.

  12. StreamWorks - A system for Dynamic Graph Search

    SciTech Connect (OSTI)

    Choudhury, Sutanay; Holder, Larry; Chin, George; Ray, Abhik; Beus, Sherman J.; Feo, John T.

    2013-06-11

    Acting on time-critical events by processing ever growing social media, news or cyber data streams is a major technical challenge. Many of these data sources can be modeled as multi-relational graphs. Mining and searching for subgraph patterns in a continuous setting requires an efficient approach to incremental graph search. The goal of our work is to enable real-time search capabilities for graph databases. This demonstration will present a dynamic graph query system that leverages the structural and semantic characteristics of the underlying multi-relational graph.

  13. Determining the role of hydration forces in protein folding

    SciTech Connect (OSTI)

    Sorenson, J.M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry] [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Hura, G. [Univ. of California, Berkeley, CA (United States)] [Univ. of California, Berkeley, CA (United States); [Lawrence Berkeley National Lab., CA (United States). Life Sciences Div.; Soper, A.K. [Rutherford Appleton Lab., Didcot (United Kingdom). ISIS Facility] [Rutherford Appleton Lab., Didcot (United Kingdom). ISIS Facility; Pertsemlidis, A. [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Biochemistry] [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Biochemistry; Head-Gordon, T. [Lawrence Berkeley National Lab., CA (United States)] [Lawrence Berkeley National Lab., CA (United States)

    1999-07-01

    One of the primary issues in protein folding is determining what forces drive folding and eventually stabilize the native state. A delicate balance exists between electrostatic forces such as hydrogen bonding and salt bridges, and the hydrophobic effect, which are present for both intramolecular protein interactions and intermolecular contributions with the surrounding aqueous environment. This article describes a combined experimental, theoretical, and computational effort to show how the complexity of aqueous hydration can influence the structure, folding and aggregation, and stability of model protein systems. The unification of the theoretical and experimental work is the development or discovery of effective amino acid interactions that implicitly include the effects of aqueous solvent. The authors show that consideration of the full range of complexity of aqueous hydration forces such as many-body effects, long-ranged character of aqueous solvation, and the assumptions made about the degree of protein hydrophobicity can directly impact the observed structure, folding, and stability of model protein systems.

  14. Gas Hydrates Research Programs: An International Review

    SciTech Connect (OSTI)

    Jorge Gabitto; Maria Barrufet

    2009-12-09

    Gas hydrates sediments have the potential of providing a huge amount of natural gas for human use. Hydrate sediments have been found in many different regions where the required temperature and pressure conditions have been satisfied. Resource exploitation is related to the safe dissociation of the gas hydrate sediments. Basic depressurization techniques and thermal stimulation processes have been tried in pilot efforts to exploit the resource. There is a growing interest in gas hydrates all over the world due to the inevitable decline of oil and gas reserves. Many different countries are interested in this valuable resource. Unsurprisingly, developed countries with limited energy resources have taken the lead in worldwide gas hydrates research and exploration. The goal of this research project is to collect information in order to record and evaluate the relative strengths and goals of the different gas hydrates programs throughout the world. A thorough literature search about gas hydrates research activities has been conducted. The main participants in the research effort have been identified and summaries of their past and present activities reported. An evaluation section discussing present and future research activities has also been included.

  15. Dynamics of micelle-nanoparticle systems undergoing shear: a coarse-grained molecular dynamics approach

    SciTech Connect (OSTI)

    Rolfe, Bryan A.; Chun, Jaehun; Joo, Yong L.

    2013-09-05

    Recent experimental work has shown that polymeric micelles can template nanoparticles via interstitial sites in shear-ordered micelle solutions. In the current study, we report simulation results based on a coarse-grained molecular dynamics (CGMD) model of a solvent/polymer/nanoparticle system. Our results demonstrate the importance of polymer concentration and the micelle corona length in 2D shear-ordering of neat block copolymer solutions. Although our results do not show strong 3D ordering during shear, we find that cessation of shear allows the system to relax into a 3D configuration of greater order than without shear. It is further shown that this post-shear relaxation is strongly dependent on the length of the micelle corona. For the first time, we demonstrate the presence and importance of a flow disturbance surrounding micelles in simple shear flow at moderate Pclet numbers. This disturbance is similar to what is observed around simulated star polymers and ellipsoids. The extent of the flow disturbance increases as expected with a longer micelle corona length. It is further suggested that without proper consideration of these dynamics, a stable nanoparticle configuration would be difficult to obtain.

  16. Systems Dynamic ToolBox for Water Resource Planning

    Energy Science and Technology Software Center (OSTI)

    2006-08-01

    The Fully Integrated System Dynamics Tookbox for Water Resources Planning (Toolbox) is a library of generic modules intended to assist in water management planning and decision making in watersheds around the world. The modules - built in a commercially available modeling environment called Powersim Studio Expert, represent the different sub-systems ina watershed, including population, agriculture, economics, climate, reservoirs, stream flows, and fish populations, and provides generic building blocks with which complex models of complex modelsmore » of complex watersheds can be assembled. The resulting models provide a tool for observing how research management decision made in one sector of a basin can affect other sectors. Improved water resource management contributes to improved public health, economic development, ecological sustainability, and overall security and stability.« less

  17. Dynamics of a Two-Dimensional System of Quantum Dipoles

    SciTech Connect (OSTI)

    Mazzanti, F.; Astrakharchik, G. E.; Boronat, J.; Zillich, R. E.

    2009-03-20

    A detailed microscopic analysis of the dynamic structure function S(k,{omega}) of a two-dimensional Bose system of dipoles polarized along the direction perpendicular to the plane is presented and discussed. Starting from ground-state quantities obtained using a quantum diffusion Monte Carlo algorithm, the density-density response is evaluated in the context of the correlated basis functions (CBF) theory. CBF predicts a sharp peak and a multiexcitation component at higher energies produced by the decay of excitations. We discuss the structure of the phonon-roton peak and show that the Feynman and Bogoliubov predictions depart from the CBF result already at low densities. We finally discuss the emergence of a roton in the spectrum, but find the roton energy not low enough to make the system unstable under density fluctuations up to the highest density considered that is close to the freezing point.

  18. Department of Energy Advance Methane Hydrates Science and Technology Projects

    Broader source: Energy.gov [DOE]

    Descriptions for Energy Department Methane Hydrates Science and Technology Projects, August 31, 2012

  19. Dark halos and elliptical galaxies as marginally stable dynamical systems

    SciTech Connect (OSTI)

    El Zant, A. A.

    2013-12-10

    The origin of equilibrium gravitational configurations is sought in terms of the stability of their trajectories, as described by the curvature of their Lagrangian configuration manifold of particle positionsa context in which subtle spurious effects originating from the singularity in the two-body potential become particularly clear. We focus on the case of spherical systems, which support only regular orbits in the collisionless limit, despite the persistence of local exponential instability of N-body trajectories in the anomalous case of discrete point particle representation even as N ? ?. When the singularity in the potential is removed, this apparent contradiction disappears. In the absence of fluctuations, equilibrium configurations generally correspond to positive scalar curvature and thus support stable trajectories. A null scalar curvature is associated with an effective, averaged equation of state describing dynamically relaxed equilibria with marginally stable trajectories. The associated configurations are quite similar to those of observed elliptical galaxies and simulated cosmological halos and are necessarily different from the systems dominated by isothermal cores, expected from entropy maximization in the context of the standard theory of violent relaxation. It is suggested that this is the case because a system starting far from equilibrium does not reach a 'most probable state' via violent relaxation, but that this process comes to an end as the system finds and (settles in) a configuration where it can most efficiently wash out perturbations. We explicitly test this interpretation by means of direct simulations.

  20. Hydrate Control for Gas Storage Operations

    SciTech Connect (OSTI)

    Jeffrey Savidge

    2008-10-31

    The overall objective of this project was to identify low cost hydrate control options to help mitigate and solve hydrate problems that occur in moderate and high pressure natural gas storage field operations. The study includes data on a number of flow configurations, fluids and control options that are common in natural gas storage field flow lines. The final phase of this work brings together data and experience from the hydrate flow test facility and multiple field and operator sources. It includes a compilation of basic information on operating conditions as well as candidate field separation options. Lastly the work is integrated with the work with the initial work to provide a comprehensive view of gas storage field hydrate control for field operations and storage field personnel.

  1. ConocoPhillips Gas Hydrate Production Test

    SciTech Connect (OSTI)

    Schoderbek, David; Farrell, Helen; Howard, James; Raterman, Kevin; Silpngarmlert, Suntichai; Martin, Kenneth; Smith, Bruce; Klein, Perry

    2013-06-30

    Work began on the ConocoPhillips Gas Hydrates Production Test (DOE award number DE-NT0006553) on October 1, 2008. This final report summarizes the entire project from January 1, 2011 to June 30, 2013.

  2. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models and to research teams for developing future gas-hydrate projects. No gas hydrates were encountered in this well; however, a wealth of information was generated and has been documented by the project team. This Topical Report documents drilling and coring operations and other daily activities.

  3. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Steve Runyon; Mike Globe; Kent Newsham; Robert Kleinberg; Doug Griffin

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists planning hydrate exploration and development projects. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this and other project reports. This Topical Report contains details describing logging operations.

  4. Dynamic breakwater and wave energy recovery and conversion system

    SciTech Connect (OSTI)

    Boros, L.J.

    1983-05-24

    A dynamic breakwater system includes at least one and preferably a plurality of dynamic breakwater assemblies, each of which includes a baffle wall member which is pivotally mounted in a body of water about an axis which extends substantially transverse to the direction of wave motion and so that a lower portion thereof is submerged below the water surface while an upper portion thereof extends above the water surface, each baffle wall member being biased such that it has a tendency to move in a direction opposite to the direction of wave motion and wherein apparatus for damping the movement of the baffle wall member when the same moves in the direction of wave motion under the force of waves impinging thereon are provided. Apparatus is provided for recovering at least a portion of the energy imparted to the baffle wall member by the waves impinging thereon and for converting the same to useful energy and generally comprises a fluid circuit supported on a stationary platform assembly and a device operatively interconnecting the baffle wall member and fluid circuit for elevating the pressure of the fluid circulating therein in response to movement of the baffle wall member caused by the waves impinging thereon.

  5. Ensemble Kalman filters for dynamical systems with unresolved turbulence

    SciTech Connect (OSTI)

    Grooms, Ian; Lee, Yoonsang; Majda, Andrew J.

    2014-09-15

    Ensemble Kalman filters are developed for turbulent dynamical systems where the forecast model does not resolve all the active scales of motion. Coarse-resolution models are intended to predict the large-scale part of the true dynamics, but observations invariably include contributions from both the resolved large scales and the unresolved small scales. The error due to the contribution of unresolved scales to the observations, called representation or representativeness error, is often included as part of the observation error, in addition to the raw measurement error, when estimating the large-scale part of the system. It is here shown how stochastic superparameterization (a multiscale method for subgridscale parameterization) can be used to provide estimates of the statistics of the unresolved scales. In addition, a new framework is developed wherein small-scale statistics can be used to estimate both the resolved and unresolved components of the solution. The one-dimensional test problem from dispersive wave turbulence used here is computationally tractable yet is particularly difficult for filtering because of the non-Gaussian extreme event statistics and substantial small scale turbulence: a shallow energy spectrum proportional to k{sup ?5/6} (where k is the wavenumber) results in two-thirds of the climatological variance being carried by the unresolved small scales. Because the unresolved scales contain so much energy, filters that ignore the representation error fail utterly to provide meaningful estimates of the system state. Inclusion of a time-independent climatological estimate of the representation error in a standard framework leads to inaccurate estimates of the large-scale part of the signal; accurate estimates of the large scales are only achieved by using stochastic superparameterization to provide evolving, large-scale dependent predictions of the small-scale statistics. Again, because the unresolved scales contain so much energy, even an accurate estimate of the large-scale part of the system does not provide an accurate estimate of the true state. By providing simultaneous estimates of both the large- and small-scale parts of the solution, the new framework is able to provide accurate estimates of the true system state.

  6. Exploring dynamics of unstable many-body systems

    SciTech Connect (OSTI)

    Volya, Alexander; Zelevinsky, Vladimir

    2014-10-15

    In this work we acquaint reader with the Continuum Shell Model (CSM), which is a proper theoretical tool for the description of physics of unstable systems. We describe the effective non-Hermitian Hamiltonian of the CSM and concentrate on specific aspects of dynamics using realistic examples. The continuum effects are discussed in the case of weakly bound heavy oxygen isotopes, where inclusion of continuum coupling is necessary to improve the traditional nuclear shell model techniques. Physics of overlapping resonances is illustrated using recent experimental information on {sup 8}B nucleus. In the limit of strong continuum coupling the many-body states restructure relative to continuum leading to a few very broad super-radiant states, while at the same time other states become narrow and nearly decoupled from decay. The recent observations of very broad alpha clustering states in {sup 18}O is one of the most transparent manifestations of super-radiance.

  7. Swarming behaviors in multi-agent systems with nonlinear dynamics

    SciTech Connect (OSTI)

    Yu, Wenwu; School of Electrical and Computer Engineering, RMIT University, Melbourne VIC 3001 ; Chen, Guanrong; Cao, Ming; L, Jinhu; Zhang, Hai-Tao

    2013-12-15

    The dynamic analysis of a continuous-time multi-agent swarm model with nonlinear profiles is investigated in this paper. It is shown that, under mild conditions, all agents in a swarm can reach cohesion within a finite time, where the upper bounds of the cohesion are derived in terms of the parameters of the swarm model. The results are then generalized by considering stochastic noise and switching between nonlinear profiles. Furthermore, swarm models with limited sensing range inducing changing communication topologies and unbounded repulsive interactions between agents are studied by switching system and nonsmooth analysis. Here, the sensing range of each agent is limited and the possibility of collision among nearby agents is high. Finally, simulation results are presented to demonstrate the validity of the theoretical analysis.

  8. Quantum tomography meets dynamical systems and bifurcations theory

    SciTech Connect (OSTI)

    Goyeneche, D.; Torre, A. C. de la

    2014-06-01

    A powerful tool for studying geometrical problems in Hilbert spaces is developed. We demonstrate the convergence and robustness of our method in every dimension by considering dynamical systems theory. This method provides numerical solutions to hard problems involving many coupled nonlinear equations in low and high dimensions (e.g., quantum tomography problem, existence and classification of Pauli partners, mutually unbiased bases, complex Hadamard matrices, equiangular tight frames, etc.). Additionally, this tool can be used to find analytical solutions and also to implicitly prove the existence of solutions. Here, we develop the theory for the quantum pure state tomography problem in finite dimensions but this approach is straightforwardly extended to the rest of the problems. We prove that solutions are always attractive fixed points of a nonlinear operator explicitly given. As an application, we show that the statistics collected from three random orthonormal bases is enough to reconstruct pure states from experimental (noisy) data in every dimension d ? 32.

  9. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01

    We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

  10. CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Qinfei; Ge, Yong; Geng, Guoqing; Bae, Sungchul; Monteiro, Paulo J. M.

    2015-01-01

    Tmore » he effect of calcium chloride (CaCl 2 ) on tricalcium silicate (C 3 S) hydration was investigated by scanning transmission X-ray microscopy (STXM) with Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra and 29 Si MAS NMR. STXM is demonstrated to be a powerful tool for studying the chemical composition of a cement-based hydration system.he Ca L 3,2 -edge NEXAFS spectra obtained by examining C 3 S hydration in the presence of CaCl 2 showed that this accelerator does not change the coordination of calcium in the calcium silicate hydrate (C-S-H), which is the primary hydration product. O K-edge NEXAFS is also very useful in distinguishing the chemical components in hydrated C 3 S. Based on the Ca L 3,2 -edge spectra and chemical component mapping, we concluded that CaCl 2 prefers to coexist with unhydrated C 3 S instead of C-S-H. In Si K-edge NEXAFS analysis, CaCl 2 increases the degree of silicate polymerization of C-S-H in agreement with the 29 Si CP/MAS NMR results, which show that the presence of CaCl 2 in hydrated C 3 S considerably accelerates the formation of middle groups ( Q 2 ) and branch sites ( Q 3 ) in the silicate chains of C-S-H gel at 1-day hydration.« less

  11. Ultrafast Structural Dynamics in Combustion Relevant Model Systems

    SciTech Connect (OSTI)

    Weber, Peter M.

    2014-03-31

    The research project explored the time resolved structural dynamics of important model reaction system using an array of novel methods that were developed specifically for this purpose. They include time resolved electron diffraction, time resolved relativistic electron diffraction, and time resolved Rydberg fingerprint spectroscopy. Toward the end of the funding period, we also developed time-resolved x-ray diffraction, which uses ultrafast x-ray pulses at LCLS. Those experiments are just now blossoming, as the funding period expired. In the following, the time resolved Rydberg Fingerprint Spectroscopy is discussed in some detail, as it has been a very productive method. The binding energy of an electron in a Rydberg state, that is, the energy difference between the Rydberg level and the ground state of the molecular ion, has been found to be a uniquely powerful tool to characterize the molecular structure. To rationalize the structure sensitivity we invoke a picture from electron diffraction: when it passes the molecular ion core, the Rydberg electron experiences a phase shift compared to an electron in a hydrogen atom. This phase shift requires an adjustment of the binding energy of the electron, which is measurable. As in electron diffraction, the phase shift depends on the molecular, geometrical structure, so that a measurement of the electron binding energy can be interpreted as a measurement of the molecules structure. Building on this insight, we have developed a structurally sensitive spectroscopy: the molecule is first elevated to the Rydberg state, and the binding energy is then measured using photoelectron spectroscopy. The molecules structure is read out as the binding energy spectrum. Since the photoionization can be done with ultrafast laser pulses, the technique is inherently capable of a time resolution in the femtosecond regime. For the purpose of identifying the structures of molecules during chemical reactions, and for the analysis of molecular species in the hot environments of combustion processes, there are several features that make the Rydberg ionization spectroscopy uniquely useful. First, the Rydberg electrons orbit is quite large and covers the entire molecule for most molecular structures of combustion interest. Secondly, the ionization does not change vibrational quantum numbers, so that even complicated and large molecules can be observed with fairly well resolved spectra. In fact, the spectroscopy is blind to vibrational excitation of the molecule. This has the interesting consequence for the study of chemical dynamics, where the molecules are invariably very energetic, that the molecular structures are observed unobstructed by the vibrational congestion that dominates other spectroscopies. This implies also that, as a tool to probe the time-dependent structural dynamics of chemically interesting molecules, Rydberg spectroscopy may well be better suited than electron or x-ray diffraction. With recent progress in calculating Rydberg binding energy spectra, we are approaching the point where the method can be evolved into a structure determination method. To implement the Rydberg ionization spectroscopy we use a molecular beam based, time-resolved pump-probe multi-photon ionization/photoelectron scheme in which a first laser pulse excites the molecule to a Rydberg state, and a probe pulse ionizes the molecule. A time-of-flight detector measures the kinetic energy spectrum of the photoelectrons. The photoelectron spectrum directly provides the binding energy of the electron, and thereby reveals the molecules time-dependent structural fingerprint. Only the duration of the laser pulses limits the time resolution. With a new laser system, we have now reached time resolutions better than 100 fs, although very deep UV wavelengths (down to 190 nm) have slightly longer instrument functions. The structural dynamics of molecules in Rydberg-excited states is obtained by delaying the probe ionization photon from the pump photon; the structural dynamics of molecules in their ground state or e

  12. Integrated system dynamics toolbox for water resources planning.

    SciTech Connect (OSTI)

    Reno, Marissa Devan; Passell, Howard David; Malczynski, Leonard A.; Peplinski, William J.; Tidwell, Vincent Carroll; Coursey, Don; Hanson, Jason; Grimsrud, Kristine; Thacher, Jennifer; Broadbent, Craig; Brookshire, David; Chemak, Janie; Cockerill, Kristan; Aragon, Carlos , Socorro, NM); Hallett, Heather , Socorro, NM); Vivoni, Enrique , Socorro, NM); Roach, Jesse

    2006-12-01

    Public mediated resource planning is quickly becoming the norm rather than the exception. Unfortunately, supporting tools are lacking that interactively engage the public in the decision-making process and integrate over the myriad values that influence water policy. In the pages of this report we document the first steps toward developing a specialized decision framework to meet this need; specifically, a modular and generic resource-planning ''toolbox''. The technical challenge lies in the integration of the disparate systems of hydrology, ecology, climate, demographics, economics, policy and law, each of which influence the supply and demand for water. Specifically, these systems, their associated processes, and most importantly the constitutive relations that link them must be identified, abstracted, and quantified. For this reason, the toolbox forms a collection of process modules and constitutive relations that the analyst can ''swap'' in and out to model the physical and social systems unique to their problem. This toolbox with all of its modules is developed within the common computational platform of system dynamics linked to a Geographical Information System (GIS). Development of this resource-planning toolbox represents an important foundational element of the proposed interagency center for Computer Aided Dispute Resolution (CADRe). The Center's mission is to manage water conflict through the application of computer-aided collaborative decision-making methods. The Center will promote the use of decision-support technologies within collaborative stakeholder processes to help stakeholders find common ground and create mutually beneficial water management solutions. The Center will also serve to develop new methods and technologies to help federal, state and local water managers find innovative and balanced solutions to the nation's most vexing water problems. The toolbox is an important step toward achieving the technology development goals of this center.

  13. Hydrophobic hydration and the anomalous partial molar volumes in ethanol-water mixtures

    SciTech Connect (OSTI)

    Tan, Ming-Liang; Te, Jerez; Cendagorta, Joseph R.; Miller, Benjamin T.; Brooks, Bernard R.; Ichiye, Toshiko

    2015-02-14

    The anomalous behavior in the partial molar volumes of ethanol-water mixtures at low concentrations of ethanol is studied using molecular dynamics simulations. Previous work indicates that the striking minimum in the partial molar volume of ethanol V{sub E} as a function of ethanol mole fraction X{sub E} is determined mainly by water-water interactions. These results were based on simulations that used one water model for the solute-water interactions but two different water models for the water-water interactions. This is confirmed here by using two more water models for the water-water interactions. Furthermore, the previous work indicates that the initial decrease is caused by association of the hydration shells of the hydrocarbon tails, and the minimum occurs at the concentration where all of the hydration shells are touching each other. Thus, the characteristics of the hydration of the tail that cause the decrease and the features of the water models that reproduce this type of hydration are also examined here. The results show that a single-site multipole water model with a charge distribution that mimics the large quadrupole and the p-orbital type electron density out of the molecular plane has “brittle” hydration with hydrogen bonds that break as the tails touch, which reproduces the deep minimum. However, water models with more typical site representations with partial charges lead to flexible hydration that tends to stay intact, which produces a shallow minimum. Thus, brittle hydration may play an essential role in hydrophobic association in water.

  14. A simple correlation to predict the hydrate quadruple point temperature for LPG mixtures

    SciTech Connect (OSTI)

    Yousif, M.H.

    1997-12-31

    A simple correlation to predict the hydrate upper quadruple point temperature, T{sub Q2B} for liquefied petroleum gas (LPG) mixtures was developed. It was developed for use as a part of a modeling and control system for a LPG pipeline in Russia. For performance reasons, a simple hydrate prediction correlation was required that could be incorporated into the real-time and predictive pipeline simulation models. The operating company required both real time and predictive simulation tools be developed to assist in preventing hydrate blockages while minimizing the use of methanol. In this particular pipeline, LPG fluid moves through the pipeline as a single phase liquid above its bubble point pressure. Because of the very low flow rates, the trace amount of water present in the LPG drops out and creates water pools at low points in the pipeline. The pipeline pressure and seasonal temperatures are conducive for hydrate formation in these pools. Methanol and monoethylene glycol (MEG) are injected in the pipeline to help prevent hydrate formation. The newly developed correlation predicts the hydrate quadruple point temperature using only the composition and the molecular weight of the LPG mixture while retaining an accuracy comparable to the statistical thermodynamic models throughout the range of normal operating conditions.

  15. On theoretical issues of computer simulations sequential dynamical systems

    SciTech Connect (OSTI)

    Barrett, C.L.; Mortveit, H.S.; Reidys, C.M.

    1998-12-01

    The authors study a class of discrete dynamical systems that is motivated by the generic structure of simulations. The systems consist of the following data: (a) a finite graph Y with vertex set {l_brace}1,...,n{r_brace} where each vertex has a binary state, (b) functions F{sub i}:F{sub 2}{sup n} {r_arrow} F{sub 2}{sup n} and (c) an update ordering {pi}. The functions F{sub i} update the binary state of vertex i as a function of the state of vertex i and its Y-neighbors and leave the states of all other vertices fixed. The update ordering is a permutation of the Y-vertices. They derive a decomposition result, characterize invertible SDS and study fixed points. In particular they analyze how many different SDS that can be obtained by reordering a given multiset of update functions and give a criterion for when one can derive concentration results on this number. Finally, some specific SDS are investigated.

  16. Dynamical transitions in large systems of mean field-coupled Landau-Stuart

    Office of Scientific and Technical Information (OSTI)

    oscillators: Extensive chaos and cluster states (Journal Article) | SciTech Connect Dynamical transitions in large systems of mean field-coupled Landau-Stuart oscillators: Extensive chaos and cluster states Citation Details In-Document Search Title: Dynamical transitions in large systems of mean field-coupled Landau-Stuart oscillators: Extensive chaos and cluster states In this paper, we study dynamical systems in which a large number N of identical Landau-Stuart oscillators are globally

  17. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Richard Sigal; Kent Newsham; Thomas Williams; Barry Freifeld; Timothy Kneafsey; Carl Sondergeld; Shandra Rai; Jonathan Kwan; Stephen Kirby; Robert Kleinberg; Doug Griffin

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu Formation and approximately 215 ft of porous sandstone were recovered in the West Sak Formation. There were gas shows in the bottom part of the Ugnu and throughout the West Sak. No hydrate-bearing zones were identified either in recovered core or on well logs. The base of the permafrost was found at about 1260 ft. With the exception of the deepest sands in the West Sak and some anomalous thin, tight zones, all sands recovered (after thawing) are unconsolidated with high porosity and high permeability. At 800 psi, Ugnu sands have an average porosity of 39.3% and geometrical mean permeability of 3.7 Darcys. Average grain density is 2.64 g/cc. West Sak sands have an average porosity of 35.5%, geometrical mean permeability of 0.3 Darcys, and average grain density of 2.70 g/cc. There were several 1-2 ft intervals of carbonate-cemented sandstone recovered from the West Sak. These intervals have porosities of only a few percent and very low permeability. On a well log they appear as resistive with a high sonic velocity. In shallow sections of other wells these usually are the only logs available. Given the presence of gas in Hot Ice No. 1, if only resistivity and sonic logs and a mud log had been available, tight sand zones may have been interpreted as containing hydrates. Although this finding does not imply that all previously mapped hydrate zones are merely tight sands, it does add a note of caution to the practice of interpreting the presence of hydrates from old well information. The methane hydrate stability zone below the Hot Ice No. 1 location includes thick sections of sandstone and conglomerate which would make excellent reservoir rocks for hydrates and below the permafrost zone shallow gas. The Ugnu formation comprises a more sand-rich section than does the West Sak formation, and the Ugnu sands when cleaned and dried are slightly more porous and significantly more permeable than the West Sak.

  18. Complex admixtures of clathrate hydrates in a water desalination method

    DOE Patents [OSTI]

    Simmons, Blake A.; Bradshaw, Robert W.; Dedrick, Daniel E.; Anderson, David W.

    2009-07-14

    Disclosed is a method that achieves water desalination by utilizing and optimizing clathrate hydrate phenomena. Clathrate hydrates are crystalline compounds of gas and water that desalinate water by excluding salt molecules during crystallization. Contacting a hydrate forming gaseous species with water will spontaneously form hydrates at specific temperatures and pressures through the extraction of water molecules from the bulk phase followed by crystallite nucleation. Subsequent dissociation of pure hydrates yields fresh water and, if operated correctly, allows the hydrate-forming gas to be efficiently recycled into the process stream.

  19. New Methane Hydrate Research: Investing in Our Energy Future | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy Methane Hydrate Research: Investing in Our Energy Future New Methane Hydrate Research: Investing in Our Energy Future August 31, 2012 - 1:37pm Addthis Methane hydrates are 3D ice-lattice structures with natural gas locked inside. If methane hydrate is either warmed or depressurized, it will release the trapped natural gas. Methane hydrates are 3D ice-lattice structures with natural gas locked inside. If methane hydrate is either warmed or depressurized, it will release the trapped

  20. Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics Model

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics Model Citation Details In-Document Search Title: Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics Model A system dynamic model was construction to evaluate the water balance for in-situ oil shale conversion. The model is based on a systems dynamics approach and uses the Powersim Studio 9(tm) software package. Three phases of an insitu retort were consider; a construction

  1. Application of Crunch-Flow Routines to Constrain Present and Past Carbon Fluxes at Gas-Hydrate Bearing Sites

    SciTech Connect (OSTI)

    Torres, Marta

    2014-01-31

    In November 2012, Oregon State University initiated the project entitled: Application of Crunch-Flow routines to constrain present and past carbon fluxes at gas-hydrate bearing sites. Within this project we developed Crunch-Flow based modeling modules that include important biogeochemical processes that need to be considered in gas hydrate environments. Our modules were applied to quantify carbon cycling in present and past systems, using data collected during several DOE-supported drilling expeditions, which include the Cascadia margin in US, Ulleung Basin in South Korea, and several sites drilled offshore India on the Bay of Bengal and Andaman Sea. Specifically, we completed modeling efforts that: 1) Reproduce the compositional and isotopic profiles observed at the eight drilled sites in the Ulleung Basin that constrain and contrast the carbon cycling pathways at chimney (high methane flux) and non-chimney sites (low methane, advective systems); 2) Simulate the Ba record in the sediments to quantify the past dynamics of methane flux in the southern Hydrate Ridge, Cascadia margin; and 3) Provide quantitative estimates of the thickness of individual mass transport deposits (MTDs), time elapsed after the MTD event, rate of sulfate reduction in the MTD, and time required to reach a new steady state at several sites drilled in the Krishna-Godavari (K-G) Basin off India. In addition we developed a hybrid model scheme by coupling a home-made MATLAB code with CrunchFlow to address the methane transport and chloride enrichment at the Ulleung Basins chimney sites, and contributed the modeling component to a study focusing on pore-scale controls on gas hydrate distribution in sediments from the Andaman Sea. These efforts resulted in two manuscripts currently under review, and contributed the modeling component of another pare, also under review. Lessons learned from these efforts are the basis of a mini-workshop to be held at Oregon State University (Feb 2014) to instruct graduate students (OSU and UW) as well as DOE staff from the NETL lab in Albany on the use of Crunch Flow for geochemical applications.

  2. Description of waste pretreatment and interfacing systems dynamic simulation model

    SciTech Connect (OSTI)

    Garbrick, D.J.; Zimmerman, B.D.

    1995-05-01

    The Waste Pretreatment and Interfacing Systems Dynamic Simulation Model was created to investigate the required pretreatment facility processing rates for both high level and low level waste so that the vitrification of tank waste can be completed according to the milestones defined in the Tri-Party Agreement (TPA). In order to achieve this objective, the processes upstream and downstream of the pretreatment facilities must also be included. The simulation model starts with retrieval of tank waste and ends with vitrification for both low level and high level wastes. This report describes the results of three simulation cases: one based on suggested average facility processing rates, one with facility rates determined so that approximately 6 new DSTs are required, and one with facility rates determined so that approximately no new DSTs are required. It appears, based on the simulation results, that reasonable facility processing rates can be selected so that no new DSTs are required by the TWRS program. However, this conclusion must be viewed with respect to the modeling assumptions, described in detail in the report. Also included in the report, in an appendix, are results of two sensitivity cases: one with glass plant water recycle steams recycled versus not recycled, and one employing the TPA SST retrieval schedule versus a more uniform SST retrieval schedule. Both recycling and retrieval schedule appear to have a significant impact on overall tank usage.

  3. Method for production of hydrocarbons from hydrates

    DOE Patents [OSTI]

    McGuire, Patrick L.

    1984-01-01

    A method of recovering natural gas entrapped in frozen subsurface gas hydrate formations in arctic regions. A hot supersaturated solution of CaCl.sub.2 or CaBr.sub.2, or a mixture thereof, is pumped under pressure down a wellbore and into a subsurface hydrate formation so as to hydrostatically fracture the formation. The CaCl.sub.2 /CaBr.sub.2 solution dissolves the solid hydrates and thereby releases the gas entrapped therein. Additionally, the solution contains a polymeric viscosifier, which operates to maintain in suspension finely divided crystalline CaCl.sub.2 /CaBr.sub.2 that precipitates from the supersaturated solution as it is cooled during injection into the formation.

  4. Dehydration of plutonium or neptunium trichloride hydrate

    DOE Patents [OSTI]

    Foropoulos, Jr., Jerry (Los Alamos, NM); Avens, Larry R. (Los Alamos, NM); Trujillo, Eddie A. (Espanola, NM)

    1992-01-01

    A process of preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride is provided.

  5. Dehydration of plutonium or neptunium trichloride hydrate

    DOE Patents [OSTI]

    Foropoulos, J. Jr.; Avens, L.R.; Trujillo, E.A.

    1992-03-24

    A process is described for preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride.

  6. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Rack, Frank; Storms, Michael; Schroeder, Derryl; Dugan, Brandon; Schultheiss, Peter

    2002-12-31

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were (1) the preliminary postcruise evaluation of the tools and measurement systems that were used during ODP Leg 204 to study hydrate deposits on Hydrate Ridge, offshore Oregon from July through September 2002; and (2) the preliminary study of the hydrate-bearing core samples preserved in pressure vessels and in liquid nitrogen cryofreezers, which are now stored at the ODP Gulf Coast Repository in College Station, TX. During ODP Leg 204, several newly modified downhole tools were deployed to better characterize the subsurface lithologies and environments hosting microbial populations and gas hydrates. A preliminary review of the use of these tools is provided herein. The DVTP, DVTP-P, APC-methane, and APC-Temperature tools (ODP memory tools) were used extensively and successfully during ODP Leg 204 aboard the D/V JOIDES Resolution. These systems provided a strong operational capability for characterizing the in situ properties of methane hydrates in subsurface environments on Hydrate Ridge during ODP Leg 204. Pressure was also measured during a trial run of the Fugro piezoprobe, which operates on similar principles as the DVTP-P. The final report describing the deployments of the Fugro Piezoprobe is provided in Appendix A of this report. A preliminary analysis and comparison between the piezoprobe and DVTP-P tools is provided in Appendix B of this report. Finally, a series of additional holes were cored at the crest of Hydrate Ridge (Site 1249) specifically geared toward the rapid recovery and preservation of hydrate samples as part of a hydrate geriatric study partially funded by the Department of Energy (DOE). In addition, the preliminary results from gamma density non-invasive imaging of the cores preserved in pressure vessels are provided in Appendix C of this report. An initial visual inspection of the samples stored in liquid nitrogen is provided in Appendix D of this report.

  7. Report of the Task Force on Methane Hydrates

    Broader source: Energy.gov [DOE]

    This report presents the findings and recommendations for the Secretary of Energy Advisory Board (SEAB) Task Force on Methane Hydrates.

  8. Draft Report of the Task Force on Methane Hydrates

    Broader source: Energy.gov [DOE]

    This report presents the findings and recommendations for the Secretary of Energy Advisory Board (SEAB) Task Force on Methane Hydrates.

  9. Laboratory evaluation of dynamic traffic assignment systems: Requirements, framework, and system design

    SciTech Connect (OSTI)

    Miaou, S.-P.; Pillai, R.S.; Summers, M.S.; Rathi, A.K.; Lieu, H.C.

    1997-01-01

    The success of Advanced Traveler Information 5ystems (ATIS) and Advanced Traffic Management Systems (ATMS) depends on the availability and dissemination of timely and accurate estimates of current and emerging traffic network conditions. Real-time Dynamic Traffic Assignment (DTA) systems are being developed to provide the required timely information. The DTA systems will provide faithful and coherent real-time, pre-trip, and en-route guidance/information which includes routing, mode, and departure time suggestions for use by travelers, ATIS, and ATMS. To ensure the credibility and deployment potential of such DTA systems, an evaluation system supporting all phases of DTA system development has been designed and presented in this paper. This evaluation system is called the DTA System Laboratory (DSL). A major component of the DSL is a ground- truth simulator, the DTA Evaluation System (DES). The DES is envisioned to be a virtual representation of a transportation system in which ATMS and ATIS technologies are deployed. It simulates the driving and decision-making behavior of travelers in response to ATIS and ATMS guidance, information, and control. This paper presents the major evaluation requirements for a DTA Systems, a modular modeling framework for the DES, and a distributed DES design. The modeling framework for the DES is modular, meets the requirements, can be assembled using both legacy and independently developed modules, and can be implemented as a either a single process or a distributed system. The distributed design is extendible, provides for the optimization of distributed performance, and object-oriented design within each distributed component. A status report on the development of the DES and other research applications is also provided.

  10. Capturing Real-Time Power System Dynamics: Opportunities and Challenges

    SciTech Connect (OSTI)

    Huang, Zhenyu; Zhou, Ning; Diao, Ruisheng; Wang, Shaobu; Elbert, Stephen T.; Meng, Da; Lu, Shuai

    2015-09-01

    The power grid evolves towards a new mix of generation and consumption that introduces new dynamic and stochastic behaviors. These emerging grid behaviors would invalidate the steady-state assumption in today’s state estimation – an essential function for real-time power grid operation. This paper examines this steady-state assumption and identifies the need for estimating dynamic states. Supporting technologies are presented as well as a proposed formulation for estimating dynamic states. Metrics for evaluating methods for solving the dynamic state estimation problem are proposed, with example results to illustrate the use of these metrics. The overall objective of this paper is to provide a basis that more research on this topic can follow.

  11. Effective quantum dynamics of interacting systems with inhomogeneous coupling

    SciTech Connect (OSTI)

    Lopez, C. E.; Retamal, J. C.; Christ, H.; Solano, E.

    2007-03-15

    We study the quantum dynamics of a single mode (particle) interacting inhomogeneously with a large number of particles and introduce an effective approach to find the accessible Hilbert space, where the dynamics takes place. Two relevant examples are given: the inhomogeneous Tavis-Cummings model (e.g., N atomic qubits coupled to a single cavity mode, or to a motional mode in trapped ions) and the inhomogeneous coupling of an electron spin to N nuclear spins in a quantum dot.

  12. Metal halogen battery construction with improved technique for producing halogen hydrate

    DOE Patents [OSTI]

    Fong, Walter L.; Catherino, Henry A.; Kotch, Richard J.

    1983-01-01

    An improved electrical energy storage system comprising, at least one cell having a positive electrode and a negative electrode separated by aqueous electrolyte, a store means wherein halogen hydrate is formed and stored as part of an aqueous material having a liquid level near the upper part of the store, means for circulating electrolyte through the cell, conduit means for transmitting halogen gas formed in the cell to a hydrate forming apparatus associated with the store, said hydrate forming apparatus including, a pump to which there is introduced quantities of the halogen gas and chilled water, said pump being located in the store and an outlet conduit leading from the pump and being substantially straight and generally vertically disposed and having an exit discharge into the gas space above the liquid level in the store, and wherein said hydrate forming apparatus is highly efficient and very resistant to plugging or jamming. The disclosure also relates to an improved method for producing chlorine hydrate in zinc chlorine batteries.

  13. Pathways through equilibrated states with coexisting phases for gas hydrate formation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Malolepsza, Edyta; Keyes, Tom

    2015-12-01

    Under ambient conditions, water freezes to either hexagonal ice or a hexagonal/cubic composite ice. The presence of hydrophobic guest molecules introduces a competing pathway: gas hydrate formation, with the guests in clathrate cages. Here, the pathways of the phase transitions are sought as sequences of states with coexisting phases, using a generalized replica exchange algorithm designed to sample them in equilibrium, avoiding nonequilibrium processes. For a dilute solution of methane in water under 200 atm, initializing the simulation with the full set of replicas leads to methane trapped in hexagonal/cubic ice, while gradually adding replicas with decreasing enthalpy produces themore » initial steps of hydrate growth. Once a small amount of hydrate is formed, water rearranges to form empty cages, eventually transforming the remainder of the system to metastable β ice, a scaffolding for hydrates. It is suggested that configurations with empty cages are reaction intermediates in hydrate formation when more guest molecules are available. Furthermore, free energy profiles show that methane acts as a catalyst reducing the barrier for β ice versus hexagonal/cubic ice formation.« less

  14. Pathways through equilibrated states with coexisting phases for gas hydrate formation

    SciTech Connect (OSTI)

    Malolepsza, Edyta; Keyes, Tom

    2015-12-01

    Under ambient conditions, water freezes to either hexagonal ice or a hexagonal/cubic composite ice. The presence of hydrophobic guest molecules introduces a competing pathway: gas hydrate formation, with the guests in clathrate cages. Here, the pathways of the phase transitions are sought as sequences of states with coexisting phases, using a generalized replica exchange algorithm designed to sample them in equilibrium, avoiding nonequilibrium processes. For a dilute solution of methane in water under 200 atm, initializing the simulation with the full set of replicas leads to methane trapped in hexagonal/cubic ice, while gradually adding replicas with decreasing enthalpy produces the initial steps of hydrate growth. Once a small amount of hydrate is formed, water rearranges to form empty cages, eventually transforming the remainder of the system to metastable β ice, a scaffolding for hydrates. It is suggested that configurations with empty cages are reaction intermediates in hydrate formation when more guest molecules are available. Furthermore, free energy profiles show that methane acts as a catalyst reducing the barrier for β ice versus hexagonal/cubic ice formation.

  15. A high dynamic range data acquisition system for a solid-state electron

    Office of Scientific and Technical Information (OSTI)

    electric dipole moment experiment (Journal Article) | SciTech Connect A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment Citation Details In-Document Search Title: A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment We have built a high precision (24-bit) data acquisition (DAQ) system capable of simultaneously sampling eight input channels for the measurement of the electric dipole

  16. Rapid gas hydrate formation processes: Will they work?

    SciTech Connect (OSTI)

    Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.

    2010-06-07

    Researchers at DOEs National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETLs 15-Liter Hydrate Cell. The results from this work demonstrate that the rapid and continuous formation of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.

  17. Comparative Assessment of Advanced Gay Hydrate Production Methods

    SciTech Connect (OSTI)

    M. D. White; B. P. McGrail; S. K. Wurstner

    2009-06-30

    Displacing natural gas and petroleum with carbon dioxide is a proven technology for producing conventional geologic hydrocarbon reservoirs, and producing additional yields from abandoned or partially produced petroleum reservoirs. Extending this concept to natural gas hydrate production offers the potential to enhance gas hydrate recovery with concomitant permanent geologic sequestration. Numerical simulation was used to assess a suite of carbon dioxide injection techniques for producing gas hydrates from a variety of geologic deposit types. Secondary hydrate formation was found to inhibit contact of the injected CO{sub 2} regardless of injectate phase state, thus diminishing the exchange rate due to pore clogging and hydrate zone bypass of the injected fluids. Additional work is needed to develop methods of artificially introducing high-permeability pathways in gas hydrate zones if injection of CO{sub 2} in either gas, liquid, or micro-emulsion form is to be more effective in enhancing gas hydrate production rates.

  18. Rapid gas hydrate formation processes: Will they work?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.

    2010-06-07

    Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETL’s 15-Liter Hydrate Cell. The results from this work demonstrate that the rapid and continuousmore » formation of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.« less

  19. Quantum diffusion dynamics in nonlinear systems: A modified kicked-rotor model

    SciTech Connect (OSTI)

    Gong Jiangbin [Department of Physics and Centre of Computational Science and Engineering, National University of Singapore, 117542 (Singapore); Wang Jiao [Temasek Laboratories and Beijing-Hong Kong-Singapore Joint Center for Nonlinear and Complex Systems (Singapore), National University of Singapore, 117542 (Singapore)

    2007-09-15

    Using a simple method analogous to a quantum rephasing technique, a simple modification to a paradigm of classical and quantum chaos is proposed. The interesting quantum maps thus obtained display remarkably rich quantum dynamics. Emphasis is placed on the destruction of dynamical localization without breaking periodicity, unbounded quantum anomalous diffusion in integrable systems, and transient dynamical localization. Experimental realizations of this work are also discussed.

