Sample records for hydrates system dynamics

  1. Hydration-dependent dynamic crossover phenomenon in protein hydration water

    E-Print Network [OSTI]

    Wang, Zhe

    The characteristic relaxation time ? of protein hydration water exhibits a strong hydration level h dependence. The dynamic crossover is observed when h is higher than the monolayer hydration level h[subscript c] =0.2–0.25 ...

  2. Dynamics of Protein Hydration Water

    E-Print Network [OSTI]

    M. Wolf; S. Emmert; R. Gulich; P. Lunkenheimer; A. Loidl

    2014-12-08T23:59:59.000Z

    We present the frequency- and temperature-dependent dielectric properties of lysozyme solutions in a broad concentration regime, measured at subzero temperatures and compare the results with measurements above the freezing point of water and on hydrated lysozyme powder. Our experiments allow examining the dynamics of unfreezable hydration water in a broad temperature range including the so-called No Man's Land (160 - 235 K). The obtained results prove the bimodality of the hydration shell dynamics and are discussed in the context of the highly-debated fragile-to-strong transition of water.

  3. Gas hydrate cool storage system

    DOE Patents [OSTI]

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

    1984-09-12T23:59:59.000Z

    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)

  4. Curvature Dependence of Hydrophobic Hydration Dynamics

    E-Print Network [OSTI]

    R. Gregor Weiß; Matthias Heyden; Joachim Dzubiella

    2015-04-08T23:59:59.000Z

    We investigate the curvature-dependence of water dynamics in the vicinity of hydrophobic spherical solutes using molecular dynamics simulations. For both, the lateral and perpendicular diffusivity as well as for H-bond kinetics of water in the first hydration shell, we find a non-monotonic solute-size dependence, exhibiting extrema close to the well-known structural crossover length scale for hydrophobic hydration. Additionally, we find an apparently anomalous diffusion for water moving parallel to the surface of small solutes, which, however, can be explained by topology effects. The intimate connection between solute curvature, water structure and dynamics has implications for our understanding of hydration dynamics at heterogeneous biomolecular surfaces.

  5. Dynamics of Kr in dense clathrate hydrates.

    SciTech Connect (OSTI)

    Klug, D. D.; Tse, J. S.; Zhao, J. Y.; Sturhahn, W.; Alp, E. E.; Tulk, C. A. (X-Ray Science Division); (National Research Council of Canada); (Univ. of Saskatchewan); (ORNL)

    2011-01-01T23:59:59.000Z

    The dynamics of Kr atoms as guests in dense clathrate hydrate structures are investigated using site specific {sup 83}Kr nuclear resonant inelastic x-ray scattering (NRIXS) spectroscopy in combination with molecular dynamics simulations. The dense structure H hydrate and filled-ice structures are studied at high pressures in a diamond anvil high-pressure cell. The dynamics of Kr in the structure H clathrate hydrate quench recovered at 77 K is also investigated. The Kr phonon density of states obtained from the experimental NRIXS data are compared with molecular dynamics simulations. The temperature and pressure dependence of the phonon spectra provide details of the Kr dynamics in the clathrate hydrate cages. Comparison with the dynamics of Kr atoms in the low-pressure structure II obtained previously was made. The Lamb-Mossbauer factor obtained from NRIXS experiments and molecular dynamics calculations are in excellent agreement and are shown to yield unique information on the strength and temperature dependence of guest-host interactions.

  6. Hydration water dynamics and instigation of protein structuralrelaxation

    SciTech Connect (OSTI)

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

    2003-09-01T23:59:59.000Z

    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.

  7. Hydration-dependent dynamics of deeply cooled water under strong confinement

    E-Print Network [OSTI]

    Bertrand, C. E.

    We have measured the hydration-level dependence of the single-particle dynamics of water confined in the ordered mesoporous silica MCM-41. The dynamic crossover observed at full hydration is absent at monolayer hydration. ...

  8. Dynamical Transition and Heterogeneous Hydration Dynamics in RNA

    E-Print Network [OSTI]

    Jeseong Yoon; Jong-Chin Lin; Changbong Hyeon; D. Thirumalai

    2014-04-24T23:59:59.000Z

    Enhanced dynamical fluctuations of RNAs, facilitated by a network of water molecules with strong interactions with RNA, are suspected to be critical in their ability to respond to a variety of cellular signals. Using atomically detailed molecular dynamics simulations at various temperatures of purine (adenine)- and preQ$_1$ sensing riboswitch aptamers, we show that water molecules in the vicinity of RNAs undergo complex dynamics depending on the local structures of the RNAs. The overall lifetimes of hydrogen bonds (HBs) of surface bound waters are more than at least 1-2 orders of magnitude longer than bulk water. Slow hydration dynamics, revealed in non-Arrhenius behavior of the relaxation time, arises from high activation barriers to break water hydrogen bonds with a nucleotide and by reduced diffusion of water. The relaxation kinetics at specific locations in the two RNAs show a broad spectrum of time scales reminiscent of glass-like behavior, suggesting that the hydration dynamics is highly heterogeneous. Both RNAs undergo dynamic transition at $T = T_D \\gtrsim 200$ K as assessed by the mean square fluctuation of hydrogen atoms $\\langle x^2\\rangle$, which undergoes an abrupt harmonic-to-anharmonic transition at $T_D$. The near universal value of $T_D$ found for these RNAs and previously for tRNA is strongly correlated with changes in hydration dynamics as $T$ is altered. Hierarchical dynamics of waters associated with the RNA surface, revealed in the motions of distinct classes of water with well-separated time scales, reflects the heterogeneous local environment on the molecular surface of RNA. At low temperatures slow water dynamics predominates over structural transitions. Our study demonstrates that the complex interplay of dynamics between water and local environment in the RNA structures could be a key determinant of the functional activities of RNA.

  9. Dynamic behavior of hydration water in calcium-silicate-hydrate gel: A quasielastic neutron scattering spectroscopy investigation

    E-Print Network [OSTI]

    Li, Hua

    The translational dynamics of hydration water confined in calcium-silicate-hydrate (C-S-H) gel was studied by quasielastic neutron scattering spectroscopy in the temperature range from 280 to 230 K. The stretch exponent ...

  10. Gas hydrate cool storage system

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

    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.

  11. Rock-physics Models for Gas-hydrate Systems Associated

    E-Print Network [OSTI]

    Texas at Austin, University of

    Rock-physics Models for Gas-hydrate Systems Associated with Unconsolidated Marine Sediments Diana at Austin, Austin, Texas, U.S.A. ABSTRACT R ock-physics models are presented describing gas-hydrate systems associated with unconsolidated marine sediments. The goals are to predict gas-hydrate concentration from

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

    E-Print Network [OSTI]

    P. M. Favi; Q. Zhang; H. O'Neill; E. Mamontov; S. O. Diallo

    2013-12-06T23:59:59.000Z

    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 $hydration fraction in both cases was about $\\sim$ 0.38 gram of water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm (2 10$^6$ 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 $\\sim$ 2-3 kV/mm for increased molecular diffusion, for which electrical breakdown is a limitation for our sample.

  13. Dynamics of biopolymers and their hydration water studied by neutron and X-ray scattering

    E-Print Network [OSTI]

    Chu, Xiang-qiang

    2010-01-01T23:59:59.000Z

    Protein functions are intimately related to their dynamics. Moreover, protein hydration water is believed to have significant influence on the dynamics of proteins. One of the evidence is that both protein and its hydration ...

  14. Experimental evidence of logarithmic relaxation in single-particle dynamics of hydrated protein molecules

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Experimental evidence of logarithmic relaxation in single-particle dynamics of hydrated protein dynamics of hydrated lysozyme powder follows a logarithmic relax- ation in the time domain. In particular

  15. Mimicking Natural Systems: Methane Hydrate Formation-Decomposition in Depleted Sediments

    SciTech Connect (OSTI)

    Eaton, M.; Jones, K; Mahajan, D

    2009-01-01T23:59:59.000Z

    We have initiated a systematic study of sediment-hydrate interaction under subsurface-mimic conditions to initially focus on marine hydrates. A major obstacle to studying natural hydrate systems has been the absence of a sophisticated mimic apparatus in which the hydrate formation phenomenon can be reproduced with precision. We have designed and constructed a bench-top unit, namely flexible integrated study of hydrates (FISH), for this purpose. The unit is fully instrumented to precisely record temperatures, pressures and changes in gas volume during absorption/evolution. The Labview software allows rapid and continuous data collection during the hydrate formation/dissociation cycle. In our integrated approach, several host sediments collected from Blake Ridge, a well-researched hydrate site, were characterized using the computed microtomography technique at Beamline X-26A of the National Synchrotron Light Source at Brookhaven National Laboratory. The characterized depleted sediments were then used to study the hydrate formation/decomposition kinetics under various pressures in the FISH unit. We report two hydrate formation methods: one under continuous methane gas-flow conditions (dynamic mode) and the other in which hydrates are formed from the dissolved gas phase by diffusion (static mode). Also reported is a depressurization method, namely the step-down pressure method, to yield gas evolution data. Data from such runs with host sediment from the deepest site (667 metres) is presented. During hydrate formation, the data reveals a temperature signature that is consistent with an exothermic hydrate formation event. In the decomposition cycle, data at various pressures was analysed to yield curves with similar slopes, suggesting a zero-order dependence. The capabilities of the FISH unit and the implications of these runs in establishing a database of sediment-hydrate kinetics and pore saturation are discussed.

  16. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle D. (Golden, CO)

    1995-01-01T23:59:59.000Z

    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.

  17. More than one dynamic crossover in protein hydration water

    E-Print Network [OSTI]

    Marco G. Mazza; Kevin Stokely; Sara E. Pagnotta; Fabio Bruni; H. Eugene Stanley; Giancarlo Franzese

    2011-08-06T23:59:59.000Z

    Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network.

  18. Hydration structure of salt solutions from ab initio molecular dynamics

    SciTech Connect (OSTI)

    Bankura, Arindam; Carnevale, Vincenzo; Klein, Michael L. [Institute for Computational Molecular Science and Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States)

    2013-01-07T23:59:59.000Z

    The solvation structures of Na{sup +}, K{sup +}, and Cl{sup -} ions in aqueous solution have been investigated using density functional theory (DFT) based Car-Parrinello (CP) molecular dynamics (MD) simulations. CPMD trajectories were collected for systems containing three NaCl or KCl ion pairs solvated by 122 water molecules using three different but commonly employed density functionals (BLYP, HCTH, and PBE) with electron correlation treated at the level of the generalized gradient approximation (GGA). The effect of including dispersion forces was analyzed through the use of an empirical correction to the DFT-GGA scheme. Special attention was paid to the hydration characteristics, especially the structural properties of the first solvation shell of the ions, which was investigated through ion-water radial distribution functions, coordination numbers, and angular distribution functions. There are significant differences between the present results obtained from CPMD simulations and those provided by classical MD based on either the CHARMM force field or a polarizable model. Overall, the computed structural properties are in fair agreement with the available experimental results. In particular, the observed coordination numbers 5.0-5.5, 6.0-6.4, and 6.0-6.5 for Na{sup +}, K{sup +}, and Cl{sup -}, respectively, are consistent with X-ray and neutron scattering studies but differ somewhat from some of the many other recent computational studies of these important systems. Possible reasons for the differences are discussed.

  19. Anomalous dynamics of confined water at low hydration

    E-Print Network [OSTI]

    P. Gallo; M. Rovere

    2003-11-12T23:59:59.000Z

    The mobility of water molecules confined in a silica pore is studied by computer simulation in the low hydration regime, where most of the molecules reside close to the hydrophilic substrate. A layer analysis of the single particle dynamics of these molecules shows an anomalous diffusion with a sublinear behaviour at long time. This behaviour is strictly connected to the long time decay of the residence time distribution analogously to water at contact with proteins.

  20. Simulation studies of slow dynamics of hydration water in lysozyme : hydration level dependence and comparison with experiment using new time domain analysis

    E-Print Network [OSTI]

    Kim, Chansoo, S.M. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    A series of Molecular Dynamics (MD) simulations using the GROMACS® package has been performed in this thesis. It is used to mimic and simulate the hydration water in Lysozyme with three different hydration levels (h = 0.3, ...

  1. The Dynamic Transition of Protein Hydration Water

    E-Print Network [OSTI]

    W. Doster; S. Busch; A. M. Gaspar; M. -S. Appavou; J. Wuttke; H. Scheer

    2010-02-12T23:59:59.000Z

    Thin layers of water on biomolecular and other nanostructured surfaces can be supercooled to temperatures not accessible with bulk water. Chen et al. [PNAS 103, 9012 (2006)] suggested that anomalies near 220 K observed by quasi-elastic neutron scattering can be explained by a hidden critical point of bulk water. Based on more sensitive measurements of water on perdeuterated phycocyanin, using the new neutron backscattering spectrometer SPHERES, and an improved data analysis, we present results that show no sign of such a fragile-to-strong transition. The inflection of the elastic intensity at 220 K has a dynamic origin that is compatible with a calorimetric glass transition at 170 K. The temperature dependence of the relaxation times is highly sensitive to data evaluation; it can be brought into perfect agreement with the results of other techniques, without any anomaly.

  2. Depth dependent dynamics in the hydration shell of a protein

    E-Print Network [OSTI]

    J. Servantie; C. Atilgan; A. R. Atilgan

    2010-07-31T23:59:59.000Z

    We study the dynamics of hydration water/protein association in folded proteins, using lysozyme and myoglobin as examples. Extensive molecular dynamics simulations are performed to identify underlying mechanisms of the dynamical transition that corresponds to the onset of amplified atomic fluctuations in proteins. The number of water molecules within a cutoff distance of each residue scales linearly with protein depth index and is not affected by the local dynamics of the backbone. Keeping track of the water molecules within the cutoff sphere, we observe an effective residence time, scaling inversely with depth index at physiological temperatures while the diffusive escape is highly reduced below the transition. A depth independent orientational memory loss is obtained for the average dipole vector of the water molecules within the sphere when the protein is functional. While below the transition temperature, the solvent is in a glassy state, acting as a solid crust around the protein, inhibiting any large scale conformational fluctuations. At the transition, most of the hydration shell unfreezes and water molecules collectively make the protein more flexible.

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

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K. (Birmingham, MI)

    1983-06-21T23:59:59.000Z

    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.

  4. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, E.D. Jr.

    1995-07-11T23:59:59.000Z

    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.

  5. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle D. (Golden, CO)

    1995-01-01T23:59:59.000Z

    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.

  6. Dynamical properties of the hydration shell of fully deuterated myoglobin

    SciTech Connect (OSTI)

    Achterhold, Klaus; Parak, Fritz G. [Physik-Department E17, Technische Universitaet Muenchen, James-Franck-Strasse 1, D-85747 Garching (Germany); Ostermann, Andreas [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), ZWE, Lichtenbergstrasse 1, D-85747 Garching (Germany); Moulin, Martine; Haertlein, Michael [ILL-EMBL Deuteration Laboratory, Partnership for Structural Biology, 6, rue Jules Horowitz, F-38042 Grenoble Cedex 9 (France); Unruh, Tobias [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), ZWE, Lichtenbergstrasse 1, D-85747 Garching (Germany); Institut fuer Physik der Kondensierten Materie, Lehrstuhl fuer Kristallographie und Strukturphysik, Staudtstrasse 3, D-91058 Erlangen (Germany)

    2011-10-15T23:59:59.000Z

    Freeze-dried perdeuterated sperm whale myoglobin was kept in a water-saturated atmosphere in order to obtain a hydration degree of 335 {sup 1}H{sub 2}O molecules per one myoglobin molecule. Incoherent neutron scattering was performed at the neutron spectrometer TOFTOF at the FRM II in an angular range of q from 0.6 to 1.8 A{sup -1} and a temperature range from 4 to 297 K. We used neutrons with a wavelength of {lambda}{alpha}E 6 A and an energy resolution of about 65 {mu}eV corresponding to motions faster than 10 ps. At temperatures above 225 K, broad lines appear in the spectra caused by quasielastic scattering. For an explanation of these lines, we assumed that there are only two types of protons, those that are part of the hydration water (72%) and those that belong to the protein (28%). The protons of the hydration water were analyzed with the diffusion model of Singwi and Sjoelander [Phys. Rev. 119, 863 (1960)]. In this model, a water molecule stays for a time {tau}{sub 0} in a bound state performing oscillatory motions. Thereafter, the molecule performs free diffusion for the time {tau}{sub 1} in a nonbound state followed again by the oscillatory motions for {tau}{sub 0} and so forth. We used the general formulation with no simplifications as {tau}{sub 0}>>{tau}{sub 1} or {tau}{sub 1}>>{tau}{sub 0}. At room temperature, we obtained {tau}{sub 0} {alpha}E 104 ps and {tau}{sub 1} {alpha}E 37 ps. For the protein bound hydrogen, the dynamics is described by a Brownian oscillator where the protons perform overdamped motions in limited space.

  7. Observation of Fragile-to-Strong Dynamic Crossover in Protein Hydration Water

    E-Print Network [OSTI]

    Sow-Hsin Chen; Li Liu; Emiliano Fratini; Piero Baglioni; Antonio Faraone; Eugene Mamontov

    2006-05-11T23:59:59.000Z

    At low temperatures proteins exist in a glassy state, a state which has no conformational flexibility and shows no biological functions. In a hydrated protein, at and above 220 K, this flexibility is restored and the protein is able to sample more conformational sub-states, thus becomes biologically functional. This 'dynamical' transition of protein is believed to be triggered by its strong coupling with the hydration water, which also shows a similar dynamic transition. Here we demonstrate experimentally that this sudden switch in dynamic behavior of the hydration water on lysozyme occurs precisely at 220 K and can be described as a Fragile-to-Strong dynamic crossover (FSC). At FSC, the structure of hydration water makes a transition from predominantly high-density (more fluid state) to low-density (less fluid state) forms derived from existence of the second critical point at an elevated pressure.

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

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    2010-01-01T23:59:59.000Z

    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 ...

  9. Natural Gas Hydrate Particles in Oil-Free Systems with Kinetic Inhibition and Slurry Viscosity Reduction

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    Natural Gas Hydrate Particles in Oil-Free Systems with Kinetic Inhibition and Slurry Viscosity, reduction of slurry viscosity, and corrosion inhibition. INTRODUCTION Water often forms gas hydrates antiagglomeration (AA) in the natural gas hydrate literature. The main limitation to application has been the need

  10. Methane escape from gas hydrate systems in marine environment, and methane-driven oceanic eruptions

    E-Print Network [OSTI]

    Zhang, Youxue

    Methane escape from gas hydrate systems in marine environment, and methane-driven oceanic eruptions are suitable for gas hydrate stability [Lunine and Stevenson, 1985]. Enor- mous amounts of methane are stored as gas hydrate and free gas in the pore space of marine sediment [Kvenvolden, 1988; Buffet, 2000

  11. Dynamic control of slow water transport by aquaporin 0: Implications for hydration

    E-Print Network [OSTI]

    Shaw, David E.

    Dynamic control of slow water transport by aquaporin 0: Implications for hydration and junction as the primary water channel in this tissue but also appears to mediate the formation of thin junctions between fiber cells. AQP0 is remarkably less water perme- able than other aquaporins, but the structural basis

  12. The dynamic response of oceanic hydrate deposits to ocean temperature change

    E-Print Network [OSTI]

    Reagan, Matthew T.

    2008-01-01T23:59:59.000Z

    of the fate of gas hydrates during transit through the oceanVA. (1998), Submarine Gas Hydrates. St. Petersburg. Gornitzgas reservoirs below gas-hydrate provinces, Nature, 427,

  13. Temperature-dependent mechanisms for the dynamics of protein-hydration waters: a molecular dynamics simulation study

    E-Print Network [OSTI]

    Michael Vogel

    2009-02-20T23:59:59.000Z

    Molecular dynamics simulations are performed to study the temperature-dependent dynamics and structures of the hydration shells of elastin-like and collagen-like peptides. For both model peptides, it is consistently observed that, upon cooling, the mechanisms for water dynamics continuously change from small-step diffusive motion to large-step jump motion, the temperature dependence of water dynamics shows a weak crossover from fragile behavior to strong behavior, and the order of the hydrogen-bond network increases. The temperature of the weak crossover from fragile to strong behavior is found to coincide with the temperature at which maximum possible order of the hydrogen-bond network is reached so that the structure becomes temperature independent. In the strong regime, the temperature dependence of water translation and rotational dynamics is characterized by an activation energy of ca. E_a=0.43 eV, consistent with results from previous dielectric spectroscopy and nuclear magnetic resonance studies on protein hydration waters. At these temperatures, a distorted pi-flip motion about the twofold molecular symmetry axes, i.e., a water-specific beta process is an important aspect of water dynamics, at least at the water-peptide interfaces. In addition, it is shown that the hydration waters exhibit pronounced dynamical heterogeneities, which can be traced back to a strong slowdown of water motion in the immediate vicinity of peptide molecules due to formation of water-peptide hydrogen bonds.

  14. 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 [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, K1A 0R6 (Canada); Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Separation Technology Group, Den Dolech 2, 5612 AZ Eindhoven (Netherlands); Kroon, Maaike C. [Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Separation Technology Group, Den Dolech 2, 5612 AZ Eindhoven (Netherlands); Peters, Cor J. [Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Separation Technology Group, Den Dolech 2, 5612 AZ Eindhoven (Netherlands); The Petroleum Institute, Chemical Engineering Department, P. O. Box 2533, Abu Dhabi (United Arab Emirates); Moudrakovski, Igor L.; Ratcliffe, Christopher I.; Ripmeester, John A., E-mail: John.Ripmeester@nrc-cnrc.gc.ca [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, K1A 0R6 (Canada); Alavi, Saman [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, K1A 0R6 (Canada); Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada)

    2014-06-07T23:59:59.000Z

    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.

  15. TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of System Behavior in Hydrate-Bearing Geologic Media

    SciTech Connect (OSTI)

    Moridis, George; Moridis, George J.; Kowalsky, Michael B.; Pruess, Karsten

    2008-03-01T23:59:59.000Z

    TOUGH+HYDRATE v1.0 is a new code for the simulation of the behavior of hydrate-bearing geologic systems. By solving the coupled equations of mass and heat balance, TOUGH+HYDRATE can model the non-isothermal gas release, phase behavior and flow of fluids and heat under conditions typical of common natural CH{sub 4}-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 v1.0 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, CH{sub 4}, 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. TOUGH+HYDRATE is the first member of TOUGH+, the successor to the TOUGH2 [Pruess et al., 1991] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRAN 95, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available.