  20. In silico studies of the properties of water hydrating a small protein

    SciTech Connect (OSTI)

    Sinha, Sudipta Kumar; Chakraborty, Kausik; Bandyopadhyay, Sanjoy; Jana, Madhurima

    2014-12-14

    Atomistic molecular dynamics simulation of an aqueous solution of the small protein HP-36 has been carried out with explicit solvent at room temperature. Efforts have been made to explore the influence of the protein on the relative packing and ordering of water molecules around its secondary structures, namely, three ?-helices. The calculations reveal that the inhomogeneous water ordering and density distributions around the helices are correlated with their relative hydrophobicity. Importantly, we have identified the existence of a narrow relatively dehydrated region containing randomly organized quasi-free water molecules beyond the first layer of bound waters at the protein surface. These water molecules with relatively weaker binding energies form the transition state separating the bound and free water molecules at the interface. Further, increased contribution of solid-like caging motions of water molecules around the protein is found to be responsible for reduced fluidity of the hydration layer. Interestingly, we notice that the hydration layer of helix-3 is more fluidic with relatively higher entropy as compared to the hydration layers of the other two helical segments. Such characteristics of helix-3 hydration layer correlate well with the activity of HP-36, as helix-3 contains the active site of the protein.

  1. SIAM conference on applications of dynamical systems. Abstracts and author index

    SciTech Connect (OSTI)

    Not Available

    1992-12-31

    A conference (Oct.15--19, 1992, Snowbird, Utah; sponsored by SIAM (Society for Industrial and Applied Mathematics) Activity Group on Dynamical Systems) was held that highlighted recent developments in applied dynamical systems. The main lectures and minisymposia covered theory about chaotic motion, applications in high energy physics and heart fibrillations, turbulent motion, Henon map and attractor, integrable problems in classical physics, pattern formation in chemical reactions, etc. The conference fostered an exchange between mathematicians working on theoretical issues of modern dynamical systems and applied scientists. This two-part document contains abstracts, conference program, and an author index.

  2. NETL Collaborates with Partners to Produce Global Outlook on Natural Gas Hydrates

    Broader source: Energy.gov [DOE]

    Researchers at the Office of Fossil Energy’s National Energy Technology Laboratory (NETL) were part of an international team, including the United Nations Environmental Programme (UNEP), that contributed to a newly released report explaining the prospect of gas hydrates as a potential worldwide energy source that can contribute in the transition to the low-carbon energy systems of the future.

  3. Dynamic

    Office of Legacy Management (LM)

    Dynamic , and Static , Res.ponse of the Government Oil Shale Mine at ' , . , Rifle, Colorado, to the Rulison Event. , . ; . . DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. p ( y c - - a 2-1 0 -4- REPORT AT (29-2) 914 USBM 1 0 0 1 UNITED STATES DEPARTMENT O F THE I NTERIOR BUREAU OF MINES e s.09 P. L. R U S S E L L RESEARCH D l RECTOR Februory 2, lB7O DYNAMIC AND STATIC RESPONSE 'OF THE GOVERNMENT

  4. Voltage Quench Dynamics of a Kondo System (Journal Article) | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Voltage Quench Dynamics of a Kondo System This content will become publicly available on January 18, 2017 « Prev Next » Title: Voltage Quench Dynamics of a Kondo System Authors: Antipov, Andrey E. ; Dong, Qiaoyuan ; Gull, Emanuel Publication Date: 2016-01-19 OSTI Identifier: 1235600 Grant/Contract Number: AC02-05CH11231 Type: Publisher's Accepted Manuscript Journal Name: Physical Review Letters Additional Journal Information: Journal Volume: 116; Journal Issue: 3; Journal ID: ISSN 0031-9007

  5. Cooperative storage of shared files in a parallel computing system with dynamic block size

    DOE Patents [OSTI]

    Bent, John M.; Faibish, Sorin; Grider, Gary

    2015-11-10

    Improved techniques are provided for parallel writing of data to a shared object in a parallel computing system. A method is provided for storing data generated by a plurality of parallel processes to a shared object in a parallel computing system. The method is performed by at least one of the processes and comprises: dynamically determining a block size for storing the data; exchanging a determined amount of the data with at least one additional process to achieve a block of the data having the dynamically determined block size; and writing the block of the data having the dynamically determined block size to a file system. The determined block size comprises, e.g., a total amount of the data to be stored divided by the number of parallel processes. The file system comprises, for example, a log structured virtual parallel file system, such as a Parallel Log-Structured File System (PLFS).

  6. Dynamic-Feature Extraction, Attribution and Reconstruction (DEAR) Method for Power System Model Reduction

    SciTech Connect (OSTI)

    Wang, Shaobu; Lu, Shuai; Zhou, Ning; Lin, Guang; Elizondo, Marcelo A.; Pai, M. A.

    2014-09-04

    In interconnected power systems, dynamic model reduction can be applied on generators outside the area of interest to mitigate the computational cost with transient stability studies. This paper presents an approach of deriving the reduced dynamic model of the external area based on dynamic response measurements, which comprises of three steps, dynamic-feature extraction, attribution and reconstruction (DEAR). In the DEAR approach, a feature extraction technique, such as singular value decomposition (SVD), is applied to the measured generator dynamics after a disturbance. Characteristic generators are then identified in the feature attribution step for matching the extracted dynamic features with the highest similarity, forming a suboptimal basis of system dynamics. In the reconstruction step, generator state variables such as rotor angles and voltage magnitudes are approximated with a linear combination of the characteristic generators, resulting in a quasi-nonlinear reduced model of the original external system. Network model is un-changed in the DEAR method. Tests on several IEEE standard systems show that the proposed method gets better reduction ratio and response errors than the traditional coherency aggregation methods.

  7. Kinetic inhibition of natural gas hydrates in offshore drilling, production, and processing operations. Annual report, January 1--December 31, 1992

    SciTech Connect (OSTI)

    1992-12-31

    Natural gas hydrates are solid crystalline compounds which form when molecules smaller than n-butane contact molecules of water at elevated pressures and reduced temperatures, both above and below the ice point. Because these crystalline compounds plug flow channels, they are undesirable. In this project the authors proposed an alternate approach of controlling hydrate formation by preventing hydrate growth into a sizeable mass which could block a flow channel. The authors call this new technique kinetic inhibition, because while it allows the system to exist in the hydrate domain, it prevents the kinetic agglomeration of small hydrate crystals to the point of pluggage of a flow channel. In order to investigate the kinetic means of inhibiting hydrate formation, they held two consortium meetings, on June 1, 1990 and on August 31, 1990. At subsequent meetings, the authors determined the following four stages of the project, necessary to reach the goal of determining a new hydrate field inhibitor: (1) a rapid screening method was to be determined for testing the hydrate kinetic formation period of many surfactants and polymer candidates (both individually and combined), the present report presents the success of two screening apparatuses: a multi-reactor apparatus which is capable of rapid, high volume screening, and the backup screening method--a viscometer for testing with gas at high pressure; (2) the construction of two high, constant pressure cells were to experimentally confirm the success of the chemicals in the rapid screening apparatus; (3) in the third phase of the work, Exxon volunteered to evaluate the performance of the best chemicals from the previous two stages in their 4 inch I.D. Multiphase flow loop in Houston; (4) in the final phase of the work, the intention was to take the successful kinetic inhibition chemicals from the previous three stages and then test them in the field in gathering lines and wells from member companies.

  8. PMU Placement for Dynamic State Tracking of Power Systems

    SciTech Connect (OSTI)

    Sun, Yannan; Du, Pengwei; Huang, Zhenyu; Kalsi, Karanjit; Diao, Ruisheng; Anderson, Kevin K.; Li, Yulan; Lee, Barry

    2011-08-04

    Accurately tracking the state variables (rotor angle and speed) is a necessity for monitoring system stability conditions and assessing the risks of large-scale system collapse. This paper explores how the number and locations of PMUs installed in the system are determined to ensure satisfactory state tracking performance. A search algorithm is presented for determining PMU placement (location and quantity). The algorithm determines a placement that gives small tracking error in polynomial time. A modified, scalable algorithm is also presented. Observability in the presence of faults is considered. Simulation results for a 16-machine and a 50-machine system are provided.

  9. Dynamic Impregnator Reactor System (Poster), NREL (National Renewable...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Several unit operations are combined into one robust system, off ering fl exible and staged process confi gurations in one vessel. Spraying, soaking, low-severity pretreat- ment,...

  10. Development of Alaskan gas hydrate resources. Final report

    SciTech Connect (OSTI)

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  11. Dynamic analysis of the urban-based low-carbon policy using system dynamics: Focused on housing and green space

    SciTech Connect (OSTI)

    Hong, Taehoon; Kim, Jimin Jeong, Kwangbok; Koo, Choongwan

    2015-02-09

    To systematically manage the energy consumption of existing buildings, the government has to enforce greenhouse gas reduction policies. However, most of the policies are not properly executed because they do not consider various factors from the urban level perspective. Therefore, this study aimed to conduct a dynamic analysis of an urban-based low-carbon policy using system dynamics, with a specific focus on housing and green space. This study was conducted in the following steps: (i) establishing the variables of urban-based greenhouse gases (GHGs) emissions; (ii) creating a stock/flow diagram of urban-based GHGs emissions; (iii) conducting an information analysis using the system dynamics; and (iv) proposing the urban-based low-carbon policy. If a combined energy policy that uses the housing sector (30%) and the green space sector (30%) at the same time is implemented, 2020 CO{sub 2} emissions will be 7.23 million tons (i.e., 30.48% below 2020 business-as-usual), achieving the national carbon emissions reduction target (26.9%). The results of this study could contribute to managing and improving the fundamentals of the urban-based low-carbon policies to reduce greenhouse gas emissions.

  12. Methane Hydrate Production Technologies to be Tested on Alaska's North

    Energy Savers [EERE]

    Slope | Department of Energy Methane Hydrate Production Technologies to be Tested on Alaska's North Slope Methane Hydrate Production Technologies to be Tested on Alaska's North Slope October 24, 2011 - 1:00pm Addthis Washington, DC - The U.S. Department of Energy, the Japan Oil, Gas and Metals National Corporation, and ConocoPhillips will work together to test innovative technologies for producing methane gas from hydrate deposits on the Alaska North Slope. The collaborative testing will

  13. Methane Hydrate Research and Modeling | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Research and Modeling Methane Hydrate Research and Modeling Research is focused on understanding the physical and chemical nature of gas hydrate-bearing sediments. These studies advance the understanding of the in situ nature of GHBS and their potential response in terms of fluid flow and geomechanical response to destabilizing forces. The latest research results from DOE projects, both current and completed, can be found on the NETL website. These include: Gas Hydrate Characterization in the

  14. Study of alinite cement hydration by impedance spectroscopy (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Study of alinite cement hydration by impedance spectroscopy Citation Details In-Document Search Title: Study of alinite cement hydration by impedance spectroscopy Two types of alinite cements, Mg-alinite and Zn-alinite, were synthesized using the reagent grade chemicals. Their hydration behavior was compared with ordinary Portland cement (OPC) using impedance spectroscopy (IS) and {sup 29}Si nuclear magnetic resonance (NMR) spectroscopy. The bulk resistance in the

  15. DOE Announces $2 Million Funding for Methane Hydrates Projects | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy 2 Million Funding for Methane Hydrates Projects DOE Announces $2 Million Funding for Methane Hydrates Projects November 7, 2005 - 12:43pm Addthis Seeks to Unlock World's Biggest Potential Source of "Ice That Burns" WASHINGTON, DC - The Department of Energy (DOE) today announced a total of $2 million in funding to five research projects that will assess the energy potential, safety, and environmental aspects of methane hydrate exploration and development. Termed the

  16. Geomechanical Performance of Hydrate-Bearing Sediment in Offshore Environments

    SciTech Connect (OSTI)

    Stephen Holditch; Tad Patzek; Jonny Rutqvist; George Moridis; Richard Plumb

    2008-03-31

    The objective of this multi-year, multi-institutional research project was to develop the knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate-bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus was on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. We have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. We also investigated the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. The objective of the UC Berkeley work was to develop a grain-scale model of hydrate-bearing sediments. Hydrate dissociation alters the strength of HBS. In particular, transformation of hydrate clusters into gas and liquid water weakens the skeleton and, simultaneously, reduces the effective stress by increasing the pore pressure. The large-scale objective of the study is evaluation of geomechanical stability of offshore oil and gas production infrastructure. At Lawrence Berkeley National Laboratory (LBNL), we have developed the numerical model TOUGH + Hydrate + FLAC3D to evaluate how the formation and disassociation of hydrates in seafloor sediments affects seafloor stability. Several technical papers were published using results from this model. LBNL also developed laboratory equipment and methods to produce realistic laboratory samples of sediments containing gas hydrates so that mechanical properties could be measured in the laboratory. These properties are required to run TOUGH + Hydrate + FLAC3D to evaluate seafloor stability issues. At Texas A&M University we performed a detailed literature review to determine what gas hydrate formation properties had been measured and reported in the literature. We then used TOUGH + Hydrate to simulate the observed gas production and reservoir pressure field data at Messoyakha. We simulated various scenarios that help to explain the field behavior. We have evaluated the effect of reservoir parameters on gas recovery from hydrates. Our work should be beneficial to others who are investigating how to produce gas from a hydrate capped gas reservoir. The results also can be used to better evaluate the process of producing gas from offshore hydrates. The Schlumberger PETREL model is used in industry to the description of geologic horizons and the special distribution of properties. An interface between FLAC3D and Petrel was built by Schlumberger to allow for efficient data entry into TOUGH + Hydrate + FLAC3D.

  17. Rapid Gas Hydrate Formation Process - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Storage Energy Storage Find More Like This Return to Search Rapid Gas Hydrate Formation Process National Energy Technology Laboratory Contact NETL About This Technology...

  18. Method for the photocatalytic conversion of gas hydrates

    DOE Patents [OSTI]

    Taylor, Charles E.; Noceti, Richard P.; Bockrath, Bradley C.

    2001-01-01

    A method for converting methane hydrates to methanol, as well as hydrogen, through exposure to light. The process includes conversion of methane hydrates by light where a radical initiator has been added, and may be modified to include the conversion of methane hydrates with light where a photocatalyst doped by a suitable metal and an electron transfer agent to produce methanol and hydrogen. The present invention operates at temperatures below 0.degree. C., and allows for the direct conversion of methane contained within the hydrate in situ.

  19. An Integrated Study Method For Exploration Of Gas Hydrate Reservoirs...

    Open Energy Info (EERE)

    based on the analysis of geochemical anomalies to the main components, such as methane and hydrocarbon series, an integrated assessment of prospective gas hydrate...

  20. Intrinsic decoherence dynamics in smooth Hamiltonian systems: Quantum-classical correspondence

    SciTech Connect (OSTI)

    Gong, Jiangbin; Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Canada M5S 3H6 (Canada)

    2003-08-01

    A direct classical analog of the quantum dynamics of intrinsic decoherence in Hamiltonian systems, characterized by the time dependence of the linear entropy of the reduced density operator, is introduced. The similarities and differences between the classical and quantum decoherence dynamics of an initial quantum state are exposed using both analytical and computational results. In particular, the classicality of early-time intrinsic decoherence dynamics is explored analytically using a second-order perturbative treatment, and an interesting connection between decoherence rates and the stability nature of classical trajectories is revealed in a simple approximate classical theory of intrinsic decoherence dynamics. The results offer deeper insights into decoherence, dynamics of quantum entanglement, and quantum chaos.

  1. Sensitivity Analysis of Dynamic Stability Indicators in Power Systems

    SciTech Connect (OSTI)

    Nguyen, Tony B.; Pai, M. A.

    2006-01-01

    Real time stability evaluation and preventive scheduling in power systems offers many challenges in a stressed power system. Through fast simulation of contingencies in real time it is possible to extract suitable information from the data and develop reliable metrics or indices to evaluate proximity of the system to an unstable condition. In this chapter we review the recent applications of the trajectory sensitivity analysis (TSA) technique in developing such indicators. Trajectory sensitivities can be used to compute critical parameters such as clearing time of circuit breakers, tie line flow, etc. in a power system by developing suitable norms for ease of interpretation. Alternatively it can be used along with the notion of Principal Singular Surfaces (PSS) to detect mode of instability (MOI). The TSA technique has the advantage that model complexity is not a limitation and the sensitivities are computed numerically. Suitable metrics are developed from these sensitivities. In addition to computing critical parameters, the TSA technique can be extended to do preventive rescheduling. A brief discussion of other applications of TSA is included as well as future areas of research.

  2. Natural gas hydrates on the North Slope of Alaska

    SciTech Connect (OSTI)

    Collett, T.S.

    1991-01-01

    Gas hydrates are crystalline substances composed of water and gas, mainly methane, in which a solid-water lattice accommodates gas molecules in a cage-like structure, or clathrate. These substances often have been regarded as a potential (unconventional) source of natural gas. Significant quantities of naturally occurring gas hydrates have been detected in many regions of the Arctic including Siberia, the Mackenzie River Delta, and the North Slope of Alaska. On the North Slope, the methane-hydrate stability zone is areally extensive beneath most of the coastal plain province and has thicknesses as great as 1000 meters in the Prudhoe Bay area. Gas hydrates have been identified in 50 exploratory and production wells using well-log responses calibrated to the response of an interval in one well where gas hydrates were recovered in a core by ARCO Alaska and EXXON. Most of these gas hydrates occur in six laterally continuous Upper Cretaceous and lower Tertiary sandstone and conglomerate units; all these gas hydrates are geographically restricted to the area overlying the eastern part of the Kuparuk River Oil Field and the western part of the Prudhoe Bay Oil Field. The volume of gas within these gas hydrates is estimated to be about 1.0 {times} 10{sup 12} to 1.2 {times} 10{sup 12} cubic meters (37 to 44 trillion cubic feet), or about twice the volume of conventional gas in the Prudhoe Bay Field. Geochemical analyses of well samples suggest that the identified hydrates probably contain a mixture of deep-source thermogenic gas and shallow microbial gas that was either directly converted to gas hydrate or first concentrated in existing traps and later converted to gas hydrate. The thermogenic gas probably migrated from deeper reservoirs along the same faults thought to be migration pathways for the large volumes of shallow, heavy oil that occur in this area. 51 refs., 11 figs., 3 tabs.

  3. CO{sub 2} HYDRATE PROCESS FOR GAS SEPARATION

    SciTech Connect (OSTI)

    G. Deppe; R. Currier; D. Spencer

    2004-01-01

    Modifications were implemented to the hydrogen flow test rig per safety review comments, and the apparatus was tested for leaks. Tests were then done using Helium/CO{sub 2} mixtures to re-verify performance prior to hydrogen testing. It was discovered that hydrate formation was more difficult to initiate, and new initiation methods were developed to improve the tests. Delivery of ETM hardware continued and buildup of the ETM system continued, the ETM is now mechanically complete. The STU (pilot plant) site selection process was resumed because Tennessee Eastman declined to participate in the program. Two potential sites were visited: The Global Energy/Conoco-Phillips Wabash River Plant, and the Tampa Electric Polk Power Plant.

  4. In situ molecular imaging of hydrated biofilm in a microfluidic reactor by ToF-SIMS

    SciTech Connect (OSTI)

    Hua, Xin; Yu, Xiao-Ying; Wang, Zhaoying; Yang, Li; Liu, Bingwen; Zhu, Zihua; Tucker, Abigail E.; Chrisler, William B.; Hill, Eric A.; Thevuthasan, Suntharampillai; Lin, Yuehe; Liu, Songqin; Marshall, Matthew J.

    2014-02-26

    The first results of using a novel single channel microfluidic reactor to enable Shewanella biofilm growth and in situ characterization using time-of-flight secondary ion mass spectrometry (ToF-SIMS) in the hydrated environment are presented. The new microfluidic interface allows direct probing of the liquid surface using ToF-SIMS, a vacuum surface technique. The detection window is an aperture of 2 m in diameter on a thin silicon nitride (SiN) membrane and it allows direct detection of the liquid surface. Surface tension of the liquid flowing inside the microchannel holds the liquid within the aperture. ToF-SIMS depth profiling was used to drill through the SiN membrane and the biofilm grown on the substrate. In situ 2D imaging of the biofilm in hydrated state was acquired, providing spatial distribution of the chemical compounds in the biofilm system. This data was compared with a medium filled microfluidic reactor devoid of biofilm and dried biofilm samples deposited on clean silicon wafers. Principle Component Analysis (PCA) was used to investigate these observations. Our results show that imaging biofilms in the hydrated environment using ToF-SIMS is possible using the unique microfluidic reactor. Moreover, characteristic biofilm fatty acids fragments were observed in the hydrated biofilm grown in the microfluidic channel, illustrating the advantage of imaging biofilm in its native environment.

  5. Insights into the structure of mixed CO2/CH4 in gas hydrates

    SciTech Connect (OSTI)

    Everett, Susan M; Rawn, Claudia J; Chakoumakos, Bryan C; Keffer, David J.; Huq, Ashfia; Phelps, Tommy Joe

    2015-01-01

    The exchange of CO2 for CH4 in natural gas hydrates is an attractive approach to methane for energy production while simultaneously sequestering CO2. In addition to the energy and environmental implications, the solid solution of clathrate hydrate (CH4)1-x(CO2)x 5.75H2O provides a model system to study how the distinct bonding and shapes of CH4 and CO2 influence the structure and properties of the compound. High-resolution neutron diffraction was used to examine mixed CO2/CH4 gas hydrates. CO2-rich hydrates had smaller lattice parameters, which were attributed to the higher affinity of the CO2 molecule interacting with H2O molecules that form the surrounding cages, and resulted in a reduction in the unit cell volume. Experimental nuclear scattering densities illustrate how the cage occupants and energy landscape change with composition. These results provide important insights on the impact and mechanisms for exchanging CH4 and CO2.

  6. Insights into the structure of mixed CO2/CH4 in gas hydrates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Everett, Susan M; Rawn, Claudia J; Chakoumakos, Bryan C; Keffer, David J.; Huq, Ashfia; Phelps, Tommy Joe

    2015-01-01

    The exchange of CO2 for CH4 in natural gas hydrates is an attractive approach to methane for energy production while simultaneously sequestering CO2. In addition to the energy and environmental implications, the solid solution of clathrate hydrate (CH4)1-x(CO2)x 5.75H2O provides a model system to study how the distinct bonding and shapes of CH4 and CO2 influence the structure and properties of the compound. High-resolution neutron diffraction was used to examine mixed CO2/CH4 gas hydrates. CO2-rich hydrates had smaller lattice parameters, which were attributed to the higher affinity of the CO2 molecule interacting with H2O molecules that form the surrounding cages,more » and resulted in a reduction in the unit cell volume. Experimental nuclear scattering densities illustrate how the cage occupants and energy landscape change with composition. These results provide important insights on the impact and mechanisms for exchanging CH4 and CO2.« less

  7. Response margins of the dynamic analysis of piping systems

    SciTech Connect (OSTI)

    Johnson, J.J.; Benda, B.J.; Chuang, T.Y.; Smith, P.D.

    1984-04-01

    This report is organized as follows: Section 2 describes the three piping systems of the Zion nuclear power plant which formed the basis of the present study. The auxiliary feedwater (AFW) piping from steam generator to containment, the residual heat removal (RHR) and safety injection piping in the auxiliary building, and the reactor coolant loops (RCL) including a portion of the branch lines were analyzed. Section 3 describes the analysis methods and the analyses performed. Section 4 presents the numerical results; the principal results presented as comparisons of response calculated by best estimate time history analysis methods vs. the SRP response spectrum technique. Section 5 draws conclusions from the results. Appendix A contains a brief description of the mathematical models that defined the structures containing the three piping systems. Response from these models provided input to the piping models. Appendix B provides a detailed derivation of the pseudostatic mode approach to the multisupport time history analysis method used in this study.

  8. Presentations from the March 27th - 28th Methane Hydrates Advisory

    Energy Savers [EERE]

    Committee Meeting | Department of Energy the March 27th - 28th Methane Hydrates Advisory Committee Meeting Presentations from the March 27th - 28th Methane Hydrates Advisory Committee Meeting PDF icon International Gas Hydrate Research PDF icon DOE's Natural Gas Hydrates Program PDF icon Gas Hydrates as a Geohazard: What Really Are the Issues? PDF icon Quantifying Climate-Hydrate Interactions: A Progress Report More Documents & Publications May 21, 2014 Committee Recommendations to

  9. Surfactant process for promoting gas hydrate formation and application of the same

    DOE Patents [OSTI]

    Rogers, Rudy E. (Starkville, MS); Zhong, Yu (Brandon, MS)

    2002-01-01

    This invention relates to a method of storing gas using gas hydrates comprising forming gas hydrates in the presence of a water-surfactant solution that comprises water and surfactant. The addition of minor amounts of surfactant increases the gas hydrate formation rate, increases packing density of the solid hydrate mass and simplifies the formation-storage-decomposition process of gas hydrates. The minor amounts of surfactant also enhance the potential of gas hydrates for industrial storage applications.

  10. Studying methane migration mechanisms at Walker Ridge, Gulf of Mexico, via 3D methane hydrate reservoir modeling

    SciTech Connect (OSTI)

    Nole, Michael; Daigle, Hugh; Mohanty, Kishore; Cook, Ann; Hillman, Jess

    2015-12-15

    We have developed a 3D methane hydrate reservoir simulator to model marine methane hydrate systems. Our simulator couples highly nonlinear heat and mass transport equations and includes heterogeneous sedimentation, in-situ microbial methanogenesis, the influence of pore size contrast on solubility gradients, and the impact of salt exclusion from the hydrate phase on dissolved methane equilibrium in pore water. Using environmental parameters from Walker Ridge in the Gulf of Mexico, we first simulate hydrate formation in and around a thin, dipping, planar sand stratum surrounded by clay lithology as it is buried to 295mbsf. We find that with sufficient methane being supplied by organic methanogenesis in the clays, a 200x pore size contrast between clays and sands allows for a strong enough concentration gradient to significantly drop the concentration of methane hydrate in clays immediately surrounding a thin sand layer, a phenomenon that is observed in well log data. Building upon previous work, our simulations account for the increase in sand-clay solubility contrast with depth from about 1.6% near the top of the sediment column to 8.6% at depth, which leads to a progressive strengthening of the diffusive flux of methane with time. By including an exponentially decaying organic methanogenesis input to the clay lithology with depth, we see a decrease in the aqueous methane supplied to the clays surrounding the sand layer with time, which works to further enhance the contrast in hydrate saturation between the sand and surrounding clays. Significant diffusive methane transport is observed in a clay interval of about 11m above the sand layer and about 4m below it, which matches well log observations. The clay-sand pore size contrast alone is not enough to completely eliminate hydrate (as observed in logs), because the diffusive flux of aqueous methane due to a contrast in pore size occurs slower than the rate at which methane is supplied via organic methanogenesis. Therefore, it is likely that additional mechanisms are at play, notably bound water activity reduction in clays. Three-dimensionality allows for inclusion of lithologic heterogeneities, which focus fluid flow and subsequently allow for heterogeneity in the methane migration mechanisms that dominate in marine sediments at a local scale. Incorporating recently acquired 3D seismic data from Walker Ridge to inform the lithologic structure of our modeled reservoir, we show that even with deep adjective sourcing of methane along highly permeable pathways, local hydrate accumulations can be sourced either by diffusive or advective methane flux; advectively-sourced hydrates accumulate evenly in highly permeable strata, while diffusively-sourced hydrates are characterized by thin strata-bound intervals with high clay-sand pore size contrasts.

  11. Dynamic simulation of the Hanford tank waste remediation system

    SciTech Connect (OSTI)

    Harmsen, R.W., Westinghouse Hanford

    1996-05-03

    Cleaning up and disposing of approximately 50 years of nuclear waste is the main mission at the U.S. Department of Energy`s Hanford Nuclear Reservation, located in the southeastern part of the state of Washington. A major element of the total cleanup effort involves retrieving, processing, and disposing of radioactive and hazardous waste stored in 177 underground storage tanks. This effort, referred to as the Tank Waste Remediation System (TWRS), is expected to cost billions of dollars and take approximately 25 years to complete. Several computer simulations of this project are being created, focusing on both programmatic and detailed engineering issues. This paper describes one such simulation activity, using the ithink(TM)computer simulation software. The ithink(TM) simulation includes a representation of the complete TWRS cleanup system, from retrieval of waste through intermediate processing and final vitrification of waste for disposal. Major issues addressed to date by the simulation effort include the need for new underground storage tanks to support TWRS activities, and the estimated design capacities for various processing facilities that are required to support legally mandated program commitment dates. This paper discusses how the simulation was used to investigate these questions.

  12. Ice method for production of hydrogen clathrate hydrates

    DOE Patents [OSTI]

    Lokshin, Konstantin; Zhao, Yusheng

    2008-05-13

    The present invention includes a method for hydrogen clathrate hydrate synthesis. First, ice and hydrogen gas are supplied to a containment volume at a first temperature and a first pressure. Next, the containment volume is pressurized with hydrogen gas to a second higher pressure, where hydrogen clathrate hydrates are formed in the process.

  13. Small stirling dynamic isotope power systems for multihundred-watt robotic missions

    SciTech Connect (OSTI)

    Bents, D.J.

    1991-01-01

    Free piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advanced radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

  14. Dynamic Analysis of Hybrid Energy Systems under Flexible Operation and Variable Renewable Generation -- Part I: Dynamic Performance Analysis and Part II: Dynamic Cost

    SciTech Connect (OSTI)

    Humberto E. Garcia; Amit Mohanty; Wen-Chiao Lin; Robert S. Cherry

    2013-04-01

    Dynamic analysis of hybrid energy systems (HES) under flexible operation and variable renewable generation is considered in order to better understand various challenges and opportunities associated with the high system variability arising from the integration of renewable energy into the power grid. Unique consequences are addressed by devising advanced HES solutions in which multiple forms of energy commodities, such as electricity and chemical products, may be exchanged. Dynamic models of various unit operations are developed and integrated within two different HES options. One HES option, termed traditional, produces electricity only and consists of a primary heat generator (PHG) (e.g., a small modular reactor), a steam turbine generator, a wind farm, and a battery storage. The other HES option, termed advanced, includes not only the components present in the traditional option but also a chemical plant complex to repurpose excess energy for non-electricity services, such as for the production of chemical goods (e.g., transportation fuel). In either case, a given HES is connected to the power grid at a point of common coupling and requested to deliver a certain electricity generation profile as dictated by a regional power grid operator based on a predicted demand curve. Dynamic analysis of these highly-coupled HES are performed to identify their key dynamical properties and limitations and to prescribe solutions for best managing and mitigating the high variability introduced from incorporating renewable energy into the energy mix. A comparative dynamic cost analysis is also conducted to determine best HES options. The cost function includes a set of metrics for computing fixed costs, such as fixed operations and maintenance (O&M) and overnight capital costs, and also variable operational costs, such as cost of variability, variable O&M cost, and cost of environmental impact, together with revenues. Assuming different options for implementing PHG (e.g., natural gas, coal, nuclear), preliminary results identify the level of renewable penetration at which a given advanced HES option (e.g., a nuclear hybrid) becomes increasingly more economical than a traditional electricity-only generation solution. Conditions are also revealed under which carbon resources may be better utilized as carbon sources for chemical production rather than as combustion material for electricity generation.

  15. Presentations from the March 27th - 28th Methane Hydrates Advisory...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the March 27th - 28th Methane Hydrates Advisory Committee Meeting Presentations from the March 27th - 28th Methane Hydrates Advisory Committee Meeting PDF icon International Gas ...

  16. Using System Dynamics to Model the Transition to Biofuels in the United States: Preprint

    SciTech Connect (OSTI)

    Bush, B.; Duffy, M.; Sandor, D.; Peterson, S.

    2008-06-01

    Transitioning to a biofuels industry that is expected to displace about 30% of current U.S. gasoline consumption requires a robust biomass-to-biofuels system-of-systems that operates in concert with the existing markets. This paper discusses employing a system dynamics approach to investigate potential market penetration scenarios for cellulosic ethanol and to help government decision makers focus on areas with greatest potential.

  17. Design an optimum safety policy for personnel safety management - A system dynamic approach

    SciTech Connect (OSTI)

    Balaji, P.

    2014-10-06

    Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making.

  18. Heat of Hydration of Low Activity Cementitious Waste Forms

    SciTech Connect (OSTI)

    Nasol, D.

    2015-07-23

    During the curing of secondary waste grout, the hydraulic materials in the dry mix react exothermally with the water in the secondary low-activity waste (LAW). The heat released, called the heat of hydration, can be measured using a TAM Air Isothermal Calorimeter. By holding temperature constant in the instrument, the heat of hydration during the curing process can be determined. This will provide information that can be used in the design of a waste solidification facility. At the Savannah River National Laboratory (SRNL), the heat of hydration and other physical properties are being collected on grout prepared using three simulants of liquid secondary waste generated at the Hanford Site. From this study it was found that both the simulant and dry mix each had an effect on the heat of hydration. It was also concluded that the higher the cement content in the dry materials mix, the greater the heat of hydration during the curing of grout.

  19. Monopole and topological electron dynamics in adiabatic spintronic and graphene systems

    SciTech Connect (OSTI)

    Tan, S.G.; Jalil, M.B.A.; Fujita, T.

    2010-08-15

    A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin's fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.

  20. A complex systems analysis of stick-slip dynamics of a laboratory fault

    SciTech Connect (OSTI)

    Walker, David M.; Tordesillas, Antoinette; Small, Michael; Behringer, Robert P.; Tse, Chi K.

    2014-03-15

    We study the stick-slip behavior of a granular bed of photoelastic disks sheared by a rough slider pulled along the surface. Time series of a proxy for granular friction are examined using complex systems methods to characterize the observed stick-slip dynamics of this laboratory fault. Nonlinear surrogate time series methods show that the stick-slip behavior appears more complex than a periodic dynamics description. Phase space embedding methods show that the dynamics can be locally captured within a four to six dimensional subspace. These slider time series also provide an experimental test for recent complex network methods. Phase space networks, constructed by connecting nearby phase space points, proved useful in capturing the key features of the dynamics. In particular, network communities could be associated to slip events and the ranking of small network subgraphs exhibited a heretofore unreported ordering.

  1. A system dynamics approach to intermodalism at the Port of Lewiston

    SciTech Connect (OSTI)

    Sebo, D.

    1996-08-01

    Intermodalism refers to interconnections among modes of transportation, e.g., road, rail, water, and air. Effective intermodal planning must cross boundaries between the public and private sectors as well as transportation modes. The development of an effective and efficient intermodal transportation system requires the identification of barriers to intermodal transportation and the investigation of the impact of proposed changes in infrastructure development, policies, regulations, and planning. A systems approach is necessary to adequately represent the interaction between the sometimes incompatible concerns of all modes and stakeholders. A systems dynamics model of intermodalism at the Port of Lewiston has been developed to highlight leverage points, hidden assumptions, second order effects resulting from feedback loops and system drivers. The purpose of this document is to present the results of the system dynamics model work.

  2. Prediction of the phase equilibria of methane hydrates using the direct phase coexistence methodology

    SciTech Connect (OSTI)

    Michalis, Vasileios K.; Costandy, Joseph; Economou, Ioannis G.; Tsimpanogiannis, Ioannis N.; Stubos, Athanassios K.

    2015-01-28

    The direct phase coexistence method is used for the determination of the three-phase coexistence line of sI methane hydrates. Molecular dynamics (MD) simulations are carried out in the isothermalisobaric ensemble in order to determine the coexistence temperature (T{sub 3}) at four different pressures, namely, 40, 100, 400, and 600 bar. Methane bubble formation that results in supersaturation of water with methane is generally avoided. The observed stochasticity of the hydrate growth and dissociation processes, which can be misleading in the determination of T{sub 3}, is treated with long simulations in the range of 10004000 ns and a relatively large number of independent runs. Statistical averaging of 25 runs per pressure results in T{sub 3} predictions that are found to deviate systematically by approximately 3.5 K from the experimental values. This is in good agreement with the deviation of 3.15 K between the prediction of TIP4P/Ice water force field used and the experimental melting temperature of ice Ih. The current results offer the most consistent and accurate predictions from MD simulation for the determination of T{sub 3} of methane hydrates. Methane solubility values are also calculated at the predicted equilibrium conditions and are found in good agreement with continuum-scale models.

  3. Protein-style dynamical transition in a non-biological polymer and a non-aqueous solvent

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mamontov, E.; Sharma, V. K.; Borreguero, J. M.; Tyagi, M.

    2016-03-15

    Using neutron scattering and molecular dynamics simulation, techniques most often associated with protein dynamical transition studies, we have investigated the microscopic dynamics of one of the most common polymers, polystyrene, which was exposed to toluene vapor, mimicking the process of protein hydration from water vapor. Polystyrene with adsorbed toluene is an example of a solvent-solute system, which, unlike biopolymers, is anhydrous and lacks hydrogen bonding. Nevertheless, it exhibits the essential traits of the dynamical transition in biomolecules, such as a specific dependence of the microscopic dynamics of both solvent and host on the temperature and the amount of solvent adsorbed.more » Ultimately, we conclude that the protein dynamical transition is a manifestation of a universal solvent-solute dynamical relationship, which is not specific to either biomolecules as solute, or aqueous media as solvent, or even a particular type of interactions between solvent and solute.« less

  4. Numerical analysis for finite-range multitype stochastic contact financial market dynamic systems

    SciTech Connect (OSTI)

    Yang, Ge; Wang, Jun; Fang, Wen

    2015-04-15

    In an attempt to reproduce and study the dynamics of financial markets, a random agent-based financial price model is developed and investigated by the finite-range multitype contact dynamic system, in which the interaction and dispersal of different types of investment attitudes in a stock market are imitated by viruses spreading. With different parameters of birth rates and finite-range, the normalized return series are simulated by Monte Carlo simulation method and numerical studied by power-law distribution analysis and autocorrelation analysis. To better understand the nonlinear dynamics of the return series, a q-order autocorrelation function and a multi-autocorrelation function are also defined in this work. The comparisons of statistical behaviors of return series from the agent-based model and the daily historical market returns of Shanghai Composite Index and Shenzhen Component Index indicate that the proposed model is a reasonable qualitative explanation for the price formation process of stock market systems.

  5. The DOE Wide Area Measurement System (WAMS) Project: Demonstration of dynamic information technology for the future power system

    SciTech Connect (OSTI)

    Mittelstadt, W.A.; Krause, P.E.; Wilson, R.E.; Overholt, P.N.; Sobajic, D.J.; Hauer, J.F.; Rizy, D.T.

    1996-07-01

    In 1989 the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) joined the US Department of Energy (DOE) in an assessment of longer-term research and development needs for future electric power system operation. The effort produced a progressively sharper vision of a future power system in which enhanced control and operation are the primary means for serving new customer demands, in an environment where increased competition, a wider range of services and vendors, and much narrower operating margins all contribute to increased system efficiencies and capacity. Technology and infrastructure for real time access to wide area dynamic information were identified as critical path elements in realizing that vision. In 1995 the DOE accordingly launched the Wide Area Measurement System (WAMS) Project jointly with the two Power Marketing Administrations (PMAs) to address these issues in a practical operating environment--the western North America power system. The Project draws upon many years of PMA effort and related collaboration among the western utilities, plus an expanding infrastructure that includes regionally involved contractors, universities, and National Laboratories plus linkages to the Electric Power Research Institute (EPRI). The WAMS project also brings added focus and resources to the evolving Western System Dynamic Information Network, or WesDINet. This is a collective response of the Western Systems Coordinating Council (WSCC) member utilities to their shared needs for direct information about power system characteristics, model fidelity, and operational performance. The WAMS project is a key source of the technology and backbone communications needed to make WesDINet a well integrated, cost effective enterprise network demonstrating the role of dynamic information technology in the emerging utility environment.

  6. Dynamics of ionisation and entanglement in the 'atom + quantum electromagnetic field' system

    SciTech Connect (OSTI)

    Sharapova, P R; Tikhonova, O V

    2012-03-31

    The dynamics of a model Rydberg atom in a strong nonclassical electromagnetic field is investigated. The field-induced transitions to the continuum involving different numbers of photons (with intermediate states in the discrete spectrum) are taken into account and the specific features of ionisation in 'squeezed' field states are considered in comparison with the case of classical light. A significant decrease in the ionisation rate is found, which is caused by the interference stabilisation of the atomic system. The entanglement of the atomic and field subsystems, the temporal dynamics of the correlations found, and the possibility of measuring them are analysed.

  7. Examination of Hydrate Formation Methods: Trying to Create Representative Samples

    SciTech Connect (OSTI)

    Kneafsey, T.J.; Rees, E.V.L.; Nakagawa, S.; Kwon, T.-H.

    2011-04-01

    Forming representative gas hydrate-bearing laboratory samples is important so that the properties of these materials may be measured, while controlling the composition and other variables. Natural samples are rare, and have often experienced pressure and temperature changes that may affect the property to be measured [Waite et al., 2008]. Forming methane hydrate samples in the laboratory has been done a number of ways, each having advantages and disadvantages. The ice-to-hydrate method [Stern et al., 1996], contacts melting ice with methane at the appropriate pressure to form hydrate. The hydrate can then be crushed and mixed with mineral grains under controlled conditions, and then compacted to create laboratory samples of methane hydrate in a mineral medium. The hydrate in these samples will be part of the load-bearing frame of the medium. In the excess gas method [Handa and Stupin, 1992], water is distributed throughout a mineral medium (e.g. packed moist sand, drained sand, moistened silica gel, other porous media) and the mixture is brought to hydrate-stable conditions (chilled and pressurized with gas), allowing hydrate to form. This method typically produces grain-cementing hydrate from pendular water in sand [Waite et al., 2004]. In the dissolved gas method [Tohidi et al., 2002], water with sufficient dissolved guest molecules is brought to hydrate-stable conditions where hydrate forms. In the laboratory, this is can be done by pre-dissolving the gas of interest in water and then introducing it to the sample under the appropriate conditions. With this method, it is easier to form hydrate from more soluble gases such as carbon dioxide. It is thought that this method more closely simulates the way most natural gas hydrate has formed. Laboratory implementation, however, is difficult, and sample formation is prohibitively time consuming [Minagawa et al., 2005; Spangenberg and Kulenkampff, 2005]. In another version of this technique, a specified quantity of gas is placed in a sample, then the sample is flooded with water and cooled [Priest et al., 2009]. We have performed a number of tests in which hydrate was formed and the uniformity of the hydrate formation was examined. These tests have primarily used a variety of modifications of the excess gas method to make the hydrate, although we have also used a version of the excess water technique. Early on, we found difficulties in creating uniform samples with a particular sand/ initial water saturation combination (F-110 Sand, {approx} 35% initial water saturation). In many of our tests we selected this combination intentionally to determine whether we could use a method to make the samples uniform. The following methods were examined: Excess gas, Freeze/thaw/form, Freeze/pressurize/thaw, Excess gas followed by water saturation, Excess water, Sand and kaolinite, Use of a nucleation enhancer (SnoMax), and Use of salt in the water. Below, each method, the underlying hypothesis, and our results are briefly presented, followed by a brief conclusion. Many of the hypotheses investigated are not our own, but were presented to us. Much of the data presented is from x-ray CT scanning our samples. The x-ray CT scanner provides a three-dimensional density map of our samples. From this map and the physics that is occurring in our samples, we are able to gain an understanding of the spatial nature of the processes that occur, and attribute them to the locations where they occur.

  8. Application of the Split Hopkinson Resonant Bar Test for Seismic Property Characterization of Hydrate-bearing Sand Undergoing Water Saturation

    SciTech Connect (OSTI)

    Nakagawa, S.; Kneafsey, T.J.

    2011-05-03

    Conventional resonant bar tests allow the measurement of seismic properties of rocks and sediments at low frequencies (several kilohertz). However, the tests require a long, slender sample which is often difficult to obtain from the deep subsurface and weak and fractured formations. We present an alternative low-frequency measurement technique to the conventional resonant bar tests. This technique involves a jacketed core sample placed between a pair of long, metal extension rods with attached seismic source and receiver—the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the added length and mass to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The proposed “Split Hopkinson Resonant Bar (SHRB)” test is applied in two steps. In the first step, extension and torsion-mode resonance frequencies and attenuation of the system are measured. Then, numerical inversions for the compressional and shear wave velocities and attenuation are performed. We initially applied the SHRB test to synthetic materials (plastics) for testing its accuracy, then used it for measuring the seismic velocities and attenuation of a rock core containing supercritical CO{sub 2}, and a sediment core while methane hydrate formed in the pore space.

  9. Using nonequilibrium dynamics to probe competing orders in a Mott-Peierls system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Y.; Moritz, B.; Chen, C. -C.; Jia, C. J.; van Veenendaal, M.; Devereaux, T. P.

    2016-02-24

    Competition between ordered phases, and their associated phase transitions, are significant in the study of strongly correlated systems. Here, we examine one aspect, the nonequilibrium dynamics of a photoexcited Mott-Peierls system, using an effective Peierls-Hubbard model and exact diagonalization. Near a transition where spin and charge become strongly intertwined, we observe antiphase dynamics and a coupling-strength-dependent suppression or enhancement in the static structure factors. The renormalized bosonic excitations coupled to a particular photoexcited electron can be extracted, which provides an approach for characterizing the underlying bosonic modes. The results from this analysis for different electronic momenta show an uneven softeningmore » due to a stronger coupling near kF. As a result, this behavior reflects the strong link between the fermionic momenta, the coupling vertices, and ultimately, the bosonic susceptibilities when multiple phases compete for the ground state of the system.« less

  10. RESONANCES REQUIRED: DYNAMICAL ANALYSIS OF THE 24 Sex AND HD 200964 PLANETARY SYSTEMS

    SciTech Connect (OSTI)

    Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.