  16. THE SYSTEM THORIUM NITRATE-WATER-NITRIC ACID AT 25 AND THE HYDRATES...

    Office of Scientific and Technical Information (OSTI)

    SYSTEM THORIUM NITRATE-WATER-NITRIC ACID AT 25 AND THE HYDRATES OF THORIUM NITRATE Re-direct Destination: times redirected to final destination ShortURL Code Published Current...

  17. Product design and development of an aerodynamic hydration system for bicycling and triathlon

    E-Print Network [OSTI]

    Cote, Mark (Mark Brian)

    2007-01-01T23:59:59.000Z

    Proper hydration and aerodynamic performance are both essential needs of a competitive cyclist or triathlete. Several aerodynamic systems have been developed for use on bicycles but few have been designed to be truly ...

  18. The dynamic response of oceanic hydrate deposits to ocean temperature change

    E-Print Network [OSTI]

    Reagan, Matthew T.

    2008-01-01T23:59:59.000Z

    Moridis, G.J. (2007), Oceanic gas hydrate instability andand salt inhibition of gas hydrate formation in the northernI.R. (1999), Thermogenic gas hydrates and hydrocarbon gases

  19. Quantum Chemical Analysis of the Excited State Dynamics of Hydrated Electrons

    E-Print Network [OSTI]

    P. O. J. Scherer; Sighart F. Fischer

    2006-02-01T23:59:59.000Z

    Quantum calculations are performed for an anion water cluster representing the first hydration shell of the solvated electron in solution. The absorption spectra from the ground state, the instant excited states and the relaxed excited states are calculated including CI-SD interactions. Analytic expressions for the nonadiabatic relaxation are presented. It is shown that the 50fs dynamics recently observed after s->p excitation is best accounted for if it is identified with the internal conversion, preceded by an adiabatic relaxation within the excited p state. In addition, transient absorptions found in the infrared are qualitatively reproduced by these calculations .

  20. Desalination utilizing clathrate hydrates (LDRD final report).

    SciTech Connect (OSTI)

    Simmons, Blake Alexander; Bradshaw, Robert W.; Dedrick, Daniel E.; Cygan, Randall Timothy (Sandia National Laboratories, Albuquerque, NM); Greathouse, Jeffery A. (Sandia National Laboratories, Albuquerque, NM); Majzoub, Eric H. (University of Missouri, Columbia, MO)

    2008-01-01T23:59:59.000Z

    Advances are reported in several aspects of clathrate hydrate desalination fundamentals necessary to develop an economical means to produce municipal quantities of potable water from seawater or brackish feedstock. These aspects include the following, (1) advances in defining the most promising systems design based on new types of hydrate guest molecules, (2) selection of optimal multi-phase reactors and separation arrangements, and, (3) applicability of an inert heat exchange fluid to moderate hydrate growth, control the morphology of the solid hydrate material formed, and facilitate separation of hydrate solids from concentrated brine. The rate of R141b hydrate formation was determined and found to depend only on the degree of supercooling. The rate of R141b hydrate formation in the presence of a heat exchange fluid depended on the degree of supercooling according to the same rate equation as pure R141b with secondary dependence on salinity. Experiments demonstrated that a perfluorocarbon heat exchange fluid assisted separation of R141b hydrates from brine. Preliminary experiments using the guest species, difluoromethane, showed that hydrate formation rates were substantial at temperatures up to at least 12 C and demonstrated partial separation of water from brine. We present a detailed molecular picture of the structure and dynamics of R141b guest molecules within water cages, obtained from ab initio calculations, molecular dynamics simulations, and Raman spectroscopy. Density functional theory calculations were used to provide an energetic and molecular orbital description of R141b stability in both large and small cages in a structure II hydrate. Additionally, the hydrate of an isomer, 1,2-dichloro-1-fluoroethane, does not form at ambient conditions because of extensive overlap of electron density between guest and host. Classical molecular dynamics simulations and laboratory trials support the results for the isomer hydrate. Molecular dynamics simulations show that R141b hydrate is stable at temperatures up to 265K, while the isomer hydrate is only stable up to 150K. Despite hydrogen bonding between guest and host, R141b molecules rotated freely within the water cage. The Raman spectrum of R141b in both the pure and hydrate phases was also compared with vibrational analysis from both computational methods. In particular, the frequency of the C-Cl stretch mode (585 cm{sup -1}) undergoes a shift to higher frequency in the hydrate phase. Raman spectra also indicate that this peak undergoes splitting and intensity variation as the temperature is decreased from 4 C to -4 C.

  1. 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.

    1997-06-17T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Sloan, Jr., Earle Dendy (Golden, CO); Christiansen, Richard Lee (Littleton, CO); Lederhos, Joseph P. (Wheatridge, CO); Long, Jin Ping (Dallas, TX); Panchalingam, Vaithilingam (Lakewood, CO); Du, Yahe (Golden, CO); Sum, Amadeu Kun Wan (Golden, CO)

    1997-01-01T23:59:59.000Z

    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.

  3. Ab initio molecular dynamics study of manganese porphine hydration and interaction with nitric oxide

    E-Print Network [OSTI]

    Kevin Leung; Craig J. Medforth

    2007-01-23T23:59:59.000Z

    The authors use ab initio molecular dynamics and the density functional theory+U (DFT+U) method to compute the hydration environment of the manganese ion in manganese (II) and manganese (III) porphines (MnP) dispersed in liquid water. These are intended as simple models for more complex water soluble porphyrins, which have important physiological and electrochemical applications. The manganese ion in Mn(II)P exhibits significant out-of-porphine plane displacement and binds strongly to a single H2O molecule in liquid water. The Mn in Mn(III)P is on average coplanar with the porphine plane and forms a stable complex with two H2O molecules. The residence times of these water molecules exceed 15 ps. The DFT+U method correctly predicts that water displaces NO from Mn(III)P-NO, but yields an ambiguous spin state for the MnP(II)-NO complex.

  4. High pressure dynamics of hydrated protein in bio-protective trehalose environment

    E-Print Network [OSTI]

    S. O. Diallo; Q. Zhang; H. O'Neill; E. Mamontov

    2014-09-11T23:59:59.000Z

    We present a pressure dependence study of the dynamics of lysozyme protein powder immersed in deuterated $\\alpha$,$\\alpha$-trehalose environment via quasi-elastic neutron scattering (QENS). The goal is to assess the baro-protective benefits of trehalose on bio-molecules by comparing the findings with those of a trehalose-free reference study. While the mean-square displacement of the trehalose-free protein (hydrated to $d_{D_2O}\\simeq$40 w\\%) as a whole, is reduced by increasing pressure, the actual observable relaxation dynamics in the pico-(ps) to nano-seconds (ns) time range remains largely unaffected by pressure - up to the maximum investigated pressure of 2.78(2) Kbar. Our observation is independent of whether or not the protein is mixed with the deuterated sugar. This suggests that the hydrated protein's conformational states at atmospheric pressure remain unaltered by hydrostatic pressures, below 2.78 Kbar. We also found the QENS response to be totally recoverable after ambient pressure conditions are restored. Circular dichroism and neutron diffraction measurements confirm that the protein structural integrity is conserved and remains intact, after pressure is released. We observe however a clear narrowing of the quasi-elastic neutron (QENS) response as the temperature is decreased from 290 K to 230 K in both cases, which we parametrize using the Kohlrausch-Williams-Watts (KWW) stretched exponential model. Only the fraction of protons that are immobile on the accessible time window of the instrument, referred to as the elastic incoherent structure factor or (EISF) is observably sensitive to pressure, increasing only marginally but systematically with increasing pressure.

  5. Ab initio investigation of the first hydration shell of protonated glycine

    SciTech Connect (OSTI)

    Wei, Zhichao; Chen, Dong, E-mail: dongchen@henu.edu.cn, E-mail: boliu@henu.edu.cn; Zhao, Huiling; Li, Yinli; Zhu, Jichun; Liu, Bo, E-mail: dongchen@henu.edu.cn, E-mail: boliu@henu.edu.cn [Institute of Photo-Biophysics, Physics and Electronics Department, Henan University, 475004 Kaifeng (China)] [Institute of Photo-Biophysics, Physics and Electronics Department, Henan University, 475004 Kaifeng (China)

    2014-02-28T23:59:59.000Z

    The first hydration shell of the protonated glycine is built up using Monte Carlo multiple minimum conformational search analysis with the MMFFs force field. The potential energy surfaces of the protonated glycine and its hydration complexes with up to eight water molecules have been scanned and the energy-minimized structures are predicted using the ab initio calculations. First, three favorable structures of protonated glycine were determined, and the micro-hydration processes showed that water can significantly stabilize the unstable conformers, and then their first hydration shells were established. Finally, we found that seven water molecules are required to fully hydrate the first hydration shell for the most stable conformer of protonated glycine. In order to analyse the hydration process, the dominant hydration sites located around the ammonium and carboxyl groups are studied carefully and systemically. The results indicate that, water molecules hydrate the protonated glycine in an alternative dynamic hydration process which is driven by the competition between different hydration sites. The first three water molecules are strongly attached by the ammonium group, while only the fourth water molecule is attached by the carboxyl group in the ultimate first hydration shell of the protonated glycine. In addition, the first hydration shell model has predicted most identical structures and a reasonable accord in hydration energy and vibrational frequencies of the most stable conformer with the conductor-like polarizable continuum model.

  6. The goal of this work is to quantify the Van der Waals interactions in systems involving gas hydrates. Gas hydrates are crystalline com-

    E-Print Network [OSTI]

    Boyer, Edmond

    gas hydrates. Gas hydrates are crystalline com- pounds that are often encountered in oil and gas briefly present the hydrate crystalline structure and the role of hydrates in oil-and gas industry the industrial contexts where they appear, we shall cite : hydrate plugs obstructing oil- or gas

  7. TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of System Behavior in Hydrate-Bearing Geologic Media

    E-Print Network [OSTI]

    Moridis, George

    2008-01-01T23:59:59.000Z

    coexistence of aqueous, gas and hydrate phases in a cell (a deposit in which water, gas and hydrate are initially atequilibrium. The initial gas and hydrate saturations are S G

  8. 2H and 13C NMR studies on the temperature-dependent water and protein dynamics in hydrated elastin, myoglobin and collagen

    E-Print Network [OSTI]

    S. A. Lusceac; C. R. Herbers; M. Vogel

    2009-04-28T23:59:59.000Z

    2H NMR spin-lattice relaxation and line-shape analyses are performed to study the temperature-dependent dynamics of water in the hydration shells of myoglobin, elastin, and collagen.

  9. Direct measurement of the correlated dynamics of the protein-backbone and proximal waters of hydration in mechanically strained elastin

    E-Print Network [OSTI]

    Cheng Sun; Odingo Mitchell; Jiaxin Huang; Gregory S. Boutis

    2011-04-05T23:59:59.000Z

    We report on the direct measurement of the correlation times of the protein backbone carbons and proximal waters of hydration in mechanically strained elastin by nuclear magnetic resonance methods. The experimental data indicate a decrease in the correlation times of the carbonyl carbons as the strain on the biopolymer is increased. These observations are in good agreement with short 4ns molecular dynamics simulations of (VPGVG)3, a well studied mimetic peptide of elastin. The experimental results also indicate a reduction in the correlation time of proximal waters of hydration with increasing strain applied to the elastomer. A simple model is suggested that correlates the increase in the motion of proximal waters of hydration to the increase in frequency of libration of the protein backbone that develops with increasing strain. Together, the reduction in the protein entropy accompanied with the increase in entropy of the proximal waters of hydration with increasing strain, support the notion that the source of elasticity is driven by an entropic mechanism arising from the change in entropy of the protein backbone.

  10. Report on Ngai et al.: Change of Caged Dynamics at Tg in hydrated proteins found after suppressing the methyl group rotation contribution"

    E-Print Network [OSTI]

    Doster, Wolfgang

    neutron scattering data of solvated proteins, the solvent is now restricted to hydration water: The authors belong to the elastic neutron scattering community, which intends to explain protein dynamics of dynamic information. The full dynamic information derivable from neutron scattering experiments

  11. Fluid dynamics of sinking carbon dioxide hydrate particle releases for direct ocean carbon sequestration

    E-Print Network [OSTI]

    Chow, Aaron C. (Aaron Chunghin), 1978-

    2008-01-01T23:59:59.000Z

    One strategy to remove anthropogenic CO? from the atmosphere to mitigate climate change is by direct ocean injection. Liquid CO? can react with seawater to form solid partially reacted CO? hydrate composite particles (pure ...

  12. Change of caged dynamics at Tg in hydrated proteins found after suppressing the methyl-group rotation contribution

    E-Print Network [OSTI]

    K. L. Ngai; S. Capaccioli; A. Paciaroni

    2011-06-29T23:59:59.000Z

    In conventional glassformers at sufficiently short times and low enough temperatures, molecules are mutually caged by the intermolecular potential. The fluctuation and dissipation from motion of caged molecules when observed by elastic incoherent neutron scattering exhibit a change in temperature dependence of the mean square displacement (MSD) at the glass transition temperature Tg. This is a general and fundamental property of caged dynamics in glassformers, which is observed always near Tg independent of the energy resolution of the spectrometer. Recently we showed the same change of T-dependence at Tg is present in proteins solvated with bioprotectants, coexisting with the dynamic transition at a higher temperature Td. In these solvated proteins, all having Tg and Td higher than the proteins hydrated by water alone, the observation of the change of T-dependence of the MSD at Tg is unobstructed by the methyl-group rotation contribution at lower temperatures. On the other hand, proteins hydrated by water alone have lower Tg and Td, and hence unambiguous evidence of the transition of MSD at Tg is hard to find. Notwithstanding, evidence on the break of the MSD at Tg can be found by deuterating the protein to suppress the methyl-group contribution. An alternative strategy is the use of a spectrometer that senses motions faster than 15 ps, which confers the benefit of shifting both the onset of methyl-group rotation contribution as well as the dynamic transition to higher temperatures, and again the change of MSD at Tg becomes evident. The break of the elastic intensity or the MSD at Tg coexists with the dynamics transition at Td in hydrated and solvated proteins. Recognition of this fact helps to remove inconsistency and conundrum encountered in interpreting the data that thwart progress in understanding the origin of the dynamic transition and its connection to biological function.

  13. Categorical Introduction to Dynamical Systems Symbolic Dynamical Systems

    E-Print Network [OSTI]

    Kahng, Byung-Jay

    Categorical Introduction to Dynamical Systems Symbolic Dynamical Systems Symbolic Embedding Examples Results Embeddings in Symbolic Dynamical Systems Jonathan Jaquette Swarthmore College July 22, 2009 Jonathan Jaquette Embeddings in Symbolic Dynamical Systems #12;Categorical Introduction

  14. Application of the Cell Potential Method To Predict Phase Equilibria of Multicomponent Gas Hydrate Systems

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Application of the Cell Potential Method To Predict Phase Equilibria of Multicomponent Gas Hydrate the first documentation nearly two centuries ago,2 natural gas clathrate-hydrates, called clathrates, have at understanding and avoiding clathrate formation. More recently, natural gas hydrates have been proposed

  15. Pressurized subsampling system for pressured gas-hydrate-bearing sediment: Microscale imaging using X-ray computed tomography

    SciTech Connect (OSTI)

    Jin, Yusuke, E-mail: u-jin@aist.go.jp; Konno, Yoshihiro; Nagao, Jiro [Production Technology Team, Methane Hydrate Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo 062-8517 (Japan)

    2014-09-01T23:59:59.000Z

    A pressurized subsampling system was developed for pressured gas hydrate (GH)-bearing sediments, which have been stored under pressure. The system subsamples small amounts of GH sediments from cores (approximately 50 mm in diameter and 300 mm in height) without pressure release to atmospheric conditions. The maximum size of the subsamples is 12.5 mm in diameter and 20 mm in height. Moreover, our system transfers the subsample into a pressure vessel, and seals the pressure vessel by screwing in a plug under hydraulic pressure conditions. In this study, we demonstrated pressurized subsampling from artificial xenon-hydrate sediments and nondestructive microscale imaging of the subsample, using a microfocus X-ray computed tomography (CT) system. In addition, we estimated porosity and hydrate saturation from two-dimensional X-ray CT images of the subsamples.

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

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    of Gas Price ($/Mscf) for Offshore Gas Hydrate StudyEvaluation of deepwater gas-hydrate systems. The Leadingfor Gas Production from Gas Hydrates Reservoirs. J. Canadian

  17. The rate of isothermal hydration of polyperfluorosulfonic acid membranes

    E-Print Network [OSTI]

    Van Nguyen, Trung; Vanderborgh, N.

    1998-05-27T23:59:59.000Z

    The Rate of Isothermal Hydration of Polyperfluorosulfonic Acid Membranes by Trung Van Nguyen * Department of Chemical and Petroleum Engineering 4006 Learned Hall The University of Kansas Lawrence, Kansas 66045-2223 and Nicholas... conditions for the three phases of a typical polymer hydration dynamic experiment. Measurements were made using a TA3000 Mettler thermal analysis system. Nitrogen was used as the carrier gas along with controlled quantities of water vapor that were...

  18. Effect of bound state of water on hydronium ion mobility in hydrated Nafion using molecular dynamics simulations

    SciTech Connect (OSTI)

    Mabuchi, Takuya, E-mail: mabuchi@nanoint.ifs.tohoku.ac.jp [Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Tokumasu, Takashi [Institute of Fluid Science, Tohoku University, Sendai, Miyagi 980-8577 (Japan)

    2014-09-14T23:59:59.000Z

    We have performed a detailed analysis of the structural properties of the sulfonate groups in terms of isolated and overlapped solvation shells in the nanostructure of hydrated Nafion membrane using classical molecular dynamics simulations. Our simulations have demonstrated the correlation between the two different areas in bound water region, i.e., the first solvation shell, and the vehicular transport of hydronium ions at different water contents. We have employed a model of the Nafion membrane using the improved force field, which is newly modified and validated by comparing the density and water diffusivity with those obtained experimentally. The first solvation shells were classified into the two types, the isolated area and the overlapped area. The mean residence times of solvent molecules explicitly showed the different behaviors in each of those areas in terms of the vehicular transport of protons: the diffusivity of classical hydronium ions in the overlapped area dominates their total diffusion at lower water contents while that in the isolated area dominates for their diffusion at higher water contents. The results provided insights into the importance role of those areas in the solvation shells for the diffusivity of vehicular transport of hydronium ions in hydrated Nafion membrane.

  19. Phase Equilibria Studies in Water-Methane System: Structural Memory-Effect of Water On Hydrate Re-Formation

    E-Print Network [OSTI]

    Kim, Brice Yoonshik

    2014-12-08T23:59:59.000Z

    Naturally-occurring hydrates are promising resources. The potential value of gas accumulation in naturally-occurring gas hydrates can exceed 16 equivalent trillion tons of oil. There are many accurate findings on properties of gas hydrates...

  20. Controls on Gas Hydrate Formation and Dissociation

    SciTech Connect (OSTI)

    Miriam Kastner; Ian MacDonald

    2006-03-03T23:59:59.000Z

    The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane supersaturated, thus bubble plumes form. The subsurface hydrology exhibits both up-flow and down-flow of fluid at rates that range between 0.5 to 214 cm/yr and 2-162 cm/yr, respectively. The fluid flow system at the mound and background sites are coupled having opposite polarities that oscillate episodically between 14 days to {approx}4 months. Stability calculations suggest that despite bottom water temperature fluctuations, of up to {approx}3 C, the Bush Hill gas hydrate mound is presently stable, as also corroborated by the time-lapse video camera images that did not detect change in the gas hydrate mound. As long as methane (and other hydrocarbon) continues advecting at the observed rates the mound would remain stable. The {_}{sup 13}C-DIC data suggest that crude oil instead of methane serves as the primary electron-donor and metabolic substrate for anaerobic sulfate reduction. The oil-dominated environment at Bush Hill shields some of the methane bubbles from being oxidized both anaerobically in the sediment and aerobically in the water column. Consequently, the methane flux across the seafloor is higher at Bush hill than at non-oil rich seafloor gas hydrate regions, such as at Hydrate Ridge, Cascadia. The methane flux across the ocean/atmosphere interface is as well higher. Modeling the methane flux across this interface at three bubble plumes provides values that range from 180-2000 {_}mol/m{sup 2} day; extrapolating it over the Gulf of Mexico basin utilizing satellite data is in progress.

  1. Application of fiber optic temperature and strain sensing technology to gas hydrates

    SciTech Connect (OSTI)

    Ulrich, Shannon M [ORNL; Madden, Megan Elwood [ORNL; Rawn, Claudia J [ORNL; Szymcek, Phillip [ORNL; Phelps, Tommy Joe [ORNL

    2008-01-01T23:59:59.000Z

    Gas hydrates may have a significant influence on global carbon cycles due to their large carbon storage capacity in the form of greenhouse gases and their sensitivity to small perturbations in local conditions. Characterizing existing gas hydrate and the formation of new hydrate within sediment systems and their response to small changes in temperature and pressure is imperative to understanding how this dynamic system functions. Fiber optic sensing technology offers a way to measure precisely temperature and strain in harsh environments such as the seafloor. Recent large-scale experiments using Oak Ridge National Laboratory's Seafloor Process Simulator were designed to evaluate the potential of fiber optic sensors to study the formation and dissociation of gas hydrates in 4-D within natural sediments. Results indicate that the fiber optic sensors are so sensitive to experimental perturbations (e.g. refrigeration cycles) that small changes due to hydrate formation or dissociation can be overshadowed.

  2. Modeling of Oceanic Gas Hydrate Instability and Methane Release in Response to Climate Change

    E-Print Network [OSTI]

    Reagan, Matthew T.

    2008-01-01T23:59:59.000Z

    Potential effects of gas hydrate on human welfare. Proc.W.S. A review of methane and gas hydrates in the dynamic,Geology of Natural Gas Hydrates, M. Max, A.H. Johnson, W.P.

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

    E-Print Network [OSTI]

    Reagan, M.