    2012-12-20

    We perform several suites of highly detailed dynamical simulations to investigate the architectures of the 24 Sextantis and HD 200964 planetary systems. The best-fit orbital solution for the two planets in the 24 Sex system places them on orbits with periods that lie very close to 2:1 commensurability, while that for the HD 200964 system places the two planets therein in orbits whose periods lie close to a 4:3 commensurability. In both cases, the proposed best-fit orbits are mutually crossing-a scenario that is only dynamically feasible if the planets are protected from close encounters by the effects of mutual mean-motion resonance (MMR). Our simulations reveal that the best-fit orbits for both systems lie within narrow islands of dynamical stability, and are surrounded by much larger regions of extreme instability. As such, we show that the planets are only feasible if they are currently trapped in mutual MMR-the 2:1 resonance in the case of 24 Sex b and c, and the 4:3 resonance in the case of HD 200964 b and c. In both cases, the region of stability is strongest and most pronounced when the planetary orbits are mutually coplanar. As the inclination of planet c with respect to planet b is increased, the stability of both systems rapidly collapses.

  11. Advanced High-Temperature Reactor Dynamic System Model Development: April 2012 Status

    SciTech Connect (OSTI)

    Qualls, A L; Cetiner, M S; Wilson, Jr, T L

    2012-04-30

    The Advanced High-Temperature Reactor (AHTR) is a large-output fluoride-salt-cooled high-temperature reactor (FHR). An early-phase preconceptual design of a 1500 MW(e) power plant was developed in 2011 [Refs. 1 and 2]. An updated version of this plant is shown as Fig. 1. FHRs feature low-pressure liquid fluoride salt cooling, coated-particle fuel, a high-temperature power cycle, and fully passive decay heat rejection. The AHTR is designed to be a “walk away” reactor that requires no action to prevent large off-site releases following even severe reactor accidents. This report describes the development of dynamic system models used to further the AHTR design toward that goal. These models predict system response during warmup, startup, normal operation, and limited off-normal operating conditions. Severe accidents that include a loss-of-fluid inventory are not currently modeled. The scope of the models is limited to the plant power system, including the reactor, the primary and intermediate heat transport systems, the power conversion system, and safety-related or auxiliary heat removal systems. The primary coolant system, the intermediate heat transport system and the reactor building structure surrounding them are shown in Fig. 2. These systems are modeled in the most detail because the passive interaction of the primary system with the surrounding structure and heat removal systems, and ultimately the environment, protects the reactor fuel and the vessel from damage during severe reactor transients. The reactor silo also plays an important role during system warmup. The dynamic system modeling tools predict system performance and response. The goal is to accurately predict temperatures and pressures within the primary, intermediate, and power conversion systems and to study the impacts of design changes on those responses. The models are design tools and are not intended to be used in reactor qualification. The important details to capture in the primary system relate to flows within the reactor vessel during severe events and the resulting temperature profiles (temperature and duration) for major components. Critical components include the fuel, reactor vessel, primary piping, and the primary-to-intermediate heat exchangers (P-IHXs). The major AHTR power system loops are shown in Fig. 3. The intermediate heat transfer system is a group of three pumped salt loops that transports the energy produced in the primary system to the power conversion system. Two dynamic system models are used to analyze the AHTR. A Matlab/Simulink-based model initiated in 2011 has been updated to reflect the evolving design parameters related to the heat flows associated with the reactor vessel. The Matlab model utilizes simplified flow assumptions within the vessel and incorporates an empirical representation of the Direct Reactor Auxiliary Cooling System (DRACS). A Dymola/Modelica model incorporates a more sophisticated representation of primary coolant flow and a physics-based representation of the three-loop DRACS thermal hydraulics. This model is not currently operating in a fully integrated mode. The Matlab model serves as a prototype and provides verification for the Dymola model, and its use will be phased out as the Dymola model nears completion. The heat exchangers in the system are sized using spreadsheet-based, steady-state calculations. The detail features of the heat exchangers are programmed into the dynamic models, and the overall dimensions are used to generate realistic plant designs. For the modeling cases where the emphasis is on understanding responses within the intermediate and primary systems, the power conversion system may be modeled as a simple boundary condition at the intermediate-to-power conversion system heat exchangers.

  12. Significance of Dynamic and Transient Analysis in the Design and Operation of Hybrid Energy Systems

    SciTech Connect (OSTI)

    Panwar, Mayank; Mohanpurkar, Manish; Hovsapian, Rob; Osorio, Julian D.

    2015-02-01

    Energy systems were historically designed and operated with a specific energy conversion objective, while managing loads and resources. In the recent years, the increased utilization of non-dispatchable renewable sources such as wind and solar has played a role in power quality and the reliability of power systems. In order to mitigate the risk associated with the non-dispatchable resources an integrated approach, such as Hybrid Energy Systems (HES), has to be taken, integrating the loads and resource management between the traditional thermal power plants and the non-dispatchable resources. As our electric energy becomes more diverse in its generation resources, the HES with its operational control system, its real-time view and its dynamic decisions making will become an essential part of the integrated energy systems and improve the overall grid reliability. The operational constraints of the energy sources on both the thermal power plants and the non-dispatchable resources in HES, plays a vital role in the planning and design stage. It is an established fact that the choice of energy source depends on the available natural resources and possible infrastructure. A critical component of decision-making depends on the complementary nature and controllability of the energy sources to supply the load demands with high reliability. Controllability of complex HES to achieve desired performance and flexibility is implemented via coordinated control systems while simultaneously generating electricity and other useful products such as useful heat or hydrogen. These systems are based on instrumentation, signal processing, control theory, and engineering system design. The entire HES along with the control systems are characterized by widely varying time constants. Hence, for a well-coordinated control and operation, we propose physics based modeling of the subsystems to assist in a dynamic and transient analysis. Dynamic and transient analysis in real and non-real time domain of the potential sources is capable of providing satisfactory results at the feasibility analysis stage. A simplified HES consisting of complementary energy sources is used to demonstrate the proposed approach. Suitable real time simulations to perform dynamic and transient analysis will be performed to verify results from the non-real time analysis. The role of such analyses, especially the real time dynamic and transient analysis for manual controls is elaborated. It is also discussed that faster than real time simulation will pave the future for controller rooms and hence manual control procedures. Multiple tools such as Real Time Simulator, Matlab®, Simulink®, PSCAD®, MOOSE, etc. are expected to be used for the HES analysis.

  13. Develop feedback system for intelligent dynamic resource allocation to improve application performance.

    SciTech Connect (OSTI)

    Gentile, Ann C.; Brandt, James M.; Tucker, Thomas; Thompson, David

    2011-09-01

    This report provides documentation for the completion of the Sandia Level II milestone 'Develop feedback system for intelligent dynamic resource allocation to improve application performance'. This milestone demonstrates the use of a scalable data collection analysis and feedback system that enables insight into how an application is utilizing the hardware resources of a high performance computing (HPC) platform in a lightweight fashion. Further we demonstrate utilizing the same mechanisms used for transporting data for remote analysis and visualization to provide low latency run-time feedback to applications. The ultimate goal of this body of work is performance optimization in the face of the ever increasing size and complexity of HPC systems.

  14. Characterizing system dynamics with a weighted and directed network constructed from time series data

    SciTech Connect (OSTI)

    Sun, Xiaoran; School of Mathematics and Statistics, The University of Western Australia, Crawley WA 6009 ; Small, Michael; Zhao, Yi; Xue, Xiaoping

    2014-06-15

    In this work, we propose a novel method to transform a time series into a weighted and directed network. For a given time series, we first generate a set of segments via a sliding window, and then use a doubly symbolic scheme to characterize every windowed segment by combining absolute amplitude information with an ordinal pattern characterization. Based on this construction, a network can be directly constructed from the given time series: segments corresponding to different symbol-pairs are mapped to network nodes and the temporal succession between nodes is represented by directed links. With this conversion, dynamics underlying the time series has been encoded into the network structure. We illustrate the potential of our networks with a well-studied dynamical model as a benchmark example. Results show that network measures for characterizing global properties can detect the dynamical transitions in the underlying system. Moreover, we employ a random walk algorithm to sample loops in our networks, and find that time series with different dynamics exhibits distinct cycle structure. That is, the relative prevalence of loops with different lengths can be used to identify the underlying dynamics.

  15. Methane Hydrate R&D | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    R&D Methane Hydrate R&D Natural gas is an important energy resource for the United States, providing nearly one-quarter of total energy use. The Department of Energy's Office of ...

  16. Gas hydrate detection and mapping on the US east coast

    SciTech Connect (OSTI)

    Ahlbrandt, T.S.; Dillon, W.P.

    1993-12-31

    Project objectives are to identify and map gas hydrate accumulations on the US eastern continental margin using remote sensing (seismic profiling) techniques and to relate these concentrations to the geological factors that-control them. In order to test the remote sensing methods, gas hydrate-cemented sediments will be tested in the laboratory and an effort will be made to perform similar physical tests on natural hydrate-cemented sediments from the study area. Gas hydrate potentially may represent a future major resource of energy. Furthermore, it may influence climate change because it forms a large reservoir for methane, which is a very effective greenhouse gas; its breakdown probably is a controlling factor for sea-floor landslides; and its presence has significant effect on the acoustic velocity of sea-floor sediments.

  17. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    SciTech Connect (OSTI)

    Fleming, E; Wen, SY; Shi, L; da Silva, AK

    2013-12-01

    A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system's dynamic behavior, such as a dynamic air flow rate into the vehicle's cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle's cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid-air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semianalytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid-air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. (C) 2013 Elsevier Ltd. All rights reserved.

  18. Integrability and nonintegrability of quantum systems. II. Dynamics in quantum phase space

    SciTech Connect (OSTI)

    Zhang, Weimin (Department of Physics, FM-15, University of Washington, Seattle, WA (USA) Department of Physics and Atmospheric Science, Drexel University, Philadelphia, PA (USA)); Feng, D.H.; Yuan, Jianmin (Department of Physics and Atmospheric Science, Drexel University, Philadelphia, PA (USA))

    1990-12-15

    Based on the concepts of integrability and nonintegrability of a quantum system presented in a previous paper (Zhang, Feng, Yuan, and Wang, Phys. Rev. A 40, 438 (1989)), a realization of the dynamics in the quantum phase space is now presented. For a quantum system with dynamical group {ital G-script} and in one of its unitary irreducible-representation carrier spaces {ital h-german}{sub {Lambda}}, the quantum phase space is a 2{ital M}{sub {Lambda}}-dimensional topological space, where {ital M}{sub {Lambda}} is the quantum-dynamical degrees of freedom. This quantum phase space is isomorphic to a coset space {ital G-script}/{ital H-script} via the unitary exponential mapping of the elementary excitation operator subspace of {ital g-script} (algebra of {ital G-script}), where {ital H-script} ({contained in}{ital G-script}) is the maximal stability subgroup of a fixed state in {ital h-german}{sub {Lambda}}. The phase-space representation of the system is realized on {ital G-script}/{ital H-script}, and its classical analogy can be obtained naturally. It is also shown that there is consistency between quantum and classical integrability. Finally, a general algorithm for seeking the manifestation of quantum chaos'' via the classical analogy is provided. Illustrations of this formulation in several important quantum systems are presented.

  19. Methane Hydrate Advisory Committee Meetings | Department of Energy

    Energy Savers [EERE]

    Meetings Methane Hydrate Advisory Committee Meetings May 7, 2015 Advisory Committee Meeting Presentations from the Advisory Committee Meeting May 21, 2014 Committee Recommendations to Secretary of Energy Advisory Committee Meeting Minutes, May 7, 2015 Federal Register Notice for May 7, 2015 Meeting May 15, 2014 Advisory Committee Meeting Federal Register Notice for May 15, 2014 Meeting Methane Hydrates Committee Meeting Agenda Advisory Committee Meeting Minutes, May 15, 2014 March 27-28, 2014

  20. Relative permeability of hydrate-bearing sediments from percolation theory and critical path analysis: theoretical and experimental results

    SciTech Connect (OSTI)

    Daigle, Hugh; Rice, Mary Anna; Daigle, Hugh

    2015-12-14

    Relative permeabilities to water and gas are important parameters for accurate modeling of the formation of methane hydrate deposits and production of methane from hydrate reservoirs. Experimental measurements of gas and water permeability in the presence of hydrate are difficult to obtain. The few datasets that do exist suggest that relative permeability obeys a power law relationship with water or gas saturation with exponents ranging from around 2 to greater than 10. Critical path analysis and percolation theory provide a framework for interpreting the saturation-dependence of relative permeability based on percolation thresholds and the breadth of pore size distributions, which may be determined easily from 3-D images or gas adsorption-desorption hysteresis. We show that the exponent of the permeability-saturation relationship for relative permeability to water is related to the breadth of the pore size distribution, with broader pore size distributions corresponding to larger exponents. Relative permeability to water in well-sorted sediments with narrow pore size distributions, such as Berea sandstone or Toyoura sand, follows percolation scaling with an exponent of 2. On the other hand, pore-size distributions determined from argon adsorption measurements we performed on clays from the Nankai Trough suggest that relative permeability to water in fine-grained intervals may be characterized by exponents as large as 10 as determined from critical path analysis. We also show that relative permeability to the gas phase follows percolation scaling with a quadratic dependence on gas saturation, but the threshold gas saturation for percolation changes with hydrate saturation, which is an important consideration in systems in which both hydrate and gas are present, such as during production from a hydrate reservoir. Our work shows how measurements of pore size distributions from 3-D imaging or gas adsorption may be used to determine relative permeabilities.

  1. RF system models for the CERN Large Hadron Collider with application to longitudinal dynamics

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Winkle, D.Van; Baudrenghien, P.; /CERN

    2011-03-03

    The LHC RF station-beam interaction strongly influences the longitudinal beam dynamics, both single bunch and collective effects. Non-linearities and noise generated within the Radio Frequency (RF) accelerating system interact with the beam and contribute to beam motion and longitudinal emittance blowup. Thus, the noise power spectrum of the RF accelerating voltage strongly affects the longitudinal beam distribution. Furthermore, the coupled-bunch instabilities are also directly affected by the RF components and the configuration of the Low Level RF (LLRF) feedback loops. In this work we present a formalism relating the longitudinal beam dynamics with the RF system configurations, an estimation of collective effects stability margins, and an evaluation of longitudinal sensitivity to various LLRF parameters and configurations.

  2. Compounding effects of fluid confinement and surface strain on the wet–dry transition, thermodynamic response, and dynamics of water–graphene systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chialvo, Ariel A.; Vlcek, Lukas; Cummings, Peter T.

    2015-01-01

    We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. In this study, we found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as wellmore » as on the slowing down of its dynamics that gives rise to anomalous diffusivity.« less

  3. COMPOUNDING EFFECTS OF FLUID CONFINEMENT AND SURFACE STRAIN ON THE WET-DRY TRANSITION AND DYNAMICS OF GRAPHENE-WATER SYSTEMS

    SciTech Connect (OSTI)

    Chialvo, Ariel A; Vlcek, Lukas; Cummings, Peter

    2015-01-01

    We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. We found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as well as on the slowing down of its dynamics that gives rise to anomalous diffusivity.

  4. COMPOUNDING EFFECTS OF FLUID CONFINEMENT AND SURFACE STRAIN ON THE WET-DRY TRANSITION AND DYNAMICS OF GRAPHENE-WATER SYSTEMS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chialvo, Ariel A; Vlcek, Lukas; Cummings, Peter

    2015-01-01

    We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. We found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as well as on themoreslowing down of its dynamics that gives rise to anomalous diffusivity.less

  5. NASA low power DIPS [Dynamic Isotope Power System] conceptual design requirements document

    SciTech Connect (OSTI)

    Johnson, G.; Determan, W.; Otting, W.

    1990-01-01

    This document describes the requirements for a low power (0.5--1.0 kwe) Dynamic Isotope Power System (DIPS) for interplanetary and space exploration missions using the Mariner Mark II spacecraft. The reference mission used to establish these requirements was the Cassini orbiter mission to Saturn. Requirements specific to two other missions (Outer Planet Orbiter/Probe and Comet Nucleus Sample Return) are also included. A list of references used to develop these requirements is provided. 17 refs., 2 figs., 2 tabs.

  6. Mathematical framework for the analysis of dynamic stochastic systems with the RAVEN code

    SciTech Connect (OSTI)

    Rabiti, C.; Mandelli, D.; Alfonsi, A.; Cogliati, J.; Kinoshita, R.

    2013-07-01

    RAVEN (Reactor Analysis and Virtual control Environment) is a software code under development at Idaho National Laboratory aimed at performing probabilistic risk assessment and uncertainty quantification using RELAP-7, for which it acts also as a simulation controller. In this paper we will present the equations characterizing a dynamic stochastic system and we will then discuss the behavior of each stochastic term and how it is accounted for in the RAVEN software design. Moreover we will present preliminary results of the implementation. (authors)

  7. Water dynamics clue to key residues in protein folding

    SciTech Connect (OSTI)

    Gao, Meng [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China)] [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China); Zhu, Huaiqiu, E-mail: hqzhu@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China)] [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China); Yao, Xin-Qiu [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China) [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China); Department of Biophysics, Kyoto University, Sakyo Kyoto 606-8502 (Japan); She, Zhen-Su, E-mail: she@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China)] [State Key Laboratory for Turbulence and Complex Systems, and Department of Biomedical Engineering, and Center for Theoretical Biology, and Center for Protein Science, Peking University, Beijing 100871 (China)

    2010-01-29

    A computational method independent of experimental protein structure information is proposed to recognize key residues in protein folding, from the study of hydration water dynamics. Based on all-atom molecular dynamics simulation, two key residues are recognized with distinct water dynamical behavior in a folding process of the Trp-cage protein. The identified key residues are shown to play an essential role in both 3D structure and hydrophobic-induced collapse. With observations on hydration water dynamics around key residues, a dynamical pathway of folding can be interpreted.

  8. Options of system integrated environment modelling in the predicated dynamic cyberspace

    SciTech Connect (OSTI)

    Janková, Martina; Dvořák, Jiří

    2015-03-10

    In this article there are briefly mentioned some selected options of contemporary conception of cybernetic system models in the corresponding and possible integratable environment with modern system dynamics thinking and all this in the cyberspace of possible projecting of predicted system characteristics. The key to new capabilities of system integration modelling in the considered cyberspace is mainly the ability to improve the environment and the system integration options, all this with the aim of modern control in the hierarchically arranged dynamic cyberspace, e.g. in the currently desired electronic business with information. The aim of this article is to assess generally the trends in the use of modern modelling methods considering the cybernetics applications verified in practice, modern concept of project management and also the potential integration of artificial intelligence in the new projecting and project management of integratable and intelligent models, e.g. with the optimal structures and adaptable behaviour.The article results from the solution of a specific research partial task at the faculty; especially the moments proving that the new economics will be based more and more on information, knowledge system defined cyberspace of modern management, are stressed in the text.

  9. Three-phase Unbalanced Transient Dynamics and Powerflow for Modeling Distribution Systems with Synchronous Machines

    SciTech Connect (OSTI)

    Elizondo, Marcelo A.; Tuffner, Francis K.; Schneider, Kevin P.

    2016-01-01

    Unlike transmission systems, distribution feeders in North America operate under unbalanced conditions at all times, and generally have a single strong voltage source. When a distribution feeder is connected to a strong substation source, the system is dynamically very stable, even for large transients. However if a distribution feeder, or part of the feeder, is separated from the substation and begins to operate as an islanded microgrid, transient dynamics become more of an issue. To assess the impact of transient dynamics at the distribution level, it is not appropriate to use traditional transmission solvers, which generally assume transposed lines and balanced loads. Full electromagnetic solvers capture a high level of detail, but it is difficult to model large systems because of the required detail. This paper proposes an electromechanical transient model of synchronous machine for distribution-level modeling and microgrids. This approach includes not only the machine model, but also its interface with an unbalanced network solver, and a powerflow method to solve unbalanced conditions without a strong reference bus. The presented method is validated against a full electromagnetic transient simulation.

  10. GRAVITATIONAL CONUNDRUM? DYNAMICAL MASS SEGREGATION VERSUS DISRUPTION OF BINARY STARS IN DENSE STELLAR SYSTEMS

    SciTech Connect (OSTI)

    De Grijs, Richard; Li, Chengyuan; Zheng, Yong; Kouwenhoven, M. B. N.; Deng, Licai; Hu, Yi; Wicker, James E.

    2013-03-01

    Upon their formation, dynamically cool (collapsing) star clusters will, within only a few million years, achieve stellar mass segregation for stars down to a few solar masses, simply because of gravitational two-body encounters. Since binary systems are, on average, more massive than single stars, one would expect them to also rapidly mass segregate dynamically. Contrary to these expectations and based on high-resolution Hubble Space Telescope observations, we show that the compact, 15-30 Myr old Large Magellanic Cloud cluster NGC 1818 exhibits tantalizing hints at the {approx}> 2{sigma} level of significance (>3{sigma} if we assume a power-law secondary-to-primary mass-ratio distribution) of an increasing fraction of F-star binary systems (with combined masses of 1.3-1.6 M {sub Sun }) with increasing distance from the cluster center, specifically between the inner 10''-20'' (approximately equivalent to the cluster's core and half-mass radii) and the outer 60''-80''. If confirmed, then this will offer support for the theoretically predicted but thus far unobserved dynamical disruption processes of the significant population of 'soft' binary systems-with relatively low binding energies compared to the kinetic energy of their stellar members-in star clusters, which we have access to here by virtue of the cluster's unique combination of youth and high stellar density.

  11. Investigation of gas hydrate-bearing sandstone reservoirs at the "Mount Elbert" stratigraphic test well, Milne Point, Alaska

    SciTech Connect (OSTI)

    Boswell, R.M.; Hunter, R.; Collett, T.; Digert, S. Inc., Anchorage, AK); Hancock, S.; Weeks, M. Inc., Anchorage, AK); Mt. Elbert Science Team

    2008-01-01

    In February 2007, the U.S. Department of Energy, BP Exploration (Alaska), Inc., and the U.S. Geological Survey conducted an extensive data collection effort at the "Mount Elbert #1" gas hydrates stratigraphic test well on the Alaska North Slope (ANS). The 22-day field program acquired significant gas hydrate-bearing reservoir data, including a full suite of open-hole well logs, over 500 feet of continuous core, and open-hole formation pressure response tests. Hole conditions, and therefore log data quality, were excellent due largely to the use of chilled oil-based drilling fluids. The logging program confirmed the existence of approximately 30 m of gashydrate saturated, fine-grained sand reservoir. Gas hydrate saturations were observed to range from 60% to 75% largely as a function of reservoir quality. Continuous wire-line coring operations (the first conducted on the ANS) achieved 85% recovery through 153 meters of section, providing more than 250 subsamples for analysis. The "Mount Elbert" data collection program culminated with open-hole tests of reservoir flow and pressure responses, as well as gas and water sample collection, using Schlumberger's Modular Formation Dynamics Tester (MDT) wireline tool. Four such tests, ranging from six to twelve hours duration, were conducted. This field program demonstrated the ability to safely and efficiently conduct a research-level openhole data acquisition program in shallow, sub-permafrost sediments. The program also demonstrated the soundness of the program's pre-drill gas hydrate characterization methods and increased confidence in gas hydrate resource assessment methodologies for the ANS.

  12. Hydrate Evolution in Response to Ongoing Environmental Shifts

    SciTech Connect (OSTI)

    Rempel, Alan

    2015-12-31

    Natural gas hydrates have the potential to become a vital domestic clean-burning energy source. However, past changes in environmental conditions have caused hydrates to become unstable and trigger both massive submarine landslides and the development of crater-like pockmarks, thereby releasing methane into the overlying seawater and atmosphere, where it acts as a powerful greenhouse gas. This project was designed to fill critical gaps in our understanding of domestic hydrate resources and improve forecasts for their response to environmental shifts. Project work can be separated into three interrelated components, each involving the development of predictive mathematical models. The first project component concerns the role of sediment properties on the development and dissociation of concentrated hydrate anomalies. To this end, we developed numerical models to predict equilibrium solubility of methane in twophase equilibrium with hydrate as a function of measureable porous medium characteristics. The second project component concerned the evolution of hydrate distribution in heterogeneous reservoirs. To this end, we developed numerical models to predict the growth and decay of anomalies in representative physical environments. The third project component concerned the stability of hydrate-bearing slopes under changing environmental conditions. To this end, we developed numerical treatments of pore pressure evolution and consolidation, then used "infinite-slope" analysis to approximate the landslide potential in representative physical environments, and developed a "rate-and-state" frictional formulation to assess the stability of finite slip patches that are hypothesized to develop in response to the dissociation of hydrate anomalies. The increased predictive capabilities that result from this work provide a framework for interpreting field observations of hydrate anomalies in terms of the history of environmental forcing that led to their development. Moreover, by taking explicit account of anomaly dissociation, project results are designed to help improve forecasts for changes in slope stability that could pose significant threats to energy infrastructure, disrupt hydrate reserves, and pollute the atmosphere with vast quantities of methane. This report presents the details of our work and outlines some of the highlights from our findings.

  13. Effect of temperature on the hydration of Portland cement blended with siliceous fly ash

    SciTech Connect (OSTI)

    Deschner, Florian; Lothenbach, Barbara; Winnefeld, Frank; Neubauer, Jrgen

    2013-10-15

    The effect of temperature on the hydration of Portland cement pastes blended with 50 wt.% of siliceous fly ash is investigated within a temperature range of 7 to 80 C. The elevation of temperature accelerates both the hydration of OPC and fly ash. Due to the enhanced pozzolanic reaction of the fly ash, the change of the composition of the CSH and the pore solution towards lower Ca and higher Al and Si concentrations is shifted towards earlier hydration times. Above 50 C, the reaction of fly ash also contributes to the formation of siliceous hydrogarnet. At 80 C, ettringite and AFm are destabilised and the released sulphate is partially incorporated into the CSH. The observed changes of the phase assemblage in dependence of the temperature are confirmed by thermodynamic modelling. The increasingly heterogeneous microstructure at elevated temperatures shows an increased density of the CSH and a higher coarse porosity. -- Highlights: The reaction of quartz powder at 80 C strongly enhances the compressive strength. Almost no strength increase of fly ash blended OPC at 80 C was found after 2 days. Siliceous hydrogarnet is formed upon the reaction of fly ash at high temperatures. Temperature dependent change of the system was simulated by thermodynamic modelling. Destabilisation of ettringite above 50 C correlates with sulphate content of CSH.

  14. New Natural Gas Storage and Transportation Capabilities Utilizing Rapid Methane Hydrate Formation Techniques

    SciTech Connect (OSTI)

    Brown, T.D.; Taylor, C.E.; Bernardo, M.

    2010-01-01

    Natural gas (methane as the major component) is a vital fossil fuel for the United States and around the world. One of the problems with some of this natural gas is that it is in remote areas where there is little or no local use for the gas. Nearly 50 percent worldwide natural gas reserves of ~6,254.4 trillion ft3 (tcf) is considered as stranded gas, with 36 percent or ~86 tcf of the U.S natural gas reserves totaling ~239 tcf, as stranded gas [1] [2]. The worldwide total does not include the new estimates by U.S. Geological Survey of 1,669 tcf of natural gas north of the Arctic Circle, [3] and the U.S. ~200,000 tcf of natural gas or methane hydrates, most of which are stranded gas reserves. Domestically and globally there is a need for newer and more economic storage, transportation and processing capabilities to deliver the natural gas to markets. In order to bring this resource to market, one of several expensive methods must be used: 1. Construction and operation of a natural gas pipeline 2. Construction of a storage and compression facility to compress the natural gas (CNG) at 3,000 to 3,600 psi, increasing its energy density to a point where it is more economical to ship, or 3. Construction of a cryogenic liquefaction facility to produce LNG, (requiring cryogenic temperatures at <-161 C) and construction of a cryogenic receiving port. Each of these options for the transport requires large capital investment along with elaborate safety systems. The Department of Energy's Office of Research and Development Laboratories at the National Energy Technology Laboratory (NETL) is investigating new and novel approaches for rapid and continuous formation and production of synthetic NGHs. These synthetic hydrates can store up to 164 times their volume in gas while being maintained at 1 atmosphere and between -10 to -20C for several weeks. Owing to these properties, new process for the economic storage and transportation of these synthetic hydrates could be envisioned for stranded gas reserves. The recent experiments and their results from the testing within NETL's 15-Liter Hydrate Cell Facility exhibit promising results. Introduction of water at the desired temperature and pressure through an NETL designed nozzle into a temperature controlled methane environment within the 15-Liter Hydrate Cell allowed for instantaneous formation of methane hydrates. The instantaneous and continuous hydrate formation process was repeated over several days while varying the flow rate of water, its' temperature, and the overall temperature of the methane environment. These results clearly indicated that hydrates formed immediately after the methane and water left the nozzle at temperatures above the freezing point of water throughout the range of operating conditions. [1] Oil and Gas Journal Vol. 160.48, Dec 22, 2008. [2] http://www.eia.doe.gov/oiaf/servicerpt/natgas/chapter3.html and http://www.eia.doe.gov/oiaf/servicerpt/natgas/pdf/tbl7.pdf [3] U.S. Geological Survey, Circum-Arctic Resource Appraisal: Estimates of Undiscovered Oil and Gas North of the Arctic Circle, May 2008.

  15. Influence of system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas

    SciTech Connect (OSTI)

    Song, Y. L.; Huang, F.; He, Y. F.; Wu, L.; Liu, Y. H.; Chen, Z. Y.; Yu, M. Y.

    2015-06-15

    Influence of the system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas is investigated through laboratory experiment and molecular dynamics simulation. The micro-structures, defect numbers, and pair correlation function of the dust clusters are studied for different system temperatures. The dust grains' trajectories, the mean square displacement, and the corresponding self-diffusion coefficient of the clusters are calculated for different temperatures for illustrating the phase properties of the dust clusters. The simulation results confirm that with the increase in system temperature, the micro-structures and dynamics of dust clusters are gradually changed, which qualitatively agree with experimental results.

  16. Self-consistent field theory based molecular dynamics with linear system-size scaling

    SciTech Connect (OSTI)

    Richters, Dorothee; Khne, Thomas D.

    2014-04-07

    We present an improved field-theoretic approach to the grand-canonical potential suitable for linear scaling molecular dynamics simulations using forces from self-consistent electronic structure calculations. It is based on an exact decomposition of the grand canonical potential for independent fermions and does neither rely on the ability to localize the orbitals nor that the Hamilton operator is well-conditioned. Hence, this scheme enables highly accurate all-electron linear scaling calculations even for metallic systems. The inherent energy drift of Born-Oppenheimer molecular dynamics simulations, arising from an incomplete convergence of the self-consistent field cycle, is circumvented by means of a properly modified Langevin equation. The predictive power of the present approach is illustrated using the example of liquid methane under extreme conditions.

  17. System and method for reducing combustion dynamics and NO.sub.x in a combustor

    DOE Patents [OSTI]

    Uhm, Jong H.; Johnson, Thomas Edward

    2015-11-20

    A system for reducing combustion dynamics and NO.sub.x in a combustor includes a tube bundle that extends radially across at least a portion of the combustor, wherein the tube bundle comprises an upstream surface axially separated from a downstream surface. A shroud circumferentially surrounds the upstream and downstream surfaces. A plurality of tubes extends through the tube bundle from the upstream surface through the downstream surface, wherein the downstream surface is stepped to produce tubes having different lengths through the tube bundle. A method for reducing combustion dynamics and NO.sub.x in a combustor includes flowing a working fluid through a plurality of tubes radially arranged between an upstream surface and a downstream surface of an end cap that extends radially across at least a portion of the combustor, wherein the downstream surface is stepped.

  18. Study of multiband disordered systems using the typical medium dynamical cluster approximation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Yi; Terletska, Hanna; Moore, C.; Ekuma, Chinedu; Tam, Ka-Ming; Berlijn, Tom; Ku, Wei; Moreno, Juana; Jarrell, Mark

    2015-11-06

    We generalize the typical medium dynamical cluster approximation to multiband disordered systems. Using our extended formalism, we perform a systematic study of the nonlocal correlation effects induced by disorder on the density of states and the mobility edge of the three-dimensional two-band Anderson model. We include interband and intraband hopping and an intraband disorder potential. Our results are consistent with those obtained by the transfer matrix and the kernel polynomial methods. We also apply the method to KxFe2-ySe2 with Fe vacancies. Despite the strong vacancy disorder and anisotropy, we find the material is not an Anderson insulator. Moreover our resultsmore » demonstrate the application of the typical medium dynamical cluster approximation method to study Anderson localization in real materials.« less

  19. Control method and system for hydraulic machines employing a dynamic joint motion model

    DOE Patents [OSTI]

    Danko, George

    2011-11-22

    A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

  20. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Frank R. Rack

    2006-09-20

    Cooperative Agreement DE-FC26-01NT41329 between Joint Oceanographic Institutions and DOE-NETL was divided into two phases based on successive proposals and negotiated statements of work pertaining to activities to sample and characterize methane hydrates on ODP Leg 204 (Phase 1) and on IODP Expedition 311 (Phase 2). The Phase 1 Final Report was submitted to DOE-NETL in April 2004. This report is the Phase 2 Final Report to DOE-NETL. The primary objectives of Phase 2 were to sample and characterize methane hydrates using the systems and capabilities of the D/V JOIDES Resolution during IODP Expedition 311, to enable scientists the opportunity to establish the mass and distribution of naturally occurring gas and gas hydrate at all relevant spatial and temporal scales, and to contribute to the DOE methane hydrate research and development effort. The goal of the work was to provide expanded measurement capabilities on the JOIDES Resolution for a dedicated hydrate cruise to the Cascadia continental margin off Vancouver Island, British Columbia, Canada (IODP Expedition 311) so that hydrate deposits in this region would be well characterized and technology development continued for hydrate research. IODP Expedition 311 shipboard activities on the JOIDES Resolution began on August 28 and were concluded on October 28, 2005. The statement of work for this project included three primary tasks: (1) research management oversight, provided by JOI; (2) mobilization, deployment and demobilization of pressure coring and core logging systems, through a subcontract with Geotek Ltd.; and, (3) mobilization, deployment and demobilization of a refrigerated container van that will be used for degassing of the Pressure Core Sampler and density logging of these pressure cores, through a subcontract with the Texas A&M Research Foundation (TAMRF). Additional small tasks that arose during the course of the research were included under these three primary tasks in consultation with the DOE-NETL Program Manager. All tasks outlined in the original statement of work were accomplished except for the deployment and use of the X-ray CT system under Subtask 2-2. This reduction in scope provided resources that were applied to other activities to support the overall project. Post-expedition analysis of results and report writing will continue beyond this reporting period, however, all field deployments associated with this project have been successfully concluded as of this writing.

  1. Embedded Sensors and Controls to Improve Component Performance and Reliability - System Dynamics Modeling and Control System Design

    SciTech Connect (OSTI)

    Melin, Alexander M.; Kisner, Roger A.; Fugate, David L.

    2013-10-01

    This report documents the current status of the modeling, control design, and embedded control research for the magnetic bearing canned rotor pump being used as a demonstration platform for deeply integrating instrumentation and controls (I{\\&}C) into nuclear power plant components. This pump is a highly inter-connected thermo/electro/mechanical system that requires an active control system to operate. Magnetic bearings are inherently unstable system and without active, moment by moment control, the rotor would contact fixed surfaces in the pump causing physical damage. This report details the modeling of the pump rotordynamics, fluid forces, electromagnetic properties of the protective cans, active magnetic bearings, power electronics, and interactions between different dynamical models. The system stability of the unforced and controlled rotor are investigated analytically. Additionally, controllers are designed using proportional derivative (PD) control, proportional integral derivative (PID) control, voltage control, and linear quadratic regulator (LQR) control. Finally, a design optimization problem that joins the electrical, mechanical, magnetic, and control system design into one problem to balance the opposing needs of various design criteria using the embedded system approach is presented.

  2. Integrating Natural Gas Hydrates in the Global Carbon Cycle

    SciTech Connect (OSTI)

    David Archer; Bruce Buffett

    2011-12-31

    We produced a two-dimensional geological time- and basin-scale model of the sedimentary margin in passive and active settings, for the simulation of the deep sedimentary methane cycle including hydrate formation. Simulation of geochemical data required development of parameterizations for bubble transport in the sediment column, and for the impact of the heterogeneity in the sediment pore fluid flow field, which represent new directions in modeling methane hydrates. The model is somewhat less sensitive to changes in ocean temperature than our previous 1-D model, due to the different methane transport mechanisms in the two codes (pore fluid flow vs. bubble migration). The model is very sensitive to reasonable changes in organic carbon deposition through geologic time, and to details of how the bubbles migrate, in particular how efficiently they are trapped as they rise through undersaturated or oxidizing chemical conditions and the hydrate stability zone. The active margin configuration reproduces the elevated hydrate saturations observed in accretionary wedges such as the Cascadia Margin, but predicts a decrease in the methane inventory per meter of coastline relative to a comparable passive margin case, and a decrease in the hydrate inventory with an increase in the plate subduction rate.

  3. Methane Hydrate Field Program. Development of a Scientific Plan for a Methane Hydrate-Focused Marine Drilling, Logging and Coring Program

    SciTech Connect (OSTI)

    Collett, Tim; Bahk, Jang-Jun; Frye, Matt; Goldberg, Dave; Husebo, Jarle; Koh, Carolyn; Malone, Mitch; Shipp, Craig; Torres, Marta; Myers, Greg; Divins, David; Morell, Margo

    2013-12-31

    This topical report represents a pathway toward better understanding of the impact of marine methane hydrates on safety and seafloor stability and future collection of data that can be used by scientists, engineers, managers and planners to study climate change and to assess the feasibility of marine methane hydrate as a potential future energy resource. Our understanding of the occurrence, distribution and characteristics of marine methane hydrates is incomplete; therefore, research must continue to expand if methane hydrates are to be used as a future energy source. Exploring basins with methane hydrates has been occurring for over 30 years, but these efforts have been episodic in nature. To further our understanding, these efforts must be more regular and employ new techniques to capture more data. This plan identifies incomplete areas of methane hydrate research and offers solutions by systematically reviewing known methane hydrate “Science Challenges” and linking them with “Technical Challenges” and potential field program locations.

  4. Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 10, Basin analysis, formation and stability of gas hydrates of the Aleutian Trench and the Bering Sea

    SciTech Connect (OSTI)

    Krason, J.; Ciesnik, M.

    1987-01-01

    Four major areas with inferred gas hydrates are the subject of this study. Two of these areas, the Navarin and the Norton Basins, are located within the Bering Sea shelf, whereas the remaining areas of the Atka Basin in the central Aleutian Trench system and the eastern Aleutian Trench represent a huge region of the Aleutian Trench-Arc system. All four areas are geologically diverse and complex. Particularly the structural features of the accretionary wedge north of the Aleutian Trench still remain the subjects of scientific debates. Prior to this study, suggested presence of the gas hydrates in the four areas was based on seismic evidence, i.e., presence of bottom simulating reflectors (BSRs). Although the disclosure of the BSRs is often difficult, particularly under the structural conditions of the Navarin and Norton basins, it can be concluded that the identified BSRs are mostly represented by relatively weak and discontinuous reflectors. Under thermal and pressure conditions favorable for gas hydrate formation, the relative scarcity of the BSRs can be attributed to insufficient gas supply to the potential gas hydrate zone. Hydrocarbon gas in sediment may have biogenic, thermogenic or mixed origin. In the four studied areas, basin analysis revealed limited biogenic hydrocarbon generation. The migration of the thermogenically derived gases is probably diminished considerably due to the widespread diagenetic processes in diatomaceous strata. The latter processes resulted in the formation of the diagenetic horizons. The identified gas hydrate-related BSRs seem to be located in the areas of increased biogenic methanogenesis and faults acting as the pathways for thermogenic hydrocarbons.

  5. Development and application of the dynamic system doctor to nuclear reactor probabilistic risk assessments.

    SciTech Connect (OSTI)

    Kunsman, David Marvin; Aldemir, Tunc; Rutt, Benjamin; Metzroth, Kyle; Catalyurek, Umit; Denning, Richard; Hakobyan, Aram; Dunagan, Sean C.

    2008-05-01

    This LDRD project has produced a tool that makes probabilistic risk assessments (PRAs) of nuclear reactors - analyses which are very resource intensive - more efficient. PRAs of nuclear reactors are being increasingly relied on by the United States Nuclear Regulatory Commission (U.S.N.R.C.) for licensing decisions for current and advanced reactors. Yet, PRAs are produced much as they were 20 years ago. The work here applied a modern systems analysis technique to the accident progression analysis portion of the PRA; the technique was a system-independent multi-task computer driver routine. Initially, the objective of the work was to fuse the accident progression event tree (APET) portion of a PRA to the dynamic system doctor (DSD) created by Ohio State University. Instead, during the initial efforts, it was found that the DSD could be linked directly to a detailed accident progression phenomenological simulation code - the type on which APET construction and analysis relies, albeit indirectly - and thereby directly create and analyze the APET. The expanded DSD computational architecture and infrastructure that was created during this effort is called ADAPT (Analysis of Dynamic Accident Progression Trees). ADAPT is a system software infrastructure that supports execution and analysis of multiple dynamic event-tree simulations on distributed environments. A simulator abstraction layer was developed, and a generic driver was implemented for executing simulators on a distributed environment. As a demonstration of the use of the methodological tool, ADAPT was applied to quantify the likelihood of competing accident progression pathways occurring for a particular accident scenario in a particular reactor type using MELCOR, an integrated severe accident analysis code developed at Sandia. (ADAPT was intentionally created with flexibility, however, and is not limited to interacting with only one code. With minor coding changes to input files, ADAPT can be linked to other such codes.) The results of this demonstration indicate that the approach can significantly reduce the resources required for Level 2 PRAs. From the phenomenological viewpoint, ADAPT can also treat the associated epistemic and aleatory uncertainties. This methodology can also be used for analyses of other complex systems. Any complex system can be analyzed using ADAPT if the workings of that system can be displayed as an event tree, there is a computer code that simulates how those events could progress, and that simulator code has switches to turn on and off system events, phenomena, etc. Using and applying ADAPT to particular problems is not human independent. While the human resources for the creation and analysis of the accident progression are significantly decreased, knowledgeable analysts are still necessary for a given project to apply ADAPT successfully. This research and development effort has met its original goals and then exceeded them.

  6. Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems. Final report

    SciTech Connect (OSTI)

    Harty, R.B.; Durand, R.E.

    1993-03-01

    An integration study was performed by Rocketdyne under contract to NASA-LeRC. The study was concerned with coupling an SP-0100 reactor to either a Brayton or Stirling power conversion system. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power conversion redundancy. This study resulted in selecting three operating engines and one stand-by unit. Integration design studies indicated that either the Brayton or Stirling power conversion systems could be integrated with the PS-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to off-set the Stirling integration advantage. From a performance consideration, the Brayton had a 9 percent mass advantage, and the Stirling had a 50 percent radiator advantage.

  7. Using System Dynamics to Model the Transition to Biofuels in the United States

    SciTech Connect (OSTI)

    Bush, B.; Duffy, M.; Sandor, D.; Peterson, S.

    2008-01-01

    Today, the U.S. consumes almost 21 million barrels of crude oil per day; approximately 60% of the U.S. demand is supplied by imports. The transportation sector alone accounts for two-thirds of U.S. petroleum use. Biofuels, liquid fuels produced from domestically-grown biomass, have the potential to displace about 30% of current U.S. gasoline consumption. Transitioning to a biofuels industry on this scale will require the creation of a robust biomass-to-biofuels system-of-systems that operates in concert with the existing agriculture, forestry, energy, and transportation markets. The U.S. Department of Energy is employing a system dynamics approach to investigate potential market penetration scenarios for cellulosic ethanol, and to aid decision makers in focusing government actions on the areas with greatest potential to accelerate the deployment of biofuels and ultimately reduce the nationpsilas dependence on imported oil.

  8. Dynamics of quantum-classical hybrid systems: Effect of matter-wave pressure

    SciTech Connect (OSTI)

    Shen, J. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Huang, X. L. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029 (China); Yi, X. X. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Centre for Quantum Technologies and Department of Physics, National University of Singapore, Singapore 117543 (Singapore); Wu Chunfeng; Oh, C. H. [Centre for Quantum Technologies and Department of Physics, National University of Singapore, Singapore 117543 (Singapore)

    2010-12-15

    Radiation pressure affects the kinetics of a system exposed to radiation and it constitutes the basis of laser cooling. In this article, we study matter-wave pressure through examining the dynamics of a quantum-classical hybrid system. The quantum and classical subsystems are affected mutually via a changing boundary condition. Two systems, that is, an atom and a Bose-Einstein condensate (BEC), are considered as the quantum subsystems, while an oscillating wall is taken as the classical subsystem. We show that the classical subsystem would experience a force proportional to Q{sup -3} from the quantum atom, where Q denotes the distance between the two walls, whereas it acquires an additional force proportional to Q{sup -2} from the BEC due to the atom-atom interaction in the BEC. These forces can be understood as the matter-wave pressure.