    2012-01-01T23:59:59.000Z

    Moridis GJ. Oceanic gas hydrate instability and dissociationKA. Potential effects of gas hydrate on human welfare, Proc.WS. A review of methane and gas hydrates in the dynamic,

  4. Glasslike dynamical behavior of the plastocyanin hydration water Anna Rita Bizzarri, Alessandro Paciaroni, and Salvatore Cannistraro

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    in the proximity of the protein surface 3,12 . Such a phenomenon, experimentally supported by neutron scattering 3 PC 5 ; an experimental confirmation of this result was provided very recently by neutron scattering diffusion matches the onset of the dynamical transition observed in the protein. The intermediate scattering

  5. Phase Equilibria Studies in Water-Methane System: Structural Memory-Effect of Water On Hydrate Re-Formation 

    E-Print Network [OSTI]

    Kim, Brice Yoonshik

    2014-12-08T23:59:59.000Z

    Naturally-occurring hydrates are promising resources. The potential value of gas accumulation in naturally-occurring gas hydrates can exceed 16 equivalent trillion tons of oil. There are many accurate findings on properties ...

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

    SciTech Connect (OSTI)

    Frank Rack; Gerhard Bohrmann; Anne Trehu; Michael Storms; Derryl Schroeder; ODP Leg 204 Shipboard Scientific Party

    2002-09-30T23:59:59.000Z

    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.

  7. Cosmological dynamical systems

    E-Print Network [OSTI]

    Genly Leon; Carlos R. Fadragas

    2014-12-18T23:59:59.000Z

    In this book are studied, from the perspective of the dynamical systems, several Universe models. In chapter 1 we give a bird's eye view on cosmology and cosmological problems. Chapter 2 is devoted to a brief review on some results and useful tools from the qualitative theory of dynamical systems. They provide the theoretical basis for the qualitative study of concrete cosmological models. Chapters 1 and 2 are a review of well-known results. Chapters 3, 4, 5 and 6 are devoted to our main results. In these chapters are extended and settled in a substantially different, more strict mathematical language, several results obtained by one of us in arXiv:0812.1013 [gr-qc]; arXiv:1009.0689 [gr-qc]; arXiv:0904.1577[gr-qc]; and arXiv:0909.3571 [hep-th]. In chapter 6, we provide a different approach to the subject discussed in astro-ph/0503478. Additionally, we perform a Poincar\\'e compactification process allowing to construct a global phase space containing all the cosmological information in both finite and infinite regions for all the models.

  8. Multiple stage multiple filter hydrate store

    DOE Patents [OSTI]

    Bjorkman, H.K. Jr.

    1983-05-31T23:59:59.000Z

    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.

  9. Multiple stage multiple filter hydrate store

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K. (Birmingham, MI)

    1983-05-31T23:59:59.000Z

    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.

  10. Methane hydrate research at NETL: Research to make methane production from hydrates a reality

    SciTech Connect (OSTI)

    Taylor, C.E.; Link, D.D.; English, N.

    2007-03-01T23:59:59.000Z

    Research is underway at NETL to understand the physical properties of methane hydrates. Five key areas of research that need further investigation have been identified. These five areas, i.e. thermal properties of hydrates in sediments, kinetics of natural hydrate dissociation, hysteresis effects, permeability of sediments to gas flow and capillary pressures within sediments, and hydrate distribution at porous scale, are important to the production models that will be used for producing methane from hydrate deposits. NETL is using both laboratory experiments and computational modeling to address these five key areas. The laboratory and computational research reinforce each other by providing feedback. The laboratory results are used in the computational models and the results from the computational modeling is used to help direct future laboratory research. The data generated at NETL will be used to help fulfill The National Methane Hydrate R&D Program of a “long-term supply of natural gas by developing the knowledge and technology base to allow commercial production of methane from domestic hydrate deposits by the year 2015” as outlined on the NETL Website [NETL Website, 2005. http://www.netl.doe.gov/scngo/Natural%20Gas/hydrates/index.html]. Laboratory research is accomplished in one of the numerous high-pressure hydrate cells available ranging in size from 0.15 mL to 15 L in volume. A dedicated high-pressure view cell within the Raman spectrometer allows for monitoring the formation and dissociation of hydrates. Thermal conductivity of hydrates (synthetic and natural) at a certain temperature and pressure is performed in a NETL-designed cell. Computational modeling studies are investigating the kinetics of hydrate formation and dissociation, modeling methane hydrate reservoirs, molecular dynamics simulations of hydrate formation, dissociation, and thermal properties, and Monte Carlo simulations of hydrate formation and dissociation.

  11. Kuramoto dynamics in Hamiltonian systems

    E-Print Network [OSTI]

    Dirk Witthaut; Marc Timme

    2013-05-08T23:59:59.000Z

    The Kuramoto model constitutes a paradigmatic model for the dissipative collective dynamics of coupled oscillators, characterizing in particular the emergence of synchrony. Here we present a classical Hamiltonian (and thus conservative) system with 2N state variables that in its action-angle representation exactly yields Kuramoto dynamics on N-dimensional invariant manifolds. We show that the synchronization transition on a Kuramoto manifold emerges where the transverse Hamiltonian action dynamics becomes unstable. The uncovered Kuramoto dynamics in Hamiltonian systems thus distinctly links dissipative to conservative dynamics.

  12. Prototyping of a real size air-conditioning system using a tetra-n-butylammonium bromide semiclathrate hydrate slurry as secondary two-phase refrigerant

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    semiclathrate hydrate slurry as secondary two-phase refrigerant ­ Experimental investigations and modelling). Abstract Among innovative processes developed in the field of refrigeration systems, technologies) is used as secondary refrigerant. The production of the slurry can be smoothed over day and night. Upon

  13. Connecting curves for dynamical systems

    E-Print Network [OSTI]

    R. Gilmore; Jean-Marc Ginoux; Timothy Jones; C. Letellier; U. S. Freitas

    2010-03-08T23:59:59.000Z

    We introduce one dimensional sets to help describe and constrain the integral curves of an $n$ dimensional dynamical system. These curves provide more information about the system than the zero-dimensional sets (fixed points) do. In fact, these curves pass through the fixed points. Connecting curves are introduced using two different but equivalent definitions, one from dynamical systems theory, the other from differential geometry. We describe how to compute these curves and illustrate their properties by showing the connecting curves for a number of dynamical systems.

  14. 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.

  15. Queuing models System dynamics models

    E-Print Network [OSTI]

    Glushko, Robert J.

    models Value chain models Business Model / Organizational Perspective Process Perspective Information#12;#12;#12;#12;Queuing models System dynamics models #12;#12;#12;#12;Blueprint or touchpoint

  16. Increasing gas hydrate formation temperature for desalination of high salinity produced water with secondary guests

    SciTech Connect (OSTI)

    Cha, Jong-Ho [ORISE; Seol, Yongkoo [U.S. DOE

    2013-01-01T23:59:59.000Z

    We suggest a new gas hydrate-based desalination process using water-immiscible hydrate formers; cyclopentane (CP) and cyclohexane (CH) as secondary hydrate guests to alleviate temperature requirements for hydrate formation. The hydrate formation reactions were carried out in an isobaric condition of 3.1 MPa to find the upper temperature limit of CO2 hydrate formation. Simulated produced water (8.95 wt % salinity) mixed with the hydrate formers shows an increased upper temperature limit from ?2 °C for simple CO2 hydrate to 16 and 7 °C for double (CO2 + CP) and (CO2 + CH) hydrates, respectively. The resulting conversion rate to double hydrate turned out to be similar to that with simple CO2 hydrate at the upper temperature limit. Hydrate formation rates (Rf) for the double hydrates with CP and CH are shown to be 22 and 16 times higher, respectively, than that of the simple CO2 hydrate at the upper temperature limit. Such mild hydrate formation temperature and fast formation kinetics indicate increased energy efficiency of the double hydrate system for the desalination process. Dissociated water from the hydrates shows greater than 90% salt removal efficiency for the hydrates with the secondary guests, which is also improved from about 70% salt removal efficiency for the simple hydrates.

  17. Hydrate-phobic surfaces

    E-Print Network [OSTI]

    Smith, Jonathan David, S.M. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Clathrate hydrate formation and subsequent plugging of deep-sea oil and gas pipelines represent a significant bottleneck for ultra deep-sea production. Current methods for hydrate mitigation focus on injecting thermodynamic ...

  18. 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.

    2010-05-01T23:59:59.000Z

    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.

  19. In situ apparatus for the study of clathrate hydrates relevant to solar system bodies using synchrotron X-ray diffraction and Raman spectroscopy

    E-Print Network [OSTI]

    Day, Sarah J; Evans, Aneurin; Parker, Julia E

    2015-01-01T23:59:59.000Z

    Clathrate hydrates are believed to play a significant role in various solar system environments, e.g. comets, and the surfaces and interiors of icy satellites, however the structural factors governing their formation and dissociation are poorly understood. We demonstrate the use of a high pressure gas cell, combined with variable temperature cooling and time-resolved data collection, to the in situ study of clathrate hydrates under conditions relevant to solar system environments. Clathrates formed and processed within the cell are monitored in situ using synchrotron X-ray powder diffraction and Raman spectroscopy. X-ray diffraction allows the formation of clathrate hydrates to be observed as CO2 gas is applied to ice formed within the cell. Complete conversion is obtained by annealing at temperatures just below the ice melting point. A subsequent rise in the quantity of clathrate is observed as the cell is thermally cycled. Four regions between 100-5000cm-1 are present in the Raman spectra that carry feature...

  20. Hydration of the lower stratosphere by ice crystal geysers over land convective systems

    E-Print Network [OSTI]

    Khaykin, S.

    The possible impact of deep convective overshooting over land has been explored by six simultaneous soundings of water vapour, particles and ozone in the lower stratosphere next to Mesoscale Convective Systems (MCSs) during ...

  1. CFD Modeling of Methane Production from Hydrate-Bearing Reservoir

    SciTech Connect (OSTI)

    Gamwo, I.K.; Myshakin, E.M.; Warzinski, R.P.

    2007-04-01T23:59:59.000Z

    Methane hydrate is being examined as a next-generation energy resource to replace oil and natural gas. The U.S. Geological Survey estimates that methane hydrate may contain more organic carbon the the world's coal, oil, and natural gas combined. To assist in developing this unfamiliar resource, the National Energy Technology Laboratory has undertaken intensive research in understanding the fate of methane hydrate in geological reservoirs. This presentation reports preliminary computational fluid dynamics predictions of methane production from a subsurface reservoir.

  2. Dynamical systems probabilistic risk assessment.

    SciTech Connect (OSTI)

    Denman, Matthew R.; Ames, Arlo Leroy

    2014-03-01T23:59:59.000Z

    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.

  3. Methane Hydrate Field Program

    SciTech Connect (OSTI)

    None

    2013-12-31T23:59:59.000Z

    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

  4. Gas Hydrate Storage of Natural Gas

    SciTech Connect (OSTI)

    Rudy Rogers; John Etheridge

    2006-03-31T23:59:59.000Z

    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.

  5. Relation Between the Widom Line and the Dynamic Crossover in Bulk Water and in Protein Hydration Water

    E-Print Network [OSTI]

    Stanley, H. Eugene

    are the derivatives of the state functions with respect to temperature [e.g., isobaric heat capacity CP (H/T)P ] have displaying a liquid-liquid critical point, the relation between changes in dynamic and thermodynamic anomalies arising from the presence of the liquid-liquid critical point. We find a correlation between

  6. Methane hydrate gas production: evaluating and exploiting the solid gas resource

    SciTech Connect (OSTI)

    McGuire, P.L.

    1981-01-01T23:59:59.000Z

    Methane hydrate gas could be a tremendous energy resource if methods can be devised to produce this gas economically. This paper examines two methods of producing gas from hydrate deposits by the injection of hot water or steam, and also examines the feasibility of hydraulic fracturing and pressure reduction as a hydrate gas production technique. A hydraulic fracturing technique suitable for hydrate reservoirs and a system for coring hydrate reservoirs are also described.

  7. Detection and Production of Methane Hydrate

    SciTech Connect (OSTI)

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

    2011-12-31T23:59:59.000Z

    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.

  8. From dynamical systems to renormalization

    SciTech Connect (OSTI)

    Menous, Frédéric [Département de Mathématiques, Bât. 425, UMR 8628, CNRS, Université Paris-Sud, 91405 Orsay Cedex (France)] [Département de Mathématiques, Bât. 425, UMR 8628, CNRS, Université Paris-Sud, 91405 Orsay Cedex (France)

    2013-09-15T23:59:59.000Z

    In this paper we study logarithmic derivatives associated to derivations on completed graded Lie algebra, as well as the existence of inverses. These logarithmic derivatives, when invertible, generalize the exp-log correspondence between a Lie algebra and its Lie group. Such correspondences occur naturally in the study of dynamical systems when dealing with the linearization of vector fields and the non linearizability of a resonant vector fields corresponds to the non invertibility of a logarithmic derivative and to the existence of normal forms. These concepts, stemming from the theory of dynamical systems, can be rephrased in the abstract setting of Lie algebra and the same difficulties as in perturbative quantum field theory (pQFT) arise here. Surprisingly, one can adopt the same ideas as in pQFT with fruitful results such as new constructions of normal forms with the help of the Birkhoff decomposition. The analogy goes even further (locality of counter terms, choice of a renormalization scheme) and shall lead to more interactions between dynamical systems and quantum field theory.

  9. Glass durability evaluation using product consistency, single-pass flow-through, and vapor hydration tests

    SciTech Connect (OSTI)

    Feng, X.; Hrma, P.; Kim, D. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1996-12-31T23:59:59.000Z

    The current approach to assessing chemical durability of waste glasses focuses on a suite of short-term laboratory tests such as dynamic single-pass flow-through (SPFT) tests, static product consistency tests (PCT), and vapor hydration tests. The behavior of the glasses in the three types of tests is quite different, but each test provides insight into the glass corrosion process. The PCT data showed that at constant alumina, silica, and sodium levels the glass durability order for different glass systems is: Boron-series > Boron-Calcium-series > Calcium-series, while the opposite order is observed in SPFT tests. The order for vapor hydration tests is similar to that observed in the PCT tests. The PCT results are consistent with the current understanding of glass structure and are consistent with vapor hydration tests. The SPFT results can be explained using arguments based on solution chemistry.

  10. Chemically reacting plumes, gas hydrate dissociation and dendrite solidification

    E-Print Network [OSTI]

    Conroy, Devin Thomas

    2008-01-01T23:59:59.000Z

    II Gas hydrates Introductionto gas hydrates . . . . . . . . . . 1.127 Gas hydrate dissociation in porous media . 1.

  11. Dynamical Systems and Applications of Nonlinear Functional Analysis to Dynamical Systems

    E-Print Network [OSTI]

    Zhang, Meirong

    Dynamical Systems and Applications of Nonlinear Functional Analysis to Dynamical Systems Meirong consists of three parts. In Part 1 we introduce some basic concepts in dynamical systems, including limit sets, nonwandering sets, topological conjugacy, clas- sification of discrete dynamical systems under

  12. Logarithmic Decay in Single-Particle Relaxation of Hydrated Lysozyme Powder Marco Lagi,1,2

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Logarithmic Decay in Single-Particle Relaxation of Hydrated Lysozyme Powder Marco Lagi,1,2 Piero-dynamics of protein amino acids of hydrated lysozyme powder around the physiological temperature by means of molecular and their hydration water display a feature known as boson peak, typical of strong glass formers [3]; (3) the protein

  13. World-Systems as Dynamic Networks

    E-Print Network [OSTI]

    White, Douglas R.

    World-Systems as Dynamic Networks Christopher Chase-Dunn Institute for Research on World-Systems on comparative world-systems for the workshop on `analyzing complex macrosystems as dynamic networks" at the Santa Fe Institute, April 29- 30, 2004. (8341 words) v. 4-22-04 1 #12;The comparative world-systems

  14. Iodine as a tracer of organic material: 129 I results from gas hydrate

    E-Print Network [OSTI]

    Fehn, Udo

    Iodine as a tracer of organic material: 129 I results from gas hydrate systems and fore arc fluids of this system, investigations of gas hydrates from the Peru Margin (ODP 201, Site 1230) and of fluids collected for these fluids. The results are in good agreement with earlier investigations of gas hydrate systems at Blake

  15. X-ray Scanner for ODP Leg 204: Drilling Gas Hydrates on Hydrate Ridge, Cascadia Continental Margin

    E-Print Network [OSTI]

    Freifeld, Barry; Kneafsey, Tim; Pruess, Jacob; Reiter, Paul; Tomutsa, Liviu

    2002-01-01T23:59:59.000Z

    International Conference of Gas Hydrates, Yokohama, Japan.Prospectus, Drilling Gas Hydrates On Hydrate Ridge, CascadiaLeg 204: Drilling Gas Hydrates on Hydrate Ridge, Cascadia

  16. Confined water in the low hydration regime

    E-Print Network [OSTI]

    P. Gallo; M. Rapinesi; M. Rovere

    2002-04-05T23:59:59.000Z

    Molecular dynamics results on water confined in a silica pore in the low hydration regime are presented. Strong layering effects are found due to the hydrophilic character of the substrate. The local properties of water are studied as function of both temperature and hydration level. The interaction of the thin films of water with the silica atoms induces a strong distortion of the hydrogen bond network. The residence time of the water molecules is dependent on the distance from the surface. Its behavior shows a transition from a brownian to a non-brownian regime approaching the substrate in agreement with results found in studies of water at contact with globular proteins.

  17. (GAS HYDRATES) 2 ()

    E-Print Network [OSTI]

    : ... ... .... .... «» , 28 2007 : « » #12; · ·· #12; 2 #12; (GAS HYDRATES) #12;Y · µ 2 µ () µ · µ µ · µ µ µ ·µ: - - µ CO2 - - #12; - 3S·2M·1L·34H3S

  18. Fe-containing phases in hydrated cements

    SciTech Connect (OSTI)

    Dilnesa, B.Z., E-mail: belay.dilnesa@gmail.com [Empa, Laboratory for Concrete and Construction Chemistry, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Wieland, E. [Paul Scherrer Institute, Laboratory for Waste Management, 5232 Villigen PSI (Switzerland); Lothenbach, B. [Empa, Laboratory for Concrete and Construction Chemistry, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Dähn, R. [Paul Scherrer Institute, Laboratory for Waste Management, 5232 Villigen PSI (Switzerland); Scrivener, K.L. [Ecole Polytechnique Federal de Lausanne (EPFL), Laboratory for Construction Materials, 1015 Lausanne (Switzerland)

    2014-04-01T23:59:59.000Z

    In this study synchrotron X-ray absorption spectroscopy (XAS) has been applied, an element specific technique which allows Fe-containing phases to be identified in the complex mineral mixture of hydrated cements. Several Fe species contributed to the overall Fe K-edge spectra recorded on the cement samples. In the early stage of cement hydration ferrite was the dominant Fe-containing mineral. Ferrihydrite was detected during the first hours of the hydration process. After 1 day the formation of Al- and Fe-siliceous hydrogarnet was observed, while the amount of ferrihydrite decreased. The latter finding agrees with thermodynamic modeling, which predicts the formation of Fe-siliceous hydrogarnet in Portland cement systems. The presence of Al- and Fe-containing siliceous hydrogarnet was further substantiated in the residue of hydrated cement by performing a selective dissolution procedure. - Highlights: • Fe bound to ferrihydrite at early age hydration • Fe found to be stable in siliceous hydrogarnet at longer term age hydration • Fe-containing AFt and AFm phases are less stable than siliceous hydrogarnet. • The study demonstrates EXAFS used to identify amorphous or poorly crystalline phases.

  19. Marine electromagnetic methods for gas hydrate characterization

    E-Print Network [OSTI]

    Weitemeyer, Karen Andrea

    2008-01-01T23:59:59.000Z

    1.2 Gas Hydrates . . . . . . . .1.2.1 Distribution of Gas Hydrates . . . . . . . . . . .1.2.2 Importance of Gas Hydrates . . . . .

  20. Marine Electromagnetic Methods for Gas Hydrate Characterization

    E-Print Network [OSTI]

    Weitemeyer, Karen A

    2008-01-01T23:59:59.000Z

    1.2 Gas Hydrates . . . . . . . .1.2.1 Distribution of Gas Hydrates . . . . . . . . . . .1.2.2 Importance of Gas Hydrates . . . . .

  1. Kinetic limits of dynamical systems

    E-Print Network [OSTI]

    Jens Marklof

    2014-08-06T23:59:59.000Z

    Since the pioneering work of Maxwell and Boltzmann in the 1860s and 1870s, a major challenge in mathematical physics has been the derivation of macroscopic evolution equations from the fundamental microscopic laws of classical or quantum mechanics. Macroscopic transport equations lie at the heart of many important physical theories, including fluid dynamics, condensed matter theory and nuclear physics. The rigorous derivation of macroscopic transport equations is thus not only a conceptual exercise that establishes their consistency with the fundamental laws of physics: the possibility of finding deviations and corrections to classical evolution equations makes this subject both intellectually exciting and relevant in practical applications. The plan of these lectures is to develop a renormalisation technique that will allow us to derive transport equations for the kinetic limits of two classes of simple dynamical systems, the Lorentz gas and kicked Hamiltonians (or linked twist maps). The technique uses the ergodic theory of flows on homogeneous spaces (homogeneous flows for short), and is based on joint work with Andreas Str\\"ombergsson.

  2. September 11, 2008 12:55 Dynamical Systems monotonereacs Dynamical Systems

    E-Print Network [OSTI]

    Banaji,. Murad

    September 11, 2008 12:55 Dynamical Systems monotonereacs Dynamical Systems Vol. 00, No. 00, Month 200x, 1­30 RESEARCH ARTICLE Monotonicity in chemical reaction systems Murad Banajia, a Department) This paper discusses the question of when the dynamical systems arising from chemical reac- tion networks

  3. The structure of tame minimal dynamical systems

    E-Print Network [OSTI]

    Eli Glasner

    2006-09-18T23:59:59.000Z

    A dynamical version of the Bourgain-Fremlin-Talagrand dichotomy shows that the enveloping semigroup of a dynamical system is either very large and contains a topological copy of $\\beta \\N$, or it is a "tame" topological space whose topology is determined by the convergence of sequences. In the latter case the dynamical system is called tame. We use the structure theory of minimal dynamical systems to show that, when the acting group is Abelian, a tame metric minimal dynamical system (i) is almost automorphic (i.e. it is an almost 1-1 extension of an equicontinuous system), and (ii) admits a unique invariant probability measure such that the corresponding measure preserving system is measure theoretically isomorphic to the Haar measure system on the maximal equicontinuous factor.

  4. Methane Hydrate Formation and Dissocation in a Partially Saturated Sand--Measurements and Observations

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.; Seol, Yongkoo; Freifeld, Barry; Taylor, Charles E.; Gupta, Arvind

    2005-03-01T23:59:59.000Z

    We performed a sequence of tests on a partially water-saturated sand sample contained in an x-ray transparent aluminum pressure vessel that is conducive to x-ray computed tomography (CT) observation. These tests were performed to gather data for estimation of thermal properties of the sand/water/gas system and the sand/hydrate/water/gas systems, as well as data to evaluate the kinetic nature of hydrate dissociation. The tests included mild thermal perturbations for the estimation of the thermal properties of the sand/water/gas system, hydrate formation, thermal perturbations with hydrate in the stability zone, hydrate dissociation through thermal stimulation, additional hydrate formation, and hydrate dissociation through depressurization with thermal stimulation. Density changes throughout the sample were observed as a result of hydrate formation and dissociation, and these processes induced capillary pressure changes that altered local water saturation.

  5. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

    Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)

    2003-01-01T23:59:59.000Z

    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).

  6. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

    Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)

    1999-01-01T23:59:59.000Z

    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).

  7. Zeno Dynamics for Open Quantum Systems

    E-Print Network [OSTI]

    J. E. Gough

    2014-04-09T23:59:59.000Z

    In this paper we formulate limit Zeno dynamics of general open systems as the adiabatic elimination of fast components. We are able to exploit previous work on adiabatic elimination of quantum stochastic models to give explicitly the conditions under which open Zeno dynamics will exist. The open systems formulation is further developed as a framework for Zeno master equations, and Zeno filtering (that is, quantum trajectories based on a limit Zeno dynamical model). We discuss several models from the point of view of quantum control. For the case of linear quantum stochastic systems we present a condition for stability of the asymptotic Zeno dynamics.

  8. Imaging Hydrated Microbial Extracellular Polymers: Comparative...

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

    Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy . Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron...

  9. NMR and dielectric studies of hydrated collagen and elastin: Evidence for a delocalized secondary relaxation

    E-Print Network [OSTI]

    Sorin A. Lusceac; Markus Rosenstihl; Michael Vogel; Catalin Gainaru; Ariane Fillmer; Roland Böhmer

    2010-04-23T23:59:59.000Z

    Using a combination of dielectric spectroscopy and solid-state deuteron NMR, the hydration water dynamics of connective tissue proteins is studied at sub-ambient temperatures. In this range, the water dynamics follows an Arrhenius law. A scaling analysis of dielectric losses, 'two-phase' NMR spectra, and spin-lattice relaxation times consistently yield evidence for a Gaussian distribution of energy barriers. With the dielectric data as input, random-walk simulations of a large-angle, quasi-isotropic water reorientation provide an approximate description of stimulated-echo data on hydrated elastin. This secondary process takes place in an essentially rigid energy landscape, but in contrast to typical {\\beta}-relaxations it is quasi-isotropic and delocalized. The delocalization is inferred from previous NMR diffusometry experiments. To emphasize the distinction from conventional {\\beta}-processes, for aqueous systems such a matrix-decoupled relaxation was termed a {\

  10. Effect of Elevated Curing Temperature on Early Hydration and Microstructure of Composite Cements

    E-Print Network [OSTI]

    Sheffield, University of

    Effect of Elevated Curing Temperature on Early Hydration and Microstructure of Composite Cements J, Seascale, Cumbria, CA20 1PG, UK Abstract The heat of hydration of a number of composite cement systems has microscopy. Results showed that increasing the hydration temperature increased the rate of heat output

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

    SciTech Connect (OSTI)

    Bryant, Steven; Juanes, Ruben

    2011-12-31T23:59:59.000Z

    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 di

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

    SciTech Connect (OSTI)

    Bryant, Steven; Juanes, Ruben

    2011-12-31T23:59:59.000Z

    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

  13. Protein viscoelastic dynamics: a model system

    E-Print Network [OSTI]

    Craig Fogle; Joseph Rudnick; David Jasnow

    2015-02-02T23:59:59.000Z

    A model system inspired by recent experiments on the dynamics of a folded protein under the influence of a sinusoidal force is investigated and found to replicate many of the response characteristics of such a system. The essence of the model is a strongly over-damped oscillator described by a harmonic restoring force for small displacements that reversibly yields to stress under sufficiently large displacement. This simple dynamical system also reveals unexpectedly rich behavior, exhibiting a series of dynamical transitions and analogies with equilibrium thermodynamic phase transitions. The effects of noise and of inertia are briefly considered and described.

  14. SIAM conference on applications of dynamical systems

    SciTech Connect (OSTI)

    Not Available

    1992-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Collett, T.S. (USGS); Riedel, M. (McGill Univ., Montreal, Quebec, Canada); Cochran, J.R. (Columbia Univ., Palisades, NY); Boswell, R.M.; Kumar, Pushpendra (Oil and Natural Gas Corporation Ltd., Navi Mumbai, India); Sathe, A.V. (Oil and Natural Gas Corporation Ltd., Uttaranchal, INDIA)

    2008-07-01T23:59:59.000Z

    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).

  16. Distributed Termination Detection for Dynamic Systems

    E-Print Network [OSTI]

    Dhamdhere, Dhananjay Madhav

    Distributed Termination Detection for Dynamic Systems D. M. Dhamdhere \\Lambda Sridhar R. Iyer E for detecting the termination of a dis­ tributed computation is presented. The algorithm does not require global are provided. Keywords Distributed algorithms, Distributed computation, Distributed termination, Dynamic

  17. Ion desolvation as a mechanism for kinetic isotope fractionation in aqueous systems

    E-Print Network [OSTI]

    Hofmann, A.E.

    2014-01-01T23:59:59.000Z

    Radnai T (1993) Structure and dynamics of hydrated ions.  Radnai T (1993) Structure and dynamics of hydrated ions.  Radnai T (1993) Structure and dynamics of hydrated ions.  

  18. Investigating the Metastability of Clathrate Hydrates for Energy Storage

    SciTech Connect (OSTI)

    Koh, Carolyn Ann [Colorado School of Mines

    2014-11-18T23:59:59.000Z

    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.

  19. Ecology & Earth Systems Dynamics for Educators

    E-Print Network [OSTI]

    Amin, S. Massoud

    Ecology & Earth Systems Dynamics for Educators July 21-25, 2014 CI 5540-003 (86282) 3 Credits Science and Earth Science curricula in Minnesota public schools. It is designed primarily for middle

  20. Dynamic Scene Description System ---ODYS Jacek Malec

    E-Print Network [OSTI]

    Malec, Jacek

    ODYS (Opis DYnamicznej Sceny robota), is able to analyse descriptions of consecutive frames for analysing and describing dynamic scene of a robot is presented. The system, called ODYS (Opis DYnamicznej

  1. 17 System Dynamics in Transdisciplinary Research

    E-Print Network [OSTI]

    Richner, Heinz

    in Kyrgyzstan, we illustrate how the use of system dynamics helped to deal with the complexity of the problems management; Kyrgyzstan. #12;Research for Sustainable Development: Foundations, Experiences, and Perspectives

  2. System dynamics, market microstructure and asset pricing

    E-Print Network [OSTI]

    Leika, Mindaugas

    2013-01-01T23:59:59.000Z

    Traditional asset pricing approaches are not able to explain extreme volatility and tail events that characterized financial markets in the past decade. System Dynamics theory, which is still underutilized in financial ...

  3. Ab initio molecular dynamics simulations reveal localization and time evolution dynamics of an excess electron in heterogeneous CO{sub 2}–H{sub 2}O systems

    SciTech Connect (OSTI)

    Liu, Ping; Zhao, Jing; Liu, Jinxiang; Zhang, Meng; Bu, Yuxiang, E-mail: byx@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)] [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)

    2014-01-28T23:59:59.000Z

    In view of the important implications of excess electrons (EEs) interacting with CO{sub 2}–H{sub 2}O clusters in many fields, using ab initio molecular dynamics simulation technique, we reveal the structures and dynamics of an EE associated with its localization and subsequent time evolution in heterogeneous CO{sub 2}–H{sub 2}O mixed media. Our results indicate that although hydration can increase the electron-binding ability of a CO{sub 2} molecule, it only plays an assisting role. Instead, it is the bending vibrations that play the major role in localizing the EE. Due to enhanced attraction of CO{sub 2}, an EE can stably reside in the empty, low-lying ?{sup *} orbital of a CO{sub 2} molecule via a localization process arising from its initial binding state. The localization is completed within a few tens of femtoseconds. After EE trapping, the ?OCO angle of the core CO{sub 2}{sup ?} oscillates in the range of 127°?142°, with an oscillation period of about 48 fs. The corresponding vertical detachment energy of the EE is about 4.0 eV, which indicates extreme stability of such a CO{sub 2}-bound solvated EE in [CO{sub 2}(H{sub 2}O){sub n}]{sup ?} systems. Interestingly, hydration occurs not only on the O atoms of the core CO{sub 2}{sup ?} through formation of O?H–O H–bond(s), but also on the C atom, through formation of a C?H–O H–bond. In the latter binding mode, the EE cloud exhibits considerable penetration to the solvent water molecules, and its IR characteristic peak is relatively red-shifted compared with the former. Hydration on the C site can increase the EE distribution at the C atom and thus reduce the C?H distance in the C?H–O H–bonds, and vice versa. The number of water molecules associated with the CO{sub 2}{sup ?} anion in the first hydration shell is about 4?7. No dimer-core (C{sub 2}O{sub 4}{sup ?}) and core-switching were observed in the double CO{sub 2} aqueous media. This work provides molecular dynamics insights into the localization and time evolution dynamics of an EE in heterogeneous CO{sub 2}–H{sub 2}O media.

  4. Computation with perturbed dynamical systems Olivier Bournez

    E-Print Network [OSTI]

    Graça, Daniel S.

    power of dynamical systems robust to infinitesimal perturbations. Previous work on the subject has deserved much attention is concerned with computer aided verification of hybrid/continuous systems [AP04 systems. In opposition, using a different model for noise (infinitesimal perturbations), it was shown [Fr

  5. Power Spectra for Deterministic Chaotic Dynamical Systems

    E-Print Network [OSTI]

    Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne #3; Georg A. Gottwald y 8 observables. For slowly mixing systems such as Pomeau-Manneville intermittency maps, where the power spectrum done for mixing Axiom A systems [19] where the power spectrum is analytic apart from isolated

  6. Power Spectra for Deterministic Chaotic Dynamical Systems

    E-Print Network [OSTI]

    Gottwald, Georg A.

    Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne Georg A. Gottwald 23 July observables. For slowly mixing systems such as Pomeau-Manneville intermittency maps, where the power spectrum done for mixing Axiom A systems [19] where the power spectrum is analytic apart from isolated

  7. Stochastic dynamic systems fl T. Soderstrom, 1997

    E-Print Network [OSTI]

    Flener, Pierre

    Stochastic dynamic systems Chapter 10 c fl T. S¨oderstr¨om, 1997 1 Optimal stochastic control ffl controllers c fl T. S¨oderstr¨om, 1997 2 Optimal stochastic control ­ some illustrative examples System x¨oderstr¨om, 1997 3 Optimal stochastic control ­ Deterministic system Criterion J = x 2 (N) = [ax(N \\Gamma 1) + bu

  8. Dynamical System Analysis for a phantom model

    E-Print Network [OSTI]

    Nilanjana Mahata; Subenoy Chakraborty

    2014-04-24T23:59:59.000Z

    The paper deals with a dynamical system analysis related to phantom cosmological model . Here gravity is coupled to phantom scalar field having scalar coupling function and a potential. The field equations are reduced to an autonomous dynamical system by a suitable redefinition of the basic variables and assuming some suitable form of the potential function. Finally, critical points are evaluated, their nature have been analyzed and corresponding cosmological scenario has been discussed.

  9. Anholonomy and Geometrical Localization in Dynamical Systems

    E-Print Network [OSTI]

    Radha Balakrishnan; Indubala Satija

    2003-03-31T23:59:59.000Z

    We characterize the geometrical and topological aspects of a dynamical system by associating a geometric phase with a phase space trajectory. Using the example of a nonlinear driven damped oscillator, we show that this phase is resilient to fluctuations, responds to all bifurcations in the system, and also finds new geometric transitions. Enriching the phase space description is a novel phenomenon of ``geometrical localization'' which manifests itself as a significant deviation from planar dynamics over a short time interval.

  10. A pilot-scale continuous-jet hydrate reactor

    SciTech Connect (OSTI)

    Szymcek, Phillip [ORNL; McCallum, Scott [Oak Ridge Associated Universities (ORAU); Taboada Serrano, Patricia L [ORNL; Tsouris, Costas [ORNL

    2008-01-01T23:59:59.000Z

    A three-phase, pilot-scale continuous-jet hydrate reactor (CJHR) has been developed for the production of gas hydrates. The reactor receives water and a hydrate-forming species to produce the solid gas hydrate. The CJHR has been tested for the production of CO{sub 2} hydrate for the purpose of ocean carbon sequestration. Formation of CO{sub 2} hydrate was investigated using various reactor/injector designs in a 72-l high-pressure vessel. Designs of the CJHR varied from single-capillary to multiple-capillary injectors that dispersed (1) liquid CO{sub 2} into water or (2) water into liquid CO{sub 2}. The novel injector is designed to improve the dispersion of one reactant into the other and, thus, eliminate mass transfer barriers that negatively affect conversion. An additional goal was an increase in production rates of two orders of magnitude. The designed injectors were tested in both distilled and saline water. Hydrate production experiments were conducted at different CO{sub 2} and water flow rates and for pressures and temperatures equivalent to intermediate ocean depths (1100-1700 m). The pilot-scale reactor with the novel injection system successfully increased hydrate production rates and efficiency.

  11. Global Dynamics in Galactic Triaxial Systems I

    E-Print Network [OSTI]

    Pablo M. Cincotta; Claudia M. Giordano; Josefa Perez; .

    2006-04-21T23:59:59.000Z

    In this paper we present a theoretical analysis of the global dynamics in a triaxial galactic system using a 3D integrable Hamiltonian as a simple representation. We include a thorough discussion on the effect of adding a generic non--integrable perturbation to the global dynamics of the system. We adopt the triaxial Stackel Hamiltonian as the integrable model and compute its resonance structure in order to understand its global dynamics when a perturbation is introduced. Also do we take profit of this example in order to provide a theoretical discussion about diffussive processes taking place in phase space.

  12. Logarithmic Decay in Single-Particle Relaxation of Hydrated Lysozyme Powder

    E-Print Network [OSTI]

    Baglioni, Piero

    We present the self-dynamics of protein amino acids of hydrated lysozyme powder around the physiological temperature by means of molecular dynamics simulations. The self-intermediate scattering functions of the amino acid ...

  13. Methane Hydrate Formation and Dissociation in a PartiallySaturated Core-Scale Sand Sample

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.; Seol,Yongkoo; Freifeld, Barry M.; Taylor, Charles E.; Gupta, Arvind

    2005-11-03T23:59:59.000Z

    We performed a sequence of tests on a partiallywater-saturated sand sample contained in an x-ray transparent aluminumpressure vessel that is conducive to x-ray computed tomography (CT)observation. These tests were performed to gather data for estimation ofthermal properties of the sand/water/gas system and thesand/hydrate/water/gas systems, as well as data to evaluate the kineticnature of hydrate dissociation. The tests included mild thermalperturbations for the estimation of the thermal properties of thesand/water/gas system, hydrate formation, thermal perturbations withhydrate in the stability zone, hydrate dissociation through thermalstimulation, additional hydrate formation, and hydrate dissociationthrough depressurization with thermal stimulation. Density changesthroughout the sample were observed as a result of hydrate formation anddissociation, and these processes induced capillary pressure changes thataltered local water saturation.

  14. Calcium-Silicate-Hydrate in cementitious systems : chemomechanical correlations, extreme temperature behavior, and kinetics and morphology of in-situ formation

    E-Print Network [OSTI]

    Jagannathan, Deepak

    2013-01-01T23:59:59.000Z

    Concrete, the second most used material on the planet, is a multi-scale heterogeneous material. A fundamental component known as Calcium-Silicate-Hydrate which forms from the reaction between cement and water is the binding ...

  15. Dynamic Impregnator Reactor System (Poster)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01T23:59:59.000Z

    IBRF poster developed for the IBRF showcase. Describes the multifarious system designed for complex feedstock impregnation and processing. IBRF feedstock system has several unit operations combined into one robust system that provides for flexible and staged process configurations, such as spraying, soaking, low-severity pretreatment, enzymatic hydrolysis, fermentation, concentration/evaporation, and distillation.

  16. Synthesis and characterization of a new structure of gas hydrate

    SciTech Connect (OSTI)

    Tulk, Christopher A [ORNL; Chakoumakos, Bryan C [ORNL; Ehm, Lars [Stony Brook University (SUNY); Klug, Dennis D [National Research Council of Canada; Parise, John B [Stony Brook University (SUNY); Yang, Ling [ORNL; Martin, Dave [Argonne National Laboratory (ANL); Ripmeester, John [National Research Council of Canada; Moudrakovski, Igor [National Research Council of Canada; Ratcliffe, Chris [National Research Council of Canada

    2009-01-01T23:59:59.000Z

    Atoms and molecules 0.4 0.9 nm in diameter can be incorporated in the cages formed by hydrogen-bonded water molecules making up the crystalline solid clathrate hydrates. There are three structural families of these hydrates , known as sI, sII and sH, and the structure usually depends on the largest guest molecule in the hydrate. Species such as Ar, Kr, Xe and methane form sI or sII hydrate, sH is unique in that it requires both small and large cage guests for stability. All three structures, containing methane, other hydrocarbons, H2S and CO2, O2 and N2 have been found in the geosphere, with sI methane hydrate by far the most abundant. At high pressures (P > 0.7 kbar) small guests (Ar, Kr, Xe, methane) are also known to form sH hydrate with multiple occupancy of the largest cage in the hydrate. The high-pressure methane hydrate of sH has been proposed as playing a role in the outer solar system, including formation models for Titan , and yet another high pressure phase of methane has been reported , although its structure remains unknown. In this study, we report a new and unique hydrate structure that is derived from the high pressure sH hydrate of xenon. After quench recovery at ambient pressure and 77 K it shows considerable stability at low temperatures (T < 160 K) and is compositionally similar to the sI Xe clathrate starting material. This evidence of structural complexity in compositionally similar clathrate compounds indicates that thermodynamic pressure temperature conditions may not be the only important factor in structure determination, but also the reaction path may have an important effect.

  17. Collective motion in a Hamiltonian dynamical system

    E-Print Network [OSTI]

    Hidetoshi Morita; Kunihiko Kaneko

    2005-06-11T23:59:59.000Z

    Oscillation of macroscopic variables is discovered in a metastable state in the Hamiltonian dynamical system of mean field XY model, the duration of which is divergent with the system size. This long-lasting periodic or quasiperiodic collective motion appears through Hopf bifurcation, which is a typical route in low-dimensional dissipative dynamical systems. The origin of the oscillation is explained, with self-consistent analysis of the distribution function, as the emergence of self-excited ``swings'' through the mean-field. The universality of the phenomena is also discussed.

  18. Reaction dynamics in polyatomic molecular systems

    SciTech Connect (OSTI)

    Miller, W.H. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01T23:59:59.000Z

    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.

  19. Modelling of Gas Clathrate Hydrate Equilibria using the Electrolyte Non-Random Two-Liquid (eNRTL) Model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Modelling of Gas Clathrate Hydrate Equilibria using the Electrolyte Non-Random Two-Liquid (e + salt2 + gas} systems (salt = NaCl, KCl, CaCl2; gas = CH4, CO2) comprising a gas clathrate hydrate phase-electrolyte aqueous systems involving gas hydrate phases. In the H-Lw-G calculations, fugacities in the gas phase were

  20. Rapid gas hydrate formation process

    DOE Patents [OSTI]

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

    2013-01-15T23:59:59.000Z

    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.

  1. Dipolar response of hydrated proteins

    E-Print Network [OSTI]

    Dmitry V. Matyushov

    2011-08-12T23:59:59.000Z

    The paper presents an analytical theory and numerical simulations of the dipolar response of hydrated proteins. The effective dielectric constant of the solvated protein, representing the average dipole moment induced at the protein by a uniform external field, shows a remarkable variation among the proteins studied by numerical simulations. It changes from 0.5 for ubiquitin to 640 for cytochrome c. The former value implies a negative dipolar susceptibility of ubiquitin, that is a dia-electric dipolar response and negative dielectrophoresis. It means that a protein carrying an average dipole of ~240 D is expected to repel from the region of a stronger electric field. This outcome is the result of a negative cross-correlation between the protein and water dipoles, compensating for the positive variance of the protein dipole in the overall dipolar susceptibility. This phenomenon can be characterized as overscreening of protein's dipole by the hydration shell. In contrast to the neutral ubiquitin, charged proteins studied here show para-electric dipolar response and positive dielectrophoresis. The protein-water dipolar cross-correlations are long-ranged, extending approximately 2 nm from the protein surface into the bulk. The analysis of numerical simulations suggests that the polarization of the protein-water interface is strongly affected by the distribution of the protein surface charge. This component of the protein dipolar response gains in importance for high frequencies, above the protein Debye peak, when the response of the protein dipole becomes dynamically arrested. The interface response found in simulations suggests a possibility of a positive increment of the high-frequency dielectric constant of the solution compared to the dielectric constant of the solvent, in support of the observed THz absorbance of protein solutions.

  2. GLOBAL ATTRACTORS OF NONAUTONOMOUS DYNAMICAL SYSTEMS AND ALMOST PERIODIC LIMIT

    E-Print Network [OSTI]

    Louisiana State University

    of general nonautonomous dynamical systems admitting the global compact attractor with special property. x 1

  3. The Great Gas Hydrate Escape

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

    and hydrogen pack into gas hydrates could enlighten alternative fuel production and carbon dioxide storage January 25, 2012 | Tags: Carver, Chemistry, Energy Technologies,...