  9. NON-EQUILIBRIUM DYNAMICS OF MANY-BODY QUANTUM SYSTEMS: FUNDAMENTALS AND NEW FRONTIER

    SciTech Connect (OSTI)

    DeMille, David; LeHur, Karyn

    2013-11-27

    Rapid progress in nanotechnology and naofabrication techniques has ushered in a new era of quantum transport experiments. This has in turn heightened the interest in theoretical understanding of nonequilibrium dynamics of strongly correlated quantum systems. This project has advanced the frontiers of understanding in this area along several fronts. For example, we showed that under certain conditions, quantum impurities out of equilibrium can be reformulated in terms of an effective equilibrium theory; this makes it possible to use the gamut of tools available for quantum systems in equilibrium. On a different front, we demonstrated that the elastic power of a transmitted microwave photon in circuit QED systems can exhibit a many-body Kondo resonance. We also showed that under many circumstances, bipartite fluctuations of particle number provide an effective tool for studying many-body physics—particularly the entanglement properties of a many-body system. This implies that it should be possible to measure many-body entanglement in relatively simple and tractable quantum systems. In addition, we studied charge relaxation in quantum RC circuits with a large number of conducting channels, and elucidated its relation to Kondo models in various regimes. We also extended our earlier work on the dynamics of driven and dissipative quantum spin-boson impurity systems, deriving a new formalism that makes it possible to compute the full spin density matrix and spin-spin correlation functions beyond the weak coupling limit. Finally, we provided a comprehensive analysis of the nonequilibrium transport near a quantum phase transition in the case of a spinless dissipative resonant-level model. This project supported the research of two Ph.D. students and two postdoctoral researchers, whose training will allow them to further advance the field in coming years.

  10. Dynamics of cavity fields with dissipative and amplifying couplings through multiple quantum two-state systems

    SciTech Connect (OSTI)

    Haeyrynen, Teppo; Oksanen, Jani; Tulkki, Jukka [Department of Biomedical Engineering and Computational Science, Aalto University School of Science and Technology, P. O. Box 12200, FI-00076 AALTO (Finland)

    2011-01-15

    We consider simultaneous dissipative and amplifying coupling of cavity fields to multiple two-state systems. We derive a master equation for optical field in a leaky cavity coupled to a reservoir through multiple two-state systems. In our previous works we have limited our study to systems where the reservoir either solely absorbs energy (detector setup) or adds energy (amplifying setup) to the cavity through a single two-state system. In this work we allow both interactions simultaneously and derive a reduced dynamic model for the optical field. We also generalize our model to cover the coupling of the field to several two state systems and discuss its connection to macroscopic interaction, e.g., in semiconductors. Our model includes four physical parameters: the field two-state system coupling {gamma}, the excitation and deexcitation couplings of the two-state system by the reservoir {lambda}{sub A} and {lambda}{sub D}, respectively, and the mirror losses of the cavity C. We solve the steady-state fields at different regimes of these physical parameters. Furthermore, we show that, depending on the parameters, our model can describe the operation of a detector, a light emitting diode, or a laser.

  11. End-use load control for power system dynamic stability enhancement

    SciTech Connect (OSTI)

    Dagle, J.E.; Winiarski, D.W.; Donnelly, M.K.

    1997-02-01

    Faced with the prospect of increasing utilization of the transmission and distribution infrastructure without significant upgrade, the domestic electric power utility industry is investing heavily in technologies to improve network dynamic performance through a program loosely referred to as Flexible AC Transmission System (FACTS). Devices exploiting recent advances in power electronics are being installed in the power system to offset the need to construct new transmission lines. These devices collectively represent investment potential of several billion dollars over the next decade. A similar development, designed to curtail the peak loads and thus defer new transmission, distribution, and generation investment, falls under a category of technologies referred to as demand side management (DSM). A subset of broader conservation measures, DSM acts directly on the load to reduce peak consumption. DSM techniques include direct load control, in which a utility has the ability to curtail specific loads as conditions warrant. A novel approach has been conceived by Pacific Northwest National Laboratory (PNNL) to combine the objectives of FACTS and the technologies inherent in DSM to provide a distributed power system dynamic controller. This technology has the potential to dramatically offset major investments in FACTS devices by using direct load control to achieve dynamic stability objectives. The potential value of distributed versus centralized grid modulation has been examined by simulating the western power grid under extreme loading conditions. In these simulations, a scenario is analyzed in which active grid stabilization enables power imports into the southern California region to be increased several hundred megawatts beyond present limitations. Modeling results show distributed load control is up to 30 percent more effective than traditional centralized control schemes in achieving grid stability.

  12. Update on Small Modular Reactors Dynamics System Modeling Tool -- Molten Salt Cooled Architecture

    SciTech Connect (OSTI)

    Hale, Richard Edward; Cetiner, Sacit M.; Fugate, David L.; Qualls, A L.; Borum, Robert C.; Chaleff, Ethan S.; Rogerson, Doug W.; Batteh, John J.; Tiller, Michael M.

    2014-08-01

    The Small Modular Reactor (SMR) Dynamic System Modeling Tool project is in the third year of development. The project is designed to support collaborative modeling and study of various advanced SMR (non-light water cooled) concepts, including the use of multiple coupled reactors at a single site. The objective of the project is to provide a common simulation environment and baseline modeling resources to facilitate rapid development of dynamic advanced reactor SMR models, ensure consistency among research products within the Instrumentation, Controls, and Human-Machine Interface (ICHMI) technical area, and leverage cross-cutting capabilities while minimizing duplication of effort. The combined simulation environment and suite of models are identified as the Modular Dynamic SIMulation (MoDSIM) tool. The critical elements of this effort include (1) defining a standardized, common simulation environment that can be applied throughout the program, (2) developing a library of baseline component modules that can be assembled into full plant models using existing geometry and thermal-hydraulic data, (3) defining modeling conventions for interconnecting component models, and (4) establishing user interfaces and support tools to facilitate simulation development (i.e., configuration and parameterization), execution, and results display and capture.

  13. Dynamic neutron scattering on incoherent systems using efficient resonance spin flip techniques

    SciTech Connect (OSTI)

    Hussler, Wolfgang [Heinz Maier-Leibnitz Zentrum, Technische Universitt Mnchen, D-85748 Garching, Germany and Physik-Department E21, Technische Universitt Mnchen, D-85748 Garching (Germany); Kredler, Lukas [Physik-Department E21, Technische Universitt Mnchen, D-85748 Garching (Germany)

    2014-05-15

    We have performed numerical ray-tracing Monte-Carlo-simulations of incoherent dynamic neutron scattering experiments. We intend to optimize the efficiency of incoherent measurements depending on the fraction of neutrons scattered without and with spin flip at the sample. In addition to conventional spin echo, we have numerically and experimentally studied oscillating intensity techniques. The results point out the advantages of these different spin echo variants and are an important prerequisite for neutron resonance spin echo instruments like RESEDA (FRM II, Munich), to choose the most efficient technique depending on the scattering vector range and the properties of the sample system under study.

  14. Ground movements associated with gas hydrate production. Final report

    SciTech Connect (OSTI)

    Siriwardane, H.J.; Kutuk, B.

    1992-03-01

    This report deals with a study directed towards a modeling effort on production related ground movements and subsidence resulting from hydrate dissociation. The goal of this research study was to evaluate whether there could be subsidence related problems that could be an impediment to hydrate production. During the production of gas from a hydrate reservoir, it is expected that porous reservoir matrix becomes more compressible which may cause reservoir compression (compaction) under the influence of overburden weight. The overburden deformations can propagate its influence upwards causing subsidence near the surface where production equipment will be located. In the present study, the reservoir compaction is modeled by using the conventional ``stress equilibrium`` approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ``cavity`` generated by reservoir depletion. The present study is expected to provide a ``lower bound`` solution to the subsidence caused by hydrate reservoir depletion. The reservoir compaction anticipated during hydrate production was modeled by using the finite element method, which is a powerful computer modeling technique. The ground movements at the reservoir roof (i.e. reservoir compression) cause additional stresses and disturbance in the overburden strata. In this study, the reservoir compaction was modeled by using the conventional ``stress equilibrium`` approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ``cavity`` generated by reservoir depletion. The resulting stresses and ground movements were computed by using the finite element method. Based on the parameters used in this investigation, the maximum ground subsidence could vary anywhere from 0.50 to 6.50 inches depending on the overburden depth and the size of the depleted hydrate reservoir.

  15. Promotion of n-Butane isomerization activity by hydration of sulfated zirconia

    SciTech Connect (OSTI)

    Gonzalez, M.R.; Kobe, J.M.; Fogash, K.B.; Dumesic, J.A.

    1996-05-01

    The effects of sulfated zirconia catalyst hydration on the activity for n-butane isomerization is reported. The catalytic activity of of a partially hydrated catalyst is enhanced. 66 refs., 11 figs.

  16. Microsoft Word - NETL-TRS-6-2015 Detection of Hydrates on Gas...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Detection of Hydrates on Gas Bubbles during a Subsea OilGas Leak 22 July 2015 Office of ... of Hydrates on Gas Bubbles during a Subsea OilGas Leak; NETL-TRS-6- 2015; EPAct Technical ...

  17. Water Usage for In-Situ Oil Shale Retorting – A Systems Dynamics Model

    SciTech Connect (OSTI)

    Earl D. Mattson; Larry Hull; Kara Cafferty

    2012-12-01

    A system dynamic model was construction to evaluate the water balance for in-situ oil shale conversion. The model is based on a systems dynamics approach and uses the Powersim Studio 9™ software package. Three phases of an insitu retort were consider; a construction phase primarily accounts for water needed for drilling and water produced during dewatering, an operation phase includes the production of water from the retorting process, and a remediation phase water to remove heat and solutes from the subsurface as well as return the ground surface to its natural state. Throughout these three phases, the water is consumed and produced. Consumption is account for through the drill process, dust control, returning the ground water to its initial level and make up water losses during the remedial flushing of the retort zone. Production of water is through the dewatering of the retort zone, and during chemical pyrolysis reaction of the kerogen conversion. The major water consumption was during the remediation of the insitu retorting zone.

  18. Documentation of INL’s In Situ Oil Shale Retorting Water Usage System Dynamics Model

    SciTech Connect (OSTI)

    Earl D Mattson; Larry Hull

    2012-12-01

    A system dynamic model was construction to evaluate the water balance for in-situ oil shale conversion. The model is based on a systems dynamics approach and uses the Powersim Studio 9™ software package. Three phases of an in situ retort were consider; a construction phase primarily accounts for water needed for drilling and water produced during dewatering, an operation phase includes the production of water from the retorting process, and a remediation phase water to remove heat and solutes from the subsurface as well as return the ground surface to its natural state. Throughout these three phases, the water is consumed and produced. Consumption is account for through the drill process, dust control, returning the ground water to its initial level and make up water losses during the remedial flushing of the retort zone. Production of water is through the dewatering of the retort zone, and during chemical pyrolysis reaction of the kerogen conversion. The document discusses each of the three phases used in the model.

  19. Properties of gravitationally equilibrated Yukawa systemsA molecular dynamics study

    SciTech Connect (OSTI)

    Charan, Harish; Ganesh, Rajaraman Joy, Ashwin

    2014-04-15

    Using 2D Molecular Dynamics simulation, the equilibrium and dynamical properties of a gravitationally equilibrated Yukawa liquid are investigated. We observe that due to asymmetry introduced in one direction by gravity, several interesting features arise. For example, for a given value of coupling parameter ?, screening parameter ?, and according to a chosen value of gravitational force g (say in y-direction), the system is seen to exhibit super-, sub- or normal diffusion. Interestingly, x-averaged density profiles, unlike a barotropic fluid, acquires sharp, free surface with scale free linear y-dependence. As can be expected for a system with macroscopic gradients, self-diffusion calculated from Green-Kubos formalism does not agree with that obtained from Einstein-Smoluchowski diffusion. A 2D angular-radial pair correlation function g(r, ?) clearly indicates asymmetric features induced by gravity. We observe that due to compression in y-direction, though in liquid state for all values of gravity considered, the transverse mode is found to predominant as compared to the longitudinal mode, leading to a novel Anisotropic Solid-like Yukawa liquid.

  20. Generalized correlation integral vectors: A distance concept for chaotic dynamical systems

    SciTech Connect (OSTI)

    Haario, Heikki; Kalachev, Leonid; Hakkarainen, Janne

    2015-06-15

    Several concepts of fractal dimension have been developed to characterise properties of attractors of chaotic dynamical systems. Numerical approximations of them must be calculated by finite samples of simulated trajectories. In principle, the quantities should not depend on the choice of the trajectory, as long as it provides properly distributed samples of the underlying attractor. In practice, however, the trajectories are sensitive with respect to varying initial values, small changes of the model parameters, to the choice of a solver, numeric tolerances, etc. The purpose of this paper is to present a statistically sound approach to quantify this variability. We modify the concept of correlation integral to produce a vector that summarises the variability at all selected scales. The distribution of this stochastic vector can be estimated, and it provides a statistical distance concept between trajectories. Here, we demonstrate the use of the distance for the purpose of estimating model parameters of a chaotic dynamic model. The methodology is illustrated using computational examples for the Lorenz 63 and Lorenz 95 systems, together with a framework for Markov chain Monte Carlo sampling to produce posterior distributions of model parameters.

  1. Potential and flux field landscape theory. II. Non-equilibrium thermodynamics of spatially inhomogeneous stochastic dynamical systems

    SciTech Connect (OSTI)

    Wu, Wei; Wang, Jin

    2014-09-14

    We have established a general non-equilibrium thermodynamic formalism consistently applicable to both spatially homogeneous and, more importantly, spatially inhomogeneous systems, governed by the Langevin and Fokker-Planck stochastic dynamics with multiple state transition mechanisms, using the potential-flux landscape framework as a bridge connecting stochastic dynamics with non-equilibrium thermodynamics. A set of non-equilibrium thermodynamic equations, quantifying the relations of the non-equilibrium entropy, entropy flow, entropy production, and other thermodynamic quantities, together with their specific expressions, is constructed from a set of dynamical decomposition equations associated with the potential-flux landscape framework. The flux velocity plays a pivotal role on both the dynamic and thermodynamic levels. On the dynamic level, it represents a dynamic force breaking detailed balance, entailing the dynamical decomposition equations. On the thermodynamic level, it represents a thermodynamic force generating entropy production, manifested in the non-equilibrium thermodynamic equations. The Ornstein-Uhlenbeck process and more specific examples, the spatial stochastic neuronal model, in particular, are studied to test and illustrate the general theory. This theoretical framework is particularly suitable to study the non-equilibrium (thermo)dynamics of spatially inhomogeneous systems abundant in nature. This paper is the second of a series.

  2. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Rack, Frank

    2003-06-30

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) Frank Rack, Anne Trehu, and Tim Collett presented preliminary results and operational outcomes of ODP Leg 204 at the American Association of Petroleum Geologists annual meeting in Salt Lake City, UT; (2) several Leg 204 scientists participated in special hydrate sessions at the international EGS/AGU/EUG meeting in Nice, France and presented initial science results from the cruise, which included outcomes arising from this cooperative agreement; and, (3) postcruise evaluation of the data, tools and measurement systems that were used during ODP Leg 204 continued in the preparation of deliverables under this agreement. At the EGS/EUG/AGU meeting in Nice, France in April, Leg 204 Co-chiefs Anne Trehu and Gerhard Bohrmann, as well as ODP scientists Charlie Paull, Erwin Suess, and Jim Kennett, participated in a press conference on hydrates. The well-attended press conference entitled ''Gas Hydrates: Free methane found and controversy over the 'hydrate gun''' led to stories in Nature on-line and BBC radio, among others. There were six (6) oral and fifteen (15) poster presentations on ODP Leg 204 hydrate science at the EGS/AGU/EUG Meeting in Nice, France on April 6-11, 2003. This was a very strong showing at a meeting just over six month following the completion of the drilling cruise and highlighted many of the results of the leg, including the results obtained with instruments and equipment funded under this cooperative agreement. At the AAPG annual meeting in Salt Lake City, UT on May 11-14, 2003, Anne Trehu gave an oral presentation about the scientific results of Leg 204, and Frank Rack presented a poster outlining the operational and technical accomplishments. Work continued on analyzing data collected during ODP Leg 204 and preparing reports on the outcomes of Phase 1 projects as well as developing plans for Phase 2.

  3. Phase I (CATTS Theory), Phase II (Milne Point), Phase III (Hydrate Ridge)

    SciTech Connect (OSTI)

    2009-10-31

    This study introduces a new type of “cumulative seismic attribute” (CATT) which quantifies gas hydrates resources in Hydrate Ridge offshore Oregon. CATT is base on case-specific transforms that portray hydrated reservoir properties. In this study we used a theoretical rock physics model to correct measured velocity log data.

  4. Methane Hydrate Research and Development Act of 2000 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Research and Development Act of 2000 Methane Hydrate Research and Development Act of 2000 Methane Hydrate Research and Development Act of 2000 PDF icon Methane Hydrate Research and Development Act of 2000 More Documents & Publications NATIONAL DEFENSE AUTHORIZATION ACT FOR FISCAL YEAR 2000 E:\PUBLAW\PUBL404.106 Intelligence Reform and Terrorism Prevention Act - December 17, 2004

  5. Study on small-strain behaviours of methane hydrate sandy sediments using discrete element method

    SciTech Connect (OSTI)

    Yu Yanxin; Cheng Yipik; Xu Xiaomin; Soga, Kenichi

    2013-06-18

    Methane hydrate bearing soil has attracted increasing interest as a potential energy resource where methane gas can be extracted from dissociating hydrate-bearing sediments. Seismic testing techniques have been applied extensively and in various ways, to detect the presence of hydrates, due to the fact that hydrates increase the stiffness of hydrate-bearing sediments. With the recognition of the limitations of laboratory and field tests, wave propagation modelling using Discrete Element Method (DEM) was conducted in this study in order to provide some particle-scale insights on the hydrate-bearing sandy sediment models with pore-filling and cementation hydrate distributions. The relationship between shear wave velocity and hydrate saturation was established by both DEM simulations and analytical solutions. Obvious differences were observed in the dependence of wave velocity on hydrate saturation for these two cases. From the shear wave velocity measurement and particle-scale analysis, it was found that the small-strain mechanical properties of hydrate-bearing sandy sediments are governed by both the hydrate distribution patterns and hydrate saturation.

  6. Final technical report [ACCELERATED MOLECULAR DYNAMICS SIMULATIONS OF REACTIVE HYDROCARBON SYSTEMS

    SciTech Connect (OSTI)

    Stuart, Steven J.

    2014-02-25

    The research activities in this project consisted of four different sub-projects. Three different accelerated dynamics techniques (parallel replica dynamics, hyperdynamics, and temperature-accelerated dynamics) were applied to the modeling of pyrolysis of hydrocarbons. In addition, parallel replica dynamics was applied to modeling of polymerization.

  7. DOE Leads National Research Program in Gas Hydrates

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy today told Congress the agency is leading a nationwide program in search of naturally occurring natural gas hydrates - a potentially significant storehouse of methane--with far reaching implications for the environment and the nation's future energy supplies.

  8. Production of hydrocarbons from hydrates. [DOE patent application

    DOE Patents [OSTI]

    McGuire, P.L.

    1981-09-08

    An economical and safe method of producing hydrocarbons (or natural gas) from in situ hydrocarbon-containing hydrates is given. Once started, the method will be self-driven and will continue producing hydrocarbons over an extended period of time (i.e., many days).

  9. Assessment of Tools and Data for System-Level Dynamic Analyses

    SciTech Connect (OSTI)

    Steven J. Piet; Nick R. Soelberg

    2011-06-01

    The only fuel cycle for which dynamic analyses and assessments are not needed is the null fuel cycle - no nuclear power. For every other concept, dynamic analyses are needed and can influence relative desirability of options. Dynamic analyses show how a fuel cycle might work during transitions from today's partial fuel cycle to something more complete, impact of technology deployments, location of choke points, the key time lags, when benefits can manifest, and how well parts of fuel cycles work together. This report summarizes the readiness of existing Fuel Cycle Technology (FCT) tools and data for conducting dynamic analyses on the range of options. VISION is the primary dynamic analysis tool. Not only does it model mass flows, as do other dynamic system analysis models, but it allows users to explore various potential constraints. The only fuel cycle for which constraints are not important are those in concept advocates PowerPoint presentations; in contrast, comparative analyses of fuel cycles must address what constraints exist and how they could impact performance. The most immediate tool need is extending VISION to the thorium/U233 fuel cycle. Depending on further clarification of waste management strategies in general and for specific fuel cycle candidates, waste management sub-models in VISION may need enhancement, e.g., more on 'co-flows' of non-fuel materials, constraints in waste streams, or automatic classification of waste streams on the basis of user-specified rules. VISION originally had an economic sub-model. The economic calculations were deemed unnecessary in later versions so it was retired. Eventually, the program will need to restore and improve the economics sub-model of VISION to at least the cash flow stage and possibly to incorporating cost constraints and feedbacks. There are multiple sources of data that dynamic analyses can draw on. In this report, 'data' means experimental data, data from more detailed theoretical or empirical calculations on technology performance, and assumptions such as the earliest date a technology can be deployed. The only fuel cycles for which we currently have adequate data are those we are sure we will never build, e.g., a PUREX plant in the U.S. For actual candidates, even for once through LWRs, there remain missing data such as how the fuel cycle would be completed with a geologic repository. The most immediate data needs are probably basic reactor physics data for new concepts and data associated with waste management for anything other than current technology. The readiness of tools and data is fluid and depends on what purposes are envisioned to drive upcoming analyses and further definition of the waste-related characteristics of fuel cycle candidates. Tools and data sets evolve as needs evolve. Thus, much of the document explains that if the FCT program wants a certain type of analysis, then the tools and data needs are as indicated. For example, functions can be treated as either commodities or facilities. Reactors, separation, fuel fabrication, repository are treated as facility types. Other functions such as uranium mining, conversion, enrichment, and waste packaging and non-repository disposal are treated as commodities and therefore not modeled as extensively. In summary, the tools are functional and can answer many fuel cycle questions but some analyses will require that the tools be modified to support those analyses.

  10. A dynamic system matching technique for improving the accuracy of MEMS gyroscopes

    SciTech Connect (OSTI)

    Stubberud, Peter A.; Stubberud, Stephen C.; Stubberud, Allen R.

    2014-12-10

    A classical MEMS gyro transforms angular rates into electrical values through Euler's equations of angular rotation. Production models of a MEMS gyroscope will have manufacturing errors in the coefficients of the differential equations. The output signal of a production gyroscope will be corrupted by noise, with a major component of the noise due to the manufacturing errors. As is the case of the components in an analog electronic circuit, one way of controlling the variability of a subsystem is to impose extremely tight control on the manufacturing process so that the coefficient values are within some specified bounds. This can be expensive and may even be impossible as is the case in certain applications of micro-electromechanical (MEMS) sensors. In a recent paper [2], the authors introduced a method for combining the measurements from several nominally equal MEMS gyroscopes using a technique based on a concept from electronic circuit design called dynamic element matching [1]. Because the method in this paper deals with systems rather than elements, it is called a dynamic system matching technique (DSMT). The DSMT generates a single output by randomly switching the outputs of several, nominally identical, MEMS gyros in and out of the switch output. This has the effect of 'spreading the spectrum' of the noise caused by the coefficient errors generated in the manufacture of the individual gyros. A filter can then be used to eliminate that part of the spread spectrum that is outside the pass band of the gyro. A heuristic analysis in that paper argues that the DSMT can be used to control the effects of the random coefficient variations. In a follow-on paper [4], a simulation of a DSMT indicated that the heuristics were consistent. In this paper, analytic expressions of the DSMT noise are developed which confirm that the earlier conclusions are valid. These expressions include the various DSMT design parameters and, therefore, can be used as design tools for DSMT systems.

  11. Using System Dynamics to Define, Study, and Implement Smart Control Strategies on the Electric Power Grid

    SciTech Connect (OSTI)

    Lyle G. Roybal; Robert F Jeffers

    2013-07-01

    The United States electric power grid is the most complex and expansive control system in the world. Local generation control occurs at individual units based on response time and unit economics, larger regional control coordinates unit response to error conditions, and high level large-area regional control is ultimately administered by a network of humans guided by economic and resiliency related factors. Under normal operating conditions, the grid is a relatively slow moving entity that exhibits high inertia to outside stimuli, and behaves along repeatable diurnal and seasonal patterns. However, that paradigm is quickly changing because of the increasing implementation of renewable generation sources. Renewable generators by nature cannot be tightly controlled or scheduled. They appear like a negative load to the system with all of the variability associated with load on a larger scale. Also, grid-reactive loads (i.e. smart devices) can alter their consumption based on price or demand rules adding more variability to system behavior. This paper demonstrates how a systems dynamic modeling approach capable of operating over multiple time scales, can provide valuable insight into developing new “smart-grid” control strategies and devices needed to accommodate renewable generation and regulate the frequency of the grid.

  12. Applied & Computational MathematicsChallenges for the Design and Control of Dynamic Energy Systems

    SciTech Connect (OSTI)

    Brown, D L; Burns, J A; Collis, S; Grosh, J; Jacobson, C A; Johansen, H; Mezic, I; Narayanan, S; Wetter, M

    2011-03-10

    The Energy Independence and Security Act of 2007 (EISA) was passed with the goal 'to move the United States toward greater energy independence and security.' Energy security and independence cannot be achieved unless the United States addresses the issue of energy consumption in the building sector and significantly reduces energy consumption in buildings. Commercial and residential buildings account for approximately 40% of the U.S. energy consumption and emit 50% of CO{sub 2} emissions in the U.S. which is more than twice the total energy consumption of the entire U.S. automobile and light truck fleet. A 50%-80% improvement in building energy efficiency in both new construction and in retrofitting existing buildings could significantly reduce U.S. energy consumption and mitigate climate change. Reaching these aggressive building efficiency goals will not happen without significant Federal investments in areas of computational and mathematical sciences. Applied and computational mathematics are required to enable the development of algorithms and tools to design, control and optimize energy efficient buildings. The challenge has been issued by the U.S. Secretary of Energy, Dr. Steven Chu (emphasis added): 'We need to do more transformational research at DOE including computer design tools for commercial and residential buildings that enable reductions in energy consumption of up to 80 percent with investments that will pay for themselves in less than 10 years.' On July 8-9, 2010 a team of technical experts from industry, government and academia were assembled in Arlington, Virginia to identify the challenges associated with developing and deploying newcomputational methodologies and tools thatwill address building energy efficiency. These experts concluded that investments in fundamental applied and computational mathematics will be required to build enabling technology that can be used to realize the target of 80% reductions in energy consumption. In addition the finding was that there are tools and technologies that can be assembled and deployed in the short term - the next 3-5 years - that can be used to significantly reduce the cost and time effective delivery of moderate energy savings in the U.S. building stock. Simulation tools, which are a core strength of current DOE computational research programs, provide only a part of the answer by providing a basis for simulation enabled design. New investments will be required within a broad dynamics and control research agenda which must focus on dynamics, control, optimization and simulation of multi-scale energy systems during design and operation. U.S. investments in high performance and high productivity computing (HP2C) should be leveraged and coupled with advances in dynamics and control to impact both the existing building stock through retrofits and also new construction. The essential R&D areas requiring investment are: (1) Characterizing the Dynamics of Multi-scale Energy Systems; (2) Control and Optimization Methodologies of Multi-scale Energy Systems Under Uncertainty; and (3) Multiscale Modeling and Simulation Enabled Design and Operation. The concept of using design and control specific computational tools is a new idea for the building industry. The potential payoffs in terms of accelerated design cycle times, performance optimization and optimal supervisory control to obtain and maintain energy savings are huge. Recent advances in computational power, computer science, and mathematical algorithms offer the foundations to address the control problems presented by the complex dynamics of whole building systems. The key areas for focus and associated metrics with targets for establishing competitiveness in energy efficient building design and operation are: (1) Scalability - Current methodology and tools can provide design guidance for very low energy buildings in weeks to months; what is needed is hours to days. A 50X improvement is needed. (2) Installation and commissioning - Current methodology and tools can target a three month window for commissioning of building subsystems; what is needed is one week. A 10X improvement is needed. (3) Quality - Current design tools can achieve 30% accuracy; what is needed to make design decisions is 5% with quantification of uncertainty. A 5X improvement is needed. These challenges cannot be overcome by raw computational power alone and require the development of new algorithms. Here algorithms mean much more than simulating the building physics but need to be inclusive of a much better understanding of the building and the control systems associated with the building and to capture the entire set of dynamics. The algorithmsmust represent computationally new mathematical approaches to modeling, simulation, optimization and control of large multi-scale dynamic systems and bringing these elements to bear on industry in simulation enabled design approaches.

  13. Ethane enrichment and propane depletion in subsurface gases indicate gas hydrate occurrence in marine sediments at southern Hydrate Ridge offshore Oregon

    SciTech Connect (OSTI)

    Milkov, Alexei V.; Claypool, G E.; Lee, Young-Joo; Torres, Marta E.; Borowski, W S.; Tomaru, H; Sassen, Roger; Long, Philip E.

    2004-07-02

    The recognition of finely disseminated gas hydrate in deep marine sediments heavily depends on various indirect techniques because this mineral quickly decomposes upon recovery from in situ pressure and temperature conditions. Here, we discuss molecular properties of closely spaced gas voids (formed as a result of core recovery) and gas hydrates from an area of relatively low gas flux at the flanks of the southern Hydrate Ridge Offshore Oregon (ODP Sites 1244, 1245 and 1247).

  14. Effect of bubble size and density on methane conversion to hydrate

    SciTech Connect (OSTI)

    Leske, J.; Taylor, C.E.; Ladner, E.P.

    2007-03-01

    Research is underway at NETL to understand the physical properties of methane hydrates. One area of investigation is the storage of methane as methane hydrates. An economical and efficient means of storing methane in hydrates opens many commercial opportunities such as transport of stranded gas, off-peak storage of line gas, etc.We have observed during our investigations that the ability to convert methane to methane hydrate is enhanced by foaming of the methanewater solution using a surfactant. The density of the foam, along with the bubble size, is important in the conversion of methane to methane hydrate.

  15. Improved Protein Arrays for Quantitative Systems Analysis of the Dynamics of Signaling Pathway Interactions

    SciTech Connect (OSTI)

    YANG, CHIN-RANG

    2013-12-11

    Astronauts and workers in nuclear plants who repeatedly exposed to low doses of ionizing radiation (IR, <10 cGy) are likely to incur specific changes in signal transduction and gene expression in various tissues of their body. Remarkable advances in high throughput genomics and proteomics technologies enable researchers to broaden their focus from examining single gene/protein kinetics to better understanding global gene/protein expression profiling and biological pathway analyses, namely Systems Biology. An ultimate goal of systems biology is to develop dynamic mathematical models of interacting biological systems capable of simulating living systems in a computer. This Glue Grant is to complement Dr. Boothman’s existing DOE grant (No. DE-FG02-06ER64186) entitled “The IGF1/IGF-1R-MAPK-Secretory Clusterin (sCLU) Pathway: Mediator of a Low Dose IR-Inducible Bystander Effect” to develop sensitive and quantitative proteomic technology that suitable for low dose radiobiology researches. An improved version of quantitative protein array platform utilizing linear Quantum dot signaling for systematically measuring protein levels and phosphorylation states for systems biology modeling is presented. The signals are amplified by a confocal laser Quantum dot scanner resulting in ~1000-fold more sensitivity than traditional Western blots and show the good linearity that is impossible for the signals of HRP-amplification. Therefore this improved protein array technology is suitable to detect weak responses of low dose radiation. Software is developed to facilitate the quantitative readout of signaling network activities. Kinetics of EGFRvIII mutant signaling was analyzed to quantify cross-talks between EGFR and other signaling pathways.

  16. Tricalcium aluminate hydration in additivated systems. A crystallograp...

    Office of Scientific and Technical Information (OSTI)

    Synchrotron radiation X-ray powder diffraction has been used to monitor the evolution of ... diffractograms collected allowed us to monitor the evolution of phases weight fraction. ...

  17. Geomechanical Performance of Hydrate-Bearing Sediments in Offshore Environments

    SciTech Connect (OSTI)

    Stephen A. Holditch

    2006-12-31

    The main objective of this study is to develop the necessary knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus is on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. To achieve this objective, we have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. To be sure our geomechanical modeling is realistic, we are also investigating the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. In Phase II of the project, we will review all published core data and generate additional core data to verify the models. To generate data for our models, we are using data from the literature and we will be conducting laboratory studies in 2007 that generate data to (1) evaluate the conceptual pore-scale models, (2) calibrate the mathematical models, (3) determine dominant relations and critical parameters defining the geomechanical behavior of HBS, and (4) establish relationships between the geomechanical status of HBS and the corresponding geophysical signature. The milestones for Phase I of this project are given as follows: Literature survey on typical sediments containing gas hydrates in the ocean (TAMU); Recommendations on how to create typical sediments in the laboratory (TAMU); Demonstrate that typical sediments can be created in a repeatable manner in the laboratory and gas hydrates can be created in the pore space (TAMU); Develop a conceptual pore-scale model based on available data and reports (UCB); Test the developed pore-scale concepts on simple configurations and verify the results against known measurements and observations (UCB); Complete the FLAC3D routines that will be linked with the reservoir model (LBNL); Complete the TOUGH+/HYDRATE modifications and extensions (LBNL); Complete the TOUGH+/FLAC3D interaction interface (LBNL); Integrate and test the coupled geomechanical numerical model TFxH/FLAC3D (LBNL); and Demonstrate that Petrel can be used to develop an earth model for providing data to the TOUGH+/FLAC3D (SLB).

  18. Conceptual design of the HTTR-IS hydrogen production system - dynamic simulation code development for advanced process heat exchanger in the HTTR-IS system

    SciTech Connect (OSTI)

    Sato, Hiroyuki; Kubo, Shinji; Sakaba, Nariaki; Ohashi, Hirofumi; Sano, Naoki; Nishihara, Tetsuo; Kunitomi, Kazuhiko

    2007-07-01

    The objective of this study is to confirm the availability of proposed mitigation methodology against thermal load increase events initiated by the thermochemical water splitting IS process hydrogen production system (IS process) coupling with the High temperature Engineering Test Reactor (HTTR). Japan Atomic Energy Agency (JAEA) has been performing the development of dynamic simulation code which can evaluate complex phenomena in the HTTR-IS system all at one once to achieve the requirement. The notable feature of the developed code is the Advanced Process Heat Exchanger (APHX) module which enables to estimate the IS process thermal load variation considering phase change and chemical reaction behavior assumed in the APHX. In this paper, two cases of dynamic calculation for the thermal load increase events were performed using the newly developed APHX module. The results of the analytical studies clearly show the availability of the developed model for dynamic simulation of the HTTR-IS system and the thermal load increase mitigation methodology. (authors)

  19. The use of electrical impedance spectroscopy for monitoring the hydration products of Portland cement mortars with high percentage of pozzolans

    SciTech Connect (OSTI)

    Cruz, J.M.; Fita, I.C.; Soriano, L.; Pay, J.; Borrachero, M.V.

    2013-08-15

    In this paper, mortars and pastes containing large replacement of pozzolan were studied by mechanical strength, thermogravimetric analysis (TGA), scanning electronic microscopy (SEM), mercury intrusion porosimetry (MIP) and electrical impedance spectroscopy (EIS). The effect of metakaolin (35%) and fly ash (60%) was evaluated and compared with an inert mineral addition (andalusite). The portlandite content was measured, finding that the pozzolanic reaction produced cementing systems with all portlandite fixed. The EIS measurements were analyzed by the equivalent electrical circuit (EEC) method. An EEC with three branches in parallel was applied. The dc resistance was related to the degree of hydration and allowed us to characterize plain and blended mortars. A constant phase element (CPE) quantified the electrical properties of the hydration products located in the solidsolution interface and was useful to distinguish the role of inert and pozzolanic admixtures present in the cement matrix.

  20. Theoretical study of the KKK system and dynamical generation of the K(1460) resonance

    SciTech Connect (OSTI)

    Martinez Torres, A.; Jido, D.; Kanada-En'yo, Y.

    2011-06-15

    The KKK system is investigated with a coupled-channel approach based on solving the Faddeev equations considering the KKK, K{pi}{pi}, and K{pi}{eta} channels and using as input two-body t matrices that generate dynamically the f{sub 0}(980) and a{sub 0}(980) resonances. In the present calculation, a quasibound state around 1420 MeV with total isospin I=1/2 and spin-parity J{sup {pi}=}0{sup -} is found below the three-kaon threshold. This state can be identified with the K(1460) resonance listed by the Particle Data Group. We also study the KKK system in a single-channel three-body potential model with two-body effective KK and KK interactions, in which the KK interaction is adjusted to reproduce the properties of the f{sub 0}(980) and a{sub 0}(980) resonances as KK bound states, obtaining a very similar result to the one found in the Faddeev approach.

  1. Imaging hydrated microbial extracellular polymers: Comparative analysis by electron microscopy

    SciTech Connect (OSTI)

    Dohnalkova, A.C.; Marshall, M. J.; Arey, B. W.; Williams, K. H.; Buck, E. C.; Fredrickson, J. K.

    2011-01-01

    Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryogenic electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of the hydrated bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in their collapse into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.

  2. High Pressure Sensing and Dynamics Using High Speed Fiber Bragg Grating Interrogation Systems

    SciTech Connect (OSTI)

    Rodriguez, G.; Sandberg, R. L.; Lalone, B. M.; Marshall, B. R.; Grover, M.; Stevens, G. D.; Udd, E.

    2014-06-01

    Fiber Bragg gratings (FBGs) are developing into useful sensing tools for measuring high pressure dynamics in extreme environments under shock loading conditions. Approaches using traditional diode array coupled FBG interrogation systems are often limited to readout speeds in the sub-MHz range. For shock wave physics, required detection speeds approaching 100 MHz are desired. We explore the use of two types of FBG sensing systems that are aimed at applying this technology as embedded high pressure probes for transient shock events. Both approaches measure time resolved spectral shifts in the return light from short (few mm long) uniform FBGs at 1550 nm. In the first approach, we use a fiber coupled spectrometer to demultiplex spectral channels into an array (up to 12) of single element InGaAs photoreceivers. By monitoring the detectors during a shock impact event with high speed recording, we are able to track the pressure induced spectral shifting in FBG down to a time resolution of 20 ns. In the second approach, developed at the Special Technologies Lab, a coherent mode-locked fiber laser is used to illuminate the FBG sensor. After the sensor, wavelength-to-time mapping is accomplished with a chromatic dispersive element, and entire spectra are sampled using a single detector at the modelocked laser repetition rate of 50 MHz. By sampling with a 12 GHz InGaAs detector, direct wavelength mapping in time is recorded, and the pressure induced FBG spectral shift is sampled at 50 MHz. Here, the sensing systems are used to monitor the spectral shifts of FBGs that are immersed into liquid water and shock compressed using explosives. In this configuration, the gratings survive to pressures approaching 50 kbar. We describe both approaches and present the measured spectral shifts from the shock experiments.

  3. Properties and hydration of blended cements with steelmaking slag

    SciTech Connect (OSTI)

    Kourounis, S.; Tsivilis, S. . E-mail: stsiv@central.ntua.gr; Tsakiridis, P.E.; Papadimitriou, G.D.; Tsibouki, Z.

    2007-06-15

    The present research study investigates the properties and hydration of blended cements with steelmaking slag, a by-product of the conversion process of iron to steel. For this purpose, a reference sample and three cements containing up to 45% w/w steel slag were tested. The steel slag fraction used was the '0-5 mm', due to its high content in calcium silicate phases. Initial and final setting time, standard consistency, flow of normal mortar, autoclave expansion and compressive strength at 2, 7, 28 and 90 days were measured. The hydrated products were identified by X-ray diffraction while the non-evaporable water was determined by TGA. The microstructure of the hardened cement pastes and their morphological characteristics were examined by scanning electron microscopy. It is concluded that slag can be used in the production of composite cements of the strength classes 42.5 and 32.5 of EN 197-1. In addition, the slag cements present satisfactory physical properties. The steel slag slows down the hydration of the blended cements, due to the morphology of contained C{sub 2}S and its low content in calcium silicates.

  4. Order and disorder in calcium–silicate–hydrate

    SciTech Connect (OSTI)

    Bauchy, M.; Qomi, M. J. Abdolhosseini; Ulm, F.-J.; Pellenq, R. J.-M.

    2014-06-07

    Despite advances in the characterization and modeling of cement hydrates, the atomic order in Calcium–Silicate–Hydrate (C–S–H), the binding phase of cement, remains an open question. Indeed, in contrast to the former crystalline model, recent molecular models suggest that the nanoscale structure of C–S–H is amorphous. To elucidate this issue, we analyzed the structure of a realistic simulated model of C–S–H, and compared the latter to crystalline tobermorite, a natural analogue of C–S–H, and to an artificial ideal glass. The results clearly indicate that C–S–H appears as amorphous, when averaged on all atoms. However, an analysis of the order around each atomic species reveals that its structure shows an intermediate degree of order, retaining some characteristics of the crystal while acquiring an overall glass-like disorder. Thanks to a detailed quantification of order and disorder, we show that, while C–S–H retains some signatures of a tobermorite-like layered structure, hydrated species are completely amorphous.

  5. A system dynamic modeling approach for evaluating municipal solid waste generation, landfill capacity and related cost management issues

    SciTech Connect (OSTI)

    Kollikkathara, Naushad; Feng Huan; Yu Danlin

    2010-11-15

    As planning for sustainable municipal solid waste management has to address several inter-connected issues such as landfill capacity, environmental impacts and financial expenditure, it becomes increasingly necessary to understand the dynamic nature of their interactions. A system dynamics approach designed here attempts to address some of these issues by fitting a model framework for Newark urban region in the US, and running a forecast simulation. The dynamic system developed in this study incorporates the complexity of the waste generation and management process to some extent which is achieved through a combination of simpler sub-processes that are linked together to form a whole. The impact of decision options on the generation of waste in the city, on the remaining landfill capacity of the state, and on the economic cost or benefit actualized by different waste processing options are explored through this approach, providing valuable insights into the urban waste-management process.

  6. A high dynamic range data acquisition system for a solid-state...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: A high dynamic ... a master board for DAQ control and eight individual ... OSTI Identifier: 22063771 Resource Type: Journal Article ...

  7. Design of small Stirling Dynamic Isotope Power System for robotic space missions

    SciTech Connect (OSTI)

    Bents, D.J.; Schreiber, J.G.; Withrow, C.A.; McKissock, B.I. ); Schmitz, P.C. )

    1993-01-10

    Design of a multihundred-watt Dynamic Isotope Power System (DIPS) based on the U.S. Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE) technology is being pursued as a potential lower cost alternative to radioisotope thermoelectric generator (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. Unlike previous DIPS designs which were based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled down to multihundred-watt unit size while preserving size and mass competitiveness with RTGs. Preliminary characterization of units in the output power ranges 200--600 We indicate that on an electrical watt basis the GPHS/small Stirling DIPS will be roughly equivalent to an advanced RTG in size and mass but require less than a third of the isotope inventory.

  8. Analysis of liquid natural gas as a truck fuel: a system dynamics approach

    SciTech Connect (OSTI)

    Bray, M.A.; Sebo, D.E.; Mason, T.L.; Mills, J.I.; Rice, R.E.

    1996-10-01

    The purpose of this analysis is to evaluate the potential for growth in use of liquid natural gas (LNG) fueled trucks. . A system dynamics model was constructed for the analysis and a variety of scenarios were investigated. The analysis considers the economics of LNG fuel in the context of the trucking industry to identify barriers to the increased use of LNG trucks and potential interventions or leverage points which may overcome these barriers. The study showed that today, LNG use in trucks is not yet economically viable. A large change in the savings from fuel cost or capital cost is needed for the technology to take off. Fleet owners have no way now to benefit from the environmental benefits of LNG fuel nor do they benefit from the clean burning nature of the fuel. Changes in the fuel cost differential between diesel and LNG are not a research issue. However, quantifying the improvements in reliability and wear from the use of clean fuel could support increased maintenance and warranty periods. Many people involved in the use of LNG for trucks believe that LNG has the potential to occupy a niche within the larger diesel truck business. But if LNG in trucks can become economic, the spread of fuel stations and technology improvements could lead to LNG trucks becoming the dominant technology. An assumption in our simulation work is that LNG trucks will be purchased when economically attractive. None of the simulation results show LNG becoming economic but then only to the level of a niche market.