  4. Robust services in dynamic systems

    E-Print Network [OSTI]

    Rodrigues, Rodrigo Seromenho Miragaia, 1975-

    2005-01-01T23:59:59.000Z

    Our growing reliance on online services accessible on the Internet demands highly- available systems that work correctly without interruption. This thesis extends previous work on Byzantine-fault-tolerant replication to ...

  5. Very Large System Dynamics Models - Lessons Learned

    SciTech Connect (OSTI)

    Jacob J. Jacobson; Leonard Malczynski

    2008-10-01T23:59:59.000Z

    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.

  6. Soft Biometrics Database: A Benchmark For Keystroke Dynamics Biometric Systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Soft Biometrics Database: A Benchmark For Keystroke Dynamics Biometric Systems Syed Zulkarnain Syed authentication resulting in a more se- cure verification system. Soft biometrics allows a refinement the existing biometric modalities, authentication systems based on keystroke dynamics are particularly

  7. 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.

    2007-01-01T23:59:59.000Z

    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.

  8. Topics for GGAM Prelim A. Dynamical systems

    E-Print Network [OSTI]

    Hunter, John K.

    layer problems · Poincar´e-Lindstedt method for periodic solutions of ODEs · Method of multiple scales for oscillatory solutions of ODEs · WKB method References · For A and parts of C related to ODEs: S. H. Strogatz Oscillations, Dynamical Systems, and Bifurcations of Vector Fields; I. Stakgold, Green's Functions and Boundary

  9. Quintessence Scalar Field: A Dynamical Systems Study

    E-Print Network [OSTI]

    Nandan Roy; Narayan Banerjee

    2014-02-27T23:59:59.000Z

    The present work deals with a dynamical systems study of quintessence potentials leading to the present accelerated expansion of the universe. The principal interest is to check for late time attractors which give an accelerated expansion for the universe. Two examples are worked out, namely the exponential and the power-law potentials.

  10. Stochastic dynamic systems fl T. Soderstrom, 1997

    E-Print Network [OSTI]

    Flener, Pierre

    Stochastic dynamic systems Chapter 5 c fl T. S¨oderstr¨om, 1997 1 Optimal estimation ffl The conditional mean ffl Best linear estimate ffl ML estimation c fl T. S¨oderstr¨om, 1997 2 Optimal estimation criterion 2. Symmetric cond pdf c fl T. S¨oderstr¨om, 1997 3 Best linear estimate Given Ex = mx ; Ey = my E

  11. Dynamic Positioning Systems Usability and Interaction Styles

    E-Print Network [OSTI]

    Dunlop, Mark D.

    started offshore- drilling in search of larger deposits of oil. With this, a new generation of vessels on interaction with Dynamic Positioning Systems (DP) and how new interaction styles can be introduced to make/multi-touch combined with hand-gestures to create a new type of user-experience. The aim for this research

  12. Methane hydrate formation and dissociation in a partially saturated core-scale sand sample

    SciTech Connect (OSTI)

    Kneafsey, T.J. (LBNL); Tomutsa, L. (LBNL); Moridis, G.J. (LBNL); Seol, Y. (LBNL); Freifeld, B.M. (LBNL); Taylor, C.E.; Gupta, A. (Colorado School of Mines, Golden, CO)

    2007-03-01T23:59:59.000Z

    We performed a series of experiments to provide data for validating numerical models of gas hydrate behavior in porous media. Methane hydrate was formed and dissociated under various conditions in a large X-ray transparent pressure vessel, while pressure and temperature were monitored. In addition, X-ray computed tomography (CT) was used to determine local density changes during the experiment. The goals of the experiments were to observe changes occurring due to hydrate formation and dissociation, and to collect data to evaluate the importance of hydrate dissociation kinetics in porous media. In the series of experiments, we performed thermal perturbations on the sand/water/gas system, formed methane hydrate, performed thermal perturbations on the sand/hydrate/water/gas system resulting in hydrate formation and dissociation, formed hydrate in the resulting partially dissociated system, and dissociated the hydrate by depressurization coupled with thermal stimulation. Our CT work shows significant water migration in addition to possible shifting of mineral grains in response to hydrate formation and dissociation. The extensive data including pressure, temperatures at multiple locations, and density from CT data is described.

  13. Dynamical real numbers and living systems

    E-Print Network [OSTI]

    Dhurjati Prasad Datta

    2010-01-11T23:59:59.000Z

    Recently uncovered second derivative discontinuous solutions of the simplest linear ordinary differential equation define not only an nonstandard extension of the framework of the ordinary calculus, but also provide a dynamical representation of the ordinary real number system. Every real number can be visualized as a living cell -like structure, endowed with a definite evolutionary arrow. We discuss the relevance of this extended calculus in the study of living systems. We also present an intelligent version of the Newton's first law of motion.

  14. Dynamical Analysis of a Networked Control System

    E-Print Network [OSTI]

    Guofeng Zhang; Guanrong Chen; Tongwen Chen; Maria D'Amico

    2014-05-18T23:59:59.000Z

    A new network data transmission strategy was proposed in Zhang \\& Chen [2005] (arXiv:1405.2404), where the resulting nonlinear system was analyzed and the effectiveness of the transmission strategy was demonstrated via simulations. In this paper, we further generalize the results of Zhang \\& Chen [2005] in the following ways: 1) Construct first-return maps of the nonlinear systems formulated in Zhang \\& Chen [2005] and derive several existence conditions of periodic orbits and study their properties. 2) Formulate the new system as a hybrid system, which will ease the succeeding analysis. 3) Prove that this type of hybrid systems is not structurally stable based on phase transition which can be applied to higher-dimensional cases effortlessly. 4) Simulate a higher-dimensional model with emphasis on their rich dynamics. 5) Study a class of continuous-time hybrid systems as the counterparts of the discrete-time systems discussed above. 6) Propose new controller design methods based on this network data transmission strategy to improve the performance of each individual system and the whole network. We hope that this research and the problems posed here will rouse interests of researchers in such fields as control, dynamical systems and numerical analysis.

  15. Spatiotemporal dynamics in a spatial plankton system

    E-Print Network [OSTI]

    Ranjit Kumar Upadhyay; Weiming Wang; N. K. Thakur

    2011-03-17T23:59:59.000Z

    In this paper, we investigate the complex dynamics of a spatial plankton-fish system with Holling type III functional responses. We have carried out the analytical study for both one and two dimensional system in details and found out a condition for diffusive instability of a locally stable equilibrium. Furthermore, we present a theoretical analysis of processes of pattern formation that involves organism distribution and their interaction of spatially distributed population with local diffusion. The results of numerical simulations reveal that, on increasing the value of the fish predation rates, the sequences spots $\\rightarrow$ spot-stripe mixtures$\\rightarrow$ stripes$\\rightarrow$ hole-stripe mixtures holes$\\rightarrow$ wave pattern is observed. Our study shows that the spatially extended model system has not only more complex dynamic patterns in the space, but also has spiral waves.

  16. Dynamics of heat transfer between nano systems

    E-Print Network [OSTI]

    Svend-Age Biehs; Girish S. Agarwal

    2012-10-18T23:59:59.000Z

    We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.

  17. SUESS ET AL.: SEA FLOOR METHANE HYDRATES AT HYDRATE RIDGE, CASCADIA MARGIN Sea Floor Methane Hydrates at Hydrate Ridge, Cascadia Margin

    E-Print Network [OSTI]

    Goldfinger, Chris

    a variety of gas hydrates in near-surface sediments. Hydrate formation and destruction continuously shape established that the uppermost sediment column contains several distinct layers of gas hydrate which the seafloor to the atmosphere. 1. INTRODUCTION The biogeochemical processes associated with gas hydrate

  18. Response of oceanic hydrate-bearing sediments to thermalstresses

    SciTech Connect (OSTI)

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

    2006-05-01T23:59:59.000Z

    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.

  19. Hydration and Conductivity in Natural Rubber Latex Gloves

    E-Print Network [OSTI]

    Bennett, John K.

    Hydration and Conductivity in Natural Rubber Latex Gloves John K. Bennett, PhD, PE Department of natural rubber latex (NRL) gloves have been of clinical interest since the concept of using an electrical result is that most natural rubber latex gloves have dynamic electrical behavior that precludes the use

  20. Nonsmooth dynamic optimization of systems with varying structure

    E-Print Network [OSTI]

    Yunt, Mehmet, 1975-

    2011-01-01T23:59:59.000Z

    In this thesis, an open-loop numerical dynamic optimization method for a class of dynamic systems is developed. The structure of the governing equations of the systems under consideration change depending on the values of ...

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

    SciTech Connect (OSTI)

    Spencer, Elinor [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Ross, Dr. Nancy [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Parker, Stewart F. [ISIS Facility, Rutherford Appleton Laboratory (ISIS)] [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Kolesnikov, Alexander I [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    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].

  2. A Gentle Introduction to Dynamical Systems Theory

    E-Print Network [OSTI]

    Beer, Randall D.

    A Gentle Introduction to Dynamical Systems Theory Reading: Chapter 1 #12;IU/COGS-Q580/Beer Isaac = -F2 = G m1m2 r2 #12;IU/COGS-Q580/Beer Henri Poincaré and His 3 Bodies Diacu, F. and Holmes, P. (1996 to almost all differential equations cannot be expressed as an explicit formula #12;IU/COGS-Q580/Beer

  3. Stochastic dynamic systems fl T. Soderstrom, 1997

    E-Print Network [OSTI]

    Flener, Pierre

    Stochastic dynamic systems Chapter 2 c fl T. S¨oderstr¨om, 1997 1 Some probability theory ffl Basic facts ffl Conditional distributions ffl Complex­valued Gaussian variables c fl T. S¨oderstr¨om, 1997 2) increasing ffl limx!1 F(x) = 1 ffl lim x!\\Gamma1 F (x) = 0 c fl T. S¨oderstr¨om, 1997 3 Random variables

  4. Stochastic dynamic systems fl T. Soderstrom, 1997

    E-Print Network [OSTI]

    Flener, Pierre

    Stochastic dynamic systems Chapter 9 c fl T. S¨oderstr¨om, 1997 1 Nonlinear filtering ffl Extended(t)H(t)P(tjt \\Gamma 1) â?? x(t + 1jt) = f(t; â?? x(tjt)) F(t) = @f(t;x) @x fi fi fi x=â??x(tjt) G(t) = g(t; x)j x=â??x(tjt) P

  5. SYMBOLIC AND ALGEBRAIC DYNAMICAL SYSTEMS DOUGLAS LIND AND KLAUS SCHMIDT

    E-Print Network [OSTI]

    Lind, Douglas A.

    SYMBOLIC AND ALGEBRAIC DYNAMICAL SYSTEMS DOUGLAS LIND AND KLAUS SCHMIDT ____________ Date: September 30, 2000. 1 #12; 2 DOUGLAS LIND

  6. Simulation Algorithms in Vehicle System Dynamics MARTIN ARNOLD

    E-Print Network [OSTI]

    , hydraulic and other system components [1, 2], see also [3] for a summary of recent developments and [4 an overview on classical and more advanced simu- lation algorithms in vehicle system dynamics that are closelySimulation Algorithms in Vehicle System Dynamics MARTIN ARNOLD SUMMARY Multi-body dynamics may

  7. Learning to Control Dynamic Systems with Automatic Quantization

    E-Print Network [OSTI]

    Ling, Charles X.

    Learning to Control Dynamic Systems with Automatic Quantization Charles X. Ling Department: Learning to Control with Automatic Quantization. 1 #12; 1 Introduction Controlling a dynamic system to control dynamic systems with unknown models is a challenging research problem. However, most previous work

  8. Painting a Picture of Gas Hydrate Distribution with Thermal Images

    SciTech Connect (OSTI)

    Weinberger, Jill L.; Brown, Kevin M.; Long, Philip E.

    2005-02-25T23:59:59.000Z

    Large uncertainties about the energy resource potential and role in global climate change of gas hydrates result from uncertainty about how much hydrate is contained in marine sediments. During Leg 204 of the Ocean Drilling Program (ODP) to the accretionary complex of the Cascadia subduction zone, the entire gas hydrate stability zone was sampled in contrasting geological settings defined by a 3D seismic survey. By integrating results from different methods, including several new techniques developed for Leg 204, we overcome the problem of spatial under-sampling inherent in robust methods traditionally used for estimating the hydrate content of cores and obtain a high-resolution, quantitative estimate of the total amount and spatial variability of gas hydrate in this structural system. We conclude that high gas hydrate content (30-40% of pore space of 20-26% of total volume) is restricted to the upper tens of meters below the seafloor near the summit of the structure, where vigorous fluid venting occurs.

  9. 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 [Sandia National Laboratories, Unknown, Unknown; Vander Meer, Robert Charles,

    2015-01-01T23:59:59.000Z

    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.

  10. Obstacle penetrating dynamic radar imaging system

    DOE Patents [OSTI]

    Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)

    2006-12-12T23:59:59.000Z

    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.

  11. Strategies for gas production from oceanic Class 3 hydrate accumulations

    E-Print Network [OSTI]

    Moridis, George J.; Reagan, Matthew T.

    2007-01-01T23:59:59.000Z

    coexistence of aqueous, gas and hydrate phases, indicatingIntrinsic Rate of Methane Gas Hydrate Decomposition”, Chem.Makogon, Y.F. , “Gas hydrates: frozen energy,” Recherche

  12. Response of oceanic hydrate-bearing sediments to thermal stresses

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    c) aqueous, gas and hydrate phase saturations, (d) waterIntrinsic Rate of Methane Gas Hydrate Decomposition”, Chem.Western Nankai Trough”, in Gas Hydrates: Challenges for the

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

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    permeability measurements of gas hydrate-bearing sediments,International Conference on Gas Hydrates, edited, p. 1058,2009), Influence of gas hydrate morphology on the seismic

  14. Preliminary relative permeability estimates of methane hydrate-bearing sand

    E-Print Network [OSTI]

    Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.

    2006-01-01T23:59:59.000Z

    gas production from gas hydrate reservoirs. We estimated theof gas production from gas hydrate reservoirs. Fieldpermeability function in gas hydrate-bearing sediments is

  15. Wind turbine control systems: Dynamic model development using system identification and the fast structural dynamics code

    SciTech Connect (OSTI)

    Stuart, J.G.; Wright, A.D.; Butterfield, C.P.

    1996-10-01T23:59:59.000Z

    Mitigating the effects of damaging wind turbine loads and responses extends the lifetime of the turbine and, consequently, reduces the associated Cost of Energy (COE). Active control of aerodynamic devices is one option for achieving wind turbine load mitigation. Generally speaking, control system design and analysis requires a reasonable dynamic model of {open_quotes}plant,{close_quotes} (i.e., the system being controlled). This paper extends the wind turbine aileron control research, previously conducted at the National Wind Technology Center (NWTC), by presenting a more detailed development of the wind turbine dynamic model. In prior research, active aileron control designs were implemented in an existing wind turbine structural dynamics code, FAST (Fatigue, Aerodynamics, Structures, and Turbulence). In this paper, the FAST code is used, in conjunction with system identification, to generate a wind turbine dynamic model for use in active aileron control system design. The FAST code is described and an overview of the system identification technique is presented. An aileron control case study is used to demonstrate this modeling technique. The results of the case study are then used to propose ideas for generalizing this technique for creating dynamic models for other wind turbine control applications.

  16. 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.

    2010-11-01T23:59:59.000Z

    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.

  17. Multicavity SCRF calculation of ion hydration energies

    SciTech Connect (OSTI)

    Diercksen, B.H.F. [Max-Planck-Institut Fuer Astrophysik, Muenchen (Germany); Karelson, M. [Univ. of Tartu (Estonia); Tamm, T. [Univ. of Florida, Gainesville, FL (United States)

    1994-12-31T23:59:59.000Z

    The hydration energies of the proton, hydroxyl ion, and several inorganic ions were calculated using the multicavity self-consistent reaction field (MCa SCRF) method developed for the quantum-mechanical modeling of rotationally or flexible systems in dielectric media. The ionic complexes H{sub 3}O{sup +}(H2O){sub 4}, OH{sup {minus}}(H2O){sub 4}, NH{sup +}{sub 4}(H2O){sub 4}, and Hal{sup {minus}}(H2O){sub 4}, where Hal = F, Cl, or Br, have been studied. Each complex was divided between five spheres, corresponding to the central ion and four water molecules in their first coordination sphere, respectively. Each cavity was surrounded by a polarizable medium with the dielectric permittivity of water at room temperature (80). The ionic hydration energies of ions were divided into specific and nonspecific parts. After accounting for the cavity-formation energy using scaled particle theory, good agreement between the total calculated and experimental hydration energies was obtained for all ions studied.

  18. Technology reviews: Dynamic curtain wall systems

    SciTech Connect (OSTI)

    Schuman, J.; Rubinstein, F.; Papamichael, K.; Beltran, L.; Lee, E.S.; Selkowitz, S.

    1992-09-01T23:59:59.000Z

    We present a representative review of existing, emerging, and future technology options in each of five hardware and systems areas in envelope and lighting technologies: lighting systems, glazing systems, shading systems, daylighting optical systems, and dynamic curtain wall systems. The term technology is used here to describe any design choice for energy efficiency, ranging from individual components to more complex systems to general design strategies. The purpose of this task is to characterize die state of the art in envelope and lighting technologies in order to identify those with promise for advanced integrated systems, with an emphasis on California commercial buildings. For each technology category, the following activities have been attempted to the extent possible: Identify key performance characteristics and criteria for each technology. Determine the performance range of available technologies. Identify the most promising technologies and promising trends in technology advances. Examine market forces and market trends. Develop a continuously growing in-house database to be used throughout the project. A variety of information sources have been used in these technology characterizations, including miscellaneous periodicals, manufacturer catalogs and cut sheets, other research documents, and data from previous computer simulations. We include these different sources in order to best show the type and variety of data available, however publication here does not imply our guarantee of these data. Within each category, several broad classes are identified, and within each class we examine the generic individual technologies that fall into that class.

  19. Impact of admixtures on the hydration kinetics of Portland cement

    SciTech Connect (OSTI)

    Cheung, J., E-mail: Josephine.H.Cheung@grace.com [W.R. Grace, 62 Whittemore Avenue, Cambridge MA 02140 (United States); Jeknavorian, A. [W.R. Grace, 62 Whittemore Avenue, Cambridge MA 02140 (United States); Roberts, L. [Roberts Consulting Group LLC, 44 Windsor Avenue, Acton MA 01720 (United States); Silva, D. [W.R. Grace, 62 Whittemore Avenue, Cambridge MA 02140 (United States)

    2011-12-15T23:59:59.000Z

    Most concrete produced today includes either chemical additions to the cement, chemical admixtures in the concrete, or both. These chemicals alter a number of properties of cementitious systems, including hydration behavior, and it has been long understood by practitioners that these systems can differ widely in response to such chemicals. In this paper the impact on hydration of several classes of chemicals is reviewed with an emphasis on the current understanding of interactions with cement chemistry. These include setting retarders, accelerators, and water reducing dispersants. The ability of the chemicals to alter the aluminate-sulfate balance of cementitious systems is discussed with a focus on the impact on silicate hydration. As a key example of this complex interaction, unusual behavior sometimes observed in systems containing high calcium fly ash is highlighted.

  20. Dynamic Reactive Power Control of Isolated Power Systems

    E-Print Network [OSTI]

    Falahi, Milad

    2012-10-03T23:59:59.000Z

    This dissertation presents dynamic reactive power control of isolated power systems. Isolated systems include MicroGrids in islanded mode, shipboard power systems operating offshore, or any other power system operating in islanded mode intentionally...

  1. Structural system identification: Structural dynamics model validation

    SciTech Connect (OSTI)

    Red-Horse, J.R.

    1997-04-01T23:59:59.000Z

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  2. Reliability of dynamic systems under limited information.

    SciTech Connect (OSTI)

    Field, Richard V., Jr. (.,; .); Grigoriu, Mircea

    2006-09-01T23:59:59.000Z

    A method is developed for reliability analysis of dynamic systems under limited information. The available information includes one or more samples of the system output; any known information on features of the output can be used if available. The method is based on the theory of non-Gaussian translation processes and is shown to be particularly suitable for problems of practical interest. For illustration, we apply the proposed method to a series of simple example problems and compare with results given by traditional statistical estimators in order to establish the accuracy of the method. It is demonstrated that the method delivers accurate results for the case of linear and nonlinear dynamic systems, and can be applied to analyze experimental data and/or mathematical model outputs. Two complex applications of direct interest to Sandia are also considered. First, we apply the proposed method to assess design reliability of a MEMS inertial switch. Second, we consider re-entry body (RB) component vibration response during normal re-entry, where the objective is to estimate the time-dependent probability of component failure. This last application is directly relevant to re-entry random vibration analysis at Sandia, and may provide insights on test-based and/or model-based qualification of weapon components for random vibration environments.

  3. Thermal Properties of Methane Hydrate by Experiment and Modeling and Impacts on Technology

    SciTech Connect (OSTI)

    Warzinski, R.P.; Gamwo, I.K.; Rosenbaum, E.M.; Jiang, Hao; Jordan, K.D.; English, N.J. (Univ. College Dublin, IRELAND); Shaw, D.W. (Geneva College, Beaver Falls, PA)

    2008-07-01T23:59:59.000Z

    Thermal properties of pure methane hydrate, under conditions similar to naturally occurring hydrate-bearing sediments being considered for potential production, have been determined both by a new experimental technique and by advanced molecular dynamics simulation (MDS). A novel single-sided, Transient Plane Source (TPS) technique has been developed and used to measure thermal conductivity and thermal diffusivity values of low-porosity methane hydrate formed in the laboratory. The experimental thermal conductivity data are closely matched by results from an equilibrium MDS method using in-plane polarization of the water molecules. MDS was also performed using a non-equilibrium model with a fully polarizable force field for water. The calculated thermal conductivity values from this latter approach were similar to the experimental data. The impact of thermal conductivity on gas production from a hydrate-bearing reservoir was also evaluated using the Tough+/Hydrate reservoir simulator.

  4. Dynamic data filtering system and method

    DOE Patents [OSTI]

    Bickford, Randall L; Palnitkar, Rahul M

    2014-04-29T23:59:59.000Z

    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. The dynamics of power system markets Fernando L. Alvarado

    E-Print Network [OSTI]

    The dynamics of power system markets Fernando L. Alvarado Department of Electrical and Computer describing the marketplace. Dynamic market equations provide additional insights into the behavior studies the impact of various policies on the dynamic behavior of power system markets. The impact

  6. Modelling and simulation of multidisciplinary dynamic systems Lead: A. Fakri.

    E-Print Network [OSTI]

    Baudoin, Geneviève

    Modelling and simulation of multidisciplinary dynamic systems Lead: A. Fakri. Permanent members: P. Integration of various engineering disciplines and the consideration of the dynamic control need a concurrent suited for the energy exchanges to study multidisciplinary dynamic engineering systems modelling. Our

  7. Dynamics of two-dimensional dipole systems

    SciTech Connect (OSTI)

    Golden, Kenneth I.; Kalman, Gabor J.; Hartmann, Peter; Donko, Zoltan [Department of Mathematics and Statistics, Department of Physics, University of Vermont, Burlington, Vermont 05401 (United States); Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary and Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States)

    2010-09-15T23:59:59.000Z

    Using a combined analytical/molecular dynamics approach, we study the current fluctuation spectra and longitudinal and transverse collective mode dispersions of the classical two-dimensional (point) dipole system (2DDS) characterized by the {phi}{sub D}(r)={mu}{sup 2}/r{sup 3} repulsive interaction potential; {mu} is the electric dipole strength. The interest in the 2DDS is twofold. First, the quasi-long-range 1/r{sup 3} interaction makes the system a unique classical many-body system, with a remarkable collective mode behavior. Second, the system may be a good model for a closely spaced semiconductor electron-hole bilayer, a system that is in the forefront of current experimental interest. The longitudinal collective excitations, which are of primary interest for the liquid phase, are acoustic at long wavelengths. At higher wave numbers and for sufficiently high coupling strength, we observe the formation of a deep minimum in the dispersion curve preceded by a sharp maximum; this is identical to what has been observed in the dispersion of the zero-temperature bosonic dipole system, which in turn emulates so-called roton-maxon excitation spectrum of the superfluid {sup 4}He. The analysis we present gives an insight into the emergence of this apparently universal structure, governed by strong correlations. We study both the liquid and the crystalline solid state. We also observe the excitation of combination frequencies, resembling the roton-roton, roton-maxon, etc. structures in {sup 4}He.

  8. Reasoning about Dynamic Systems and Bifurcations Juan J. Flores

    E-Print Network [OSTI]

    Bailey-Kellogg, Chris

    A bifurcation occurs in a dynamic system when the structure of the system itself and therefore also its qual of an electrical power system changes during the day, etc. Changes in the parameters, even if they are infinitesReasoning about Dynamic Systems and Bifurcations Juan J. Flores juanf@zeus.umich.mx Division de

  9. Structural and Dynamic Changes in Concurrent Systems: Reconfigurable Petri Nets

    E-Print Network [OSTI]

    Alpuente, María

    Structural and Dynamic Changes in Concurrent Systems: Reconfigurable Petri Nets Marisa Llorens subject to dynamic changes using extensions of Petri nets. We begin by introducing the notion of net rewriting system. In a net rewriting system, a system configuration is described as a Petri net and a change

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

    SciTech Connect (OSTI)

    Dunbar, John

    2012-12-31T23:59:59.000Z

    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.

  11. 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.

    2007-09-01T23:59:59.000Z

    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

  12. Open Systems Dynamics for Propagating Quantum Fields

    E-Print Network [OSTI]

    Ben Q. Baragiola

    2014-08-18T23:59:59.000Z

    In this dissertation, I explore interactions between matter and propagating light. The electromagnetic field is modeled as a reservoir of quantum harmonic oscillators successively streaming past a quantum system. Each weak and fleeting interaction entangles the light and the system, and the light continues its course. Within the framework of open quantum systems, the light is eventually traced out, leaving the reduced quantum state of the system as the primary mathematical subject. Two major results are presented. The first is a master equation approach for a quantum system interacting with a traveling wave packet prepared with a definite number of photons. In contrast to quasi-classical states, such as coherent or thermal fields, these N-photon states possess temporal mode entanglement, and local interactions in time have nonlocal consequences. The second is a model for a three-dimensional light-matter interface for an atomic ensemble interacting with a paraxial laser beam and its application to the generation of QND spin squeezing. Both coherent and incoherent dynamics due to spatially inhomogeneous atom-light coupling across the ensemble are accounted for. Measurement of paraxially scattered light can generate squeezing of an atomic spin wave, while diffusely scattered photons lead to spatially local decoherence.

  13. 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.

    2009-08-15T23:59:59.000Z

    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.

  14. SOFT-GLUON DYNAMICS FOR HEAVY QUARK-ANTIQUARK SYSTEMS

    E-Print Network [OSTI]

    Shizuya, Ken-ichi

    2013-01-01T23:59:59.000Z

    gluons Ak, system, the binding energy bE and soft gluons inbe SOFT-GLUON DYNAMICS FOR HEAVY QUAR_K-ANTIQUARK SYSTEMS s·soft external perturbations (via gluons sof·ter than the system

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

    E-Print Network [OSTI]

    Sherman, Max H.

    2011-01-01T23:59:59.000Z

    Dynamic Control of Ventilation Systems M.H. Sherman and I.S.a defined mechanical ventilation system to provide minimumair as part of ventilation system operation changes with

  16. Stellar and dynamical evolution within triple systems

    E-Print Network [OSTI]

    P. P. Eggleton; L. G. Kiseleva

    1995-10-20T23:59:59.000Z

    About 5-15% of stellar systems are at least triple. About 1% of systems with a primary of $\\tgs 1 \\Mscun$ are triple with a {\\it longer} peri od that is less than 30y, and so may in principle be capable of Roche-lobe overflow in both the inner and the outer orbits, at different times. We discuss possible evolutionary paths for these systems, some of which may lead to objects that are difficult to understand in the context of purely binary evolution. An example is OW Gem, a binary containing two supergiants (spectral types F and G) with masses that difffer by a factor of 1.5. There is also a triple-star pathway which could lead rather naturally to low-mass X-ray binaries; whereas binary pathways often appear rather contrived. We also discuss some dynamical pr ocesses involved in the 3-body problem. A number of triple stars are found in clusters. Similar systems can be created by gravitational capture during N-body simulations of Galactic clusters, especially if there is a n assumed primordial binary population. We discuss the properties of these triples , and note that many can be quite long-lived.

  17. Synchronization of hypernetworks of coupled dynamical systems

    E-Print Network [OSTI]

    Francesco Sorrentino

    2012-03-14T23:59:59.000Z

    We consider synchronization of coupled dynamical systems when different types of interactions are simultaneously present. We assume that a set of dynamical systems are coupled through the connections of two or more distinct networks (each of which corresponds to a distinct type of interaction), and we refer to such a system as a hypernetwork. Applications include neural networks formed of both electrical gap junctions and chemical synapses, the coordinated motion of shoals of fishes communicating through both vision and flow sensing, and hypernetworks of coupled chaotic oscillators. We first analyze the case of a hypernetwork formed of $m=2$ networks. We look for necessary and sufficient conditions for synchronization. We attempt at reducing the linear stability problem in a master stability function form, i.e., at decoupling the effects of the coupling functions from the structure of the networks. Unfortunately, we are unable to obtain a reduction in a master stability function form for the general case. However, we show that such a reduction is possible in three cases of interest: (i) the Laplacian matrices associated with the two networks commute; (ii) one of the two networks is unweighted and fully connected; (iii) one of the two networks is such that the coupling strength from node $i$ to node $j$ is a function of $j$ but not of $i$. Furthermore, we define a class of networks such that if either one of the two coupling networks belongs to this class, the reduction can be obtained independently of the other network. As an example of interest, we study synchronization of a neural hypernetwork for which the connections can be either chemical synapses or electrical gap junctions. We propose a generalization of our stability results to the case of hypernetworks formed of $m\\geq 2$ networks.

  18. Solubility of Hematite Revisited: Effects of Hydration

    E-Print Network [OSTI]

    Burgos, William

    immediately after synthesis, but [Fe(III)diss] increased with hydration time to be consistent with the predicted solubility of goethite or hydrous ferric oxide (HFO), hydrated analogues of hematite. X an equilibrium with goethite or HFO. This is the first experimental confirmation that the interfacial hydration

  19. DISCRETE AND CONTINUOUS Website: http://AIMsciences.org DYNAMICAL SYSTEMS

    E-Print Network [OSTI]

    Shiau, LieJune

    well known fact: When there is dry friction, the force necessary to put the system into motion. 806­815 OPERATOR SPLITTING METHOD FOR FRICTION CONSTRAINED DYNAMICAL SYSTEMS LieJune Shiau Department-discretization of those relations mod- eling a class of dynamical systems with friction was discussed. The main goal

  20. Sensitivity, Approximation and Uncertainty in Power System Dynamic Simulation

    E-Print Network [OSTI]

    1 Sensitivity, Approximation and Uncertainty in Power System Dynamic Simulation Ian A. Hiskens, Fellow, IEEE Jassim Alseddiqui Student Member, IEEE Abstract-- Parameters of power system models the influence of uncertainty in simulations of power system dynamic behaviour. It is shown that trajectory

  1. Dynamic Power Management for Portable Systems Tajana Simunic

    E-Print Network [OSTI]

    De Micheli, Giovanni

    Dynamic Power Management for Portable Systems Tajana Simunic Computer Systems Laboratory Stanford delivering high performance. Dynamic power management (DPM) policies trade off the performance for the power by commands issued by a power manager (PM) that observes the workload of the system and decides when and how

  2. Hybrid Renewable Energy Systems for a Dynamically Positioned Buoy

    E-Print Network [OSTI]

    Wood, Stephen L.

    of the vessel and environmental conditions, power requirements for DP tend to be quite substantial and costly of powering a low cost, simple, dynamic positioning system. This system was implemented on a dynamically a theoretical hybrid renewable energy system to power it, thereby improving on the station keeping buoy (SKB

  3. Methods and systems for combustion dynamics reduction

    DOE Patents [OSTI]

    Kraemer, Gilbert Otto (Greer, SC); Varatharajan, Balachandar (Cincinnati, OH); Srinivasan, Shiva (Greer, SC); Lynch, John Joseph (Wilmington, NC); Yilmaz, Ertan (Albany, NY); Kim, Kwanwoo (Greer, SC); Lacy, Benjamin (Greer, SC); Crothers, Sarah (Greenville, SC); Singh, Kapil Kumar (Rexford, NY)

    2009-08-25T23:59:59.000Z

    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.

  4. RAPID DYNAMICAL CHAOS IN AN EXOPLANETARY SYSTEM

    SciTech Connect (OSTI)

    Deck, Katherine M.; Winn, Joshua N. [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Holman, Matthew J.; Carter, Joshua A.; Ragozzine, Darin [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Lissauer, Jack J. [NASA Ames Research Center, Moffet Field, CA 94035 (United States)

    2012-08-10T23:59:59.000Z

    We report on the long-term dynamical evolution of the two-planet Kepler-36 system, which consists of a super-Earth and a sub-Neptune in a tightly packed orbital configuration. The orbits of the planets, which we studied through numerical integrations of initial conditions that are consistent with observations of the system, are chaotic with a Lyapunov time of only {approx}10 years. The chaos is a consequence of a particular set of orbital resonances, with the inner planet orbiting 34 times for every 29 orbits of the outer planet. The rapidity of the chaos is due to the interaction of the 29:34 resonance with the nearby first-order 6:7 resonance, in contrast to the usual case in which secular terms in the Hamiltonian play a dominant role. Only one contiguous region of phase space, accounting for {approx}4.5% of the sample of initial conditions studied, corresponds to planetary orbits that do not show large-scale orbital instabilities on the timescale of our integrations ({approx}200 million years). Restricting the orbits to this long-lived region allows a refinement of estimates of the masses and radii of the planets. We find that the long-lived region consists of the initial conditions that satisfy the Hill stability criterion by the largest margin. Any successful theory for the formation of this system will need to account for why its current state is so close to unstable regions of phase space.

  5. Thermodynamics of quantum systems under dynamical control

    E-Print Network [OSTI]

    D. Gelbwaser-Klimovsky; Wolfgang Niedenzu; Gershon Kurizki

    2015-03-04T23:59:59.000Z

    In this review the debated rapport between thermodynamics and quantum mechanics is addressed in the framework of the theory of periodically-driven/controlled quantum-thermodynamic machines. The basic model studied here is that of a two-level system (TLS), whose energy is periodically modulated while the system is coupled to thermal baths. When the modulation interval is short compared to the bath memory time, the system-bath correlations are affected, thereby causing cooling or heating of the TLS, depending on the interval. In steady state, a periodically-modulated TLS coupled to two distinct baths constitutes the simplest quantum heat machine (QHM) that may operate as either an engine or a refrigerator, depending on the modulation rate. We find their efficiency and power-output bounds and the conditions for attaining these bounds. An extension of this model to multilevel systems shows that the QHM power output can be boosted by the multilevel degeneracy. These results are used to scrutinize basic thermodynamic principles: (i) Externally-driven/modulated QHMs may attain the Carnot efficiency bound, but when the driving is done by a quantum device ("piston"), the efficiency strongly depends on its initial quantum state. Such dependence has been unknown thus far. (ii) The refrigeration rate effected by QHMs does not vanish as the temperature approaches absolute zero for certain quantized baths, e.g., magnons, thous challenging Nernst's unattainability principle. (iii) System-bath correlations allow more work extraction under periodic control than that expected from the Szilard-Landauer principle, provided the period is in the non-Markovian domain. Thus, dynamically-controlled QHMs may benefit from hitherto unexploited thermodynamic resources.

  6. Dynamic Positioning System as Dynamic Energy Storage on Diesel-Electric Ships

    E-Print Network [OSTI]

    Johansen, Tor Arne

    1 Dynamic Positioning System as Dynamic Energy Storage on Diesel-Electric Ships Tor A. Johansen in order to implement energy storage in the kinetic and potential energy of the ship motion using the DP in order to relate the dynamic energy storage capacity to the maximum allowed ship position deviation

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

    SciTech Connect (OSTI)

    Kowalsky, Michael B.; Moridis, George J.

    2006-11-29T23:59:59.000Z

    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.

  8. Can xenon in water inhibit ice growth? Molecular dynamics of phase transitions in water$-$Xe system

    E-Print Network [OSTI]

    Vasilii I. Artyukhov; Alexander Yu. Pulver; Alex Peregudov; Igor Artyuhov

    2014-07-11T23:59:59.000Z

    Motivated by recent experiments showing the promise of noble gases as cryoprotectants, we perform molecular dynamics modeling of phase transitions in water with xenon under cooling. We study the structure and dynamics of xenon water solution as a function of temperature. Homogeneous nucleation of clathrate hydrate phase is observed and characterized. As the temperature is further reduced we observe hints of dissociation of clathrate due to stronger hydrophobic hydration, pointing towards a possible instability of clathrate at cryogenic temperatures and conversion to an amorphous phase comprised of "xenon + hydration shell" Xe$\\cdot$(H$_{2}$O)$_{21.5}$ clusters. Simulations of ice$-$xenon solution interface in equilibrium and during ice growth reveal the effects of xenon on the ice$-$liquid interface, where adsorbed xenon causes roughening of ice surface but does not preferentially form clathrate. These results provide evidence against the ice-blocker mechanism of xenon cryoprotection.

  9. New techniques for monitoring cement hydration under simulated well conditions

    SciTech Connect (OSTI)

    Luke, K.; Hall, C.; Jones, T. [Schlumberger Cambridge Research (United Kingdom); Barnes, P.; Turillas, X.; Lewis, A. [Univ. of London (United Kingdom). Birkbeck College

    1995-11-01T23:59:59.000Z

    Fourier transform infrared spectroscopy and synchrotron X-ray powder diffraction methods are described for studying cement hydration chemistry at temperatures up to 200 C, covering the normal temperature range of wellbore cementing. The methods provide complementary information on the transformation of silicate, ferrite and sulfate minerals. The thermal decomposition of the cement mineral ettringite is shown to occur at 114 C in a sealed system in contact with water. The FTIR spectrum of a well cement slurry hydrating at 150 C and 2,000 psi is analyzed. The anomalous thickening time behavior of certain cements around 75--100 C is discussed in the light of new data on the hydration of a Class G cement at 65 and 95 C, with and without retarder.

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

    SciTech Connect (OSTI)

    Rau, Dr. Donald [National Institutes of Health

    2008-01-01T23:59:59.000Z

    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.

  11. 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.

    2011-07-01T23:59:59.000Z

    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.

  12. NATURAL GAS HYDRATES STORAGE PROJECT PHASE II. CONCEPTUAL DESIGN AND ECONOMIC STUDY

    SciTech Connect (OSTI)

    R.E. Rogers

    1999-09-27T23:59:59.000Z

    DOE Contract DE-AC26-97FT33203 studied feasibility of utilizing the natural-gas storage property of gas hydrates, so abundantly demonstrated in nature, as an economical industrial process to allow expanded use of the clean-burning fuel in power plants. The laboratory work achieved breakthroughs: (1) Gas hydrates were found to form orders of magnitude faster in an unstirred system with surfactant-water micellar solutions. (2) Hydrate particles were found to self-pack by adsorption on cold metal surfaces from the micellar solutions. (3) Interstitial micellar-water of the packed particles were found to continue forming hydrates. (4) Aluminum surfaces were found to most actively collect the hydrate particles. These laboratory developments were the bases of a conceptual design for a large-scale process where simplification enhances economy. In the design, hydrates form, store, and decompose in the same tank in which gas is pressurized to 550 psi above unstirred micellar solution, chilled by a brine circulating through a bank of aluminum tubing in the tank employing gas-fired refrigeration. Hydrates form on aluminum plates suspended in the chilled micellar solution. A low-grade heat source, such as 110 F water of a power plant, circulates through the tubing bank to release stored gas. The design allows a formation/storage/decomposition cycle in a 24-hour period of 2,254,000 scf of natural gas; the capability of multiple cycles is an advantage of the process. The development costs and the user costs of storing natural gas in a scaled hydrate process were estimated to be competitive with conventional storage means if multiple cycles of hydrate storage were used. If more than 54 cycles/year were used, hydrate development costs per Mscf would be better than development costs of depleted reservoir storage; above 125 cycles/year, hydrate user costs would be lower than user costs of depleted reservoir storage.

  13. High-pressure gas hydrates 

    E-Print Network [OSTI]

    Loveday, J. S.; Nelmes, R. J.

    It has long been known that crystalline hydrates are formed by many simple gases that do not interact strongly with water, and in most cases the gas molecules or atoms occupy 'cages' formed by a framework of water molecules. The majority...

  14. Estimating Power System Dynamic States Using Extended Kalman Filter

    SciTech Connect (OSTI)

    Huang, Zhenyu; Schneider, Kevin P.; Nieplocha, Jaroslaw; Zhou, Ning

    2014-10-31T23:59:59.000Z

    Abstract—The state estimation tools which are currently deployed in power system control rooms are based on a steady state assumption. As a result, the suite of operational tools that rely on state estimation results as inputs do not have dynamic information available and their accuracy is compromised. This paper investigates the application of Extended Kalman Filtering techniques for estimating dynamic states in the state estimation process. The new formulated “dynamic state estimation” includes true system dynamics reflected in differential equations, not like previously proposed “dynamic state estimation” which only considers the time-variant snapshots based on steady state modeling. This new dynamic state estimation using Extended Kalman Filter has been successfully tested on a multi-machine system. Sensitivity studies with respect to noise levels, sampling rates, model errors, and parameter errors are presented as well to illustrate the robust performance of the developed dynamic state estimation process.

  15. Lyapunov Mode Dynamics in Hard-Disk Systems

    E-Print Network [OSTI]

    D. J. Robinson; G. P. Morriss

    2007-09-20T23:59:59.000Z

    The tangent dynamics of the Lyapunov modes and their dynamics as generated numerically - {\\it the numerical dynamics} - is considered. We present a new phenomenological description of the numerical dynamical structure that accurately reproduces the experimental data for the quasi-one-dimensional hard-disk system, and shows that the Lyapunov mode numerical dynamics is linear and separate from the rest of the tangent space. Moreover, we propose a new, detailed structure for the Lyapunov mode tangent dynamics, which implies that the Lyapunov modes have well-defined (in)stability in either direction of time. We test this tangent dynamics and its derivative properties numerically with partial success. The phenomenological description involves a time-modal linear combination of all other Lyapunov modes on the same polarization branch and our proposed Lyapunov mode tangent dynamics is based upon the form of the tangent dynamics for the zero modes.

  16. The Dynamics of Poor Systems of Galaxies

    E-Print Network [OSTI]

    A. Mahdavi; M. J. Geller; H. Boehringer; M. J. Kurtz; M. Ramella

    1999-01-08T23:59:59.000Z

    We assemble and observe a sample of poor galaxy systems that is suitable for testing N-body simulations of hierarchical clustering (Navarro, Frenk, & White 1997; NFW) and other dynamical halo models (e.g., Hernquist 1990). We (1) determine the parameters of the density profile rho(r) and the velocity dispersion profile sigma(R), (2) separate emission-line galaxies from absorption-line galaxies, examining the model parameters and as a function of spectroscopic type, and (3) for the best-behaved subsample, constrain the velocity anisotropy parameter, beta, which determines the shapes of the galaxy orbits. The NFW universal profile and the Hernquist (1990) model both provide good descriptions of the spatial data. In most cases an isothermal sphere is ruled out. Systems with declining sigma(R) are well-matched by theoretical profiles in which the star-forming galaxies have predominantly radial orbits (beta > 0); many of these galaxies are probably falling in for the first time. There is significant evidence for spatial segregation of the spectroscopic classes regardless of sigma(R).

  17. Handbook of gas hydrate properties and occurrence

    SciTech Connect (OSTI)

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

    1983-12-01T23:59:59.000Z

    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.

  18. Enhancement of Hydrogen Storage Capacity in Hydrate Lattices

    SciTech Connect (OSTI)

    Yoo, Soohaeng; Xantheas, Sotiris S.