  9. Collaborative Research: Robust Climate Projections and Stochastic Stability of Dynamical Systems

    SciTech Connect (OSTI)

    Ghil, Michael; McWilliams, James; Neelin, J. David; Zaliapin, Ilya; Chekroun, Mickael; Kondrashov, Dmitri; Simonnet, Eric

    2011-10-13

    The project was completed along the lines of the original proposal, with additional elements arising as new results were obtained. The originally proposed three thrusts were expanded to include an additional, fourth one. (i) The e#11;ffects of stochastic perturbations on climate models have been examined at the fundamental level by using the theory of deterministic and random dynamical systems, in both #12;nite and in#12;nite dimensions. (ii) The theoretical results have been implemented #12;first on a delay-diff#11;erential equation (DDE) model of the El-Nino/Southern-Oscillation (ENSO) phenomenon. (iii) More detailed, physical aspects of model robustness have been considered, as proposed, within the stripped-down ICTP-AGCM (formerly SPEEDY) climate model. This aspect of the research has been complemented by both observational and intermediate-model aspects of mid-latitude and tropical climate. (iv) An additional thrust of the research relied on new and unexpected results of (i) and involved reduced-modeling strategies and associated prediction aspects have been tested within the team's empirical model reduction (EMR) framework. Finally, more detailed, physical aspects have been considered within the stripped-down SPEEDY climate model. The results of each of these four complementary e#11;fforts are presented in the next four sections, organized by topic and by the team members concentrating on the topic under discussion.

  10. Four Critical Needs to Change the Hydrate Energy Paradigm from Assessment to Production: The 2007 Report to Congress by the U.S. Federal methane Hydrate Advisory Committee

    SciTech Connect (OSTI)

    Mahajan,D.; Sloan, D.; Brewer, P.; Dutta, N.; Johnson, A.; Jones, E.; Juenger, K.; Kastner, M.; Masutani, S.; Swenson, R.; Whelan, J.; Wilson, s.; Woolsey, R.

    2009-03-11

    This work summarizes a two-year study by the U.S. Federal Methane Hydrate Advisory Committee recommending the future needs for federally-supported hydrate research. The Report was submitted to the US Congress on August 14, 2007 and includes four recommendations regarding (a) permafrost hydrate production testing, (b) marine hydrate viability assessment (c) climate effect of hydrates, and (d) international cooperation. A secure supply of natural gas is a vital goal of the U.S. national energy policy because natural gas is the cleanest and most widely used of all fossil fuels. The inherent cleanliness of natural gas, with the lowest CO2 emission per unit of heat energy of any fossil fuel, means substituting gas for coal and fuel oil will reduce emissions that can exacerbate the greenhouse effect. Both a fuel and a feedstock, a secure and reasonably priced supply of natural gas is important to industry, electric power generators, large and small commercial enterprises, and homeowners. Because each volume of solid gas hydrate contains as much as 164 standard volumes of methane, hydrates can be viewed as a concentrated form of natural gas equivalent to compressed gas but less concentrated than liquefied natural gas (LNG). Natural hydrate accumulations worldwide are estimated to contain 700,000 TCF of natural gas, of which 200,000 TCF are located within the United States. Compared with the current national annual consumption of 22 TCF, this estimate of in-place gas in enormous. Clearly, if only a fraction of the hydrated methane is recoverable, hydrates could constitute a substantial component of the future energy portfolio of the Nation (Figure 1). However, recovery poses a major technical and commercial challenge. Such numbers have sparked interest in natural gas hydrates as a potential, long-term source of energy, as well as concerns about any potential impact the release of methane from hydrates might have on the environment. Energy-hungry countries such as India and Japan are outspending the United States on hydrate science and engineering R&D by a factor of 10, and may bring this resource to market as much as a decade before the United States.

  11. Statistical dynamics of classical systems: A self-consistent field approach

    SciTech Connect (OSTI)

    Grzetic, Douglas J. Wickham, Robert A.; Shi, An-Chang

    2014-06-28

    We develop a self-consistent field theory for particle dynamics by extremizing the functional integral representation of a microscopic Langevin equation with respect to the collective fields. Although our approach is general, here we formulate it in the context of polymer dynamics to highlight satisfying formal analogies with equilibrium self-consistent field theory. An exact treatment of the dynamics of a single chain in a mean force field emerges naturally via a functional Smoluchowski equation, while the time-dependent monomer density and mean force field are determined self-consistently. As a simple initial demonstration of the theory, leaving an application to polymer dynamics for future work, we examine the dynamics of trapped interacting Brownian particles. For binary particle mixtures, we observe the kinetics of phase separation.

  12. Hydrates Annual FY13 Format (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Hydrates Annual FY13 Format Citation Details In-Document Search Title: Hydrates Annual FY13 Format Authors: Seol, Yongkoo ; Guthrie, George Publication Date: 2014-04-11 OSTI Identifier: 1128555 Report Number(s): NETL-PUB-930 Resource Type: Technical Report Research Org: National Energy Technology Laboratory - In-house Research Sponsoring Org: USDOE Office of Fossil Energy (FE) Country of Publication: United States Language: English Subject: 03 NATURAL GAS; 58 GEOSCIENCES natural gas hydrates;

  13. The U.S. DOE Methane Hydrate R&D Program Publications and Presentations Resulting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    U.S. DOE Methane Hydrate R&D Program Publications and Presentations Resulting from DOE-Supported Methane Hydrate R&D 1999-2016 Including a Listing of DOE-Sponsored Student Researchers March 2016 U.S. DOE Methane Hydrate R&D Program Bibliography Page 2 Table of Contents Section I: Documentation of Support for Education .................................................................................... 6 Undergraduate (B.S. and B.E.), Master of Science (M.S.), Doctoral (Ph.D.), and

  14. U.S. and Japan Complete Successful Field Trial of Methane Hydrate

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Production Technologies | Department of Energy Japan Complete Successful Field Trial of Methane Hydrate Production Technologies U.S. and Japan Complete Successful Field Trial of Methane Hydrate Production Technologies May 2, 2012 - 10:40am Addthis WASHINGTON, DC - U.S. Energy Secretary Steven Chu announced today the completion of a successful, unprecedented test of technology in the North Slope of Alaska that was able to safely extract a steady flow of natural gas from methane hydrates - a

  15. U.S. and Japan Complete Successful Field Trial of Methane Hydrate

    Energy Savers [EERE]

    Production Technologies | Department of Energy and Japan Complete Successful Field Trial of Methane Hydrate Production Technologies U.S. and Japan Complete Successful Field Trial of Methane Hydrate Production Technologies May 2, 2012 - 1:00pm Addthis Washington, DC - U.S. Energy Secretary Steven Chu announced today the completion of a successful, unprecedented test of technology in the North Slope of Alaska that was able to safely extract a steady flow of natural gas from methane hydrates -

  16. Dynamic simulation of a solar-driven carbon dioxide transcritical power system for small scale combined heat and power production

    SciTech Connect (OSTI)

    Chen, Y.; Lundqvist, Per; Pridasawas, Wimolsiri

    2010-07-15

    Carbon dioxide is an environmental benign natural working fluid and has been proposed as a working media for a solar-driven power system. In the current work, the dynamic performance of a small scale solar-driven carbon dioxide power system is analyzed by dynamic simulation tool TRNSYS 16 and Engineering Equation Solver (EES) using co-solving technique. Both daily performance and yearly performance of the proposed system have been simulated. Different system operating parameters, which will influence the system performance, have been discussed. Under the Swedish climatic condition, the maximum daily power production is about 12 kW h and the maximum monthly power production is about 215 kW h with the proposed system working conditions. Besides the power being produced, the system can also produce about 10 times much thermal energy, which can be used for space heating, domestic hot water supply or driving absorption chillers. The simulation results show that the proposed system is a promising and environmental benign alternative for conventional low-grade heat source utilization system. (author)

  17. Studies of Reaction Kinetics of Methane Hydrate Dissocation in Porous Media

    SciTech Connect (OSTI)

    Moridis, George J.; Seol, Yongkoo; Kneafsey, Timothy J.

    2005-03-10

    The objective of this study is the description of the kinetic dissociation of CH4-hydrates in porous media, and the determination of the corresponding kinetic parameters. Knowledge of the kinetic dissociation behavior of hydrates can play a critical role in the evaluation of gas production potential of gas hydrate accumulations in geologic media. We analyzed data from a sequence of tests of CH4-hydrate dissociation by means of thermal stimulation. These tests had been conducted on sand cores partially saturated with water, hydrate and CH4 gas, and contained in an x-ray-transparent aluminum pressure vessel. The pressure, volume of released gas, and temperature (at several locations within the cores) were measured. To avoid misinterpreting local changes as global processes, x-ray computed tomography scans provided accurate images of the location and movement of the reaction interface during the course of the experiments. Analysis of the data by means of inverse modeling (history matching ) provided estimates of the thermal properties and of the kinetic parameters of the hydration reaction in porous media. Comparison of the results from the hydrate-bearing porous media cores to those from pure CH4-hydrate samples provided a measure of the effect of the porous medium on the kinetic reaction. A tentative model of composite thermal conductivity of hydrate-bearing media was also developed.

  18. Presentations from the March 27th - 28th Methane Hydrates Advisory...

    Broader source: Energy.gov (indexed) [DOE]

    More Documents & Publications May 21, 2014 Committee Recommendations to Secretary of Energy Methane Hydrate Annual Reports Presentations from the May 7, 2015 Advisory Committee...

  19. Data from Alaska Test Could Help Advance Methane Hydrate R&D

    Broader source: Energy.gov [DOE]

    Methane Hydrates present an enormous energy resource. The Energy Department is working to advance technologies and reap the possible benefits for a more secure energy future.

  20. Ground movements associated with gas hydrate production. Progress report, October 1--December 31, 1992

    SciTech Connect (OSTI)

    Siriwardane, H.J.

    1992-12-31

    The grantee will evaluate the influence of hydrate production on ground subsidence near the wellbore and the surface. The objective of this research will be achieved by using computer simulations of what is expected in a hydrate reservoir during the production stage as reported by hydrate production models and available data. The model will be based on theories of continuum mechanics, thermomechanics of hydrate production, principles of rock mechanics and geomechanics, and special features of geomaterials under cold temperatures such as those found in permafrost regions. The research work involved in the proposed investigation will be divided into three major tasks; mechanics of subsidence in permafrost regions, modeling of subsidence, and parametric studies.

  1. Thermal dissociation behavior and dissociation enthalpies of methane-carbon dioxide mixed hydrates

    SciTech Connect (OSTI)

    Kwon, T.H.; Kneafsey, T.J.; Rees, E.V.L.

    2011-02-15

    Replacement of methane with carbon dioxide in hydrate has been proposed as a strategy for geologic sequestration of carbon dioxide (CO{sub 2}) and/or production of methane (CH{sub 4}) from natural hydrate deposits. This replacement strategy requires a better understanding of the thermodynamic characteristics of binary mixtures of CH{sub 4} and CO{sub 2} hydrate (CH{sub 4}-CO{sub 2} mixed hydrates), as well as thermophysical property changes during gas exchange. This study explores the thermal dissociation behavior and dissociation enthalpies of CH{sub 4}-CO{sub 2} mixed hydrates. We prepared CH{sub 4}-CO{sub 2} mixed hydrate samples from two different, well-defined gas mixtures. During thermal dissociation of a CH{sub 4}-CO{sub 2} mixed hydrate sample, gas samples from the head space were periodically collected and analyzed using gas chromatography. The changes in CH{sub 4}-CO{sub 2} compositions in both the vapor phase and hydrate phase during dissociation were estimated based on the gas chromatography measurements. It was found that the CO{sub 2} concentration in the vapor phase became richer during dissociation because the initial hydrate composition contained relatively more CO{sub 2} than the vapor phase. The composition change in the vapor phase during hydrate dissociation affected the dissociation pressure and temperature; the richer CO{sub 2} in the vapor phase led to a lower dissociation pressure. Furthermore, the increase in CO{sub 2} concentration in the vapor phase enriched the hydrate in CO{sub 2}. The dissociation enthalpy of the CH{sub 4}-CO{sub 2} mixed hydrate was computed by fitting the Clausius-Clapeyron equation to the pressure-temperature (PT) trace of a dissociation test. It was observed that the dissociation enthalpy of the CH{sub 4}-CO{sub 2} mixed hydrate lays between the limiting values of pure CH{sub 4} hydrate and CO{sub 2} hydrate, increasing with the CO{sub 2} fraction in the hydrate phase.

  2. Ethanol Distribution, Dispensing, and Use: Analysis of a Portion of the Biomass-to-Biofuels Supply Chain Using System Dynamics

    SciTech Connect (OSTI)

    Vimmerstedt, L. J.; Bush, B.; Peterson, S.

    2012-05-01

    The Energy Independence and Security Act of 2007 targets use of 36 billion gallons of biofuels per year by 2022. Achieving this may require substantial changes to current transportation fuel systems for distribution, dispensing, and use in vehicles. The U.S. Department of Energy and the National Renewable Energy Laboratory designed a system dynamics approach to help focus government action by determining what supply chain changes would have the greatest potential to accelerate biofuels deployment. The National Renewable Energy Laboratory developed the Biomass Scenario Model, a system dynamics model which represents the primary system effects and dependencies in the biomass-to-biofuels supply chain. The model provides a framework for developing scenarios and conducting biofuels policy analysis. This paper focuses on the downstream portion of the supply chain-represented in the distribution logistics, dispensing station, and fuel utilization, and vehicle modules of the Biomass Scenario Model. This model initially focused on ethanol, but has since been expanded to include other biofuels. Some portions of this system are represented dynamically with major interactions and feedbacks, especially those related to a dispensing station owner's decision whether to offer ethanol fuel and a consumer's choice whether to purchase that fuel. Other portions of the system are modeled with little or no dynamics; the vehicle choices of consumers are represented as discrete scenarios. This paper explores conditions needed to sustain an ethanol fuel market and identifies implications of these findings for program and policy goals. A large, economically sustainable ethanol fuel market (or other biofuel market) requires low end-user fuel price relative to gasoline and sufficient producer payment, which are difficult to achieve simultaneously. Other requirements (different for ethanol vs. other biofuel markets) include the need for infrastructure for distribution and dispensing and widespread use of high ethanol blends in flexible-fuel vehicles.

  3. Basic research in engineering: process and systems dynamics and control. High priority research needs relevent to energy

    SciTech Connect (OSTI)

    Rabins, M.J.; Edgar, T.F.; Richardson, H.H.; Zaborszky, J.

    1980-02-01

    At a workshop held in Denver, Colorado, on June 20 to 23, 1979, Process and Systems Dynamics and Control (PSDC) is concerned with the development and control of system behavior, performance criteria, and theories of control and optimization. This report presents a set of high-priority basic engineering research needs in the PSDC field which are important to the development of future energy technologies. The ten high priority generic research areas were aggregeted into four major research needs recommended for DOE support: on-line optimization and control, systems methodology, measurement methodology and instrumentation, and modeling.

  4. State-of-the-art review of computational fluid dynamics modeling for fluid-solids systems

    SciTech Connect (OSTI)

    Lyczkowski, R.W.; Bouillard, J.X.; Ding, J.; Chang, S.L.; Burge, S.W.

    1994-05-12

    As the result of 15 years of research (50 staff years of effort) Argonne National Laboratory (ANL), through its involvement in fluidized-bed combustion, magnetohydrodynamics, and a variety of environmental programs, has produced extensive computational fluid dynamics (CFD) software and models to predict the multiphase hydrodynamic and reactive behavior of fluid-solids motions and interactions in complex fluidized-bed reactors (FBRS) and slurry systems. This has resulted in the FLUFIX, IRF, and SLUFIX computer programs. These programs are based on fluid-solids hydrodynamic models and can predict information important to the designer of atmospheric or pressurized bubbling and circulating FBR, fluid catalytic cracking (FCC) and slurry units to guarantee optimum efficiency with minimum release of pollutants into the environment. This latter issue will become of paramount importance with the enactment of the Clean Air Act Amendment (CAAA) of 1995. Solids motion is also the key to understanding erosion processes. Erosion rates in FBRs and pneumatic and slurry components are computed by ANL`s EROSION code to predict the potential metal wastage of FBR walls, intervals, feed distributors, and cyclones. Only the FLUFIX and IRF codes will be reviewed in the paper together with highlights of the validations because of length limitations. It is envisioned that one day, these codes with user-friendly pre and post-processor software and tailored for massively parallel multiprocessor shared memory computational platforms will be used by industry and researchers to assist in reducing and/or eliminating the environmental and economic barriers which limit full consideration of coal, shale and biomass as energy sources, to retain energy security, and to remediate waste and ecological problems.

  5. HYDRATE RESEARCH ACTIVITIES THAT BOTH SUPPORT AND DERIVE FROM THE MONITORING STATION/SEA-FLOOR OBSERVATORY, MISSISSIPPI CANYON 118, NORTHERN GULF OF MEXICO

    SciTech Connect (OSTI)

    Lutken, Carol

    2013-07-31

    A permanent observatory has been installed on the seafloor at Federal Lease Block, Mississippi Canyon 118 (MC118), northern Gulf of Mexico. Researched and designed by the Gulf of Mexico Hydrates Research Consortium (GOM-HRC) with the geological, geophysical, geochemical and biological characterization of in situ gas hydrates systems as the research goal, the site has been designated by the Bureau of Ocean Energy Management as a permanent Research Reserve where studies of hydrates and related ocean systems may take place continuously and cooperatively into the foreseeable future. The predominant seafloor feature at MC118 is a carbonate-hydrate complex, officially named Woolsey Mound for the founder of both the GOM-HRC and the concept of the permanent seafloor hydrates research facility, the late James Robert “Bob” Woolsey. As primary investigator of the overall project until his death in mid-2008, Woolsey provided key scientific input and served as chief administrator for the Monitoring Station/ Seafloor Observatory (MS-SFO). This final technical report presents highlights of research and accomplishments to date. Although not all projects reached the status originally envisioned, they are all either complete or positioned for completion at the earliest opportunity. All Department of Energy funds have been exhausted in this effort but, in addition, leveraged to great advantage with additional federal input to the project and matched efforts and resources. This report contains final reports on all subcontracts issued by the University of Mississippi, Administrators of the project, Hydrate research activities that both support and derive from the monitoring station/sea-floor Observatory, Mississippi Canyon 118, northern Gulf of Mexico, as well as status reports on the major components of the project. All subcontractors have fulfilled their primary obligations. Without continued funds designated for further project development, the Monitoring Station/Seafloor Observatory is in danger of lapsing into disuse. However, for the present, interest in the site on the continental slope is healthy and The Center for Marine Resources and Environmental Technology continues to coordinate all activity at the MS/SFO as arranged through the BOEM in 2005. Field and laboratory research projects and findings are reviewed, new technologies and tests described. Many new sensors, systems and two custom ROVs have been developed specifically for this project. Characteristics of marine gas hydrates are dramatically more refined than when the project was initiated and include appear in sections entitled Accomplishments, Products and Publications.

  6. X-ray CT Observations of Methane Hydrate Distribution Changes over Time in a Natural Sediment Core from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well

    SciTech Connect (OSTI)

    Kneafsey, T.J.; Rees, E.V.L.

    2010-03-01

    When maintained under hydrate-stable conditions, methane hydrate in laboratory samples is often considered a stable and immobile solid material. Currently, there do not appear to be any studies in which the long-term redistribution of hydrates in sediments has been investigated in the laboratory. These observations are important because if the location of hydrate in a sample were to change over time (e.g. by dissociating at one location and reforming at another), the properties of the sample that depend on hydrate saturation and pore space occupancy would also change. Observations of hydrate redistribution under stable conditions are also important in understanding natural hydrate deposits, as these may also change over time. The processes by which solid hydrate can move include dissociation, hydrate-former and water migration in the gas and liquid phases, and hydrate formation. Chemical potential gradients induced by temperature, pressure, and pore water or host sediment chemistry can drive these processes. A series of tests were performed on a formerly natural methane-hydrate-bearing core sample from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well, in order to observe hydrate formation and morphology within this natural sediment, and changes over time using X-ray computed tomography (CT). Long-term observations (over several weeks) of methane hydrate in natural sediments were made to investigate spatial changes in hydrate saturation in the core. During the test sequence, mild buffered thermal and pressure oscillations occurred within the sample in response to laboratory temperature changes. These oscillations were small in magnitude, and conditions were maintained well within the hydrate stability zone.

  7. Ab Initio Thermodynamic Model for Magnesium Carbonates and Hydrates

    SciTech Connect (OSTI)

    Chaka, Anne M.; Felmy, Andrew R.

    2014-03-28

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogs of Ca-based hydrated carbonates monohydrocalcite and ikaite which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  8. Hydration studies of calcium sulfoaluminate cements blended with fly ash

    SciTech Connect (OSTI)

    Garca-Mat, M.; De la Torre, A.G.; Len-Reina, L.; Aranda, M.A.G.; CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona ; Santacruz, I.

    2013-12-15

    The main objective of this work is to study the hydration and properties of calcium sulfoaluminate cement pastes blended with fly ash (FA) and the corresponding mortars at different hydration ages. Laboratory X-ray powder diffraction, rheological studies, thermal analysis, porosimetry and compressive strength measurements were performed. The analysis of the diffraction data by Rietveld method allowed quantifying crystalline phases and overall amorphous contents. The studied parameters were: i) FA content, 0, 15 and 30 wt.%; and ii) water addition, water-to-CSA mass ratio (w/CSA = 0.50 and 0.65), and water-to-binder mass ratio (w/b = 0.50). Finally, compressive strengths after 6 months of 0 and 15 wt.% FA [w/CSA = 0.50] mortars were similar: 73 2 and 72 3 MPa, respectively. This is justified by the filler effect of the FA as no strong evidences of reactivity of FA with CSA were observed. These results support the partial substitution of CSA cements with FA with the economic and environmental benefits.

  9. The thermodynamic properties of hydrated -Al2O3 nanoparticles

    SciTech Connect (OSTI)

    Spencer, Elinor; Huang, Baiyu; Parker, Stewart F.; Kolesnikov, Alexander I; Ross, Dr. Nancy; Woodfield, Brian

    2013-01-01

    In this paper we report a combined calorimetric and inelastic neutron scattering (INS) study of hydrated -Al2O3 ( -alumina) nanoparticles. These complementary techniques have enabled a comprehensive evaluation of the thermodynamic properties of this technological and industrially important metal oxide to be achieved. The isobaric heat capacity (Cp) data presented herein provide further critical insights into the much-debated chemical composition of -alumina nanoparticles. Furthermore, the isochoric heat capacity (Cv) of the surface water, which is so essential to the stability of all metal-oxides at the nanoscale, has been extracted from the high-resolution INS data and differs significantly from that of ice Ih due to the dominating influence of strong surface-water interactions. This study also encompassed the analysis of four -alumina samples with differing pore diameters [4.5 (1), 13.8 (2), 17.9 (3), and 27.2 nm (4)], and the results obtained allow us to unambiguously conclude that the water content and pore size have no influence on the thermodynamic behaviour of hydrated -alumina nanoparticles.

  10. Newly Installed Alaska North Slope Well Will Test Innovative Hydrate Production Technologies

    Broader source: Energy.gov [DOE]

    A fully instrumented well that will test innovative technologies for producing methane gas from hydrate deposits has been safely installed on the North Slope of Alaska. As a result, the "Iġnik Sikumi" (Iñupiaq for "fire in the ice") gas hydrate field trial well will be available for field experiments as early as winter 2011-12.

  11. METHANE HYDRATE STUDIES: DELINEATING PROPERTIES OF HOST SEDIMENTS TO ESTABLISH REPRODUCIBLE DECOMPOSITION KINETICS.

    SciTech Connect (OSTI)

    Mahajan, Devinder; Jones, Keith W.; Feng, Huan; Winters, William J.

    2004-12-01

    The use of methane hydrate as an energy source requires development of a reliable method for its extraction from its highly dispersed locations in oceanic margin sediments and permafrost. The high pressure (up to 70 MPa) and low temperature (272 K to 278 K) conditions under which hydrates are stable in the marine environment can be mimicked in a laboratory setting and several kinetic studies of pure methane hydrate decomposition have been reported. However, the effect of host sediments on methane hydrate occurrence and decomposition are required to develop reliable hydrate models. In this paper, we describe methods to measure sediment properties as they relate to pore-space methane gas hydrate. Traditional geotechnical techniques are compared to the micrometer level by use of the synchrotron Computed Microtomography (CMT) technique. CMT was used to measure the porosity at the micrometer level and to show pore-space pathways through field samples. Porosities for three sediment samples: one from a site on Georges Bank and two from the known Blake Ridge methane hydrate site, from different depths below the mud line were measured by traditional drying and by the new CMT techniques and found to be in good agreement. The integration of the two analytical approaches is necessary to enable better understanding of methane hydrate interactions with the surrounding sediment particles.

  12. Development of a Numerical Simulator for Analyzing the Geomechanical Performance of Hydrate-Bearing Sediments

    SciTech Connect (OSTI)

    Rutqvist, Jonny; Rutqvist, J.; Moridis, G.J.

    2008-06-01

    In this paper, we describe the development and application of a numerical simulator that analyzes the geomechanical performance of hydrate-bearing sediments, which may become an important future energy supply. The simulator is developed by coupling a robust numerical simulator of coupled fluid flow, hydrate thermodynamics, and phase behavior in geologic media (TOUGH+HYDRATE) with an established geomechanical code (FLAC3D). We demonstrate the current simulator capabilities and applicability for two examples of geomechanical responses of hydrate bearing sediments during production-induced hydrate dissociation. In these applications, the coupled geomechanical behavior within hydrate-bearing seducements are considered through a Mohr-Coulomb constitutive model, corrected for changes in pore-filling hydrate and ice content, based on laboratory data. The results demonstrate how depressurization-based gas production from oceanic hydrate deposits may lead to severe geomechanical problems unless care is taken in designing the production scheme. We conclude that the coupled simulator can be used to design production strategies for optimizing production, while avoiding damaging geomechanical problems.

  13. Gas hydrates on the Atlantic Continental Margin of the United States - controls on concentration

    SciTech Connect (OSTI)

    Dillon, W.P.; Fehlhaber, K.; Coleman, D.F. ); Lee, M.W. )

    1993-01-01

    Large volumes of gas hydrates exist within ocean-floor deposits at water depths exceeding about 300 to 500 m. They cement a surface layer of sediments as much as about 1,000 m thick, limited at its base by increasing temperature. Gas hydrates are identified by drilled samples and by their characteristic responses in seismic reflection profiles. These seismic responses include, at the base of the hydrate-cemented surface layer, a marked velocity decrease and a sea-floor-paralleling reflection (known as the bottom-simulating reflection, or BSR), and, within the hydrate-cemented layer, a reduction in amplitude of seismic reflections (known as blanking), which is apparently caused by cementation of strata. By using seismic-reflection data we have mapped the volume of hydrate and thickness of the hydrate-cemented layer off the US East Coast. The sources of gas at these concentrations are probably bacterial generation of methane at the locations of rapid deposition, and possibly the migration of deep, thermogenic gap up faults near diapirs. The thickness of the gas-hydrate layer decreases markedly at landslide scars, possibly due to break-down of hydrate resulting from pressure reduction caused by removal of sediment by the slide. Gas traps appear to exist where a seal is formed by the gas-hydrate-cemented layer. Such traps are observed (1) where the sea floor forms a dome, and therefore the bottom-paralleling, hydrate-cemented layer also forms a dome; (2) above diapirs, where the greater thermal conductivity of salt creates a warm spot and salt ions act as antifreeze, both effects resulting in a local shallowing of the base of the hydrate; and (3) at locations where strata dip relative to the sea floor, and the updip regions of porous strata are sealed by the gas-hydrate-cemented layer to form a trap. In such situations the gas in the hydrate-sealed trap, as well as the gas that forms the hydrate, may become a resource. 32 refs., 19 figs.

  14. Unconventional gas hydrate seals may trap gas off southeast US. [North Carolina, South Carolina

    SciTech Connect (OSTI)

    Dillion, W.P.; Grow, J.A.; Paull, C.K.

    1980-01-07

    Seismic profiles have indicated to the US Geological Survey that an unconventional seal, created by gas hydrates that form in near-bottom sediments, may provide gas traps in continental slopes and rises offshore North and South Carolina. The most frequently cited evidence for the presence of gas hydrate in ocean sediments is the observation of a seismic reflection event that occurs about 1/2 s below and parallel with the seafloor. If gas-hydrate traps do exist, they will occur at very shallow sub-bottom depths of about 1600 ft (500m). Exploration of such traps will probably take place in the federally controlled Blake Ridge area off the coast of South Carolina where seismic data suggest a high incidence of gas hydrates. However, drilling through the gas-hydrate-cemented layer may require new engineering techniques for sealing the casing.

  15. IN-SITU SAMPLING AND CHARACTERIZATION OF NATURALLY OCCURRING MARINE METHANE HYDRATE USING THE D/V JOIDES RESOLUTION

    SciTech Connect (OSTI)

    Rack, Frank R.; Dickens, Gerald; Ford, Kathryn; Schroeder, Derryl; Storms, Michael

    2002-08-01

    The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the preparation of tools and measurement systems for deployment, testing and use on ODP Leg 204, which will study hydrate deposits on Hydrate Ridge, offshore Oregon. Additional accomplishments were related to the postcruise evaluation of tools and measurements systems used on ODP Leg 201 along the Peru margin from January through March, 2002. The operational results from the use of the Pressure Core Sampler (PCS) tool and the PCS Gas Manifold on ODP Leg 201 are evaluated in this progress report in order to prepare for the upcoming deployments on ODP Leg 204 in July, 2002. The PCS was deployed 17 times during ODP Leg 201 and successfully retrieved cores from a broad range of lithologies and sediment depths along the Peru margin. Eleven deployments were entirely successful, collecting between 0.5 and 1.0 meters of sediment at greater than 75% of hydrostatic pressure. The PCS gas manifold was used in conjunction with the Pressure Core Sampler (PCS) throughout ODP Leg 201 to measure the total volume and composition of gases recovered in sediment cores associated with methane gas hydrates. The FUGRO Pressure Corer (FPC), one of the HYACE/HYACINTH pressure coring tools, was also deployed on the D/V JOIDES Resolution during ODP Legs 201 to field-test this coring system at three shallow-water sites located offshore Peru. The field-testing of these tools provides a corollary benefit to DOE/NETL at no cost to this project. The testing of these tools on the D/V JOIDES Resolution was negotiated as part of a cooperative agreement between JOI/ODP and the HYACINTH partners. The DVTP, DVTP-P, APC-methane, and APC-Temperature tools (ODP memory tools) were used extensively during ODP Leg 201. The data obtained from the successful deployments of these tools is still being evaluated by the scientists and engineers involved in this testing; however, preliminary results are presented in this report. An infrared-thermal imaging system (IR-TIS) was deployed for the first time on ODP Leg 201. This system was used to identify methane hydrate intervals in the recovered cores. Initial discussions of these experiments are provided in this report. This report is an overview of the field measurements made on recovered sediment cores and the downhole measurements made during ODP Leg 201. These results are currently being used to incorporate the ''lessons learned'' from these deployments to prepare for a dedicated ODP leg to study the characteristics of naturally-occurring hydrates in the subsurface environment of Hydrate Ridge, offshore Oregon during ODP Leg 204, which will take place from July through September, 2002.

  16. Energy Department Expands Research into Methane Hydrates, a Vast, Untapped Potential Energy Resource of the U.S.

    Broader source: Energy.gov [DOE]

    Projects Will Determine Whether methane Hydrates Are an Economically and Environmentally Viable Option for America's Energy Future

  17. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    SciTech Connect (OSTI)

    Boswell, R.D.; Shelander, D.; Lee, M.; Latham, T.; Collett, T.; Guerin, G.; Moridis, G.; Reagan, M.; Goldberg, D.

    2009-07-15

    A unique set of high-quality downhole shallow subsurface well log data combined with industry standard 3D seismic data from the Alaminos Canyon area has enabled the first detailed description of a concentrated gas hydrate accumulation within sand in the Gulf of Mexico. The gas hydrate occurs within very fine grained, immature volcaniclastic sands of the Oligocene Frio sand. Analysis of well data acquired from the Alaminos Canyon Block 818 No.1 ('Tigershark') well shows a total gas hydrate occurrence 13 m thick, with inferred gas hydrate saturation as high as 80% of sediment pore space. Average porosity in the reservoir is estimated from log data at approximately 42%. Permeability in the absence of gas hydrates, as revealed from the analysis of core samples retrieved from the well, ranges from 600 to 1500 millidarcies. The 3-D seismic data reveals a strong reflector consistent with significant increase in acoustic velocities that correlates with the top of the gas-hydrate-bearing sand. This reflector extends across an area of approximately 0.8 km{sup 2} and delineates the minimal probable extent of the gas hydrate accumulation. The base of the inferred gas-hydrate zone also correlates well with a very strong seismic reflector that indicates transition into units of significantly reduced acoustic velocity. Seismic inversion analyses indicate uniformly high gas-hydrate saturations throughout the region where the Frio sand exists within the gas hydrate stability zone. Numerical modeling of the potential production of natural gas from the interpreted accumulation indicates serious challenges for depressurization-based production in settings with strong potential pressure support from extensive underlying aquifers.

  18. Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration

    SciTech Connect (OSTI)

    Djikaev, Y. S. Ruckenstein, E.

    2013-11-14

    The thermodynamics of hydration is expected to change gradually from entropic for small solutes to enthalpic for large ones. The small-to-large crossover lengthscale of hydrophobic hydration depends on the thermodynamic conditions of the solvent such as temperature, pressure, presence of additives, etc. We attempt to shed some light on the temperature dependence of the crossover lengthscale by using a probabilistic approach to water hydrogen bonding that allows one to obtain an analytic expression for the number of bonds per water molecule as a function of both its distance to a solute and solute radius. Incorporating that approach into the density functional theory, one can examine the solute size effects on its hydration over the entire small-to-large lengthscale range at a series of different temperatures. Knowing the dependence of the hydration free energy on the temperature and solute size, one can also obtain its enthalpic and entropic contributions as functions of both temperature and solute size. These functions can provide some interesting insight into the temperature dependence of the crossover lengthscale of hydrophobic hydration. The model was applied to the hydration of spherical particles of various radii in water in the temperature range from T = 293.15 K to T = 333.15 K. The model predictions for the temperature dependence of the hydration free energy of small hydrophobes are consistent with the experimental and simulational data on the hydration of simple molecular solutes. Three alternative definitions for the small-to-large crossover length-scale of hydrophobic hydration are proposed, and their temperature dependence is obtained. Depending on the definition and temperature, the small-to-large crossover in the hydration mechanism is predicted to occur for hydrophobes of radii from one to several nanometers. Independent of its definition, the crossover length-scale is predicted to decrease with increasing temperature.

  19. Permeability and porosity of hydrate-bearing sediments in the northern Gulf of Mexico

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Daigle, Hugh; Cook, Ann; Malinverno, Alberto

    2015-10-14

    Hydrate-bearing sands are being actively explored because they contain the highest concentrations of hydrate and are the most economically recoverable hydrate resource. However, relatively little is known about the mechanisms or timescales of hydrate formation, which are related to methane supply, fluid flux, and host sediment properties such as permeability. We used logging-while-drilling data from locations in the northern Gulf of Mexico to develop an effective medium theory-based model for predicting permeability based on clay-sized sediment fraction. The model considers permeability varying between sand and clay endpoint permeabilities that are defined from laboratory data. We verified the model using permeabilitymore » measurements on core samples from three boreholes, and then used the model to predict permeability in two wells drilled in Walker Ridge Block 313 during the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II expedition in 2009. We found that the cleanest sands (clay-sized fraction <0.05) had intrinsic (hydrate-free) permeability contrasts of 5-6 orders of magnitude with the surrounding clays, which is sufficient to provide focused hydrate formation due to advection of methane from a deep source or diffusion of microbial methane from nearby clay layers. In sands where the clay-sized fraction exceeds 0.05, the permeability reduces significantly and focused flow is less pronounced. In these cases, diffusion of dissolved microbial methane is most likely the preferred mode of methane supply for hydrate formation. In conclusion, our results provide important constraints on methane supply mechanisms in the Walker Ridge area and have global implications for evaluating rates of methane migration and hydrate formation in hydrate-bearing sands.« less

  20. Permeability and porosity of hydrate-bearing sediments in the northern Gulf of Mexico

    SciTech Connect (OSTI)

    Daigle, Hugh; Cook, Ann; Malinverno, Alberto

    2015-10-14

    Hydrate-bearing sands are being actively explored because they contain the highest concentrations of hydrate and are the most economically recoverable hydrate resource. However, relatively little is known about the mechanisms or timescales of hydrate formation, which are related to methane supply, fluid flux, and host sediment properties such as permeability. We used logging-while-drilling data from locations in the northern Gulf of Mexico to develop an effective medium theory-based model for predicting permeability based on clay-sized sediment fraction. The model considers permeability varying between sand and clay endpoint permeabilities that are defined from laboratory data. We verified the model using permeability measurements on core samples from three boreholes, and then used the model to predict permeability in two wells drilled in Walker Ridge Block 313 during the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II expedition in 2009. We found that the cleanest sands (clay-sized fraction <0.05) had intrinsic (hydrate-free) permeability contrasts of 5-6 orders of magnitude with the surrounding clays, which is sufficient to provide focused hydrate formation due to advection of methane from a deep source or diffusion of microbial methane from nearby clay layers. In sands where the clay-sized fraction exceeds 0.05, the permeability reduces significantly and focused flow is less pronounced. In these cases, diffusion of dissolved microbial methane is most likely the preferred mode of methane supply for hydrate formation. In conclusion, our results provide important constraints on methane supply mechanisms in the Walker Ridge area and have global implications for evaluating rates of methane migration and hydrate formation in hydrate-bearing sands.

  1. High-bandwidth Modulation of H2/Syngas Fuel to Control Combustion Dynamics in Micro-Mixing Lean Premix Systems

    SciTech Connect (OSTI)

    Jeff Melzak; Tim Lieuwen; Adel Mansour

    2012-01-31

    The goal of this program was to develop and demonstrate fuel injection technologies that will facilitate the development of cost-effective turbine engines for Integrated Gasification Combined Cycle (IGCC) power plants, while improving efficiency and reducing emissions. The program involved developing a next-generation multi-point injector with enhanced stability performance for lean premix turbine systems that burn hydrogen (H2) or synthesis gas (syngas) fuels. A previously developed injector that demonstrated superior emissions performance was improved to enhance static flame stability through zone staging and pilot sheltering. In addition, piezo valve technology was implemented to investigate the potential for enhanced dynamic stability through high-bandwidth modulation of the fuel supply. Prototype injector and valve hardware were tested in an atmospheric combustion facility. The program was successful in meeting its objectives. Specifically, the following was accomplished: Demonstrated improvement of lean operability of the Parker multi-point injector through staging of fuel flow and primary zone sheltering; Developed a piezo valve capable of proportional and high-bandwidth modulation of gaseous fuel flow at frequencies as high as 500 Hz; The valve was shown to be capable of effecting changes to flame dynamics, heat release, and acoustic signature of an atmospheric combustor. The latter achievement indicates the viability of the Parker piezo valve technology for use in future adaptively controlled systems for the mitigation of combustion instabilities, particularly for attenuating combustion dynamics under ultra-lean conditions.

  2. Scientific Objectives of the Gulf of Mexico Gas Hydrate JIP Leg II Drilling

    SciTech Connect (OSTI)

    Jones, E.; Latham, T.; McConnell, D.; Frye, M.; Hunt, J.; Shedd, W.; Shelander, D.; Boswell, R.M.; Rose, K.K.; Ruppel, C.; Hutchinson, D.; Collett, T.; Dugan, B.; Wood, W.

    2008-05-01

    The Gulf of Mexico Methane Hydrate Joint Industry Project (JIP) has been performing research on marine gas hydrates since 2001 and is sponsored by both the JIP members and the U.S. Department of Energy. In 2005, the JIP drilled the Atwater Valley and Keathley Canyon exploration blocks in the Gulf of Mexico to acquire downhole logs and recover cores in silt- and clay-dominated sediments interpreted to contain gas hydrate based on analysis of existing 3-D seismic data prior to drilling. The new 2007-2009 phase of logging and coring, which is described in this paper, will concentrate on gas hydrate-bearing sands in the Alaminos Canyon, Green Canyon, and Walker Ridge protraction areas. Locations were selected to target higher permeability, coarser-grained lithologies (e.g., sands) that have the potential for hosting high saturations of gas hydrate and to assist the U.S. Minerals Management Service with its assessment of gas hydrate resources in the Gulf of Mexico. This paper discusses the scientific objectives for drilling during the upcoming campaign and presents the results from analyzing existing seismic and well log data as part of the site selection process. Alaminos Canyon 818 has the most complete data set of the selected blocks, with both seismic data and comprehensive downhole log data consistent with the occurrence of gas hydrate-bearing sands. Preliminary analyses suggest that the Frio sandstone just above the base of the gas hydrate stability zone may have up to 80% of the available sediment pore space occupied by gas hydrate. The proposed sites in the Green Canyon and Walker Ridge areas are also interpreted to have gas hydrate-bearing sands near the base of the gas hydrate stability zone, but the choice of specific drill sites is not yet complete. The Green Canyon site coincides with a 4-way closure within a Pleistocene sand unit in an area of strong gas flux just south of the Sigsbee Escarpment. The Walker Ridge site is characterized by a sand-prone sedimentary section that rises stratigraphically across the base of the gas hydrate stability zone and that has seismic indicators of gas hydrate. Copyright 2008, Offshore Technology Conference

  3. Geologic interrelations relative to gas hydrates within the North Slope of Alaska: Task No. 6, Final report

    SciTech Connect (OSTI)

    Collett, T.S.; Bird, K.J.; Kvenvolden, K.A.; Magoon, L.B.

    1988-01-01

    The five primary objectives of the US Geological Survey North Slope Gas Hydrate Project were to: (1) Determine possible geologic controls on the occurrence of gas hydrate; (2) locate and evaluate possible gas-hydrate-bearing reservoirs; (3) estimate the volume of gas within the hydrates; (4) develop a model for gas-hydrate formation; and (5) select a coring site for gas-hydrate sampling and analysis. Our studies of the North Slope of Alaska suggest that the zone in which gas hydrates are stable is controlled primarily by subsurface temperatures and gas chemistry. Other factors, such as pore-pressure variations, pore-fluid salinity, and reservior-rock grain size, appear to have little effect on gas hydrate stability on the North Slope. Data necessary to determine the limits of gas hydrate stability field are difficult to obtain. On the basis of mud-log gas chromatography, core data, and cuttings data, methane is the dominant species of gas in the near-surface (0--1500 m) sediment. Gas hydrates were identified in 34 wells utilizing well-log responses calibrated to the response of an interval in one well where gas hydrates were actually recovered in a core by an oil company. A possible scenario describing the origin of the interred gas hydrates on the North Slope involves the migration of thermogenic solution- and free-gas from deeper reservoirs upward along faults into the overlying sedimentary rocks. We have identified two (dedicated) core-hole sites, the Eileen and the South-End core-holes, at which there is a high probability of recovering a sample of gas hydrate. At the Eileen core-hole site, at least three stratigraphic units may contain gas hydrate. The South-End core-hole site provides an opportunity to study one specific rock unit that appears to contain both gas hydrate and oil. 100 refs., 72 figs., 24 tabs.

  4. Origin of Entropy Convergence in Hydrophobic Hydration and Protein Folding

    SciTech Connect (OSTI)

    Garde, S.; Hummer, G.; Garcia, A.E.; Paulaitis, M.E.; Pratt, L.R. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); [Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States); [Department of Chemical Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    1996-12-01

    An information theory model of hydrophobic effects is used to construct a molecular explanation why hydrophobic solvation entropies of protein unfolding measured by high sensitivity calorimetry converge to zero at a common convergence temperature. The entropy convergence follows directly from the weak temperature dependence of occupancy fluctuations {l_angle}{delta}{ital n}{sup 2}{r_angle} for molecular-scale volumes in water. The macroscopic expression of the contrasting entropic behavior of water relative to common organic solvents is the {ital relative} temperature insensitivity of the water isothermal compressibility compared to hydrocarbon liquids. The information theory model used provides a quantitative description of small molecule hydration and, in addition, predicts that the value of the entropy at convergence is slightly {ital negative}. Interpretations of entropic contributions to protein folding should account for this result. {copyright} {ital 1996 The American Physical Society.}

  5. Contribution of oceanic gas hydrate dissociation to the formation of Arctic Ocean methane plumes

    SciTech Connect (OSTI)

    Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M.

    2011-06-01

    Vast quantities of methane are trapped in oceanic hydrate deposits, and there is concern that a rise in the ocean temperature will induce dissociation of these hydrate accumulations, potentially releasing large amounts of carbon into the atmosphere. Because methane is a powerful greenhouse gas, such a release could have dramatic climatic consequences. The recent discovery of active methane gas venting along the landward limit of the gas hydrate stability zone (GHSZ) on the shallow continental slope (150 m - 400 m) west of Svalbard suggests that this process may already have begun, but the source of the methane has not yet been determined. This study performs 2-D simulations of hydrate dissociation in conditions representative of the Arctic Ocean margin to assess whether such hydrates could contribute to the observed gas release. The results show that shallow, low-saturation hydrate deposits, if subjected to recently observed or future predicted temperature changes at the seafloor, can release quantities of methane at the magnitudes similar to what has been observed, and that the releases will be localized near the landward limit of the GHSZ. Both gradual and rapid warming is simulated, along with a parametric sensitivity analysis, and localized gas release is observed for most of the cases. These results resemble the recently published observations and strongly suggest that hydrate dissociation and methane release as a result of climate change may be a real phenomenon, that it could occur on decadal timescales, and that it already may be occurring.

  6. Physical property changes in hydrate-bearingsediment due to depressurization and subsequent repressurization

    SciTech Connect (OSTI)

    Kneafsey, Timothy; Waite, W.F.; Kneafsey, T.J.; Winters, W.J.; Mason, D.H.

    2008-06-01

    Physical property measurements of sediment cores containing natural gas hydrate are typically performed on material exposed at least briefly to non-in situ conditions during recovery. To examine effects of a brief excursion from the gas-hydrate stability field, as can occur when pressure cores are transferred to pressurized storage vessels, we measured physical properties on laboratory-formed sand packs containing methane hydrate and methane pore gas. After depressurizing samples to atmospheric pressure, we repressurized them into the methane-hydrate stability field and remeasured their physical properties. Thermal conductivity, shear strength, acoustic compressional and shear wave amplitudes and speeds are compared between the original and depressurized/repressurized samples. X-ray computed tomography (CT) images track how the gas-hydrate distribution changes in the hydrate-cemented sands due to the depressurization/repressurization process. Because depressurization-induced property changes can be substantial and are not easily predicted, particularly in water-saturated, hydrate-bearing sediment, maintaining pressure and temperature conditions throughout the core recovery and measurement process is critical for using laboratory measurements to estimate in situ properties.

  7. Dynamics of the Coupled Human-climate System Resulting from Closed-loop Control of Solar Geoengineering

    SciTech Connect (OSTI)

    MacMartin, Douglas; Kravitz, Benjamin S.; Keith, David; Jarvis, Andrew

    2014-07-08

    If solar radiation management (SRM) were ever implemented, feedback of the observed climate state might be used to adjust the radiative forcing of SRM, in order to compensate for uncertainty in either the forcing or the climate response; this would also compensate for unexpected changes in the system, e.g. a nonlinear change in climate sensitivity. This feedback creates an emergent coupled human-climate system, with entirely new dynamics. In addition to the intended response to greenhouse-gas induced changes, the use of feedback would also result in a geoengineering response to natural climate variability. We use a simple box-diffusion dynamic model to understand how changing feedback-control parameters and time delay affect the behavior of this coupled natural-human system, and verify these predictions using the HadCM3L general circulation model. In particular, some amplification of natural variability is unavoidable; any time delay (e.g., to average out natural variability, or due to decision-making) exacerbates this amplification, with oscillatory behavior possible if there is a desire for rapid correction (high feedback gain), but a delayed response needed for decision making. Conversely, the need for feedback to compensate for uncertainty, combined with a desire to avoid excessive amplification, results in a limit on how rapidly SRM could respond to uncertain changes.

  8. Method and apparatus for recovering a gas from a gas hydrate located on the ocean floor

    DOE Patents [OSTI]

    Wyatt, Douglas E.

    2001-01-01

    A method and apparatus for recovering a gas from a gas hydrate on the ocean floor includes a flexible cover, a plurality of steerable base members secured to the cover, and a steerable mining module. A suitable source for inflating the cover over the gas hydrate deposit is provided. The mining module, positioned on the gas hydrate deposit, is preferably connected to the cover by a control cable. A gas retrieval conduit or hose extends upwardly from the cover to be connected to a support ship on the ocean surface.

  9. In-Situ Sampling and Characterization of Naturally Occuring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Rack, Frank; Guerin, Gilles; Goldberg, David

    2003-12-31

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) Leg 204 scientific party members presented preliminary results and operational outcomes of ODP Leg 204 at the American Geophysical Union Fall meeting, which was held in San Francisco, CA; and, (2) a report was prepared by Dr. Gilles Guerin and David Goldberg from Lamont-Doherty Earth Observatory of Columbia University on their postcruise evaluation of the data, tools and measurement systems that were used for vertical seismic profiling (VSP) experiments during ODP Leg 204. The VSP report is provided herein. Intermediate in scale and resolution between the borehole data and the 3-D seismic surveys, the Vertical Seismic Profiles (VSP) carried during Leg 204 were aimed at defining the gas hydrate distribution on hydrate ridge, and refining the signature of gas hydrate in the seismic data. VSP surveys were attempted at five sites, following completion of the conventional logging operations. Bad hole conditions and operational difficulties did not allow to record any data in hole 1245E, but vertical and constant offset VSP were successful in holes 1244E, 1247B and 1250F, and walk-away VSP were successfully completed in holes 1244E, 1250F and 1251H. Three different tools were used for these surveys. The vertical VSP provided the opportunity to calculate interval velocity that could be compared and validated with the sonic logs in the same wells. The interval velocity profiles in Holes 1244E and 1247B are in very good agreement with the sonic logs. Information about the Leg 204 presentations at the AGU meeting are included in a separate Topical Report, which has been provided to DOE/NETL in addition to this Quarterly Report. Work continued on analyzing data collected during ODP Leg 204 and preparing reports on the outcomes of Phase 1 projects as well as developing plans for Phase 2.

  10. Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics

    SciTech Connect (OSTI)

    Persson, Rasmus A. X.; Chu, Jhih-Wei, E-mail: jwchu@nctu.edu.tw [Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Voulgarakis, Nikolaos K. [Department of Mathematics, Washington State University, Richland, Washington 99372 (United States)

    2014-11-07

    Fluctuating hydrodynamics (FHD) is a general framework of mesoscopic modeling and simulation based on conservational laws and constitutive equations of linear and nonlinear responses. However, explicit representation of electrical forces in FHD has yet to appear. In this work, we devised an Ansatz for the dynamics of dipole moment densities that is linked with the Poisson equation of the electrical potential ? in coupling to the other equations of FHD. The resulting ?-FHD equations then serve as a platform for integrating the essential forces, including electrostatics in addition to hydrodynamics, pressure-volume equation of state, surface tension, and solvent-particle interactions that govern the emergent behaviors of molecular systems at an intermediate scale. This unique merit of ?-FHD is illustrated by showing that the water dielectric function and ion hydration free energies in homogeneous and heterogenous systems can be captured accurately via the mesoscopic simulation. Furthermore, we show that the field variables of ?-FHD can be mapped from the trajectory of an all-atom molecular dynamics simulation such that model development and parametrization can be based on the information obtained at a finer-grained scale. With the aforementioned multiscale capabilities and a spatial resolution as high as 5 , the ?-FHD equations represent a useful semi-explicit solvent model for the modeling and simulation of complex systems, such as biomolecular machines and nanofluidics.

  11. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Rack, Frank; Schultheiss, Peter

    2005-12-31

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were the implementation of a scientific ocean drilling expedition to study marine methane hydrates along the Cascadia margin, in the NE Pacific as part of Integrated Ocean Drilling Program (IODP) Expedition 311 using the R/V JOIDES Resolution and the deployment of all required equipment and personnel to provide the required services during this expedition. IODP Expedition 311 shipboard activities on the JOIDES Resolution began on August 28 and were concluded on October 28, 2005. New ODP Pressure Coring System (PCS) aluminum autoclave chambers were fabricated prior to the expedition. During the expedition, 16 PCS autoclaves containing pressure cores were X-rayed before and after depressurization using a modified Geotek MSCL-P (multi-sensor core logger-pressure) system. These PCS cores were density scanned using the MSCL-V (multi-sensor core logger-vertical) during depressurization to monitor gas evolution. The MSCL-V was set up in a 20-foot-long refrigerated container provided by Texas A&M University through the JOI contract with TAMRF. IODP Expedition 311 was the first time that PCS cores were examined before (using X-ray), during (using MSCL-V gamma density) and after (using X-ray) degassing to determine the actual volume and distribution of sediment and gas hydrate in the pressurized core, which will be important for more accurate determination of mass balances between sediment, gas, gas hydrate, and fluids in the samples collected. Geotek, Ltd was awarded a contract by JOI to provide equipment and personnel to perform pressure coring and related work on IODP Expedition 311 (Cascadia Margin Gas Hydrates). Geotek, Ltd. provided an automated track for use with JOI's infrared camera systems. Four auxiliary monitors showed infrared core images in real time to aid hydrate identification and sampling. Images were collected from 185 cores during the expedition and processed to provide continuous core temperature data. The HYACINTH pressure coring tools, subsystems, and core logging systems were mobilized to Astoria, Oregon. Both HYACINTH pressure coring tools, the HRC (HYACE Rotary Corer) and the FPC (Fugro Pressure Corer) were mobilized and used during the expedition. Two HYACINTH engineers supervised the use of the tools and five good pressure cores were obtained. Velocity, density and X-ray linear scanning data were collected from these cores at near in situ pressure using the MSCL-P system. Dr. Barry Freifeld from Lawrence Berkeley National Laboratory provided an X-ray source and detector for X-ray imaging of pressure cores and helped Geotek with the design and mobilization of the MSCL-P system. Pressure core handling, transfer, and logging was performed in a refrigerated 20-foot container supplied by Geotek, Ltd. After scanning, the pressure cores were stored for on-shore analysis in aluminum barrels. Additional studies were conducted at the Pacific Geoscience Center (PGC), where a shore based laboratory was established after Expedition 311.

  12. Bioenergy market competition for biomass: A system dynamics review of current policies

    SciTech Connect (OSTI)

    Jacob J. Jacobson; Robert Jeffers

    2013-07-01

    There is growing interest in the United States and abroad to increase the use of biomass as an energy source due to environmental and energy security benefits. In the United States, the biofuel and biopower industries are regulated by different policies and different agencies and have different drivers, which impact the maximum price the industries are willing to pay for biomass. This article describes a dynamic computer simulation model that analyzes future behavior of bioenergy feedstock markets based on varying policy and technical options. The model simulates the long-term dynamics of these markets by treating advanced biomass feedstocks as a commodity and projecting the total demand of each industry, as well as the market price over time. The model is used for an analysis of the United States bioenergy feedstock market that projects supply, demand, and market price given three independent buyers: domestic biopower, domestic biofuels, and foreign exports. With base-case assumptions, the biofuels industry is able to dominate the market and meet the federal Renewable Fuel Standard (RFS) targets for advanced biofuels. Further analyses suggest that United States bioenergy studies should include estimates of export demand for biomass in their projections, and that GHG-limiting policy would partially shield both industries from export dominance.

  13. GreenPower Trap Water-Muffler System | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    This hydrated EGR system reduces NOx and enhances fuel efficiency, and the DPF is catalyzed by the fuel-borne catalyst generated by the oil-borne catalyst system PDF icon deer09_rim.pdf More Documents & Publications DPF -"Hydrated EGR" Fuel Saver System GreenPowerTM Trap-Muffler

  14. Gas mixing system for imaging of nanomaterials under dynamic environments by environmental transmission electron microscopy

    SciTech Connect (OSTI)

    Akatay, M. Cem; Zvinevich, Yury; Ribeiro, Fabio H. E-mail: estach@bnl.gov; Baumann, Philipp; Stach, Eric A. E-mail: estach@bnl.gov

    2014-03-15

    A gas mixing manifold system that is capable of delivering a stable pressure stream of a desired composition of gases into an environmental transmission electron microscope has been developed. The system is designed to provide a stable imaging environment upon changes of either the composition of the gas mixture or upon switching from one gas to another. The design of the system is described and the response of the pressure inside the microscope, the sample temperature, and sample drift in response to flow and composition changes of the system are reported.

  15. Intramolecular and nonlinear dynamics

    SciTech Connect (OSTI)

    Davis, M.J.

    1993-12-01

    Research in this program focuses on three interconnected areas. The first involves the study of intramolecular dynamics, particularly of highly excited systems. The second area involves the use of nonlinear dynamics as a tool for the study of molecular dynamics and complex kinetics. The third area is the study of the classical/quantum correspondence for highly excited systems, particularly systems exhibiting classical chaos.

  16. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Rack, Frank; Schroeder, Derryl; Storms, Michael

    2001-03-31

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were the deployment of tools and measurement systems for testing on ODP Leg 201, which is intended to study hydrate deposits on the Peru margin as part of other scientific investigations. Additional accomplishments were related to the continuing evolution of tools and measurements systems in preparation for deployment on ODP Leg 204, Hydrate Ridge, offshore Oregon in July 2002. The design for PCS Gas Manifold was finalized and parts were procured to assemble the gas manifold and deploy this system with the Pressure Core Sampler (PCS) tool on ODP Leg 201. The PCS was deployed 17 times during ODP Leg 201 and successfully retrieved cores from a broad range of lithologies and sediment depths along the Peru margin. Eleven deployments were entirely successful, collecting between 0.5 and 1.0 meters of sediment at greater than 75% of hydrostatic pressure. The PCS gas manifold was used in conjunction with the Pressure Core Sampler (PCS) throughout ODP Leg 201 to measure the total volume and composition of gases recovered in sediment cores associated with methane hydrates. The results of these deployments will be the subject of a future progress report. The FUGRO Pressure Corer (FPC), one of the HYACE/HYACINTH pressure coring tools, and two FUGRO engineers were deployed on the D/V JOIDES Resolution during ODP Legs 201 to field-test this coring system at sites located offshore Peru. The HYACINTH project is a European Union (EU) funded effort to develop tools to characterize methane hydrate and measure physical properties under in-situ conditions. The field-testing of these tools provides a corollary benefit to DOE/NETL at no cost to this project. The opportunity to test these tools on the D/V JOIDES Resolution was negotiated as part of a cooperative agreement between JOI/ODP and the HYACINTH partners. The DVTP, DVTP-P, APC-methane, and APC-Temperature tools (ODP memory tools) were deployed onboard the R/V JOIDES Resolution and used extensively during ODP Leg 201. Preliminary results indicate successful deployments of these tools. An infrared-thermal imaging system (IR-TIS) was delivered to JOI/ODP for testing and use on ODP Leg 201 to identify methane hydrate intervals in the recovered cores. The results of these experiments will be the subject of a future progress report. This report presents an overview of the primary methods used for deploying the ODP memory tools and PCS on ODP Leg 201 and the preliminary operational results of this leg. Discussions regarding the laboratory analysis of the recovered cores and downhole measurements made during these deployments will be covered in a future progress report.

  17. LIHE Spectral Dynamics and Jaguar Data Acquisition System Measurement Assurance Results 2014.

    SciTech Connect (OSTI)

    Covert, Timothy T.; Willis, Michael David; Radtke, Gregg Arthur

    2015-06-01

    The Light Initiated High Explosive (LIHE) facility performs high rigor, high consequence impulse testing for the nuclear weapons (NW) community. To support the facility mission, LIHE's extensive data acquisition system (DAS) is comprised of several discrete components as well as a fully integrated system. Due to the high consequence and high rigor of the testing performed at LIHE, a measurement assurance plan (MAP) was developed in collaboration with NW system customers to meet their data quality needs and to provide assurance of the robustness of the LIHE DAS. While individual components of the DAS have been calibrated by the SNL Primary Standards Laboratory (PSL), the integrated nature of this complex system requires verification of the complete system, from end-to-end. This measurement assurance plan (MAP) report documents the results of verification and validation procedures used to ensure that the data quality meets customer requirements.

  18. Method of evaluating, expanding, and collapsing connectivity regions within dynamic systems

    DOE Patents [OSTI]

    Bailey, David A. (Schenectady, NY)

    2004-11-16

    An automated process defines and maintains connectivity regions within a dynamic network. The automated process requires an initial input of a network component around which a connectivity region will be defined. The process automatically and autonomously generates a region around the initial input, stores the region's definition, and monitors the network for a change. Upon detecting a change in the network, the effect is evaluated, and if necessary the regions are adjusted and redefined to accommodate the change. Only those regions of the network affected by the change will be updated. This process eliminates the need for an operator to manually evaluate connectivity regions within a network. Since the automated process maintains the network, the reliance on an operator is minimized; thus, reducing the potential for operator error. This combination of region maintenance and reduced operator reliance, results in a reduction of overall error.

  19. Development of Alaskan gas hydrate resources: Annual report, October 1986--September 1987

    SciTech Connect (OSTI)

    Sharma, G.D.; Kamath, V.A.; Godbole, S.P.; Patil, S.L.; Paranjpe, S.G.; Mutalik, P.N.; Nadem, N.

    1987-10-01

    Solid ice-like mixtures of natural gas and water in the form of natural gas hydrated have been found immobilized in the rocks beneath the permafrost in Arctic basins and in muds under the deep water along the American continental margins, in the North Sea and several other locations around the world. It is estimated that the arctic areas of the United States may contain as much as 500 trillion SCF of natural gas in the form of gas hydrates (Lewin and Associates, 1983). While the US Arctic gas hydrate resources may have enormous potential and represent long term future source of natural gas, the recovery of this resource from reservoir frozen with gas hydrates has not been commercialized yet. Continuing study and research is essential to develop technologies which will enable a detailed characterization and assessment of this alternative natural gas resource, so that development of cost effective extraction technology.

  20. Kinetics of Methane Hydrate Decomposition Studied via in Situ Low Temperature X-ray Powder Diffraction

    SciTech Connect (OSTI)

    Everett, Susan M; Rawn, Claudia J; Keffer, David J.; Mull, Derek L; Payzant, E Andrew; Phelps, Tommy Joe

    2013-01-01

    Gas hydrates are known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice termed self-preservation or anomalous preservation. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Two regions of slowed decomposition for methane hydrate, 180 200 K and 230 260 K, were observed, and the kinetics were studied by in situ low temperature x-ray powder diffraction. The kinetic constants for ice formation from methane hydrate were determined by the Avrami model within each region and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180 200 K was 42 kJ/mol and for 230 260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.

  1. U.S. and Japan Complete Successful Field Trial of Methane Hydrate...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... This test was the first ever field trial of a methane hydrate production methodology ... The next stages of the Department's research effort will be aimed in part at evaluating ...

  2. Ground movements associated with gas hydrate production. Progress report, July 1--September 30, 1992

    SciTech Connect (OSTI)

    Siriwardane, H.J.

    1992-12-31

    The grantee will evaluate the influence of hydrate production on ground subsidence near the wellbore and the surface. The objective of this research will be achieved by using computer simulations of what is expected in a hydrate reservoir during the production stage as reported by hydrate production models and available data. The model will be based on theories of continuum mechanics, thermomechanics of hydrate production, principles of rock mechanics and geomechanics, and special features of geomaterials under cold temperatures such as those found in permafrost regions. The research work involved in the proposed investigation will be divided into three major tasks: (1) Mechanics of subsidence in permafrost regions; (2) modeling of subsidence; and (3) parametric studies. Progress reports are presented for tasks 1 and 2.

  3. Substantially self-powered method and apparatus for recovering hydrocarbons from hydrocarbon-containing solid hydrates

    DOE Patents [OSTI]

    Elliott, G.R.B.; Barraclough, B.L.; Vanderborgh, N.E.

    1981-02-19

    A method and apparatus are provided for producing gaseous hydrocarbons from formations comprising solid hydrocarbon hydrates located under either a body of land or a body of water. The vast natural resources of such hydrocarbon hydrates can thus now be economically mined. Relatively warm brine or water is brought down from an elevation above that of the hydrates through a portion of the apparatus, and passes in contact with the hydrates, thus melting them. The liquid then continues up another portion of the apparatus carrying entrained hydrocarbon vapors in the form of bubbles, which can easily be separated from the liquid. After a short startup procedure, the process and apparatus are substantially self-powered.

  4. Substantially self-powered method and apparatus for recovering hydrocarbons from hydrocarbon-containing solid hydrates

    DOE Patents [OSTI]

    Elliott, Guy R. B. (Los Alamos, NM); Barraclough, Bruce L. (Santa Fe, NM); Vanderborgh, Nicholas E. (Los Alamos, NM)

    1983-01-01

    A method and apparatus are provided for producing gaseous hydrocarbons from formations comprising solid hydrocarbon hydrates located under either a body of land or a body of water. The vast natural resources of such hydrocarbon hydrates can thus now be economically mined. Relatively warm brine or water is brought down from an elevation above that of the hydrates through a portion of the apparatus and passes in contact with the hydrates, thus melting them. The liquid then continues up another portion of the apparatus, carrying entrained hydrocarbon vapors in the form of bubbles, which can easily be separated from the liquid. After a short startup procedure, the process and apparatus are substantially self-powered.

  5. Apparatus for recovering gaseous hydrocarbons from hydrocarbon-containing solid hydrates

    DOE Patents [OSTI]

    Elliott, Guy R. B. (Los Alamos, NM); Barraclough, Bruce L. (Santa Fe, NM); Vanderborgh, Nicholas E. (Los Alamos, NM)

    1984-01-01

    A method and apparatus are provided for producing gaseous hydrocarbons from formations comprising solid hydrocarbon hydrates located under either a body of land or a body of water. The vast natural resources of such hydrocarbon hydrates can thus now be economically mined. Relatively warm brine or water is brought down from an elevation above that of the hydrates through a portion of the apparatus and passes in contact with the hydrates, thus melting them. The liquid then continues up another portion of the apparatus, carrying entrained hydrocarbon vapors in the form of bubbles, which can easily be separated from the liquid. After a short startup procedure, the process and apparatus are substantially self-powered.

  6. Results from DOE Expedition Confirm Existence of Resource-Quality Gas Hydrate in Gulf of Mexico

    Broader source: Energy.gov [DOE]

    Gas hydrate, a potentially immense energy resource, occurs at high saturations within reservoir-quality sands in the Gulf of Mexico, according to reports released by the Office of Fossil Energy's National Energy Technology Laboratory.

  7. DOE Expedition Discovers the First Gulf of Mexico Resource-Quality Gas Hydrate Deposits

    Broader source: Energy.gov [DOE]

    The Office of Fossil Energy's National Energy Technology Laboratory has established that gas hydrate can and does occur at high saturations within reservoir-quality sands in the Gulf of Mexico.

  8. Direct visualization of the hydration layer on alumina nanoparticles with the fluid cell STEM in situ

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Firlar, Emre; ?nar, Simge; Kashyap, Sanjay; Akinc, Mufit; Prozorov, Tanya

    2015-05-21

    Rheological behavior of aqueous suspensions containing nanometer-sized powders is of relevance to many branches of industry. Unusually high viscosities observed for suspensions of nanoparticles compared to those of micron size powders cannot be explained by current viscosity models. Formation of so-called hydration layer on alumina nanoparticles in water was hypothesized, but never observed experimentally. We report here on the direct visualization of aqueous suspensions of alumina with the fluid cell in situ. We observe the hydration layer formed over the particle aggregates and show that such hydrated aggregates constitute new particle assemblies and affect the flow behavior of the suspensions.moreWe discuss how these hydrated nanoclusters alter the effective solid content and the viscosity of nanostructured suspensions. Our findings elucidate the source of high viscosity observed for nanoparticle suspensions and are of direct relevance to many industrial sectors including materials, food, cosmetics, pharmaceutical among others employing colloidal slurries with nanometer-scale particles.less

  9. Data from Innovative Methane Hydrate Test on Alaska's North Slope Now Available on NETL Website

    Broader source: Energy.gov [DOE]

    Data from an innovative test conducted last year that used CO2 and N2 injection to release natural gas from methane hydrates at a well on the Alaska North Slope is now available to researchers and the public.

  10. Shared and Dynamic Libraries

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Some "out-of-the-box" applications require DSLs and some popular applications like Python use DSLs as well. Using System Shared and Dynamic Libraries "System" DSLs include...

  11. TRAJECTORY SENSITIVITY ANALYSIS FOR DYNAMIC SECURITY ASSESSMENT AND OTHER APPLICATIONS IN POWER SYSTEMS

    SciTech Connect (OSTI)

    Nguyen, Tony B.; Pai, M. A.

    2014-07-10

    Real time stability evaluation and preventive scheduling in power systems offer many challenges in a stressed power system. Trajectory sensitivity analysis (TSA) is a useful tool for this and other applications in the emerging smart grid area. In this chapter we outline the basic approach of TSA, to extract suitable information from the data and develop reliable metrics or indices to evaluate proximity of the system to an unstable condition. Trajectory sensitivities can be used to compute critical parameters such as clearing time of circuit breakers, tie line flow, etc. in a power system by developing suitable norms for ease of interpretation. The TSA technique has the advantage that model complexity is not a limitation, and the sensitivities can be computed numerically. Suitable metrics are developed from these sensitivities. The TSA technique can be extended to do preventive rescheduling. A brief discussion of other applications of TSA in placement of distributed generation is indicated.

  12. On computing stress in polymer systems involving multi-body potentials from molecular dynamics simulation

    SciTech Connect (OSTI)

    Fu, Yao E-mail: jhsong@cec.sc.edu; Song, Jeong-Hoon E-mail: jhsong@cec.sc.edu

    2014-08-07

    Hardy stress definition has been restricted to pair potentials and embedded-atom method potentials due to the basic assumptions in the derivation of a symmetric microscopic stress tensor. Force decomposition required in the Hardy stress expression becomes obscure for multi-body potentials. In this work, we demonstrate the invariance of the Hardy stress expression for a polymer system modeled with multi-body interatomic potentials including up to four atoms interaction, by applying central force decomposition of the atomic force. The balance of momentum has been demonstrated to be valid theoretically and tested under various numerical simulation conditions. The validity of momentum conservation justifies the extension of Hardy stress expression to multi-body potential systems. Computed Hardy stress has been observed to converge to the virial stress of the system with increasing spatial averaging volume. This work provides a feasible and reliable linkage between the atomistic and continuum scales for multi-body potential systems.

  13. FROZEN HEAT A GLOBAL OUTLOOK ON METHANE GAS HYDRATES EXECUTIVE SUMMARY

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    FROZEN HEAT A GLOBAL OUTLOOK ON METHANE GAS HYDRATES EXECUTIVE SUMMARY Beaudoin, Y. C., Boswell, R., Dallimore, S. R., and Waite, W. (eds), 2014. Frozen Heat: A UNEP Global Outlook on Methane Gas Hydrates. United Nations Environment Programme, GRID-Arendal. © United Nations Environment Programme, 2014 This publication may be reproduced in whole or in part and in any form for educational or non-profit purposes without special permission from the copyright holder, provided acknowledgement of the

  14. The Importance of Hydration | U.S. DOE Office of Science (SC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Importance of Hydration Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic Energy Sciences Advisory Committee (BESAC) Community Resources Contact Information Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3081 F: (301) 903-6594 E: Email Us More Information » 08.01.15 The Importance of Hydration Spectroscopy combined with theory

  15. GAS METHANE HYDRATES-RESEARCH STATUS, ANNOTATED BIBLIOGRAPHY, AND ENERGY IMPLICATIONS

    SciTech Connect (OSTI)

    James Sorensen; Jaroslav Solc; Bethany Bolles

    2000-07-01

    The objective of this task as originally conceived was to compile an assessment of methane hydrate deposits in Alaska from available sources and to make a very preliminary evaluation of the technical and economic feasibility of producing methane from these deposits for remote power generation. Gas hydrates have recently become a target of increased scientific investigation both from the standpoint of their resource potential to the natural gas and oil industries and of their positive and negative implications for the global environment After we performed an extensive literature review and consulted with representatives of the U.S. Geological Survey (USGS), Canadian Geological Survey, and several oil companies, it became evident that, at the current stage of gas hydrate research, the available information on methane hydrates in Alaska does not provide sufficient grounds for reaching conclusions concerning their use for energy production. Hence, the original goals of this task could not be met, and the focus was changed to the compilation and review of published documents to serve as a baseline for possible future research at the Energy & Environmental Research Center (EERC). An extensive annotated bibliography of gas hydrate publications has been completed. The EERC will reassess its future research opportunities on methane hydrates to determine where significant initial contributions could be made within the scope of limited available resources.

  16. Infrared signature of micro-hydration in the organophosphate sarin: An ab initio study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Alam, Todd M.; Pearce, Charles Joseph

    2015-06-28

    The infrared (IR) spectra of micro-hydrated Sarin•(H2O)n clusters containing between one and four explicit waters have been studied using ab initio density functional theory (DFT) methods. The phosphate group P=O bond vibration region (~1270 to 1290 cm–1) revealed the largest frequency variation with hydration, with a frequency red shift reflecting the direct hydrogen bond formation between the P=O of Sarin and water. Small variations to the P-F stretch (~810 to 815 cm–1) and the C-O-P vibrational modes (~995 to 1004 cm–1) showed that the water interactions with these functional groups were minor, and that the structures of Sarin were notmore » extensively perturbed in the hydrated complexes. Increasing the number of explicit hydration waters produced only small vibrational changes in the lowest free energy complexes. These minor changes were consistent with a single water-phosphate hydrogen bond being the dominant structure, though a second water-phosphate hydrogen bond was observed in some complexes and was identified by an additional red shift of the P=O bond vibration. As a result, the H2O•H2O vibrational modes (~3450 to 3660 cm–1) increased in complexity with higher hydration levels and reflect the extended hydrogen bonding networks formed between the explicit waters in the hydrated Sarin clusters.« less

  17. Shared and Dynamic Libraries

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Shared and Dynamic Libraries Shared and Dynamic Libraries The Edison system can support applications that use dynamic shared libraries (DSL) on the compute nodes. Some "out-of-the-box" applications require DSLs and some popular applications like Python use DSLs as well. Using System Shared and Dynamic Libraries "System" DSLs include those that support software packages found in "typical" Linux distributions, e.g. Python and Perl. To build an application that will

  18. Shared and Dynamic Libraries

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Shared and Dynamic Libraries Shared and Dynamic Libraries The Hopper system can support applications that use dynamic shared libraries (DSL) on the compute nodes. Some "out-of-the-box" applications require DSLs and some popular applications like Python use DSLs as well. Using System Shared and Dynamic Libraries "System" DSLs include those that support software packages found in "typical" Linux distributions, e.g. Python and Perl. To build an application that will

  19. DETECTION OF WIDESPREAD HYDRATED MATERIALS ON VESTA BY THE VIR IMAGING SPECTROMETER ON BOARD THE DAWN MISSION

    SciTech Connect (OSTI)

    De Sanctis, M. C.; Ammannito, E.; Palomba, E.; Longobardo, A.; Capaccioni, F.; Capria, M. T.; Tosi, F.; Zambon, F.; Carraro, F.; Fonte, S.; Frigeri, A.; Magni, G.; Combe, J.-Ph.; McCord, T. B.; Marchi, S.; Mittlefehldt, D. W.; Pieters, C. M.; Sunshine, J.; Raymond, C. A.; Russell, C. T.; and others

    2012-10-20

    Water plays a key role in the evolution of terrestrial planets, and notably in the occurrence of Earth's oceans. However, the mechanism by which water has been incorporated into these bodies-including Earth-is still extensively debated. Here we report the detection of widespread 2.8 {mu}m OH absorption bands on the surface of the asteroid Vesta by the VIR imaging spectrometer on board Dawn. These observations are surprising as Vesta is fully differentiated with a basaltic surface. The 2.8 {mu}m OH absorption is distributed across Vesta's surface and shows areas enriched and depleted in hydrated materials. The uneven distribution of hydrated mineral phases is unexpected and indicates ancient processes that differ from those believed to be responsible for OH on other airless bodies, like the Moon. The origin of Vestan OH provides new insight into the delivery of hydrous materials in the main belt and may offer new scenarios on the delivery of hydrous minerals in the inner solar system, suggesting processes that may have played a role in the formation of terrestrial planets.

  20. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Frank Rack

    2005-06-30

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were to refine budgets and operational plans for Phase 2 of this cooperative agreement based on the scheduling of a scientific ocean drilling expedition to study marine methane hydrates along the Cascadia margin, in the NE Pacific as part of the Integrated Ocean Drilling Program (IODP) using the R/V JOIDES Resolution. The proposed statement of work for Phase 2 will include three primary tasks: (1) research management oversight, provided by JOI; (2) mobilization, deployment and demobilization of pressure coring and core logging systems, through a subcontract with Geotek Ltd., who will work with Fugro and Lawrence Berkeley National Laboratory to accomplish some of the subtasks; and, (3) mobilization, deployment and demobilization of a refrigerated container van that will be used for degassing of the Pressure Core Sampler and density logging of these pressure cores, through a subcontract with the Texas A&M Research Foundation (TAMRF). More details about these tasks are provided in the following sections of this report. The appendices to this report contain a copy of the scientific prospectus for the upcoming IODP Expedition 311 (Cascadia Margin Hydrates), which provides details of operational and scientific planning for this expedition.

  1. Two-level system in spin baths: Non-adiabatic dynamics and heat transport

    SciTech Connect (OSTI)

    Segal, Dvira

    2014-04-28

    We study the non-adiabatic dynamics of a two-state subsystem in a bath of independent spins using the non-interacting blip approximation, and derive an exact analytic expression for the relevant memory kernel. We show that in the thermodynamic limit, when the subsystem-bath coupling is diluted (uniformly) over many (infinite) degrees of freedom, our expression reduces to known results, corresponding to the harmonic bath with an effective, temperature-dependent, spectral density function. We then proceed and study the heat current characteristics in the out-of-equilibrium spin-spin-bath model, with a two-state subsystem bridging two thermal spin-baths of different temperatures. We compare the behavior of this model to the case of a spin connecting boson baths, and demonstrate pronounced qualitative differences between the two models. Specifically, we focus on the development of the thermal diode effect, and show that the spin-spin-bath model cannot support it at weak (subsystem-bath) coupling, while in the intermediate-strong coupling regime its rectifying performance outplays the spin-boson model.

  2. Online remote control systems for static and dynamic compression and decompression using diamond anvil cells

    SciTech Connect (OSTI)

    Sinogeikin, Stanislav V. Smith, Jesse S.; Rod, Eric; Lin, Chuanlong; Kenney-Benson, Curtis; Shen, Guoyin

    2015-07-15

    The ability to remotely control pressure in diamond anvil cells (DACs) in accurate and consistent manner at room temperature, as well as at cryogenic and elevated temperatures, is crucial for effective and reliable operation of a high-pressure synchrotron facility such as High Pressure Collaborative Access Team (HPCAT). Over the last several years, a considerable effort has been made to develop instrumentation for remote and automated pressure control in DACs during synchrotron experiments. We have designed and implemented an array of modular pneumatic (double-diaphragm), mechanical (gearboxes), and piezoelectric devices and their combinations for controlling pressure and compression/decompression rate at various temperature conditions from 4 K in cryostats to several thousand Kelvin in laser-heated DACs. Because HPCAT is a user facility and diamond cells for user experiments are typically provided by users, our development effort has been focused on creating different loading mechanisms and frames for a variety of existing and commonly used diamond cells rather than designing specialized or dedicated diamond cells with various drives. In this paper, we review the available instrumentation for remote static and dynamic pressure control in DACs and show some examples of their applications to high pressure research.

  3. Thermodynamic analysis of hydration in human serum heme-albumin

    SciTech Connect (OSTI)

    Baroni, Simona; Pariani, Giorgio; Fanali, Gabriella; Longo, Dario; Ascenzi, Paolo; Aime, Silvio; Fasano, Mauro

    2009-07-31

    Ferric human serum heme-albumin (heme-HSA) shows a peculiar nuclear magnetic relaxation dispersion (NMRD) behavior that allows to investigate structural and functional properties. Here, we report a thermodynamic analysis of NMRD profiles of heme-HSA between 20 and 60 {sup o}C to characterize its hydration. NMRD profiles, all showing two Lorentzian dispersions at 0.3 and 60 MHz, were analyzed in terms of modulation of the zero field splitting tensor for the S = {sup 5}/{sub 2} manifold. Values of correlation times for tensor fluctuation ({tau}{sub v}) and chemical exchange of water molecules ({tau}{sub M}) show the expected temperature dependence, with activation enthalpies of -1.94 and -2.46 {+-} 0.2 kJ mol{sup -1}, respectively. The cluster of water molecules located in the close proximity of the heme is progressively reduced in size by increasing the temperature, with {Delta}H = 68 {+-} 28 kJ mol{sup -1} and {Delta}S = 200 {+-} 80 J mol{sup -1} K{sup -1}. These results highlight the role of the water solvent in heme-HSA structure-function relationships.

  4. Gas Hydrate Characterization in the GoM using Marine EM Methods

    SciTech Connect (OSTI)

    Constable, Steven

    2012-03-31

    In spite of the importance of gas hydrate as a low-carbon fuel, a possible contributor to rapid climate change, and a significant natural hazard, our current understanding about the amount and distribution of submarine gas hydrate is somewhat poor; estimates of total volume vary by at least an order of magnitude, and commercially useful concentrations of hydrate have remained an elusive target. This is largely because conventional geophysical tools have intrinsic limitations in their ability to quantitatively image hydrate. It has long been known from well logs that gas hydrate is resistive compared to the host sediments, and electrical and electromagnetic methods have been proposed and occasionally used to image hydrates. This project seeks to expand our capabilities to use electromagnetic methods to explore for gas hydrate in the marine environment. An important basic science aspect of our work was to quantify the resistivity of pure gas hydrate as a function of temperature at seafloor pressures. We designed, constructed, and tested a highpressure cell in which hydrate could be synthesized and then subjected to electrical conductivity measurements. Impedance spectroscopy at frequencies between 20 Hz and 2 MHz was used to separate the effect of the blocking electrodes from the intrinsic conductivity of the hydrate. We obtained very reproducible results that showed that pure methane hydrate was several times more resistive than the water ice that seeded the synthesis, 20,000 {Ohm}m at 0{degrees} C, and that the activation energy is 30.6 kJ/mol over the temperature range of -15 to 15{degrees} C. Adding silica sand to the hydrate, however, showed that the addition of the extra phase caused the conductivity of the assemblage to increase in a counterintuitive way. The fact that the increased conductivity collapsed after a percolation threshold was reached, and that the addition of glass beads does not produce a similar increase in conductivity, together suggest that while the surface of the gas hydrate grains are not intrinsically conductive, the presence of sand does increase their conductivity. In the field component of this project, we carried out an 18day cruise on the R.V. Roger Revelle in the Gulf of Mexico from 7th-26th October 2008 to collect controlled-source electromagnetic (CSEM) data over four hydrate prospects; blocks AC 818, WR 313, GC 955, and MC 118. During these surveys we deployed 30 ocean bottom electromagnetic (OBEM) recorders a total of 94 times at four survey areas and towed the Scripps Undersea Electromagnetic Source Instrument (SUESI) a total of 103 hours. SUESI transmission was 200 A on a 50 m dipole antenna at heights of 70-100 m above the seafloor. We also towed a neutrally buoyant 3-axis electric field recorder behind the SUESI antenna at a constant offset of 300 m. The use of a towed receiver that is "flown" above the seafloor allowed us to operate in areas where seafloor infrastructure such as wellheads, pipelines, and installed scientific equipment existed. We reduced the data to apparent resistivity psuedosections. The most compelling results come from the hydrate observatory at MC 118, where a localized resistivity anomaly is clearly identified under the southeast crater in an otherwise uniform 1 {Ohm}m background. The data from MC 118 also show that authigenic carbonate does not necessarily express itself as a confounding resistor, as was feared at the start of this project. While the results from the other prospects are much more complicated, the data are well correlated with known geology, and line to line agreement is good. Although these data are not amenable to 1D inversion as was initially hoped, we expect to use a newly developed 2D CSEM inversion code to continue to get useful information from this rich data set.

  5. Preliminary potentiometric map and flow dynamic characteristics for the upper-basalt confined aquifer system

    SciTech Connect (OSTI)

    Spane, F.A. Jr.; Raymond, R.G.

    1993-09-01

    This report presents the first comprehensive Hanford Site-wide potentiometric map for the upper-basalt confined aquifer system (i.e., the upper Saddle Mountains Basalt). In constructing the potentiometric map, over forty on-site and off-site monitoring wells and boreholes were used. The potentiometric map developed for the upper-basalt confined aquifer is consistent with the areal head pattern indicated for the Mabton interbed, which is a deeper and more areally extensive confined aquifer underlying the Hanford Site. Salient features for the upper-basalt confined aquifer system potentiometric map are described.

  6. Dynamic reduction of dimensions of a document vector in a document search and retrieval system

    DOE Patents [OSTI]

    Jiao, Yu; Potok, Thomas E.

    2011-05-03

    The method and system of the invention involves processing each new document (20) coming into the system into a document vector (16), and creating a document vector with reduced dimensionality (17) for comparison with the data model (15) without recomputing the data model (15). These operations are carried out by a first computer (11) while a second computer (12) updates the data model (18), which can be comprised of an initial large group of documents (19) and is premised on the computing an initial data model (13, 14, 15) to provide a reference point for determining document vectors from documents processed from the data stream (20).

  7. Integrated dynamic policy management methodology and system for strategic environmental assessment of golf course installation policy in Taiwan

    SciTech Connect (OSTI)

    Chen, Ching-Ho; Liu, Wei-Lin; Liaw, Shu-Liang

    2011-01-15

    Strategic environmental assessment (SEA) focuses primarily on assessing how policies, plans, and programs (PPPs) influence the sustainability of the involved regions. However, the processes of assessing policies and developing management strategies for pollution load and resource use are usually separate in the current SEA system. This study developed a policy management methodology to overcome the defects generated during the above processes. This work first devised a dynamic management framework using the methods of systems thinking, system dynamics, and Managing for Results (MFRs). Furthermore, a driving force-pressure-state-impact-response (DPSIR) indicator system was developed. The golf course installation policy was applied as a case study. Taiwan, counties of Taiwan, and the golf courses within those individual counties were identified as a system, subsystems, and objects, respectively. This study identified an object-linked double-layer framework with multi-stage-option to simultaneously to quantify golf courses in each subsystem and determine ratios of abatement and allocation for pollution load and resource use of each golf course. The DPSIR indicator values for each item of each golf course in each subsystem are calculated based on the options taken in the two decision layers. The summation of indicator values for all items of all golf courses in all subsystems according to various options is defined as the sustainability value of the policy. An optimization model and a system (IDPMS) were developed to obtain the greatest sustainability value of the policy, while golf course quantity, human activity intensity, total quantities of pollution load and resource use are simultaneously obtained. The solution method based on enumeration of multiple bounds for objectives and constraints (EMBOC) was developed for the problem with 1.95 x 10{sup 128} combinations of possible options to solve the optimal solution in ten minutes using a personal computer with 3.0 GHz CPU. This study obtain the policy with the optimal environmental sustainability value in Taiwan is 102 golf courses. Human activity intensity and total quantities of pollution load and resource use which are concurrently obtained are less than those of the existing policy and the existing quantities in 2006. The optimal solution remains unchanged under most sensitivity analysis conditions, unless the weights and constraints are extremely changed. The analytical results indicate that the proposed methodology can be used to assist the authorities for simultaneously generating and assessing the policy during the SEA process.

  8. The Research Path to Determining the Natural Gas Supply Potential of Marine Gas Hydrates

    SciTech Connect (OSTI)

    Boswell, R.M.; Rose, K.K.; Baker, R.C.

    2008-06-01

    A primary goal of the U.S. National Interagency Gas Hydrates R&D program is to determine the natural gas production potential of marine gas hydrates. In pursuing this goal, four primary areas of effort are being conducted in parallel. First, are wide-ranging basic scientific investigations in both the laboratory and in the field designed to advance the understanding of the nature and behavior of gas hydrate bearing sediments (GHBS). This multi-disciplinary work has wide-ranging direct applications to resource recovery, including assisting the development of exploration and production technologies through better rock physics models for GHBS and also in providing key data for numerical simulations of productivity, reservoir geomechanical response, and other phenomena. In addition, fundamental science efforts are essential to developing a fuller understanding of the role gas hydrates play in the natural environment and the potential environmental implications of gas hydrate production, a critical precursor to commercial extraction. A second area of effort is the confirmation of resource presence and viability via a series of multi-well marine drilling expeditions. The collection of data in the field is essential to further clarifying what proportion of the likely immense in-place marine gas hydrate resource exists in accumulations of sufficient quality to represent potential commercial production prospects. A third research focus area is the integration of geologic, geophysical, and geochemical field data into an effective suite of exploration tools that can support the delineation and characterization commercial gas hydrate prospects prior to drilling. The fourth primary research focus is the development and testing of well-based extraction technologies (including drilling, completion, stimulation and production) that can safely deliver commercial gas production rates from gas hydrate reservoirs in a variety of settings. Initial efforts will take advantage of the relatively favorable economics of conducting production tests in Arctic gas-hydrate bearing sandstones with the intent of translating the knowledge gained to later testing in marine sandstone reservoirs. The full and concurrent pusuit of each of these research topics is essential to the determining the future production potential of naturally-occuring gas hydrates.