    2012-02-16T23:59:59.000Z

    First principles electronic structure calculations of the gas phase pentagonal dodecahedron (H2O)20 (D-cage) and tetrakaidecahedron (H2O)24 (T-cage), which are building blocks of structure I (sI) hydrate lattice, suggest that these can accommodate up to a maximum of 5 and 7 guest hydrogen molecules, respectively. For the pure hydrogen hydrate, Born-Oppenheimer Molecular Dynamics (BOMD) simulations of periodic (sI) hydrate lattices indicate that the guest molecules are released into the vapor phase via the hexagonal phases of the larger T-cages. An additional mechanism for the migration between neighboring D- and T-cages was found to occur through a shared pentagonal face via the breaking and reforming of a hydrogen bond. This molecular mechanism is also found for the expulsion of a CH4 molecule from the D-cage. The presence of methane in the larger T-cages was found to block this release, therefore suggesting possible scenarios for the stabilization of these mixed guest clathrate hydrates and the potential enhancement of their hydrogen storage capacity.

  19. Laboratory measurements on core-scale sediment/hydrate samples to predice reservoir behavior

    E-Print Network [OSTI]

    Kneafsey, Timothy J.; Seol, Yongkoo; Moridis, George J.; Tomutsa, Liviu; Freifeld, Barry M.

    2008-01-01T23:59:59.000Z

    International Conference on Gas Hydrates, Trondheim, Norway,coring of near-surface gas hydrate sediments on HydrateInternational Conference on Gas Hydrates, Trondheim, Norway,

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

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    Collett, T.S. , 1993. Natural gas hydrates of the Prudhoe2008. Mechanical Properties of Natural Gas Hydrate Bearinggas hydrate reservoir. Natural Gas Hydrate: In Oceanic and

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

    Office of Environmental Management (EM)

    from the March 27th - 28th Methane Hydrates Advisory Committee Meeting International Gas Hydrate Research DOE's Natural Gas Hydrates Program Gas Hydrates as a Geohazard: What...

  2. Laboratory measurements on core-scale sediment/hydrate samples to predice reservoir behavior

    E-Print Network [OSTI]

    Kneafsey, Timothy J.; Seol, Yongkoo; Moridis, George J.; Tomutsa, Liviu; Freifeld, Barry M.

    2008-01-01T23:59:59.000Z

    International Conference on Gas Hydrates, Yokohama, May 19-International Conference on Gas Hydrates, Trondheim, Norway,coring of near-surface gas hydrate sediments on Hydrate

  3. Analysis of Power System Dynamics Subject to Stochastic Power Injections

    E-Print Network [OSTI]

    DeVille, Lee

    to the computation of long-term power system state statistics; and to short-term probabilistic dynamic performance/reliability of renewable re- sources such as wind energy conversion systems (WECS) and photovoltaic energy conversion

  4. Applications of axial and radial compressor dynamic system modeling

    E-Print Network [OSTI]

    Spakovszky, Zoltán S. (Zoltán Sándor), 1972-

    2001-01-01T23:59:59.000Z

    The presented work is a compilation of four different projects related to axial and centrifugal compression systems. The projects are related by the underlying dynamic system modeling approach that is common in all of them. ...

  5. A short Introduction to Dynamical Systems Joseph Paez Chavez

    E-Print Network [OSTI]

    Páez Chávez, Joseph

    , Ecuador jpaez@espol.edu.ec September 22, 2011 Abstract In this manuscript the concept of dynamical systems of the solar system and the three-body problem by means of ODEs. In order to simplify the analysis, Poincar

  6. Model reduction for nonlinear dynamical systems with parametric uncertainties

    E-Print Network [OSTI]

    Zhou, Yuxiang Beckett

    2012-01-01T23:59:59.000Z

    Nonlinear dynamical systems are known to be sensitive to input parameters. In this thesis, we apply model order reduction to an important class of such systems -- one which exhibits limit cycle oscillations (LCOs) and ...

  7. Methane hydrate formation and dissociationin a partially saturatedcore-scale sand sample

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.; Seol,Yongkoo; Freifeld, Barry M.; Taylor, Charles E.; Gupta, Arvind

    2006-02-03T23:59:59.000Z

    We performed a series of experiments to provide data forvalidating numerical models of gas hydrate behavior in porous media.Methane hydrate was formed and dissociated under various conditions in alarge X-ray transparent pressure vessel, while pressure and temperaturewere monitored. In addition, X-ray computed tomography (CT) was used todetermine local density changes during the experiment. The goals of theexperiments were to observe changes occurring due to hydrate formationand dissociation, and to collect data to evaluate the importance ofhydrate dissociation kinetics in porous media. In the series ofexperiments, we performed thermal perturbations on the sand/water/gassystem, formed methane hydrate, performed thermal perturbations on thesand/hydrate/water/gas system resulting in hydrate formation anddissociation, formed hydrate in the resulting partially dissociatedsystem, and dissociated the hydrate by depressurization coupled withthermal stimulation. Our CT work shows significant water migration inaddition to possible shifting of mineral grains in response to hydrateformation and dissociation. The extensive data including pressure,temperatures at multiple locations, and density from CT data isdescribed.

  8. MEASUREMENT, FILTERING AND CONTROL IN QUANTUM OPEN DYNAMICAL SYSTEMS.

    E-Print Network [OSTI]

    Belavkin, Viacheslav P.

    Markovian dynam- ical system with a quantum linear transmission line is studied. The optimal quantum multi-stage decision rule consisting of the classical linear optimal control strategy and quantum optimal ...lteringMEASUREMENT, FILTERING AND CONTROL IN QUANTUM OPEN DYNAMICAL SYSTEMS. V. P. BELAVKIN Abstract

  9. Optimal Measurement and Control in Quantum Dynamical Systems.

    E-Print Network [OSTI]

    Belavkin, Viacheslav P.

    Optimal Measurement and Control in Quantum Dynamical Systems. V P Belavkin Institute of Physics-dimensional linear Markovian dynamical system with a quantum linear transmission line is studied. The optimal quantum multi-stage decision rule consisting of the classical linear optimal control strategy and quantum

  10. Input Design for Nonlinear Stochastic Dynamic Systems -A Particle Filter

    E-Print Network [OSTI]

    Schön, Thomas

    Input Design for Nonlinear Stochastic Dynamic Systems - A Particle Filter Approach R. Bhushan in nonlinear stochastic dynamic systems. The approach relies on minimizing a function of the covariance]). There has also been work done on obtaining finite sam- ple covariance estimates (Weyer et al. [1999], Weyer

  11. Robustness of chimera states in complex dynamical systems

    E-Print Network [OSTI]

    Lai, Ying-Cheng

    Robustness of chimera states in complex dynamical systems Nan Yao1,2 , Zi-Gang Huang2,3 , Ying State University, Tempe, Arizona 85287, USA. The remarkable phenomenon of chimera state in systems distinct types of dynamical behaviors, in spite of identity of the oscillators. But how robust are chimera

  12. Dynamic wind turbine models in power system simulation tool

    E-Print Network [OSTI]

    Dynamic wind turbine models in power system simulation tool DIgSILENT Anca D. Hansen, Florin Iov Iov, Poul Sørensen, Nicolaos Cutululis, Clemens Jauch, Frede Blaabjerg Title: Dynamic wind turbine system simulation tool PowerFactory DIgSILENT for different wind turbine concepts. It is the second

  13. OBSERVING LYAPUNOV EXPONENTS OF INFINITE-DIMENSIONAL DYNAMICAL SYSTEMS

    E-Print Network [OSTI]

    Ott, William

    OBSERVING LYAPUNOV EXPONENTS OF INFINITE-DIMENSIONAL DYNAMICAL SYSTEMS WILLIAM OTT, MAURICIO A. RIVAS, AND JAMES WEST Abstract. Can the Lyapunov exponents of infinite-dimensional dynamical systems spaces generated by evolution partial differential equations. Contents 1. Introduction 1 1.1. Lyapunov

  14. The Center for Control, Dynamical Systems, and Computation Spring Seminars

    E-Print Network [OSTI]

    Akhmedov, Azer

    operator we obtain has been useful for modeling of sampled-data systems and power systems. FurthermoreThe Center for Control, Dynamical Systems, and Computation Spring Seminars Presents Frequency model reduction, linear systems, and time-varying systems. Recently he has also been working on reduced

  15. High-surface-area hydrated lime for SO2 control

    SciTech Connect (OSTI)

    Rostam-Abadi, M.; Moran, D.L. (Illinois State Geological Survey, Champaign, IL (United States). Minerals Engineering Section)

    1993-03-01T23:59:59.000Z

    Since 1986, the Illinois State Geological Survey (ISGS), has been developing a process to produce high-surface-area hydrated lime (HSAHL) with more activity for adsorbing SO2 than commercially available hydrated lime. HSAHL prepared by the ISGS method as considerably higher surface area and porosity, and smaller mean particle diameter and crystallite size than commercial hydrated lime. The process has been optimized in a batch, bench-scale reactor and has been scaled-up to a 20--100 lb/hr process optimization unit (POU). Experiments have been conducted to optimize the ISGS hydration process and identify key parameters influencing hydrate properties for SO2 capture (surface area, porosity, particle size, and crystallite size). The known how is available to tailor properties of hydrated limes for specific SO2 removal applications. Pilot-scale tests conducted with the HSAHL under conditions typical of burning high-sulfur coals have achieved up to 90% SO2 capture in various DSI systems. The removal results are enough to bring most high-sulfur coals into compliance with acid rain legislation goals for the year 2000. The focus of the POU program is to generate critical engineering data necessary for the private sector to scale-up the process to a commercial level and provide estimates of the optimal cost of construction and operation of a commercial plant. ISGS is currently participating in a clean coal technology program (CCT-1) by providing 50 tons of HSAHL for a demonstration test at Illinois Power's Hennepin station in January 1993.

  16. On existence and uniqueness of the carrying simplex for competitive dynamical systems

    E-Print Network [OSTI]

    Hirsch, Morris W

    2008-01-01T23:59:59.000Z

    simplex for competitive dynamical systems',Journal of Biological Dynamics,2:2,169 — 179 To link to this Article:

  17. Sensitivity Analysis of Gas Production from Class 2 and Class 3 Hydrate Deposits

    SciTech Connect (OSTI)

    Reagan, Matthew; Moridis, George; Zhang, Keni

    2008-05-01T23:59:59.000Z

    Gas hydrates are solid crystalline compounds in which gas molecules are lodged within the lattices of an ice-like crystalline solid. The vast quantities of hydrocarbon gases trapped in hydrate formations in the permafrost and in deep ocean sediments may constitute a new and promising energy source. Class 2 hydrate deposits are characterized by a Hydrate-Bearing Layer (HBL) that is underlain by a saturated zone of mobile water. Class 3 hydrate deposits are characterized by an isolated Hydrate-Bearing Layer (HBL) that is not in contact with any hydrate-free zone of mobile fluids. Both classes of deposits have been shown to be good candidates for exploitation in earlier studies of gas production via vertical well designs - in this study we extend the analysis to include systems with varying porosity, anisotropy, well spacing, and the presence of permeable boundaries. For Class 2 deposits, the results show that production rate and efficiency depend strongly on formation porosity, have a mild dependence on formation anisotropy, and that tighter well spacing produces gas at higher rates over shorter time periods. For Class 3 deposits, production rates and efficiency also depend significantly on formation porosity, are impacted negatively by anisotropy, and production rates may be larger, over longer times, for well configurations that use a greater well spacing. Finally, we performed preliminary calculations to assess a worst-case scenario for permeable system boundaries, and found that the efficiency of depressurization-based production strategies are compromised by migration of fluids from outside the system.

  18. Generic solar photovoltaic system dynamic simulation model specification.

    SciTech Connect (OSTI)

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

    2013-10-01T23:59:59.000Z

    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.

  19. Noble gases and radiocarbon in natural gas hydrates Gisela Winckler

    E-Print Network [OSTI]

    Aeschbach-Hertig, Werner

    Noble gases and radiocarbon in natural gas hydrates Gisela Winckler Lamont-Doherty Earth 2001; published 24 May 2002. [1] In samples of pure natural gas hydrates from Hydrate Ridge, Cascadia ones preferentially incorporated into the gas hydrate structure. The hydrate methane is devoid of 14 C

  20. Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Structural evolution with hydration and heating

    SciTech Connect (OSTI)

    Sodeye, Akinbode [Department of Polymer Science and Engineering, University of Massachusetts; Huang, Tianzi [University of Tennessee, Knoxville (UTK); Gido, Samuel [University of Massachusetts, Amherst; Mays, Jimmy [ORNL

    2011-01-01T23:59:59.000Z

    Small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS) have been used to study the structural changes in fluorinated polyisoprene/sulfonated polystyrene (FISS) diblock copolymers as they evolved from the dry state to the water swollen state. A dilation of the nanometer-scale hydrophilic domains has been observed as hydration increased, with greater dilation occurring in the more highly sulfonated samples or upon hydration at higher temperatures. Furthermore, a decrease in the order in these phase separated structures is observed upon swelling. The glass transition temperatures of the fluorinated blocks have been observed to decrease upon hydration of these materials, and at the highest hydration levels, differential scanning calorimetry (DSC) has shown the presence of tightly bound water. A precipitous drop in the mechanical integrity of the 50% sulfonated materials is also observed upon exceeding the glass transition temperature (Tg), as measured by dynamic mechanical analysis (DMA).

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

    SciTech Connect (OSTI)

    Hutchinson, D.R. (USGS); Shelander, D. (Schlumberger, Houston, TX); Dai, J. (Schlumberger, Hoston, TX); McConnell, D. (AOA Geophysics, Inc., Houston, TX); Shedd, W. (Minerals Management Service); Frye, M. (Minerals Management Service); Ruppel, C. (USGS); Boswell, R.; Jones, E. (Chevron Energy Technology Corp., Houston, TX); Collett, T.S. (USGS); Rose, K.; Dugan, B. (Rice Univ., Houston, TX); Wood, W. (U.S. Naval Research Laboratory); Latham, T. (Chevron Energy Technology Corp., Houston, TX)

    2008-07-01T23:59:59.000Z

    In the late spring of 2008, the Chevron-led Gulf of Mexico Gas Hydrate Joint Industry Project (JIP) expects to conduct an exploratory drilling and logging campaign to better understand gas hydrate-bearing sands in the deepwater Gulf of Mexico. The JIP Site Selection team selected three areas to test alternative geological models and geophysical interpretations supporting the existence of potential high gas hydrate saturations in reservoir-quality sands. The three sites are near existing drill holes which provide geological and geophysical constraints in Alaminos Canyon (AC) lease block 818, Green Canyon (GC) 955, and Walker Ridge (WR) 313. At the AC818 site, gas hydrate is interpreted to occur within the Oligocene Frio volcaniclastic sand at the crest of a fold that is shallow enough to be in the hydrate stability zone. Drilling at GC955 will sample a faulted, buried Pleistocene channel-levee system in an area characterized by seafloor fluid expulsion features, structural closure associated with uplifted salt, and abundant seismic evidence for upward migration of fluids and gas into the sand-rich parts of the sedimentary section. Drilling at WR313 targets ponded sheet sands and associated channel/levee deposits within a minibasin, making this a non-structural play. The potential for gas hydrate occurrence at WR313 is supported by shingled phase reversals consistent with the transition from gas-charged sand to overlying gas-hydrate saturated sand. Drilling locations have been selected at each site to 1) test geological methods and models used to infer the occurrence of gas hydrate in sand reservoirs in different settings in the northern Gulf of Mexico; 2) calibrate geophysical models used to detect gas hydrate sands, map reservoir thicknesses, and estimate the degree of gas hydrate saturation; and 3) delineate potential locations for subsequent JIP drilling and coring operations that will collect samples for comprehensive physical property, geochemical and other analyses.

  2. Ion Hydration and Associated Defects in Hydrogen Bond Network of Water: Observation of Reorientationally Slow Water Molecules Beyond First Hydration Shell in Aqueous Solutions of MgCl$_2$

    E-Print Network [OSTI]

    Upayan Baul; Satyavani Vemparala

    2014-12-18T23:59:59.000Z

    Effects of presence of ions, at moderate to high concentrations, on dynamical properties of water molecules are investigated through classical molecular dynamics simulations using two well known non-polarizable water models. Simulations reveal that the presence of magnesium chloride (MgCl$_2$) induces perturbations in the hydrogen bond network of water leading to the formation of bulk-like domains with \\textquoteleft defect sites\\textquoteright~on boundaries of such domains: water molecules at such defect sites have less number of hydrogen bonds than those in bulk water. Reorientational autocorrelation functions for dipole vectors of such defect water molecules are computed at different concentrations of ions and compared with system of pure water. Earlier experimental and simulation studies indicate significant differences in reorientational dynamics for water molecules in the first hydration shell of many dissolved ions. Results of this study suggest that defect water molecules, which are beyond the first hydration shells of ions, also experience significant slowing down of reorientation times as a function of concentration in the case of MgCl$_2$. However, addition of cesium chloride(CsCl) to water does not perturb the hydrogen bond network of water significantly even at higher concentrations. This difference in behavior between MgCl$_2$ and CsCl is consistent with the well-known Hofmeister series.

  3. Hydrate-phobic surfaces: fundamental studies in clathrate hydrate adhesion reduction

    E-Print Network [OSTI]

    Smith, J. David

    Clathrate hydrate formation and subsequent plugging of deep-sea oil and gas pipelines represent a significant bottleneck for deep-sea oil and gas operations. Current methods for hydrate mitigation are expensive and energy ...

  4. Development of Alaskan gas hydrate resources

    SciTech Connect (OSTI)

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

    1991-06-01T23:59:59.000Z

    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.

  5. A Model Checking Approach to Evaluating System Level Dynamic Power Management Policies for Embedded Systems

    E-Print Network [OSTI]

    Gupta, Rajesh

    A Model Checking Approach to Evaluating System Level Dynamic Power Management Policies for Embedded, and laptops, controlling power dissipation is an important system design issue [2]. This is either because enforced at the system level. In [3], a system modeling ap- proach for dynamic power management strategy

  6. Dynamic Scheduling of Flexible Manufacturing Systems

    E-Print Network [OSTI]

    Reddy, K. Rama Bhupal

    To date, group scheduling research has primarily focused on examining the performance of different group heuristics under various experimental conditions. However, the dynamic selection of group heuristics has not received ...

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

    SciTech Connect (OSTI)

    Seol, Yongkoo, E-mail: Yongkoo.Seol@netl.doe.gov; Choi, Jeong-Hoon; Dai, Sheng [National Energy Technology Laboratory, U.S. Department of Energy, Morgantown, West Virginia 26507 (United States)

    2014-08-01T23:59:59.000Z

    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.

  8. SECULAR ORBITAL DYNAMICS OF HIERARCHICAL TWO-PLANET SYSTEMS

    SciTech Connect (OSTI)

    Veras, Dimitri; Ford, Eric B., E-mail: veras@astro.ufl.ed [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States)

    2010-06-01T23:59:59.000Z

    The discovery of multi-planet extrasolar systems has kindled interest in using their orbital evolution as a probe of planet formation. Accurate descriptions of planetary orbits identify systems that could hide additional planets or be in a special dynamical state, and inform targeted follow-up observations. We combine published radial velocity data with Markov Chain Monte Carlo analyses in order to obtain an ensemble of masses, semimajor axes, eccentricities, and orbital angles for each of the five dynamically active multi-planet systems: HD 11964, HD 38529, HD 108874, HD 168443, and HD 190360. We dynamically evolve these systems using 52,000 long-term N-body integrations that sample the full range of possible line-of-sight and relative inclinations, and we report on the system stability, secular evolution, and the extent of the resonant interactions. We find that planetary orbits in hierarchical systems exhibit complex dynamics and can become highly eccentric and maybe significantly inclined. Additionally, we incorporate the effects of general relativity in the long-term simulations and demonstrate that it can qualitatively affect the dynamics of some systems with high relative inclinations. The simulations quantify the likelihood of different dynamical regimes for each system and highlight the dangers of restricting simulation phase space to a single set of initial conditions or coplanar orbits.

  9. Physical Properties of Gas Hydrates: A Review

    SciTech Connect (OSTI)

    Gabitto, Jorge [Prairie View A& M University; Tsouris, Costas [ORNL

    2010-01-01T23:59:59.000Z

    Methane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately 1016?m3 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.

  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

    2009-06-15T23:59:59.000Z

    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. Fractal and Chaotic Dynamics in Nervous Systems Chris C. King

    E-Print Network [OSTI]

    King, Chris

    Fractal and Chaotic Dynamics in Nervous Systems Chris C. King Department of Mathematics & Statistics, University of Auckland. Abstract : This paper presents a review of fractal and chaotic dynamics distributed processing models and their relation to chaos and overviews reasons why chaotic and fractal

  12. Transition state theory and dynamical corrections in ergodic systems

    E-Print Network [OSTI]

    Van Den Eijnden, Eric

    Transition state theory and dynamical corrections in ergodic systems Fabio A. Tal and Eric Vanden, New York University, New York, USA Abstract. The results of transition state theory are derived manifold. A new perspective on how to compute the dynamical corrections to the TST transition frequency

  13. Amplitude death in coupled slow and fast dynamical systems

    E-Print Network [OSTI]

    Kajari Gupta; G. Ambika

    2014-06-25T23:59:59.000Z

    We study how mismatch between dynamical time scales of interacting identical systems can result in the suppression of collective dynamics leading to amplitude death. We find that the inability of the interacting systems to fall in step leads to difference in phase as well as change in amplitude. If the mismatch is small, the systems settle to a frequency synchronised state with constant phase difference. But as mismatch in time scale increases, the systems have to compromise to a state of no oscillations. We establish that this regime of amplitude death exists in a net work of identical systems also for sufficient number of slow systems. For standard nonlinear systems, the regions of quenched dynamics in the parameter plane and the transition curves are studied analytically and confirmed by numerical simulations.

  14. Effects of Antiagglomerants on the Interactions between Hydrate Particles

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    InterScience (www.interscience.wiley.com). Hydrate inbibition in natural gas production­574, 2008 Keywords: gas hydrates, antiagglomeration, capillary force, steric repulsion, natural gas production Introduction The undesirable formation of gas hydrates in natural gas pipelines

  15. Brain Prostheses as a Dynamic System (Immortalizing the Human Brain?)

    E-Print Network [OSTI]

    Vadim Astakhov; Tamara Astakhova

    2007-05-17T23:59:59.000Z

    Interest in development of brain prostheses, which might be proposed to recover mental functions lost due to neuron-degenerative disease or trauma, requires new methods in molecular engineering and nanotechnology to build artificial brain tissues. We develop a Dynamic Core model to analyze complexity of damaged biological neural network as well as transition and recovery of the system functionality due to changes in the system environment. We provide a method to model complexity of physical systems which might be proposed as an artificial tissue or prosthesis. Delocalization of Dynamic Core model is developed to analyze migration of mental functions in dynamic bio-systems which undergo architecture transition induced by trauma. Term Dynamic Core is used to define a set of causally related functions and Delocalization is used to describe the process of migration. Information geometry and topological formalisms are proposed to analyze information processes. A holographic model is proposed to construct dynamic environment with self-poetic Dynamic Core which preserve functional properties under transition from one host to another. We found statistical constraints for complex systems which conserve a Dynamic Core under environment transition. Also we suggest those constraints might provide recommendations for nanotechnologies and tissue engineering used in development of an artificial brain tissue.

  16. Selection of hydrate suppression methods for gas streams

    SciTech Connect (OSTI)

    Behrens, S.D.; Covington, K.K.; Collie, J.T. III

    1999-07-01T23:59:59.000Z

    This paper will discuss and compare the methods used to suppress hydrate formation in natural gas streams. Included in the comparison will be regenerated systems using ethylene glycol and non-regenerated systems using methanol. A comparison will be made between the quantities of methanol and ethylene glycol required to achieve a given a suppression. A discussion of BTEX emissions resulting from the ethylene glycol regenerator along with the effect or process variables on these emissions is also given.

  17. Approximate dynamic programming with applications in multi-agent systems

    E-Print Network [OSTI]

    Valenti, Mario J. (Mario James), 1976-

    2007-01-01T23:59:59.000Z

    This thesis presents the development and implementation of approximate dynamic programming methods used to manage multi-agent systems. The purpose of this thesis is to develop an architectural framework and theoretical ...

  18. Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems

    E-Print Network [OSTI]

    Müller-Olm, Markus

    Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems Ahmed Bouajjani1, Markus M¨uller-Olm Bouajjani, Markus M¨uller-Olm, and Tayssir Touili parallel calls. In a multithreaded program such a command

  19. Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems

    E-Print Network [OSTI]

    Müller-Olm, Markus

    Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems Ahmed Bouajjani 1 , Markus MË?uller­Olm #12; 474 Ahmed Bouajjani, Markus MË?uller­Olm, and Tayssir Touili parallel calls. In a multithreaded

  20. Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems

    E-Print Network [OSTI]

    Touili, Tayssir

    Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems Ahmed Bouajjani 1 , Markus MË?uller­Olm Bouajjani, Markus MË?uller­Olm, and Tayssir Touili parallel calls. In a multithreaded program such a command

  1. Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems

    E-Print Network [OSTI]

    Müller-Olm, Markus

    Regular Symbolic Analysis of Dynamic Networks of Pushdown Systems Ahmed Bouajjani1, Markus M¨uller-Olm #12;474 Ahmed Bouajjani, Markus M¨uller-Olm, and Tayssir Touili parallel calls. In a multithreaded

  2. SYMBOLIC AND ALGEBRAIC DYNAMICAL SYSTEMS DOUGLAS LIND AND KLAUS SCHMIDT

    E-Print Network [OSTI]

    Haase, Markus

    SYMBOLIC AND ALGEBRAIC DYNAMICAL SYSTEMS DOUGLAS LIND AND KLAUS SCHMIDT Date: September 30, 2000. 1 #12;2 DOUGLAS LIND AND KLAUS SCHMIDT Part 1. Introduction This article gives a brief survey of a class

  3. SYMBOLIC AND ALGEBRAIC DYNAMICAL SYSTEMS DOUGLAS LIND AND KLAUS SCHMIDT

    E-Print Network [OSTI]

    Lind, Douglas A.

    SYMBOLIC AND ALGEBRAIC DYNAMICAL SYSTEMS DOUGLAS LIND AND KLAUS SCHMIDT Date: September 30, 2000. 1 #12; 2 DOUGLAS LIND AND KLAUS SCHMIDT Part 1. Introduction This article gives a brief survey

  4. DYNAMIC PARTIAL FPGA RECONFIGURATION IN A PROTOTYPE MICROPROCESSOR SYSTEM

    E-Print Network [OSTI]

    Najjar, Walid A.

    and dynamically loaded to run on the FPGA. 1. INTRODUCTION A Configurable System-on-a-Chip (CSoC) has one or more microprocessors integrated with a field programmable gate array (FPGA). These CSoC devices' high transistor

  5. Frequency-based structural damage identification and dynamic system characterisation 

    E-Print Network [OSTI]

    Mao, Lei

    2012-11-29T23:59:59.000Z

    This thesis studies structural dynamic system identification in a frequency-based framework. The basic consideration stems from the fact that frequencies may generally be measured with higher accuracy than other pertinent ...

  6. Experimental formation of massive hydrate deposits from accumulation of CH4 gas bubbles within synthetic and natural sediments

    SciTech Connect (OSTI)

    Madden, Megan Elwood [ORNL; Szymcek, Phillip [ORNL; Ulrich, Shannon M [ORNL; McCallum, Scott D [ORNL; Phelps, Tommy Joe [ORNL

    2009-01-01T23:59:59.000Z

    In order for methane to be economically produced from the seafloor, prediction and detection of massive hydrate deposits will be necessary. In many cases, hydrate samples recovered from seafloor sediments appear as veins or nodules, suggesting that there are strong geologic controls on where hydrate is likely to accumulate. Experiments have been conducted examining massive hydrate accumulation from methane gas bubbles within natural and synthetic sediments in a large volume pressure vessels through temperature and pressure data, as well as visual observations. Observations of hydrate growth suggest that accumulation of gas bubbles within void spaces and at sediment interfaces likely results in the formation of massive hydrate deposits. Methane hydrate was first observed as a thin film forming at the gas/water interface of methane bubbles trapped within sediment void spaces. As bubbles accumulated, massive hydrate growth occurred. These experiments suggest that in systems containing free methane gas, bubble pathways and accumulation points likely control the location and habit of massive hydrate deposits.

  7. Dynamic System Performance of SISO, MISO and MIMO Alamouti Schemes

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Dynamic System Performance of SISO, MISO and MIMO Alamouti Schemes Dorra Ben Cheikh Battikh , Jean, coupecho, godlewski}@enst.fr Abstract--In this paper, the performance of a SISO system, a 2 × 1 MISO multiplexing tradeoff for a 2 × 1 MISO system. Many other techniques have been proposed to exploit antennas

  8. Model Reduction Near Periodic Orbits of Hybrid Dynamical Systems

    E-Print Network [OSTI]

    Sastry, S. Shankar

    manipulation in manufacturing [2], gene regulation in cells [3], and power generation in electrical systems [41 Model Reduction Near Periodic Orbits of Hybrid Dynamical Systems Samuel A. Burden, Shai Revzen system. We demonstrate reduction of a high­dimensional underactuated mechanical model for terrestrial

  9. Dynamically Quantifying and Improving the Reliability of Distributed Storage Systems

    E-Print Network [OSTI]

    Bianchini, Ricardo

    Dynamically Quantifying and Improving the Reliability of Distributed Storage Systems Rekha Bachwani-scale storage systems can be significantly improved by using bet- ter reliability metrics and more efficient on a distributed storage system based on erasure codes. We find that MinI improves relia- bility significantly

  10. Optimized Dynamical Decoupling in ?-Type n-Level Quantum Systems

    E-Print Network [OSTI]

    Linping Chan; Shuang Cong

    2014-04-28T23:59:59.000Z

    In this paper, we first design a type of Bang-Bang (BB) operation group to reduce the phase decoherence in a {\\Xi}-type n-level quantum system based on the dynamical decoupling mechanism. Then, we derive two kinds of dynamical decoupling schemes: periodic dynamical decoupling (PDD) and Uhrig dynamical decoupling (UDD). We select the non-diagonal element of density matrix as a reference index, and investigate the behavior of quantum coherence of the {\\Xi}-type n-level atom under these two dynamical decoupling schemes proposed. At last, we choose a {\\Xi}-type six-level atom as a system controlled, and use the decoupling schemes proposed to suppress the phase decoherence. The simulation experiments and the comparison results are given.

  11. A review of dynamic characteristics of magnetically levitated vehicle systems

    SciTech Connect (OSTI)

    Cai, Y.; Chen, S.S.

    1995-11-01T23:59:59.000Z

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety-related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade-off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  12. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite...

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

    Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical...

  13. aluminate cements hydration: Topics by E-print Network

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

    early stage hydration of different classes of oilwell cement Bentz, Dale P. 5 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  14. Stepwise hydration of the cyanide anion: A temperature-controlled...

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

    Stepwise hydration of the cyanide anion: A temperature-controlled photoelectron spectroscopy and ab initio computational study Stepwise hydration of the cyanide anion: A...

  15. Editorial Comment on the Special Issue of "Information in Dynamical Systems and Complex Systems"

    E-Print Network [OSTI]

    Erik M. Bollt; Jie Sun

    2015-05-16T23:59:59.000Z

    This special issue collects contributions from the participants of the "Information in Dynamical Systems and Complex Systems" workshop, which cover a wide range of important problems and new approaches that lie in the intersection of information theory and dynamical systems. The contributions include theoretical characterization and understanding of the different types of information flow and causality in general stochastic processes, inference and identification of coupling structure and parameters of system dynamics, rigorous coarse-grain modeling of network dynamical systems, and exact statistical testing of fundamental information-theoretic quantities such as the mutual information. The collective efforts reported herein reflect a modern perspective of the intimate connection between dynamical systems and information flow, leading to the promise of better understanding and modeling of natural complex systems and better/optimal design of engineering systems.

  16. THE DYNAMICS OF THREE-PLANET SYSTEMS: AN APPROACH FROM A DYNAMICAL SYSTEM

    SciTech Connect (OSTI)

    Shikita, Bungo; Yamada, Shoichi [Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Koyama, Hiroko, E-mail: shikita@heap.phys.waseda.ac.j [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2010-04-01T23:59:59.000Z

    We study in detail the motions of three planets interacting with each other under the influence of a central star. It is known that the system with more than two planets becomes unstable after remaining quasi-stable for long times, leading to highly eccentric orbital motions or ejections of some of the planets. In this paper, we are concerned with the underlying physics for this quasi-stability as well as the subsequent instability and advocate the so-called stagnant motion in the phase space, which has been explored in the field of a dynamical system. We employ the Lyapunov exponent, the power spectra of orbital elements, and the distribution of the durations of quasi-stable motions to analyze the phase-space structure of the three-planet system, the simplest and hopefully representative one that shows the instability. We find from the Lyapunov exponent that the system is almost non-chaotic in the initial quasi-stable state whereas it becomes intermittently chaotic thereafter. The non-chaotic motions produce the horizontal dense band in the action-angle plot whereas the voids correspond to the chaotic motions. We obtain power laws for the power spectra of orbital eccentricities. Power-law distributions are also found for the durations of quasi-stable states. With all these results combined together, we may reach the following picture: the phase space consists of the so-called KAM tori surrounded by satellite tori and imbedded in the chaotic sea. The satellite tori have a self-similar distribution and are responsible for the scale-free power-law distributions of the duration times. The system is trapped around one of the KAM torus and the satellites for a long time (the stagnant motion) and moves to another KAM torus with its own satellites from time to time, corresponding to the intermittent chaotic behaviors.

  17. System-environment correlations and Non-Markovian dynamics

    E-Print Network [OSTI]

    Ansgar Pernice; Julius Helm; Walter T. Strunz

    2012-05-16T23:59:59.000Z

    We determine the total state dynamics of a dephasing open quantum system using the standard environment of harmonic oscillators. Of particular interest are random unitary approaches to the same reduced dynamics and system-environment correlations in the full model. Concentrating on a model with an at times negative dephasing rate, the issue of "non-Markovianity" will also be addressed. Crucially, given the quantum environment, the appearance of non-Markovian dynamics turns out to be accompanied by a loss of system-environment correlations. Depending on the initial purity of the qubit state, these system-environment correlations may be purely classical over the whole relevant time scale, or there may be intervals of genuine system-environment entanglement. In the latter case, we see no obvious relation between the build-up or decay of these quantum correlations and "Non-Markovianity".

  18. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

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

    2005-02-01T23:59:59.000Z

    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.

  19. Non-Markovian dynamics in open quantum systems

    E-Print Network [OSTI]

    Heinz-Peter Breuer; Elsi-Mari Laine; Jyrki Piilo; Bassano Vacchini

    2015-05-06T23:59:59.000Z

    The dynamical behavior of open quantum systems plays a key role in many applications of quantum mechanics, examples ranging from fundamental problems, such as the environment-induced decay of quantum coherence and relaxation in many-body systems, to applications in condensed matter theory, quantum transport, quantum chemistry and quantum information. In close analogy to a classical Markov process, the interaction of an open quantum system with a noisy environment is often modelled by a dynamical semigroup with a generator in Lindblad form, which describes a memoryless dynamics leading to an irreversible loss of characteristic quantum features. However, in many applications open systems exhibit pronounced memory effects and a revival of genuine quantum properties such as quantum coherence and correlations. Here, recent results on the rich non-Markovian quantum dynamics of open systems are discussed, paying particular attention to the rigorous mathematical definition, to the physical interpretation and classification, as well as to the quantification of memory effects. The general theory is illustrated by a series of examples. The analysis reveals that memory effects of the open system dynamics reflect characteristic features of the environment which opens a new perspective for applications, namely to exploit a small open system as a quantum probe signifying nontrivial features of the environment it is interacting with. This article further explores the various physical sources of non-Markovian quantum dynamics, such as structured spectral densities, nonlocal correlations between environmental degrees of freedom and correlations in the initial system-environment state, in addition to developing schemes for their local detection. Recent experiments on the detection, quantification and control of non-Markovian quantum dynamics are also discussed.

  20. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01T23:59:59.000Z

    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.

  1. Overview on Hydrate Coring, Handling and Analysis

    SciTech Connect (OSTI)

    Jon Burger; Deepak Gupta; Patrick Jacobs; John Shillinglaw

    2003-06-30T23:59:59.000Z

    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.

  2. 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)

    1999-07-01T23:59:59.000Z

    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.

  3. Diffusion of CO2 During Hydrate Formation and Dissolution

    SciTech Connect (OSTI)

    Franklin M. Orr, Jr.

    2002-08-20T23:59:59.000Z

    Experiments were performed to measure the rate of diffusion of CO2 through hydrate films. Hydrate films were created in a capillary tube, and the growth of the hydrate film was measured. Difficulties were encountered in creating hydrate repeatedly, and some non-uniform growth of the films was observed. Sufficient observations were obtained to demonstrate that hydrate growth occurs preferentially on the hydrate/water side of the interface, rather than at the hydrate/CO2 interface. Diffusion coefficients were estimated from observations of the rate of growth of the hydrate film along with estimates of the solubility of CO2 in water and of the concentration gradient across the hydrate layer. The experimental observations indicate that hydrate formation occurs much more rapidly at the hydrate water interface than at the hydrate/CO2 interface. Any growth of hydrate at the CO2/hydrate interface was too slow to be observed at the time scale of the experiments. That observation is consistent with the idea that CO2 can move more easily through the hydrate, presumably by hopping between hydrate cages, than water can move through the hydrate, presumably by lattice hopping. Estimated diffusion coefficients were in the range 1-3E-06 cm2/sec. Those values are about an order of magnitude lower than the diffusion coefficient for CO2 in liquid water, but four orders of magnitude larger than the value for diffusion of CO2 in a solid. The rate of diffusion through the hydrate controls both the creation of new hydrate at the hydrate/water interface and the rate at which CO2 dissolves in the liquid water and diffuses away from the hydrate layer. Formation of a hydrate layer reduces the rate at which CO2 dissolves in liquid water.

  4. Efficiency of Charge Transport in a Polypeptide Chain: The Hydrated System Sheh-Yi Sheu,*, Dah-Yen Yang,*, H. L. Selzle,| and E. W. Schlag*,|

    E-Print Network [OSTI]

    Sheu, Sheh-Yi

    there is very little attenuation observed. We here do extensive molecular dynamics calculations in the presenceVersity, Taipei 112, Taiwan, Institute of Atomic and Molecular Science, Academia Sinica, Taipei 106, Taiwan the original site of excitation and is typical in biological signal transduction. This model introduced

  5. Dynamics of quasi-stationary systems: Finance as an example

    E-Print Network [OSTI]

    Rinn, Philip; Peinke, Joachim; Guhr, Thomas; Schäfer, Rudi

    2015-01-01T23:59:59.000Z

    We propose a combination of cluster analysis and stochastic process analysis to characterize high-dimensional complex dynamical systems by few dominating variables. As an example, stock market data are analyzed for which the dynamical stability as well as transitions between different stable states are found. This combined method also allows to set up new criteria for merging clusters to simplify the complexity of the system. The low-dimensional approach allows to recover the high-dimensional fixed points of the system by means of an optimization procedure.

  6. Visual exploration of 2D autonomous dynamical systems

    E-Print Network [OSTI]

    Müller, Thomas

    2015-01-01T23:59:59.000Z

    In an introductory course on dynamical systems or Hamiltonian mechanics, vector field diagrams are a central tool to show a system's qualitative behaviour in a certain domain. Because of their low sampling rates and the involved issues of vector normalization, these plots give only a coarse insight and are unable to convey the vector field behaviour at locations with high variation, in particular in the neighborhood of critical points. Similarly, automatic generation of phase portraits based on traditional sampling cannot precisely capture separatrices or limit cylces. In this paper, we present ASysViewer, an application for the interactive visual exploration of two-dimensional autonomous dynamical systems using line integral convolution techniques for visualization, and grid-based techniques to extract critical points and separatrices. ASysViewer is addressed to undergraduate students during their first course in dynamical systems or Hamiltonian mechanics.

  7. Learning Nonlinear Dynamical Systems using an EM Algorithm

    E-Print Network [OSTI]

    Ghahramani, Zoubin

    Learning Nonlinear Dynamical Systems using an EM Algorithm Zoubin Ghahramani and Sam T. Roweis identi cation in linear stochastic state-space models, where the state variables are hidden from become tractable and the maximization step can be solved via systems of linear equations. 1 Stochastic

  8. Inventory management with dynamic Bayesian network software systems

    E-Print Network [OSTI]

    Barker, Jon

    Inventory management with dynamic Bayesian network software systems Mark Taylor1 and Charles Fox2 1.fox@sheffield.ac.uk Abstract. Inventory management at a single or multiple levels of a supply chain is usually performed-the-shelf graphical software systems. We show how such sys- tems may be deployed to model a simple inventory problem

  9. Robust computations with dynamical systems Olivier Bournez1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . In this paper we discuss the computational power of Lips- chitz dynamical systems which are robust in the following manner: undecidability of verification doesn't hold for Lipschitz, computable and robust systems words : Verification, Model-checking, Computable Analysis, Analog Com- putations. 1 Introduction

  10. September 23, 1997 Rare Events in Stochastic Dynamical Systems and

    E-Print Network [OSTI]

    September 23, 1997 Rare Events in Stochastic Dynamical Systems and Failures in Ultra­Reliable reliable is the system, the sharper is the approximation. In this model, we consider two types of failures that the distribution of a failure time can be approximated by an exponen­ tial law is not new in software reliability

  11. Joint International Conference on Multibody System Dynamics Asian Conference on Multibody Dynamics

    E-Print Network [OSTI]

    Leyendecker, Sigrid

    combustion engine or a satellite in space are mechanical systems containing slow and fast dynamics. Multirate, chain driven combustion engines with fast moving valves and slow moving chain drives or the motions schemes split such systems into parts which can be simulated using different time steps

  12. Methane Recovery from Hydrate-bearing Sediments

    SciTech Connect (OSTI)

    J. Carlos Santamarina; Costas Tsouris

    2011-04-30T23:59:59.000Z

    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.

  13. Dynamic Boosting Systems | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluating A Potential MicrohydroDistrict ofDongjin SemichemDukeDuracellDynamic Boosting

  14. Supercomputers model and simulate complex, dynamic systems

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

    Laboratory System has built and deployed some of the most significant high-performance computing (HPC) resources available anywhere, including 32 of the 500 fastest...

  15. Fusion dynamics of symmetric systems near barrier energies

    E-Print Network [OSTI]

    Zhao-Qing Feng; Gen-Ming Jin

    2009-09-06T23:59:59.000Z

    The enhancement of the sub-barrier fusion cross sections was explained as the lowering of the dynamical fusion barriers within the framework of the improved isospin-dependent quantum molecular dynamics (ImIQMD) model. The numbers of nucleon transfer in the neck region are appreciably dependent on the incident energies, but strongly on the reaction systems. A comparison of the neck dynamics is performed for the symmetric reactions $^{58}$Ni+$^{58}$Ni and $^{64}$Ni+$^{64}$Ni at energies in the vicinity of the Coulomb barrier. An increase of the ratios of neutron to proton in the neck region at initial collision stage is observed and obvious for neutron-rich systems, which can reduce the interaction potential of two colliding nuclei. The distribution of the dynamical fusion barriers and the fusion excitation functions are calculated and compared them with the available experimental data.

  16. Dynamic Model for Assessing Impact of Regeneration Actions on System Availability: Application to Weapon Systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Dynamic Model for Assessing Impact of Regeneration Actions on System Availability: Application) Key Words: failure, damage, regeneration, availability assessment, stochastic activity networks, Monte Carlo simulations SUMMARY & CONCLUSIONS Availability is a determining factor in systems characterization

  17. Gas Hydrates Research Programs: An International Review

    SciTech Connect (OSTI)

    Jorge Gabitto; Maria Barrufet

    2009-12-09T23:59:59.000Z

    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.

  18. The hydration mechanism of ketene: 15 years later

    E-Print Network [OSTI]

    Nguyen, Minh Tho

    the self-consistent reaction field method (SCRF) and the polarizable continuum model (PCM). The hydration

  19. IMPROVEMENT OF METHANE STORAGE IN ACTIVATED CARBON USING METHANE HYDRATE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    it to a gas hydrate formation. In fact, the gas hydrate formation in the remaining free porosity after manuscript, published in "Fifth International Conference on Gas Hydrates (ICGH 5),, Tromdheim : Norway (2005IMPROVEMENT OF METHANE STORAGE IN ACTIVATED CARBON USING METHANE HYDRATE M.L. Zanota(1) , L. Perier

  20. 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

  1. Notes 14