  9. High-speed multiframe dynamic transmission electron microscope image acquisition system with arbitrary timing

    SciTech Connect (OSTI)

    Reed, Bryan W.; DeHope, William J.; Huete, Glenn; LaGrange, Thomas B.; Shuttlesworth, Richard M.

    2015-10-20

    An electron microscope is disclosed which has a laser-driven photocathode and an arbitrary waveform generator (AWG) laser system ("laser"). The laser produces a train of temporally-shaped laser pulses of a predefined pulse duration and waveform, and directs the laser pulses to the laser-driven photocathode to produce a train of electron pulses. An image sensor is used along with a deflector subsystem. The deflector subsystem is arranged downstream of the target but upstream of the image sensor, and has two pairs of plates arranged perpendicular to one another. A control system controls the laser and a plurality of switching components synchronized with the laser, to independently control excitation of each one of the deflector plates. This allows each electron pulse to be directed to a different portion of the image sensor, as well as to be provided with an independently set duration and independently set inter-pulse spacings.

  10. Dynamic measurement of heat loss coefficients through Trombe wall glazing systems

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1981-01-01

    A Trombe wall presents a unique opportunity to measure the heat-loss coefficient through the glazing system because the wall itself can be used as a heat meter. Since the instantaneous heat flux through the outer wall surface can be determined, the heat loss coefficient at night can be calculated by dividing by the wall surface-to-ambient temperature difference. This technique has been used to determine heat-loss coefficients for Los Alamos test rooms during the winter of 1980-1981. Glazing systems studied include single and double glazing both with and without night insulation used in conjunction with a flat black paint, and both single and double glazing used in conjunction with a selective surface.

  11. Distributed Hierarchical Control Architecture for Transient Dynamics Improvement in Power Systems

    SciTech Connect (OSTI)

    Marinovici, Laurentiu D.; Lian, Jianming; Kalsi, Karanjit; Du, Pengwei; Elizondo, Marcelo A.

    2013-08-24

    In this paper, a novel distributed hierarchical coordinated control architecture is proposed for large scale power systems. The newly considered architecture facilitates frequency restoration and power balancing functions to be decoupled and implemented at different levels. At the local level, decentralized robust generator controllers are designed to quickly restore frequency after large faults and disturbances in the system. The controllers presented herein are shown to improve transient stability performance, as compared to conventional governor and excitation control. At the area level, Automatic Generation Control (AGC) is modified and coordinates with the decentralized robust controllers to reach the interchange schedule in the tie lines. The interaction of local and zonal controllers is validated through detailed simulations.

  12. Retrofit device to improve vapor compression cooling system performance by dynamic blower speed modulation

    DOE Patents [OSTI]

    Roth, Robert Paul; Hahn, David C.; Scaringe, Robert P.

    2015-12-08

    A device and method are provided to improve performance of a vapor compression system using a retrofittable control board to start up the vapor compression system with the evaporator blower initially set to a high speed. A baseline evaporator operating temperature with the evaporator blower operating at the high speed is recorded, and then the device detects if a predetermined acceptable change in evaporator temperature has occurred. The evaporator blower speed is reduced from the initially set high speed as long as there is only a negligible change in the measured evaporator temperature and therefore a negligible difference in the compressor's power consumption so as to obtain a net increase in the Coefficient of Performance.

  13. System dynamics of the competition of municipal solid waste to landfill, electricity, and liquid fuel in California

    SciTech Connect (OSTI)

    Westbrook, Jessica; Malczynski, Leonard A.; Manley, Dawn Kataoka

    2014-03-01

    A quantitative system dynamics model was created to evaluate the economic and environmental tradeoffs between biomass to electricity and to liquid fuel using MSW biomass in the state of California as a case study. From an environmental perspective, landfilling represents the worst use of MSW over time, generating more greenhouse gas (GHG) emissions compared to converting MSW to liquid fuel or to electricity. MSW to ethanol results in the greatest displacement of GHG emissions per dollar spent compared to MSW to electricity. MSW to ethanol could save the state of California approximately $60 billion in energy costs by 2050 compared to landfilling, while also reducing GHG emissions state-wide by approximately 140 million metric tons during that timeframe. MSW conversion to electricity creates a significant cost within the state's electricity sector, although some conversion technologies are cost competitive with existing renewable generation.

  14. SUPPORT OF GULF OF MEXICO HYDRATE RESEARCH CONSORTIUM: ACTIVITIES TO SUPPORT ESTABLISHMENT OF A SEA FLOOR MONITORING STATION PROJECT

    SciTech Connect (OSTI)

    Paul Higley; J. Robert Woolsey; Ralph Goodman; Vernon Asper; Boris Mizaikoff; Angela Davis

    2004-03-01

    A Consortium, designed to assemble leaders in gas hydrates research, has been established at the University of Mississippi's Center for Marine Resources and Environmental Technology, CMRET. The primary objective of the group is to design and emplace a remote monitoring station on the sea floor in the northern Gulf of Mexico by the year 2005, in an area where gas hydrates are known to be present at, or just below, the sea floor. This mission necessitates assembling a station that will monitor physical and chemical parameters of the sea water and sea floor sediments on a more-or-less continuous basis over an extended period of time. Development of the station allows for the possibility of expanding its capabilities to include biological monitoring, as a means of assessing environmental health. Establishment of the Consortium has already succeeded in fulfilling the critical need to coordinate activities, avoid redundancies and communicate effectively among researchers in this relatively new research arena. Complementary expertise, both scientific and technical, has been assembled to innovate research methods and construct necessary instrumentation. As funding for this project, scheduled to commence December 1, 2002, had only been in place for less than half of the reporting period, project progress has been less than for other reporting periods. Nevertheless, significant progress has been made and several cruises are planned for the summer/fall of 2003 to test equipment, techniques and compatibility of systems. En route to reaching the primary goal of the Consortium, the establishment of a monitoring station on the sea floor, the following achievements have been made: (1) Progress on the vertical line array (VLA) of sensors: Software and hardware upgrades to the data logger for the prototype vertical line array, including enhanced programmable gains, increased sampling rates, improved surface communications, Cabling upgrade to allow installation of positioning sensors, Incorporation of capability to map the bottom location of the VLA, Improvements in timing issues for data recording. (2) Sea Floor Probe: The Sea Floor Probe and its delivery system, the Multipurpose sled have been completed; The probe has been modified to penetrate the <1m blanket of hemipelagic ooze at the water/sea floor interface to provide the necessary coupling of the accelerometer with the denser underlying sediments. (3) Electromagnetic bubble detector and counter: Initial tests performed with standard conductivity sensors detected nonconductive objects as small as .6mm, a very encouraging result, Components for the prototype are being assembled, including a dedicated microcomputer to control power, readout and logging of the data, all at an acceptable speed. (4) Acoustic Systems for Monitoring Gas Hydrates: Video recordings of bubbles emitted from a seep in Mississippi Canyon have been made from a submersible dive and the bubbles analyzed with respect to their size, number, and rise rate; these measurements will be used to determine the parameters to build the system capable of measuring gas escaping at the site of the monitoring station; A scattering system and bubble-producing device, being assembled at USM, will be tested in the next two months, and the results compared to a physical scattering model. (5) Mid-Infrared Sensor for Continuous Methane Monitoring: Progress has been made toward minimizing system maintenance through increased capacity and operational longevity, Miniaturization of many components of the sensor systems has been completed, A software package has been designed especially for the MIR sensor data evaluation, Custom electronics have been developed that reduce power consumption and, therefore, increase the length of time the system can remain operational. (6) Seismo-acoustic characterization of sea floor properties and processes at the hydrate monitoring station. (7) Adaptation of the acoustic-logging device, developed as part of the European Union-funded research project, Sub-Gate, for monitoring temporal variations in seabe

  15. DYNAMIC STABILITY OF THE SOLAR SYSTEM: STATISTICALLY INCONCLUSIVE RESULTS FROM ENSEMBLE INTEGRATIONS

    SciTech Connect (OSTI)

    Zeebe, Richard E.

    2015-01-01

    Due to the chaotic nature of the solar system, the question of its long-term stability can only be answered in a statistical sense, for instance, based on numerical ensemble integrations of nearby orbits. Destabilization of the inner planets, leading to close encounters and/or collisions can be initiated through a large increase in Mercury's eccentricity, with a currently assumed likelihood of ?1%. However, little is known at present about the robustness of this number. Here I report ensemble integrations of the full equations of motion of the eight planets and Pluto over 5 Gyr, including contributions from general relativity. The results show that different numerical algorithms lead to statistically different results for the evolution of Mercury's eccentricity (e{sub M}). For instance, starting at present initial conditions (e{sub M}?0.21), Mercury's maximum eccentricity achieved over 5 Gyr is, on average, significantly higher in symplectic ensemble integrations using heliocentric rather than Jacobi coordinates and stricter error control. In contrast, starting at a possible future configuration (e{sub M}?0.53), Mercury's maximum eccentricity achieved over the subsequent 500 Myr is, on average, significantly lower using heliocentric rather than Jacobi coordinates. For example, the probability for e{sub M} to increase beyond 0.53 over 500 Myr is >90% (Jacobi) versus only 40%-55% (heliocentric). This poses a dilemma because the physical evolution of the real systemand its probabilistic behaviorcannot depend on the coordinate system or the numerical algorithm chosen to describe it. Some tests of the numerical algorithms suggest that symplectic integrators using heliocentric coordinates underestimate the odds for destabilization of Mercury's orbit at high initial e{sub M}.

  16. Hydration and strength development of binder based on high-calcium oil shale fly ash

    SciTech Connect (OSTI)

    Freidin, C. [Ben-Gurion Univ. of the Negev, Sede-Boqer (Israel)] [Ben-Gurion Univ. of the Negev, Sede-Boqer (Israel)

    1998-06-01

    The properties of high-calcium oil shale fly ash and low-calcium coal fly ash, which are produced in Israeli power stations, were investigated. High-calcium oil shale fly ash was found to contain a great amount of CaO{sub free} and SO{sub 3} in the form of lime and anhydrite. Mixtures of high-calcium oil shale fly ash and low-calcium coal fly ash, termed fly ash binder, were shown to cure and have improved strength. The influence of the composition and curing conditions on the compressive strength of fly ash binders was examined. The microstructure and the composition of fly ash binder after curing and long-term exposure in moist air, water and open air conditions were studied. It was determined that ettringite is the main variable in the strength and durability of cured systems. The positive effect of calcium silicate hydrates, CSH, which are formed by interaction of high-calcium oil shale fly ash and low-calcium coal fly ash components, on the carbonation and dehydration resistance of fly ash binder in open air is pronounced. It was concluded that high-calcium oil shale fly ash with high CaO{sub free} and SO{sub 3} content can be used as a binder for building products.

  17. Ground movements associated with gas hydrate production. Progress report, April 1, 1992--June 30, 1992

    SciTech Connect (OSTI)

    Siriwardane, H.J.

    1992-12-31

    An obvious consequence of hydrate dissociation is the compression of reservoir matrix causing displacements in the surrounding area. The reservoir compression is a time-dependent process which depends on the production rate. The ground movements cause additional stresses in the overburden which may result in rock mass fracture and failure. Rock failure may cause rubble formation or bulking in the fracture zone. This in turn can cause an increase in permeability for gas flow which may offset the reduction in permeability caused by closure of existing fractures during reservoir compression. The mechanics of ground movements during hydrate production can be more closely simulated by considering similarities with ground movements associated with subsidence in permafrost regions. The purpose of this research work is to investigate the potential strata movements associated with hydrate production by considering similarities with ground movements in permafrost regions. The work primarily involves numerical modeling of subsidence caused by hydrate dissociation. The investigation is based on the theories of continuum mechanics, thermomechanical behavior of frozen geo-materials, principles of rock mechanics and geomechanics. It is expected that some phases of the investigation will involve the use of finite element method, which is a powerful computer-based method which has been widely used in many areas of science and engineering. Parametric studies will be performed to predict expected strata movements and surface subsidence for different reservoir conditions and properties of geological materials. The results from this investigation will be useful in predicting the magnitude of the subsidence problem associated with gas hydrate production. The analogy of subsidence in permafrost regions may provide lower bounds for subsidence expected in hydrate reservoirs. Furthermore, it is anticipated that the results will provide insight into planning of hydrate recovery operations.

  18. Ab initio molecular orbital-configuration interaction based quantum master equation (MOQME) approach to the dynamic first hyperpolarizabilities of asymmetric π-conjugated systems

    SciTech Connect (OSTI)

    Kishi, Ryohei; Fujii, Hiroaki; Minami, Takuya; Shigeta, Yasuteru; Nakano, Masayoshi

    2015-01-22

    In this study, we apply the ab initio molecular orbital - configuration interaction based quantum master equation (MOQME) approach to the calculation and analysis of the dynamic first hyperpolarizabilities (β) of asymmetric π-conjugated molecules. In this approach, we construct the excited state models by the ab initio configuration interaction singles method. Then, time evolutions of system reduced density matrix ρ(t) and system polarization p(t) are calculated by the QME approach. Dynamic β in the second harmonic generation is calculated based on the nonperturbative definition of nonlinear optical susceptibility, using the frequency domain system polarization p(ω). Spatial contributions of electrons to β are analyzed based on the dynamic hyperpolarizability density map, which visualizes the second-order response of charge density oscillating with a frequency of 2ω. We apply the present method to the calculation of the dynamic β of a series of donor/acceptor substituted polyene oligomers, and then discuss the applicability of the MOQME method to the calculation and analysis of dynamic NLO properties of molecular systems.

  19. Energy Department Advances Research on Methane Hydrates – the World’s Largest Untapped Fossil Energy Resource

    Broader source: Energy.gov [DOE]

    Projects to research the nature and occurrence of deepwater and arctic gas hydrates and its potential for dramatically expanding U.S. energy supplies

  20. Policy Strategies and Paths to promote Sustainable Energy Systems- The dynamic Invert Simulation Tool

    SciTech Connect (OSTI)

    Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

    2006-05-01

    The European Union has established a number of targetsregarding energy efficiency, Renewable Energy Sources (RES) and CO2reductions as the 'GREEN PAPER on Energy Efficiency', the Directive for'promotion of the use of bio-fuels or other renewable fuels fortransport' or 'Directive of the European Parliament of the Council on thepromotion of cogeneration based on a useful heat demand in the internalenergy market'. A lot of the according RES and RUE measures are notattractive for investors from an economic point of view. Thereforegovernmentsall over the world have to spend public money to promotethese technologies/measures to bring them into market. These expenditureshave to be adjusted to budget concerns and should be spent mostefficiently. Therefore, the spent money has to be dedicated totechnologies and efficiency measures with the best yield in CO2 reductionwithout wasting money. The core question: "How can public money - forpromoting sustainable energy systems - be spent most efficiently toreduce GHG-emissions?" has been well investigated by the European projectInvert. In course of this project a simulation tool has been designed toanswer this core question. This paper describes the modelling with theInvert simulation tool and shows the key features necessary forsimulating the energy system. A definition of 'Promotion SchemeEfficiency' is given which allows estimating the most cost effectivetechnologies and/or efficiency measures to reduce CO2 emissions.Investigations performed with the Invert simulation tool deliver anoptimum portfolio mix of technologies and efficiency measures for eachselected region. Within Invert seven European regions were simulated andfor the Austrian case study the detailed portfolio mix is shown andpolitical conclusions are derived.

  1. Guest Molecule Exchange Kinetics for the 2012 Ignik Sikumi Gas Hydrate Field Trial

    SciTech Connect (OSTI)

    White, Mark D.; Lee, Won Suk

    2014-05-14

    A commercially viable technology for producing methane from natural gas hydrate reservoirs remains elusive. Short-term depressurization field tests have demonstrated the potential for producing natural gas via dissociation of the clathrate structure, but the long-term performance of the depressurization technology ultimately requires a heat source to sustain the dissociation. A decade of laboratory experiments and theoretical studies have demonstrated the exchange of pure CO2 and N2-CO2 mixtures with CH4 in sI gas hydrates, yielding critical information about molecular mechanisms, recoveries, and exchange kinetics. Findings indicated the potential for producing natural gas with little to no production of water and rapid exchange kinetics, generating sufficient interest in the guest-molecule exchange technology for a field test. In 2012 the U.S. DOE/NETL, ConocoPhillips Company, and Japan Oil, Gas and Metals National Corporation jointly sponsored the first field trial of injecting a mixture of N2-CO2 into a CH4-hydrate bearing formation beneath the permafrost on the Alaska North Slope. Known as the Ignik Sikumi #1 Gas Hydrate Field Trial, this experiment involved three stages: 1) the injection of a N2-CO2 mixture into a targeted hydrate-bearing layer, 2) a 4-day pressurized soaking period, and 3) a sustained depressurization and fluid production period. Data collected during the three stages of the field trial were made available after an extensive quality check. These data included continuous temperature and pressure logs, injected and recovered fluid compositions and volumes. The Ignik Sikumi #1 data set is extensive, but contains no direct evidence of the guest-molecule exchange process. This investigation is directed at using numerical simulation to provide an interpretation of the collected data. A numerical simulator, STOMP-HYDT-KE, was recently completed that solves conservation equations for energy, water, mobile fluid guest molecules, and hydrate guest molecules, for up to three gas hydrate guest molecules: CH4, CO2, and N2. The independent tracking of mobile fluid and hydrate guest molecules allows for the kinetic exchange of guest molecules between the mobile fluids and hydrate. The particular interest of this numerical investigation is to determine whether kinetic exchange parameters, determined from laboratory-scale experiments, are directly applicable to interpreting the Ignik Sikumi #1 data.

  2. Dynamic Response of an Optomechanical System to a Stationary Random Excitation in the Time Domain

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Palmer, Jeremy A.; Paez, Thomas L.

    2011-01-01

    Modern electro-optical instruments are typically designed with assemblies of optomechanical members that support optics such that alignment is maintained in service environments that include random vibration loads. This paper presents a nonlinear numerical analysis that calculates statistics for the peak lateral response of optics in an optomechanical sub-assembly subject to random excitation of the housing. The work is unique in that the prior art does not address peak response probability distribution for stationary random vibration in the time domain for a common lens-retainer-housing system with Coulomb damping. Analytical results are validated by using displacement response data from random vibration testingmore » of representative prototype sub-assemblies. A comparison of predictions to experimental results yields reasonable agreement. The Type I Asymptotic form provides the cumulative distribution function for peak response probabilities. Probabilities are calculated for actual lens centration tolerances. The probability that peak response will not exceed the centration tolerance is greater than 80% for prototype configurations where the tolerance is high (on the order of 30 micrometers). Conversely, the probability is low for those where the tolerance is less than 20 micrometers. The analysis suggests a design paradigm based on the influence of lateral stiffness on the magnitude of the response.« less

  3. Theory for dynamical self arrest and gelation in microemulsions and the block copolymer systems

    SciTech Connect (OSTI)

    Wu, Sangwook

    2005-05-01

    The main purpose of this work is to investigate the glassy behavior of microemulsions and block copolymers. The origin of glassy behavior in microemulsions and block copolymers is frustration due to a competition between short-range interaction and long range interaction. According to the charge frustrated Ising model, the competition between ferromagnetic interaction and antiferromagnetic interaction is the origin of frustration in microemulsions. The competition between entropic effects and stoichiometric constraints responsible for the formation of micelles in microemulsions can lead to the emergence of a self generated glassy behavior in these systems. In the block copolymer, the competition between the repulsive short range interaction between monomers in polymer chains and the long range interaction by chemical bonds can lead to the emergence of a self generated glassy behavior. The criteria for the fluctuation induced first order transition and our microemulsion and block copolymer glasses are essentially the same. Both are a consequence of the large phase space of low energy excitations (14) (62) (all states with momenta q which fulfill |q| = q{sub m}) and are of at the most a moderate supercooling of the liquid state is required. This is strongly supported by the observation in Ref. (14) that the metastable states which are first to appear at a fluctuation induced first order transition are the ones build by a superposition of large amplitude waves of wavenumber q{sub m}, but with random orientations and phases, i.e. just the ones which form the metastable states of our microemulsion and block copolymer glass. (38)

  4. ANALYTICAL MODELS OF EXOPLANETARY ATMOSPHERES. I. ATMOSPHERIC DYNAMICS VIA THE SHALLOW WATER SYSTEM

    SciTech Connect (OSTI)

    Heng, Kevin; Workman, Jared E-mail: jworkman@coloradomesa.edu

    2014-08-01

    Within the context of exoplanetary atmospheres, we present a comprehensive linear analysis of forced, damped, magnetized shallow water systems, exploring the effects of dimensionality, geometry (Cartesian, pseudo-spherical, and spherical), rotation, magnetic tension, and hydrodynamic and magnetic sources of friction. Across a broad range of conditions, we find that the key governing equation for atmospheres and quantum harmonic oscillators are identical, even when forcing (stellar irradiation), sources of friction (molecular viscosity, Rayleigh drag, and magnetic drag), and magnetic tension are included. The global atmospheric structure is largely controlled by a single key parameter that involves the Rossby and Prandtl numbers. This near-universality breaks down when either molecular viscosity or magnetic drag acts non-uniformly across latitude or a poloidal magnetic field is present, suggesting that these effects will introduce qualitative changes to the familiar chevron-shaped feature witnessed in simulations of atmospheric circulation. We also find that hydrodynamic and magnetic sources of friction have dissimilar phase signatures and affect the flow in fundamentally different ways, implying that using Rayleigh drag to mimic magnetic drag is inaccurate. We exhaustively lay down the theoretical formalism (dispersion relations, governing equations, and time-dependent wave solutions) for a broad suite of models. In all situations, we derive the steady state of an atmosphere, which is relevant to interpreting infrared phase and eclipse maps of exoplanetary atmospheres. We elucidate a pinching effect that confines the atmospheric structure to be near the equator. Our suite of analytical models may be used to develop decisively physical intuition and as a reference point for three-dimensional magnetohydrodynamic simulations of atmospheric circulation.

  5. IN-SITU SAMPLING AND CHARACTERIZATION OF NATURALLY OCCURRING MARINE METHANE HYDRATE USING THE D/V JOIDES RESOLUTION

    SciTech Connect (OSTI)

    Frank R. Rack

    2004-05-01

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) Frank Rack presented preliminary results and operational outcomes of ODP Leg 204 at the DOE/NETL project review and two made two presentations at the ChevronTexaco Gulf of Mexico Hydrate JIP meeting, which were both held in Westminster, CO; and, (2) postcruise evaluation of the data, tools and measurement systems that were used during ODP Leg 204 continued in the preparation of deliverables under this agreement. Work continued on analyzing data collected during ODP Leg 204 and preparing reports on the outcomes of Phase 1 projects as well as developing plans for Phase 2.

  6. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

    SciTech Connect (OSTI)

    Rutqvist, J.; Moridis, G.J.; Grover, T.; Collett, T.

    2009-02-01

    In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900 m at the Mallik and 600 m at the Mount Elbert. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure.

  7. Infrared signature of micro-hydration in the organophosphate sarin: An ab initio study

    SciTech Connect (OSTI)

    Alam, Todd M.; Pearce, Charles Joseph

    2015-06-28

    The infrared (IR) spectra of micro-hydrated Sarin•(H2O)n clusters containing between one and four explicit waters have been studied using ab initio density functional theory (DFT) methods. The phosphate group P=O bond vibration region (~1270 to 1290 cm–1) revealed the largest frequency variation with hydration, with a frequency red shift reflecting the direct hydrogen bond formation between the P=O of Sarin and water. Small variations to the P-F stretch (~810 to 815 cm–1) and the C-O-P vibrational modes (~995 to 1004 cm–1) showed that the water interactions with these functional groups were minor, and that the structures of Sarin were not extensively perturbed in the hydrated complexes. Increasing the number of explicit hydration waters produced only small vibrational changes in the lowest free energy complexes. These minor changes were consistent with a single water-phosphate hydrogen bond being the dominant structure, though a second water-phosphate hydrogen bond was observed in some complexes and was identified by an additional red shift of the P=O bond vibration. As a result, the H2O•H2O vibrational modes (~3450 to 3660 cm–1) increased in complexity with higher hydration levels and reflect the extended hydrogen bonding networks formed between the explicit waters in the hydrated Sarin clusters.

  8. Design of Isotope Heat Source for Automatic Modular Dispersal During Reentry, and Its Integration with Heat Exchangers of 6-kWe Dynamic Isotope Power System

    SciTech Connect (OSTI)

    Schock, Alfred

    1989-01-01

    In late 1986 the Air Force Space Division (AF / SD) had expressed an interest in using a Dynamic Isotope Power System (DIPS) of approximately 6-kWe to power the Boost Surveillance and Tacking System (BSTS) satellites. In support of that objective, the U.S. Department of Energy (DOE) requested Fairchild Space Company to perform a conceptual design study of the DIPS heat source and of its integration with the dynamic power conversion system, with particular emphasis on system safety. This paper describes the results of that study. The study resulted in a design for a single heat source of ~30-kWt, employing the standard 250-W General Purpose Heat Source (GPHS) modules which DOE had previously developed and safety-tested for Radioisotope Thermoelectric Generators (RTS's)

  9. Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, Xiaojing; Nelson, Johanna; Kirz, Janos; Lima, Enju; Marchesini, Stefano; Miao, Huijie; Neiman, Aaron M.; Shapiro, David; Steinbrener, Jan; Stewart, Andrew; et al

    2009-11-01

    We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 °C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.

  10. GULF OF MEXICO SEAFLOOR STABILITY AND GAS HYDRATE MONITORING STATION PROJECT

    SciTech Connect (OSTI)

    J. Robert Woolsey; Thomas M. McGee; Robin C. Buchannon

    2004-11-01

    The gas hydrates research Consortium (HRC), established and administered at the University if Mississippi's Center for Marine Research and Environmental Technology (CMRET) has been active on many fronts in FY 03. Extension of the original contract through March 2004, has allowed completion of many projects that were incomplete at the end of the original project period due, primarily, to severe weather and difficulties in rescheduling test cruises. The primary objective of the Consortium, to design and emplace a remote sea floor station for the monitoring of gas hydrates in the Gulf of Mexico by the year 2005 remains intact. However, the possibility of levering HRC research off of the Joint Industries Program (JIP) became a possibility that has demanded reevaluation of some of the fundamental assumptions of the station format. These provisions are discussed in Appendix A. Landmark achievements of FY03 include: (1) Continuation of Consortium development with new researchers and additional areas of research contribution being incorporated into the project. During this period, NOAA's National Undersea Research Program's (NURP) National Institute for Undersea Science and Technology (NIUST) became a Consortium funding partner, joining DOE and Minerals Management Service (MMS); (2) Very successful annual and semiannual meetings in Oxford Mississippi in February and September, 2003; (3) Collection of piston cores from MC798 in support of the effort to evaluate the site for possible monitoring station installation; (4) Completion of the site evaluation effort including reports of all localities in the northern Gulf of Mexico where hydrates have been documented or are strongly suspected to exist on the sea floor or in the shallow subsurface; (5) Collection and preliminary evaluation of vent gases and core samples of hydrate from sites in Green Canyon and Mississippi Canyon, northern Gulf of Mexico; (6) Monitoring of gas activity on the sea floor, acoustically and thermally; (7) Design, construction, and successful deployment of an in situ pore-water sampling device; (8) Improvements to the original Raman spectrometer (methane sensor); (9) Laboratory demonstration of the impact of bacterially-produced surfactants' rates of hydrate formation; (10) Construction and sea floor emplacement and testing--with both watergun and ship noise sources--of the prototypal vertical line array (VLA); (11) Initiation of studies of spatial controls on hydrates; (12) Compilation and analyses of seismic data, including mapping of surface anomalies; (13) Additional field verification (bottom samples recovered), in support of the site selection effort; (14) Collection and preliminary analyses of gas hydrates from new sites that exhibit variant structures; (15) Initial shear wave tests carried out in shallow water; (16) Isolation of microbes for potential medicinal products development; (17) Preliminary modeling of occurrences of gas hydrates.

  11. Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell

    SciTech Connect (OSTI)

    Huang Xiaojing; Nelson, Johanna; Lima, Enju; Miao, Huijie; Steinbrener, Jan; Stewart, Andrew; Turner, Joshua J.; Jacobsen, Chris; Kirz, Janos; Marchesini, Stefano; Shapiro, David; Neiman, Aaron M.

    2009-11-06

    We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 deg. C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.

  12. Solvent vapor recovery by pressure swing adsorption. 1: Experimental transient and periodic dynamics of the butane-activated carbon system

    SciTech Connect (OSTI)

    Liu, Y.; Holland, C.E.; Ritter, J.A.

    1998-11-01

    An experimental investigation was carried out for the separation and recovery of butane vapor (10 to 40 vol%) from nitrogen using Westvaco BAX activated carbon in a twin-bed pressure swing adsorption (PSA) system utilizing a 4-step Skarstrom-type cycle. Twenty-four runs, covering a broad range of process and initial column conditions, were performed to investigate the transient and period process dynamics. In all cases the approach to the periodic state was very slow, taking up to 160 cycles depending on the initial condition of the beds; and peak bed temperatures of up to 105 C were observed depending on both the initial condition of the beds and the process conditions. Also, the periodic state of each run was unique when approaching a new periodic state from less contaminated beds. The uniqueness of the periodic states, together with the exceedingly high peak temperatures, inferred much about the practice of preconditioning beds to avoid high temperature excursions. The periodic enriched butane vapor concentration histories also gave considerable insight into new cycle designs for improved solvent vapor enrichment.

  13. Coherent pulse interrogation system for fiber Bragg grating sensing of strain and pressure in dynamic extremes of materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, George; Jaime, Marcelo; Balakirev, Fedor; Mielke, Chuck H.; Azad, Abul; Marshall, Bruce; La Lone, Brandon M.; Henson, Bryan; Smilowitz, Laura

    2015-05-21

    A 100 MHz fiber Bragg grating (FBG) interrogation system is described and applied to strain and pressure sensing. The approach relies on coherent pulse illumination of the FBG sensor with a broadband short pulse from a femtosecond modelocked erbium fiber laser. After interrogation of the FBG sensor, a long multi-kilometer run of single mode fiber is used for chromatic dispersion to temporally stretch the spectral components of the reflected pulse from the FBG sensor. Dynamic strain or pressure induced spectral shifts in the FBG sensor are detected as a pulsed time domain waveform shift after encoding by the chromatic dispersivemoreline. Signals are recorded using a single 35 GHz photodetector and a 50 G Samples per second, 25 GHz bandwidth, digitizing oscilloscope. Application of this approach to high-speed strain sensing in magnetic materials in pulsed magnetic fields to ~150 T is demonstrated. The FBG wavelength shifts are used to study magnetic field driven magnetostriction effects in LaCoO?. A sub-microsecond temporal shift in the FBG sensor wavelength attached to the sample under first order phase change appears as a fractional length change (strain: ?L/Lless

  14. Protein Dynamics and Biocatalysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    biocatalysis.gif A model of the Michaelis complex for the TEM-1penicillin system from molecular dynamics simulations. Investigators: P. A. Bash, Northwestern University Medical...

  15. Fundamentals of Natural Gas and Species Flows from Hydrate Dissociation - Applications to Safety and Sea Floor Instability

    SciTech Connect (OSTI)

    Goodarz Ahmadi

    2006-09-30

    Semi-analytical computational models for natural gas flow in hydrate reservoirs were developed and the effects of variations in porosity and permeability on pressure and temperature profiles and the movement of a dissociation front were studied. Experimental data for variations of gas pressure and temperature during propane hydrate formation and dissociation for crushed ice and mixture of crushed ice and glass beads under laboratory environment were obtained. A thermodynamically consistent model for multiphase liquid-gas flows trough porous media was developed. Numerical models for hydrate dissociation process in one dimensional and axisymmetric reservoir were performed. The computational model solved the general governing equations without the need for linearization. A detail module for multidimensional analysis of hydrate dissociation which make use of the FLUENT code was developed. The new model accounts for gas and liquid water flow and uses the Kim-Boshnoi model for hydrate dissociation.

  16. Support of Gulf of Mexico Hydrate Research Consortium: Activities to Support Establishment of a Sea Floor Monitoring Station Project

    SciTech Connect (OSTI)

    Carol Lutken

    2006-09-30

    The Gulf of Mexico Hydrates Research Consortium (GOM-HRC) was established in 1999 to assemble leaders in gas hydrates research. The Consortium is administered by the Center for Marine Resources and Environmental Technology, CMRET, at the University of Mississippi. The primary objective of the group is to design and emplace a remote monitoring station or sea floor observatory (MS/SFO) on the sea floor in the northern Gulf of Mexico by the year 2007, in an area where gas hydrates are known to be present at, or just below, the sea floor. This mission, although unavoidably delayed by hurricanes and other disturbances, necessitates assembling a station that will monitor physical and chemical parameters of the marine environment, including sea water and sea-floor sediments, on a more-or-less continuous basis over an extended period of time. In 2005, biological monitoring, as a means of assessing environmental health, was added to the mission of the MS/SFO. Establishment of the Consortium has succeeded in fulfilling the critical need to coordinate activities, avoid redundancies and communicate effectively among researchers in the arena of gas hydrates research. Complementary expertise, both scientific and technical, has been assembled to promote innovative research methods and construct necessary instrumentation. The observatory has now achieved a microbial dimension in addition to the geophysical, geological, and geochemical components it had already included. Initial components of the observatory, a probe that collects pore-fluid samples and another that records sea floor temperatures, were deployed in Mississippi Canyon 118 in May of 2005. Follow-up deployments, planned for fall 2005, had to be postponed due to the catastrophic effects of Hurricane Katrina (and later, Rita) on the Gulf Coast. Station/observatory completion, anticipated for 2007, will likely be delayed by at least one year. The CMRET has conducted several research cruises during this reporting period: one in April, one in June, one in September. April's effort was dedicated to surveying the mound at MC118 with the Surface-Source-Deep-Receiver (SSDR) seismic surveying system. This survey was completed in June and water column and bottom samples were collected via box coring. A microbial filtering system developed by Consortium participants at the University of Georgia was also deployed, run for {approx}12 hours and retrieved. The September cruise, designed to deploy, test, and in some cases recover, geochemical and microbial instruments and experiments took place aboard Harbor Branch's Seward Johnson and employed the Johnson SeaLink manned submersible. The seafloor monitoring station/observatory is funded approximately equally by three federal Agencies: Minerals Management Services (MMS) of the Department of the Interior (DOI), National Energy Technology Laboratory (NETL) of the Department of Energy (DOE), and the National Institute for Undersea Science and Technology (NIUST), an agency of the National Oceanographic and Atmospheric Administration (NOAA). Subcontractors with FY03 funding fulfilled their technical reporting requirements in a previously submitted report (41628R10). Only unresolved matching funds issues remain and will be addressed in the report of the University of Mississippi's Office of Research and Sponsored Programs. In addition, Barrodale Computing Services Ltd. (BCS) completed their work; their final report is the bulk of the semiannual report that precedes (abstract truncated)

  17. Method and apparatus for routing data in an inter-nodal communications lattice of a massively parallel computer system by dynamically adjusting local routing strategies

    DOE Patents [OSTI]

    Archer, Charles Jens; Musselman, Roy Glenn; Peters, Amanda; Pinnow, Kurt Walter; Swartz, Brent Allen; Wallenfelt, Brian Paul

    2010-03-16

    A massively parallel computer system contains an inter-nodal communications network of node-to-node links. Each node implements a respective routing strategy for routing data through the network, the routing strategies not necessarily being the same in every node. The routing strategies implemented in the nodes are dynamically adjusted during application execution to shift network workload as required. Preferably, adjustment of routing policies in selective nodes is performed at synchronization points. The network may be dynamically monitored, and routing strategies adjusted according to detected network conditions.

  18. Anomalous dynamics of aqueous solutions of di-propylene glycol methylether confined in MCM-41 by quasielastic neutron scattering

    SciTech Connect (OSTI)

    Swenson, Jan Elamin, Khalid; Chen, Guo; Lohstroh, Wiebke; Sakai, Victoria Garcia

    2014-12-07

    The molecular dynamics of solutions of di-propylene glycol methylether (2PGME) and H{sub 2}O (or D{sub 2}O) confined in 28 Å pores of MCM-41 have been studied by quasielastic neutron scattering and differential scanning calorimetry over the concentration range 0–90 wt.% water. This system is of particular interest due to its pronounced non-monotonic concentration dependent dynamics of 2PGME in the corresponding bulk system, showing the important role of hydrogen bonding for the dynamics. In this study we have elucidated how this non-monotonic concentration dependence is affected by the confined geometry. The results show that this behaviour is maintained in the confinement, but the slowest diffusive dynamics of 2PGME is now observed at a considerably higher water concentration; at 75 wt.% water in MCM-41 compared to 30 wt.% water in the corresponding bulk system. This difference can be explained by an improper mixing of the two confined liquids. The results suggest that water up to a concentration of about 20 wt.% is used to hydrate the hydrophilic hydroxyl surface groups of the silica pores, and that it is only at higher water contents the water becomes partly mixed with 2PGME. Hence, due to this partial micro-phase separation of the two liquids larger, and thereby slower relaxing, structural entities of hydrogen bonded water and 2PGME molecules can only be formed at higher water contents than in the bulk system. However, the Q-dependence is unchanged with confinement, showing that the nature of the molecular motions is preserved. Thus, there is no indication of localization of the dynamics at length scales of less than 20 Å. The dynamics of both water and 2PGME is strongly dominated by translational diffusion at a temperature of 280 K.

  19. Direct visualization of the hydration layer on alumina nanoparticles with the fluid cell STEM in situ

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Firlar, Emre; Çınar, Simge; Kashyap, Sanjay; Akinc, Mufit; Prozorov, Tanya

    2015-05-21

    Rheological behavior of aqueous suspensions containing nanometer-sized powders is of relevance to many branches of industry. Unusually high viscosities observed for suspensions of nanoparticles compared to those of micron size powders cannot be explained by current viscosity models. Formation of so-called hydration layer on alumina nanoparticles in water was hypothesized, but never observed experimentally. We report here on the direct visualization of aqueous suspensions of alumina with the fluid cell in situ. We observe the hydration layer formed over the particle aggregates and show that such hydrated aggregates constitute new particle assemblies and affect the flow behavior of the suspensions.more » We discuss how these hydrated nanoclusters alter the effective solid content and the viscosity of nanostructured suspensions. As a result, our findings elucidate the source of high viscosity observed for nanoparticle suspensions and are of direct relevance to many industrial sectors including materials, food, cosmetics, pharmaceutical among others employing colloidal slurries with nanometer-scale particles.« less

  20. Pf1 bacteriophage hydration by magic angle spinning solid-state NMR

    SciTech Connect (OSTI)

    Sergeyev, Ivan V.; Bahri, Salima; McDermott, Ann E.; Day, Loren A.

    2014-12-14

    High resolution two- and three-dimensional heteronuclear correlation spectroscopy ({sup 1}H–{sup 13}C, {sup 1}H–{sup 15}N, and {sup 1}H–{sup 13}C–{sup 13}C HETCOR) has provided a detailed characterization of the internal and external hydration water of the Pf1 virion. This long and slender virion (2000 nm × 7 nm) contains highly stretched DNA within a capsid of small protein subunits, each only 46 amino acid residues. HETCOR cross-peaks have been unambiguously assigned to 25 amino acids, including most external residues 1–21 as well as residues 39–40 and 43–46 deep inside the virion. In addition, the deoxyribose rings of the DNA near the virion axis are in contact with water. The sets of cross-peaks to the DNA and to all 25 amino acid residues were from the same hydration water {sup 1}H resonance; some of the assigned residues do not have exchangeable side-chain protons. A mapping of the contacts onto structural models indicates the presence of water “tunnels” through a highly hydrophobic region of the capsid. The present results significantly extend and modify results from a lower resolution study, and yield a comprehensive hydration surface map of Pf1. In addition, the internal water could be distinguished from external hydration water by means of paramagnetic relaxation enhancement. The internal water population may serve as a conveniently localized magnetization reservoir for structural studies.

  1. Quasichemical analysis of the cluster-pair approximation for the thermodynamics of proton hydration

    SciTech Connect (OSTI)

    Pollard, Travis; Beck, Thomas L.

    2014-06-14

    A theoretical analysis of the cluster-pair approximation (CPA) is presented based on the quasichemical theory of solutions. The sought single-ion hydration free energy of the proton includes an interfacial potential contribution by definition. It is shown, however, that the CPA involves an extra-thermodynamic assumption that does not guarantee uniform convergence to a bulk free energy value with increasing cluster size. A numerical test of the CPA is performed using the classical polarizable AMOEBA force field and supporting quantum chemical calculations. The enthalpy and free energy differences are computed for the kosmotropic Na{sup +}/F{sup −} ion pair in water clusters of size n = 5, 25, 105. Additional calculations are performed for the chaotropic Rb{sup +}/I{sup −} ion pair. A small shift in the proton hydration free energy and a larger shift in the hydration enthalpy, relative to the CPA values, are predicted based on the n = 105 simulations. The shifts arise from a combination of sequential hydration and interfacial potential effects. The AMOEBA and quantum chemical results suggest an electrochemical surface potential of water in the range −0.4 to −0.5 V. The physical content of single-ion free energies and implications for ion-water force field development are also discussed.

  2. Balanced-activity improved inverse emulsion to inhibit brittle lutite hydration in oil fields

    SciTech Connect (OSTI)

    Olmedo, E. P.; de J. Hernandez Alvarez, R.; Barrera, C. D.; Ramos, J. D. G.

    1984-10-02

    An improved inverse emulsion for use as a drilling fluid that inhibits brittle lutite hydration. The emulsion includes a heavy oil; brine; a viscosity agent with thermostabilizing properties; an emulsifying agent; a thickening agent; a gelatinizing additive; and an alkaline earth metal hydroxide. The emulsion avoids hole collapsing and improves well gage stability.

  3. HYDRATE v1.5 OPTION OF TOUGH+ v1.5 () | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    HYDRATE v1.5 needs the TOUGH+ v1.5 core code in order to compile and execute. It is ... Other Software Info: This is an option of the TOUGH+ V1.5 Core Code. It is non-functional ...

  4. Expedition Provides New Insight on Gas Hydrates in Gulf of Mexico

    Broader source: Energy.gov [DOE]

    A joint-federal-agency 15 day research expedition in the northern Gulf of Mexico yielded innovative high-resolution seismic data and imagery that will help refine characterizations of large methane hydrate resources in the U.S. Outer Continental Shelf.

  5. New Project To Improve Characterization of U.S. Gas Hydrate Resources

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy today announced the selection of a multi-year, field-based research project designed to gain further insight into the nature, formation, occurrence and physical properties of methane hydrate‐bearing sediments for the purpose of methane hydrate resource appraisal.

  6. Modeling the Gila-San Francisco Basin using system dynamics in support of the 2004 Arizona Water Settlement Act.

    SciTech Connect (OSTI)

    Tidwell, Vincent Carroll; Sun, Amy Cha-Tien; Peplinski, William J.; Klise, Geoffrey Taylor

    2012-04-01

    Water resource management requires collaborative solutions that cross institutional and political boundaries. This work describes the development and use of a computer-based tool for assessing the impact of additional water allocation from the Gila River and the San Francisco River prescribed in the 2004 Arizona Water Settlements Act. Between 2005 and 2010, Sandia National Laboratories engaged concerned citizens, local water stakeholders, and key federal and state agencies to collaboratively create the Gila-San Francisco Decision Support Tool. Based on principles of system dynamics, the tool is founded on a hydrologic balance of surface water, groundwater, and their associated coupling between water resources and demands. The tool is fitted with a user interface to facilitate sensitivity studies of various water supply and demand scenarios. The model also projects the consumptive use of water in the region as well as the potential CUFA (Consumptive Use and Forbearance Agreement which stipulates when and where Arizona Water Settlements Act diversions can be made) diversion over a 26-year horizon. Scenarios are selected to enhance our understanding of the potential human impacts on the rivers ecological health in New Mexico; in particular, different case studies thematic to water conservation, water rights, and minimum flow are tested using the model. The impact on potential CUFA diversions, agricultural consumptive use, and surface water availability are assessed relative to the changes imposed in the scenarios. While it has been difficult to gage the acceptance level from the stakeholders, the technical information that the model provides are valuable for facilitating dialogues in the context of the new settlement.

  7. Determination of the magnetic contribution to the heat capacity of cobalt oxide nanoparticles and the thermodynamic properties of the hydration layers

    SciTech Connect (OSTI)

    Spencer, Elinor; Ross, Dr. Nancy; Parker, Stewart F.; Woodfield, Brian; Boerio-Goates, Juliana; Smith, S. J.; Olsen, R. E.; Kolesnikov, Alexander I; Navrotsky, Alexandra; Ma, C

    2011-01-01

    We present low temperature (11 K) inelastic neutron scattering (INS) data on four hydrated nanoparticle systems: 10 nm CoO 0.10H2O (1), 16 nmCo3O4 0.40H2O (2), 25 nm Co3O4 0.30H2O (3) and 40 nmCo3O4 0.026H2O (4). The vibrational densities of states were obtained for all samples and from these the isochoric heat capacity and vibrational energy for the hydration layers confined to the surfaces of these nanoparticle systems have been elucidated. The results show that water on the surface of CoO nanoparticles is more tightly bound than water confined to the surface of Co3O4, and this is reflected in the reduced heat capacity and vibrational entropy for water on CoO relative to water on Co3O4 nanoparticles. This supports the trend, seen previously, for water to be more tightly bound in materials with higher surface energies. The INS spectra for the antiferromagnetic Co3O4 particles (2 4) also show sharp and intense magnetic excitation peaks at 5 meV, and from this the magnetic contribution to the heat capacity of Co3O4 nanoparticles has been calculated; this represents the first example of use of INS data for determining the magnetic contribution to the heat capacity of any magnetic nanoparticle system.

  8. Dynamical principles in neuroscience

    SciTech Connect (OSTI)

    Rabinovich, Mikhail I.; Varona, Pablo; Selverston, Allen I.; Abarbanel, Henry D. I.

    2006-10-15

    Dynamical modeling of neural systems and brain functions has a history of success over the last half century. This includes, for example, the explanation and prediction of some features of neural rhythmic behaviors. Many interesting dynamical models of learning and memory based on physiological experiments have been suggested over the last two decades. Dynamical models even of consciousness now exist. Usually these models and results are based on traditional approaches and paradigms of nonlinear dynamics including dynamical chaos. Neural systems are, however, an unusual subject for nonlinear dynamics for several reasons: (i) Even the simplest neural network, with only a few neurons and synaptic connections, has an enormous number of variables and control parameters. These make neural systems adaptive and flexible, and are critical to their biological function. (ii) In contrast to traditional physical systems described by well-known basic principles, first principles governing the dynamics of neural systems are unknown. (iii) Many different neural systems exhibit similar dynamics despite having different architectures and different levels of complexity. (iv) The network architecture and connection strengths are usually not known in detail and therefore the dynamical analysis must, in some sense, be probabilistic. (v) Since nervous systems are able to organize behavior based on sensory inputs, the dynamical modeling of these systems has to explain the transformation of temporal information into combinatorial or combinatorial-temporal codes, and vice versa, for memory and recognition. In this review these problems are discussed in the context of addressing the stimulating questions: What can neuroscience learn from nonlinear dynamics, and what can nonlinear dynamics learn from neuroscience?.

  9. SUPPORT OF GULF OF MEXICO HYDRATE RESEARCH CONSORTIUM: ACTIVITIES TO SUPPORT ESTABLISHMENT OF A SEA FLOOR MONITORING STATION PROJECT

    SciTech Connect (OSTI)

    Paul Higley; J. Robert Woolsey; Ralph Goodman; Vernon Asper; Boris Mizaikoff; Angela Davis

    2005-09-01

    A Consortium, designed to assemble leaders in gas hydrates research, has been established at the University of Mississippi's Center for Marine Resources and Environmental Technology, CMRET. The primary objective of the group is to design and emplace a remote monitoring station on the sea floor in the northern Gulf of Mexico by the year 2005, in an area where gas hydrates are known to be present at, or just below, the sea floor. This mission necessitates assembling a station that will monitor physical and chemical parameters of the sea water and sea floor sediments on a more-or-less continuous basis over an extended period of time. Development of the station allows for the possibility of expanding its capabilities to include biological monitoring, as a means of assessing environmental health. Establishment of the Consortium has succeeded in fulfilling the critical need to coordinate activities, avoid redundancies and communicate effectively among researchers in this relatively new research arena. Complementary expertise, both scientific and technical, has been assembled to promote innovative research methods and construct necessary instrumentation. Noteworthy achievements six months into the extended life of this cooperative agreement include: (1) Progress on the vertical line array (VLA) of sensors: Analysis and repair attempts of the VLA used in the deep water deployment during October 2003 have been completed; Definition of an interface protocol for the VLA DATS to the SFO has been established; Design modifications to allow integration of the VLA to the SFO have been made; Experience gained in the deployments of the first VLA is being applied to the design of the next VLAs; One of the two planned new VLAs being modified to serve as an Oceanographic Line Array (OLA). (2) Progress on the Sea Floor Probe: The decision to replace the Sea Floor Probe technology with the borehole emplacement of a geophysical array was reversed due to the 1300m water depth at the JIP selected borehole site. The SFP concept has been revisited as a deployment technique for the subsea floor array; The SFP has been redesigned to include gravity driven emplacement of an array up to 10m into the shallow subsurface of the sea floor. (3) Progress on the Acoustic Systems for Monitoring Gas Hydrates: Video recordings of bubbles emitted from a seep in Mississippi Canyon have been analyzed for effects of currents and temperature changes; Several acoustic monitoring system concepts have been evaluated for their appropriateness to MC118, i.e., on the deep sea floor; A mock-up system was built but was rejected as too impractical for deployment on the sea floor. (4) Progress on the Electromagnetic Bubble Detector and Counter: The initial Inductive Conductivity Cell has been constructed from components acquired during the previous reporting period; Laboratory tests involving measuring bubble volume as a component of conductivity have been performed; The laboratory tests were performed in a closed system, under controlled conditions; the relationship between voltage and bubble volume appears to be linear. (5) Progress on the Mid-Infrared Sensor for Continuous Methane Monitoring: Designs and construction schematics for all electronic mounting pieces and an electronics system baseplate were finalized after extensive modeling to facilitate the successful fabrication and implementation of electronic components into the deep-sea, glass instrument housing; Construction schematics and fabrication of an electronics system baseplate have been completed with successful integration of all currently fabricated electronic mounting pieces; Modeling and design of an optics platform complementary to the constructed electronics platform for successful incorporation into ''sphereIR'' has commenced; A second generation chemometric data evaluation software package for evaluating complex spectra including corrections for baseline drifts and spectral anomalies resulting from matrix substances has been developed and will be incorporated into an optimized ''deepSniff'' program upon c

  10. Toward Production From Gas Hydrates: Current Status, Assessment of Resources, and Simulation-Based Evaluationof Technology and Potential

    SciTech Connect (OSTI)

    Reagan, Matthew; Moridis, George J.; Collett, Timothy; Boswell, Ray; Kurihara, M.; Reagan, Matthew T.; Koh, Carolyn; Sloan, E. Dendy

    2008-02-12

    Gas hydrates are a vast energy resource with global distribution in the permafrost and in the oceans. Even if conservative estimates are considered and only a small fraction is recoverable, the sheer size of the resource is so large that it demands evaluation as a potential energy source. In this review paper, we discuss the distribution of natural gas hydrate accumulations, the status of the primary international R&D programs, and the remaining science and technological challenges facing commercialization of production. After a brief examination of gas hydrate accumulations that are well characterized and appear to be models for future development and gas production, we analyze the role of numerical simulation in the assessment of the hydrate production potential, identify the data needs for reliable predictions, evaluate the status of knowledge with regard to these needs, discuss knowledge gaps and their impact, and reach the conclusion that the numerical simulation capabilities are quite advanced and that the related gaps are either not significant or are being addressed. We review the current body of literature relevant to potential productivity from different types of gas hydrate deposits, and determine that there are consistent indications of a large production potential at high rates over long periods from a wide variety of hydrate deposits. Finally, we identify (a) features, conditions, geology and techniques that are desirable in potential production targets, (b) methods to maximize production, and (c) some of the conditions and characteristics that render certain gas hydrate deposits undesirable for production.

  11. Anomalous porosity preservation and preferential accumulation of gas hydrate in the Andaman accretionary wedge, NGHP-01 site 17A

    SciTech Connect (OSTI)

    Rose, Kelly K.; Johnson, Joel E.; Torres, Marta E.; Hong, WeiLi; Giosan, Liviu; Solomon, E.; Kastner, Miriam; Cawthern, Thomas; Long, Philip E.; Schaef, Herbert T.

    2014-12-01

    In addition to well established properties that control the presence or absence of the hydrate stability zone, such as pressure, temperature, and salinity, additional parameters appear to influence the concentration of gas hydrate in host sediments. The stratigraphic record at Site 17A in the Andaman Sea, eastern Indian Ocean, illustrates the need to better understand the role pore-scale phenomena play in the distribution and presence of marine gas hydrates in a variety of subsurface settings. In this paper we integrate field-generated datasets with newly acquired sedimentology, physical property, imaging and geochemical data with mineral saturation and ion activity products of key mineral phases such as amorphous silica and calcite, to document the presence and nature of secondary precipitates that contributed to anomalous porosity preservation at Site 17A in the Andaman Sea. This study demonstrates the importance of grain-scale subsurface heterogeneities in controlling the occurrence and distribution of concentrated gas hydrate accumulations in marine sediments, and document the importance that increased permeability and enhanced porosity play in supporting gas concentrations sufficient to support gas hydrate formation. The grain scale relationships between porosity, permeability, and gas hydrate saturation documented at Site 17A likely offer insights into what may control the occurrence and distribution of gas hydrate in other sedimentary settings.

  12. Permeability of laboratory-formed methane-hydrate-bearing sand: Measurements and observations using x-ray computed tomography

    SciTech Connect (OSTI)

    Kneafsey, T. J.; Seol, Y.; Gupta, A.; Tomutsa, L.

    2010-09-15

    Methane hydrate was formed in two moist sands and a sand/silt mixture under a confining stress in an X-ray-transparent pressure vessel. Three initial water saturations were used to form three different methane-hydrate saturations in each medium. X-ray computed tomography (CT) was used to observe location-specific density changes caused by hydrate formation and flowing water. Gas-permeability measurements in each test for the dry, moist, frozen, and hydrate-bearing states are presented. As expected, the effective permeabilities (intrinsic permeability of the medium multiplied by the relative permeability) of the moist sands decreased with increasing moisture content. In a series of tests on a single sample, the effective permeability typically decreased as the pore space became more filled, in the order of dry, moist, frozen, and hydrate-bearing. In each test, water was flowed through the hydrate-bearing medium and we observed the location-specific changes in water saturation using CT scanning. We compared our data to a number of models, and our relative permeability data compare most favorably with models in which hydrate occupies the pore bodies rather than the pore throats. Inverse modeling (using the data collected from the tests) will be performed to extend the relative permeability measurements.

  13. Kinetic inhibition of natural gas hydrates in offshore drilling, production, and processing. Annual report, January 1--December 31, 1994

    SciTech Connect (OSTI)

    1994-12-31

    Natural gas hydrates are crystalline materials formed of natural gas and water at elevated pressures and reduced temperatures. Because natural gas hydrates can plug drill strings, pipelines, and process equipment, there is much effort expended to prevent their formation. The goal of this project was to provide industry with more economical hydrate inhibitors. The specific goals for the past year were to: define a rational approach for inhibitor design, using the most probable molecular mechanism; improve the performance of inhibitors; test inhibitors on Colorado School of Mines apparatuses and the Exxon flow loop; and promote sharing field and flow loop results. This report presents the results of the progress on these four goals.

  14. Equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride

    SciTech Connect (OSTI)

    Majumdar, A.; Mahmoodaghdam, E.; Bishnoi, P.R.

    2000-02-01

    Natural gas components such as hydrogen sulfide, carbon dioxide, and ethane form gas hydrates of structure I under suitable temperature and pressure conditions. Information on such conditions is vital to the oil and gas industry in order to design and operate processing equipment and pipelines so that hydrate formation is avoided. Incipient equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride were experimentally obtained in the temperature range 264--290 K and the pressure range 0.23--3.18 MPa. A variable-volume sapphire cell was used for the measurements.

  15. HEAT OF HYDRATION OF SALTSTONE MIXES-MEASUREMENT BY ISOTHERMAL CALORIMETRY

    SciTech Connect (OSTI)

    Harbour, J; Vickie Williams, V; Tommy Edwards, T

    2007-07-02

    This report provides initial results on the measurement of heat of hydration of Saltstone mixes using isothermal calorimetry. The results were obtained using a recently purchased TAM Air Model 3116 Isothermal Conduction Calorimeter. Heat of hydration is an important property of Saltstone mixes. Greater amounts of heat will increase the temperature of the curing mix in the vaults and limit the processing rate. The heat of hydration also reflects the extent of the hydraulic reactions that turn the fluid mixture into a ''stone like'' solid and consequently impacts performance properties such as permeability. Determining which factors control these reactions, as monitored by the heat of hydration, is an important goal of the variability study. Experiments with mixes of portland cement in water demonstrated that the heats measured by this technique over a seven day period match very well with the literature values of (1) seven day heats of hydration using the standard test method for heat of hydration of hydraulic cement, ASTM C 186-05 and (2) heats of hydration measured using isothermal calorimetry. The heats of hydration of portland cement or blast furnace slag in a Modular Caustic Side Solvent Extraction Unit (MCU) simulant revealed that if the cure temperature is maintained at 25 C, the amount of heat released over a seven day period is roughly 62% less than the heat released by portland cement in water. Furthermore, both the blast furnace slag and the portland cement were found to be equivalent in heat production over the seven day period in MCU. This equivalency is due to the activation of the slag by the greater than 1 Molar free hydroxide ion concentration in the simulant. Results using premix (a blend of 10% cement, 45% blast furnace slag, and 45% fly ash) in MCU, Deliquification, Dissolution and Adjustment (DDA) and Salt Waste Processing Facility (SWPF) simulants reveal that the fly ash had not significantly reacted (undergone hydration reactions) after seven days (most likely less than 5%). There were clear differences in the amount of heat released and the peak times of heat release for the three different simulants. It turns out that SWPF simulant mixes give off greater heat than does MCU and DDA simulant mixes. The temperature dependence of the heat of hydration was measured by carrying out these measurements at 25, 40 and 55 C. In general, the peak times shifted to shorter times as the isothermal temperature increased and the amount of heat released was independent of temperature for DDA and MCU but slightly higher at higher temperatures for SWPF. The goal of this study is to apply this technique to the measurement of the heat of hydration of mixes that will be made as part of the variability study. It is important to understand which variables will impact (and to what extent) the amount of heat generated and the peak times for the heat release. Those variables that can be controlled can then be tuned to adjust the heat of hydration as long as the other properties are still acceptable. The first application of heat of hydration measurements to the variability study was completed and the results presented in this report. These measurements were made using Phase VI mixes (SWPF simulants) following a statistical design that included variation in the compositional and operational variables. Variation in both the amount of heat released and the peak times for the heat release were observed. The measured ranges were 23 Joules per gram of premix for the heat release and 23 hours for the peak time of heat release at 25 C. Linear models with high R{sup 2} values and no statistical evidence for lack of fit were developed that relate the amount of heat release and the peak time for heat release for the Phase VI mixes to certain variables. The amount of heat released was a function of the aluminate and portland cement concentrations as well as the temperature of mixing. The peak time for heat release was a function of aluminate, portland cement and total nitrate plus nitrite concentrations. A comparison was made of the measured values of heat release by isothermal calorimetry to a previous study of the measurement of the heat of hydration using adiabatic calorimetry by Steimke and Fowler. After 80 hours of reaction time, the two techniques provided heat release results that were roughly in the same range. However, additional experiments at higher isothermal temperatures will be required to see how well the two measurements agree for longer times. This is due to the higher temperatures that are experienced in adiabatic calorimetry ({approx}105 C).

  16. SUPPORT OF GULF OF MEXICO HYDRATE RESEARCH CONSORTIUM: ACTIVITIES TO SUPPORT ESTABLISHMENT OF A SEA FLOOR MONITORING STATION PROJECT

    SciTech Connect (OSTI)

    Paul Higley; J. Robert Woolsey; Ralph Goodman; Vernon Asper; Boris Mizaikoff; Angela Davis

    2005-08-01

    A Consortium, designed to assemble leaders in gas hydrates research, has been established at the University of Mississippi's Center for Marine Resources and Environmental Technology, CMRET. The primary objective of the group is to design and emplace a remote monitoring station on the sea floor in the northern Gulf of Mexico by the year 2005, in an area where gas hydrates are known to be present at, or just below, the sea floor. This mission necessitates assembling a station that will monitor physical and chemical parameters of the sea water and sea floor sediments on a more-or-less continuous basis over an extended period of time. Development of the station allows for the possibility of expanding its capabilities to include biological monitoring, as a means of assessing environmental health. Establishment of the Consortium has succeeded in fulfilling the critical need to coordinate activities, avoid redundancies and communicate effectively among researchers in this relatively new research arena. Complementary expertise, both scientific and technical, has been assembled to innovate research methods and construct necessary instrumentation. A year into the life of this cooperative agreement, we note the following achievements: (1) Progress on the vertical line array (VLA) of sensors: (A) Software and hardware upgrades to the data logger for the prototype vertical line array, including enhanced programmable gains, increased sampling rates, improved surface communications, (B) Cabling upgrade to allow installation of positioning sensors, (C) Adaptation of SDI's Angulate program to use acoustic slant ranges and DGPS data to compute and map the bottom location of the vertical array, (D) Progress in T''0'' delay and timing issues for improved control in data recording, (E) Successful deployment and recovery of the VLA twice during an October, 2003 cruise, once in 830m water, once in 1305m water, (F) Data collection and recovery from the DATS data logger, (G) Sufficient energy supply and normal functioning of the pressure compensated battery even following recharge after the first deployment, (H) Survival of the acoustic modem following both deployments though it was found to have developed a slow leak through the transducer following the second deployment due, presumably, to deployment in excess of 300m beyond its rating. (2) Progress on the Sea Floor Probe: (A) The Sea Floor Probe and its delivery system, the Multipurpose sled have been completed, (B) The probe has been modified to penetrate the <1m blanket of hemipelagic ooze at the water/sea floor interface to provide the necessary coupling of the accelerometer with the denser underlying sediments, (C) The MPS has been adapted to serve as an energy source for both p- and s-wave studies at the station as well as to deploy the horizontal line arrays and the SFP. (3) Progress on the Electromagnetic Bubble Detector and Counter: (A) Components for the prototype have been assembled, including a dedicated microcomputer to control power, readout and logging of the data, all at an acceptable speed, (B) The prototype has been constructed and preliminary data collected, (C) The construction of the field system is underway. (4) Progress on the Acoustic Systems for Monitoring Gas Hydrates: (A) Video recordings of bubbles emitted from a seep in Mississippi Canyon have been made from a submersible dive and the bubbles analyzed with respect to their size, number, and rise rate. These measurements have been used to determine the parameters to build the system capable of measuring gas escaping at the site of the monitoring station, (B) Laboratory tests performed using the project prototype have produced a conductivity data set that is being used to refine parameters of the field model. (5) Progress on the Mid-Infrared Sensor for Continuous Methane Monitoring: (A) Preliminary designs of mounting pieces for electrical components of ''sphereIR'' have been completed using AutoCAD software, (B) The preliminary design of an electronics baseplate has been completed and aided in the optimization of

  17. Drilling and Production Testing the Methane Hydrate Resource Potential Associated with the Barrow Gas Fields

    SciTech Connect (OSTI)

    Steve McRae; Thomas Walsh; Michael Dunn; Michael Cook

    2010-02-22

    In November of 2008, the Department of Energy (DOE) and the North Slope Borough (NSB) committed funding to develop a drilling plan to test the presence of hydrates in the producing formation of at least one of the Barrow Gas Fields, and to develop a production surveillance plan to monitor the behavior of hydrates as dissociation occurs. This drilling and surveillance plan was supported by earlier studies in Phase 1 of the project, including hydrate stability zone modeling, material balance modeling, and full-field history-matched reservoir simulation, all of which support the presence of methane hydrate in association with the Barrow Gas Fields. This Phase 2 of the project, conducted over the past twelve months focused on selecting an optimal location for a hydrate test well; design of a logistics, drilling, completion and testing plan; and estimating costs for the activities. As originally proposed, the project was anticipated to benefit from industry activity in northwest Alaska, with opportunities to share equipment, personnel, services and mobilization and demobilization costs with one of the then-active exploration operators. The activity level dropped off, and this benefit evaporated, although plans for drilling of development wells in the BGF's matured, offering significant synergies and cost savings over a remote stand-alone drilling project. An optimal well location was chosen at the East Barrow No.18 well pad, and a vertical pilot/monitoring well and horizontal production test/surveillance well were engineered for drilling from this location. Both wells were designed with Distributed Temperature Survey (DTS) apparatus for monitoring of the hydrate-free gas interface. Once project scope was developed, a procurement process was implemented to engage the necessary service and equipment providers, and finalize project cost estimates. Based on cost proposals from vendors, total project estimated cost is $17.88 million dollars, inclusive of design work, permitting, barging, ice road/pad construction, drilling, completion, tie-in, long-term production testing and surveillance, data analysis and technology transfer. The PRA project team and North Slope have recommended moving forward to the execution phase of this project.

  18. Molecular dynamics study of interfacial confinement effects of aqueous NaCl brines in nanoporous carbon

    SciTech Connect (OSTI)

    Wander, M. C. F.; Shuford, K. L.

    2010-12-09

    In this paper, studies of aqueous electrolyte solutions in contact with a family of porous carbon geometries using classical molecular dynamics simulations are presented. These simulations provide an atomic scale depiction of ion transport dynamics in different environments to elucidate power of aqueous electrolyte supercapacitors. The electrolyte contains alkali metal and halide ions, which allow for the examination of size trends within specific geometries as well as trends in concentration. The electrode pores are modeled as planar graphite sheets and carbon nanotubes with interstices ranging from one to four nanometers. Ordered layers form parallel to the carbon surface, which facilitates focused ion motion under slightly confining conditions. As a result, the ions diffusivities are enhanced in the direction of the slit or pore. Further confining the system leads to decreased ion diffusivities. The ions are fully hydrated in all but the smallest slits and pores with those sizes showing increased ion pairing. There is strong evidence of charge separation perpendicular to the surface at all size scales, concentrations, and ion types, providing a useful baseline for examining differential capacitance behavior and future studies on energy storage. These systems show promise as high-power electrical energy storage devices.

  19. Dynamics of confined reactive water in Smectic clay-zeolite composites.

    SciTech Connect (OSTI)

    Pitman, Michael C.; Van Duin, Adri C. T.

    2012-01-01

    The dynamics of water confined to mesoporous regions in minerals such as swelling clays and zeolites is fundamental to a wide range of resource management issues impacting many processes on a global scale, including radioactive waste containment, desalination, and enhanced oil recovery. Large-scale atomic models of freely diffusing multilayer smectite particles at low hydration confined in a silicalite cage are used to investigate water dynamics in the composite environment with the ReaxFF reactive force field over a temperature range of 300 647 K. The reactive capability of the force field enabled a range of relevant surface chemistry to emerge, including acid/base equilibria in the interlayer calcium hydrates and silanol formation on the edges of the clay and inner surface of the zeolite housing. After annealing, the resulting clay models exhibit both mono- and bilayer hydration structures. Clay surface hydration redistributed markedly and yielded to silicalite water loading. We find that the absolute rates and temperature dependence of water dynamics compare well to neutron scattering data and pulse field gradient measures from relevant samples of Ca-montmorillonite and silicalite, respectively. Within an atomistic, reactive context, our results distinguish water dynamics in the interlayer Ca(OH)2 nH2O environment from water flowing over the clay surface, and from water diffusing within silicalite. We find that the diffusion of water when complexed to Ca hydrates is considerably slower than freely diffusing water over the clay surface, and the reduced mobility is well described by a difference in the Arrhenius pre-exponential factor rather than a change in activation energy.

  20. Dynamics of confined reactive water in smectite clay-zeolite composites

    SciTech Connect (OSTI)

    Pitman, Michael C.; Van Duin, Adri C. T.

    2012-01-01

    The dynamics of water confined to mesoporous regions in minerals such as swelling clays and zeolites is fundamental to a wide range of resource management issues impacting many processes on a global scale, including radioactive waste containment, desalination, and enhanced oil recovery. Large-scale atomic models of freely diffusing multilayer smectite particles at low hydration confined in a silicalite cage are used to investigate water dynamics in the composite environment with the ReaxFF reactive force field over a temperature range of 300 647 K. The reactive capability of the force field enabled a range of relevant surface chemistry to emerge, including acid/base equilibria in the interlayer calcium hydrates and silanol formation on the edges of the clay and inner surface of the zeolite housing. After annealing, the resulting clay models exhibit both mono- and bilayer hydration structures. Clay surface hydration redistributed markedly and yielded to silicalite water loading. We find that the absolute rates and temperature dependence of water dynamics compare well to neutron scattering data and pulse field gradient measures from relevant samples of Ca-montmorillonite and silicalite, respectively. Within an atomistic, reactive context, our results distinguish water dynamics in the interlayer Ca(OH)2 nH2O environment from water flowing over the clay surface, and from water diffusing within silicalite. We find that the diffusion of water when complexed to Ca hydrates is considerably slower than freely diffusing water over the clay surface, and the reduced mobility is well described by a difference in the Arrhenius pre-exponential factor rather than a change in activation energy.

  1. Kinetic inhibition of natural gas hydrates in offshore drilling, production, and processing. Annual report, January 1--December 31, 1993

    SciTech Connect (OSTI)

    1993-12-31

    Natural gas hydrates are crystalline materials formed of natural gas and water at elevated pressures and reduced temperatures. Because natural gas hydrates can plug drill strings, pipelines, and process equipment, there is much effort expended to prevent their formation. The goal of this project was to provide industry with more economical hydrate inhibitors. The specific goals for the past year were to: continue both screening and high pressure experiments to determine optimum inhibitors; investigate molecular mechanisms of hydrate formation/inhibition, through microscopic and macroscopic experiments; begin controlled tests on the Exxon pilot plant loop at their Houston facility; and continue to act as a forum for the sharing of field test results. Progress on these objectives are described in this report.

  2. Characterizing Natural Gas Hydrates in the Deep Water Gulf of Mexico: Applications for Safe Exploration and Production Activities

    SciTech Connect (OSTI)

    Bent, Jimmy

    2014-05-31

    In 2000 Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deep water portion of the Gulf of Mexico (GOM). Chevron is an active explorer and operator in the Gulf of Mexico and is aware that natural gas hydrates need to be understood to operate safely in deep water. In August 2000 Chevron worked closely with the National Energy Technology Laboratory (NETL) of the United States Department of Energy (DOE) and held a workshop in Houston, Texas to define issues concerning the characterization of natural gas hydrate deposits. Specifically, the workshop was meant to clearly show where research, the development of new technologies, and new information sources would be of benefit to the DOE and to the oil and gas industry in defining issues and solving gas hydrate problems in deep water.

  3. DOE THREE-DIMENSIONAL STRUCTURE AND PHYSICAL PROPERTIES OF A METHANE HYDRATE DEPOSIT AND GAS RESERVOIR, BLAKE RIDGE

    SciTech Connect (OSTI)

    W. Steven Holbrook

    2004-11-11

    This report contains a summary of work conducted and results produced under the auspices of award DE-FC26-00NT40921, ''DOE Three-Dimensional Structure and Physical Properties of a Methane Hydrate Deposit and Gas Reservoir, Blake Ridge.'' This award supported acquisition, processing, and interpretation of two- and three-dimensional seismic reflection data over a large methane hydrate reservoir on the Blake Ridge, offshore South Carolina. The work supported by this project has led to important new conclusions regarding (1) the use of seismic reflection data to directly detect methane hydrate, (2) the migration and possible escape of free gas through the hydrate stability zone, and (3) the mechanical controls on the maximum thickness of the free gas zone and gas escape.

  4. Low-power, ultrafast, and dynamic all-optical tunable plasmonic analog to electromagnetically induced transparency in two resonators side-coupled with a waveguide system

    SciTech Connect (OSTI)

    Wang, Boyun; Wang, Tao Li, Xiaoming; Han, Xu; Zhu, Youjiang

    2015-06-07

    We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmonic analog to electromagnetically induced transparency (EIT) in two nanodisk resonators side-coupled to a metal-insulator-metal plasmonic waveguide system. The optical Kerr effect is enhanced by the slow light effect of the plasmonic EIT-like effect and the plasmonic waveguide based on graphene-Ag composite material structures with giant effective Kerr nonlinear coefficient. The optical Kerr effect modulation method is applied to improve tuning rate with response time of subpicoseconds or even femtoseconds. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the plasmonic EIT-like system is achieved under excitation of a pump light with an intensity as low as 5.85 MW/cm{sup 2}. The group delay is controlled between 0.09 and 0.4 ps. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Results show a new direction toward the low power consumption and ultrafast responses of integration plasmonic photonic devices and all-optical dynamical storage of light devices in optical communication and quantum information processing.

  5. The Importance of Hydration | U.S. DOE Office of Science (SC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Importance of Hydration Advanced Scientific Computing Research (ASCR) ASCR Home About Research Facilities Science Highlights Benefits of ASCR Funding Opportunities Advanced Scientific Computing Advisory Committee (ASCAC) Community Resources Contact Information Advanced Scientific Computing Research U.S. Department of Energy SC-21/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-7486 F: (301) 903-4846 E: Email Us More Information » 08.01.15 The Importance of

  6. A coarse-graining approach for molecular simulation that retains the dynamics of the all-atom reference system by implementing hydrodynamic interactions

    SciTech Connect (OSTI)

    Markutsya, Sergiy; Lamm, Monica H.

    2014-11-07

    We report on a new approach for deriving coarse-grained intermolecular forces that retains the frictional contribution that is often discarded by conventional coarse-graining methods. The approach is tested for water and an aqueous glucose solution, and the results from the new implementation for coarse-grained molecular dynamics simulation show remarkable agreement with the dynamics obtained from reference all-atom simulations. The agreement between the structural properties observed in the coarse-grained and all-atom simulations is also preserved. We discuss how this approach may be applied broadly to any existing coarse-graining method where the coarse-grained models are rigorously derived from all-atom reference systems.

  7. Formation of magnesium silicate hydrate (M-S-H) cement pastes using sodium hexametaphosphate

    SciTech Connect (OSTI)

    Zhang, Tingting; Vandeperre, Luc J.; Cheeseman, Christopher R.

    2014-11-15

    Magnesium silicate hydrate (M-S-H) gel is formed by the reaction of brucite with amorphous silica during sulphate attack in concrete and M-S-H is therefore regarded as having limited cementing properties. The aim of this work was to form M-S-H pastes, characterise the hydration reactions and assess the resulting properties. It is shown that M-S-H pastes can be prepared by reacting magnesium oxide (MgO) and silica fume (SF) at low water to solid ratio using sodium hexametaphosphate (NaHMP) as a dispersant. Characterisation of the hydration reactions by x-ray diffraction and thermogravimetric analysis shows that brucite and M-S-H gel are formed and that for samples containing 60 wt.% SF and 40 wt.% MgO all of the brucites react with SF to form M-S-H gel. These M-S-H cement pastes were found to have compressive strengths in excess of 70 MPa.

  8. Computational Fluid Dynamics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    scour-tracc-cfd TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling Computational Fluid Dynamics Overview of CFD: Video Clip with Audio Computational fluid dynamics (CFD) research uses mathematical and computational models of flowing fluids to describe and predict fluid response in problems of interest, such as the flow of air around a moving vehicle or the flow of water and sediment in a river. Coupled with appropriate and prototypical

  9. Protein Dynamics and Biocatalysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Protein Dynamics and Biocatalysis Protein Dynamics and Biocatalysis 1998 Annual Report Grand Challenge Projects biocatalysis.gif A model of the Michaelis complex for the TEM-1/penicillin system from molecular dynamics simulations. Investigators: P. A. Bash, Northwestern University Medical School and M. Karplus, Harvard University Research Objectives A guiding principle of molecular biology is that the structure of a biomolecule defines its function. This principle is especially true in the case

  10. IN-SITU SAMPLING AND CHARACTERIZATION OF NATURALLY OCCURRING MARINE METHANE HYDRATE USING THE D/V JOIDES RESOLUTION

    SciTech Connect (OSTI)

    Frank R. Rack; Tim Francis; Peter Schultheiss; Philip E. Long; Barry M. Freifeld

    2005-04-01

    The primary activities accomplished during this quarter were continued efforts to develop plans for Phase 2 of this cooperative agreement based on the evolving operational planning for IODP Expedition 311, which will use the JOIDES Resolution to study marine methane hydrates along the Cascadia margin, offshore Vancouver Island. IODP Expedition 311 has been designed to further constrain the models for the formation of marine gas hydrate in subduction zone accretionary prisms. The objectives include characterizing the deep origin of the methane, its upward transport, its incorporation in gas hydrate, and its subsequent loss to the seafloor. The main attention of this expedition is on the widespread seafloor-parallel layer of dispersed gas hydrate located just above the base of the predicted stability field. In a gas hydrate formation model, methane is carried upward through regional sediment or small-scale fracture permeability, driven by the tectonic consolidation of the accretionary prism. The upward moving methane is incorporated into the gas hydrate clathrate as it enters the methane hydrate stability zone. Also important is the focusing of a portion of the upward methane flux into localized plumes or channels to form concentrations of near-seafloor gas hydrate. The amount of gas hydrate in local concentrations near the seafloor is especially important for understanding the response of marine gas hydrate to climate change. The expedition includes coring and downhole measurements at five sites across the Northern Cascadia accretionary prism. The sites will track the history of methane in an accretionary prism from (1) its production by mainly microbiological processes over a thick sediment vertical extent, (2) its upward transport through regional or locally focused fluid flow, (3) its incorporation in the regional hydrate layer above the BSR or in local concentrations at or near the seafloor, (4) methane loss from the hydrate by upward diffusion, and (5) methane oxidation and incorporation in seafloor carbonate, or expulsion to the ocean. This expedition builds on the previous Cascadia gas hydrate drilling of ODP Leg 146 and on more recent ODP Leg 204 off Oregon. Important experiments being considered for DOE/NETL funding as part of the JOI cooperative agreement include, (1) Logging-While-Drilling/Measurements-While-Drilling (LWD/MWD), (2) Pressure Core Sampling (PCS/HYACINTH) of gas hydrate, and fluid recovery under in situ conditions, (3) X-ray CT logging of whole cores under in situ conditions, and (4) Infrared thermal imaging of whole round cores to map temperature variations resulting from the presence of hydrate. Preliminary budget estimates have been made for each of these tasks and discussions are ongoing with DOE/NETL program managers to develop a final plan that can be implemented within the constraints of the available funding and logistical considerations.

  11. Tethered catalysts for the hydration of carbon dioxide

    DOE Patents [OSTI]

    Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

    2014-11-04

    A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

  12. Building Conceptual Models of Field-Scale Uranium Reactive Transport in a Dynamic Vadose Zone-Aquifer-River System

    SciTech Connect (OSTI)

    Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.

    2008-12-04

    Subsurface simulation is being used to build, test, and couple conceptual process models to better understand controls on a 0.4 km by 1.0 km uranium plume that has persisted above the drinking water standard in the groundwater of the Hanford 300 Area over the last 15 years. At this site, uranium-contaminated sediments in the vadose zone and aquifer are subject to significant variations in water levels and velocities driven by the diurnal, weekly, seasonal, and episodic Columbia River stage dynamics. Groundwater flow reversals typically occur twice a day with significant exchange of river water and groundwater in the near-river aquifer. Mixing of the dilute solution chemistry of the river with the groundwater complicates the uranium sorption behavior as the mobility of U(VI) has been shown experimentally to be a function of pH, carbonate, calcium, and uranium. Furthermore, uranium mass transfer between solid and aqueous phases has been observed to be rate-limited in the context of the high groundwater velocities resulting from the river stage fluctuations and the highly transmissive sediments (hydraulic conductivities ~1500 m/d). One- and two-dimensional vertical cross-sectional simulations of variably-saturated flow and reactive transport, based on laboratory-derived models of distributed rate mass transfer and equilibrium multicomponent surface complexation, are used to assess uranium transport at the dynamic vadose zone aquifer interface as well as changes to uranium mobility due to incursions of river water into the aquifer.

  13. The linear and nonlinear response of infinite periodic systems to static and/or dynamic electric fields. Implementation in CRYSTAL code

    SciTech Connect (OSTI)

    Kirtman, Bernard; Springborg, Michael; Rérat, Michel; Ferrero, Mauro; Lacivita, Valentina; Dovesi, Roberto; Orlando, Roberto

    2015-01-22

    An implementation of the vector potential approach (VPA) for treating the response of infinite periodic systems to static and dynamic electric fields has been initiated within the CRYSTAL code. The VPA method is based on the solution of a time-dependent Hartree-Fock or Kohn-Sham equation for the crystal orbitals wherein the usual scalar potential, that describes interaction with the field, is replaced by the vector potential. This equation may be solved either by perturbation theory or by finite field methods. With some modification all the computational procedures of molecular ab initio quantum chemistry can be adapted for periodic systems. Accessible properties include the linear and nonlinear responses of both the nuclei and the electrons. The programming of static field pure electronic (hyper)polarizabilities has been successfully tested. Dynamic electronic (hyper)polarizabilities, as well as infrared and Raman intensities, are in progress while the addition of finite fields for calculation of vibrational (hyper)polarizabilities, through nuclear relaxation procedures, will begin shortly.

  14. validation and Enhancement of Computational Fluid Dynamics and Heat Transfer Predictive Capabilities for Generation IV Reactor Systems

    SciTech Connect (OSTI)

    Robert E. Spall; Barton Smith; Thomas Hauser

    2008-12-08

    Nationwide, the demand for electricity due to population and industrial growth is on the rise. However, climate change and air quality issues raise serious questions about the wisdom of addressing these shortages through the construction of additional fossil fueled power plants. In 1997, the President's Committee of Advisors on Science and Technology Energy Research and Development Panel determined that restoring a viable nuclear energy option was essential and that the DOE should implement a R&D effort to address principal obstacles to achieving this option. This work has addressed the need for improved thermal/fluid analysis capabilities, through the use of computational fluid dynamics, which are necessary to support the design of generation IV gas-cooled and supercritical water reactors.

  15. Review of the findings of the Ignik Sikumi CO2-CH4 gas hydrate exchange field trial

    SciTech Connect (OSTI)

    Anderson, Brian J.; Boswell, Ray; Collett, Tim S.; Farrell, Helen; Ohtsuka, Satoshi; White, Mark D.

    2014-08-01

    The Ignik Sikumi Gas Hydrate Exchange Field Trial was conducted by ConocoPhillips in partnership with the U.S. Department of Energy, the Japan Oil, Gas, and Metals National Corporation, and the U.S. Geological Survey within the Prudhoe Bay Unit on the Alaska North Slope (ANS) during 2011 and 2012. The 2011 field program included drilling the vertical test well and performing extensive wireline logging through a thick section of gas-hydrate-bearing sand reservoirs that provided substantial new insight into the nature of ANS gas hydrate occurrences. The 2012 field program involved an extended, scientific field trial conducted within a single vertical well (“huff-and-puff” design) through three primary operational phases: 1) injection of a gaseous phase mixture of CO2, N2, and chemical tracers; 2) flowback conducted at down-hole pressures above the stability threshold for native CH4-hydrate, and 3) extended (30-days) flowback at pressures below the stability threshold of native CH4-hydrate. Ignik Sikumi represents the first field investigation of gas hydrate response to chemical injection, and the longest-duration field reservoir response experiment yet conducted. Full descriptions of the operations and data collected have been fully reported by ConocoPhillips and are available to the science community. The 2011 field program indicated the presence of free water within the gas hydrate reservoir, a finding with significant implications to the design of the exchange trial – most notably the use of a mixed gas injectant. While this decision resulted in a complex chemical environment within the reservoir that greatly tests current experimental and modeling capabilities – without such a mixture, it is apparent that injection could not have been achieved. While interpretation of the field data are continuing, the primary scientific findings and implications of the program are: 1) gas hydrate destabilizing is self-limiting, dispelling any notion of the potential for uncontrolled destabilization; 2) wells must be carefully designed to enable rapid remediation of well-bore blockages that will occur during any cessation in operations; 3) appropriate gas mixes can be successfully injected into hydrate-bearing reservoirs; 4) sand production can be well-managed through standard engineering controls; 5) reservoir heat exchange during depressurization was much more favorable than expected – mitigating concerns for near-well-bore freezing and enabling consideration of more aggressive pressure reduction and; 6) CO2-CH4 exchange can be accomplished in natural reservoirs. The next steps in evaluation of exchange technology should feature multiple well applications; however such field programs will require extensive preparatory experimental and numerical modeling studies and will likely be a secondary priority to further field testing of production through depressurization.

  16. Application of computational fluid dynamics for the simulation of cryogenic molecular sieve bed absorber of hydrogen isotopes recovery system for Indian LLCB-TBM

    SciTech Connect (OSTI)

    Gayathri Devi, V.; Sircar, A.; Sarkar, B.

    2015-03-15

    One of the most challenging tasks in the design of the fuel cycle system lies in the effective design of Tritium Extraction System (TES) which involves proper extraction and purification of tritium in the fuel cycle of the fusion reactor. Indian Lead Lithium cooled Ceramic Breeder Test Blanket Module (LLCB-TBM) would extract hydrogen isotopes through Cryogenic Molecular Sieve Bed (CMSB) adsorber system. A prototype Hydrogen Isotopes Recovery System (HIRS) is being developed to validate the concepts for tritium extraction by adsorption mass transfer mechanism. In this study, a design model has been developed and analyzed to simulate the adsorption mass transfer kinetics in a fixed bed adsorption column. The simulation leads primarily to effective design of HIRS, which is a state-of-the-art technology. The paper describes the process simulation approach and the results of Computational Fluid Dynamics (CFD) analysis. The effects of different operating conditions are studied to investigate their influence on the hydrogen isotopes adsorption capacity. The results of the present simulation study would be used to understand the best optimized transport phenomenon before realizing the TES as a system for LLCB-TBM. (authors)

  17. Developing Fully Coupled Dynamical Reactor Core Isolation System Models in RELAP-7 for Extended Station Black-Out Analysis

    SciTech Connect (OSTI)

    Haihua Zhao; Ling Zou; Hongbin Zhang; David Andrs; Richard Martineau

    2014-04-01

    The reactor core isolation cooling (RCIC) system in a boiling water reactor (BWR) provides makeup water to the reactor vessel for core cooling when the main steam lines are isolated and the normal supply of water to the reactor vessel is lost. It was one of the very few safety systems still available during the Fukushima Daiichi accidents after the tsunamis hit the plants and the system successfully delayed the core meltdown for a few days for unit 2 & 3. Therefore, detailed models for RCIC system components are indispensable to understand extended station black-out accidents (SBO) for BWRs. As part of the effort to develop the new generation reactor system safety analysis code RELAP-7, major components to simulate the RCIC system have been developed. This paper describes the models for those components such as turbine, pump, and wet well. Selected individual component test simulations and a simplified SBO simulation up to but before core damage is presented. The successful implementation of the simplified RCIC and wet well models paves the way to further improve the models for safety analysis by including more detailed physical processes in the near future.

  18. Entropic description of gas hydrate ice/liquid equilibrium via enhanced sampling of coexisting phases

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Malolepsza, Edyta; Kim, Jaegil; Keyes, Tom

    2015-04-28

    Metastable β ice holds small guest molecules in stable gas hydrates, so its solid/liquid equilibrium is of interest. However, aqueous crystal/liquid transitions are very difficult to simulate. A new MD algorithm generates trajectories in a generalized NPT ensemble and equilibrates states of coexisting phases with a selectable enthalpy. Furthermore, with replicas spanning the range between β ice and liquid water we find the statistical temperature from the enthalpy histograms and characterize the transition by the entropy, introducing a general computational procedure for first-order transitions.

  19. Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt

    SciTech Connect (OSTI)

    Bai, Yuanyuan; Xiang, Feng; Wang, Hong E-mail: suo@seas.harvard.edu; Chen, Baohong; Zhou, Jinxiong; Suo, Zhigang E-mail: suo@seas.harvard.edu

    2014-10-13

    Polyacrylamide hydrogels containing salt as electrolyte have been used as highly stretchable transparent electrodes in flexible electronics, but those hydrogels are easy to dry out due to water evaporation. Targeted, we try to enhance water retention capacity of polyacrylamide hydrogel by introducing highly hydratable salts into the hydrogel. These hydrogels show enhanced water retention capacity in different level. Specially, polyacrylamide hydrogel containing high content of lithium chloride can retain over 70% of its initial water even in environment with relative humidity of only 10% RH. The excellent water retention capacities of these hydrogels will make more applications of hydrogels become possible.

  20. DPF -"Hydrated EGR" Fuel Saver System | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    and Computations | Department of Energy 13 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting PDF icon vss006_salari_2013_o.pdf More Documents & Publications Vehicle Technologies Office Merit Review 2014: DOE's Effort to Improve Heavy Vehicle Fuel Efficiency through Improved Aerodynamics DOEs Effort to Reduce Truck Aerodynamic Drag through Joint Experiments and Computations Vehicle Technologies Office Merit Review 2015: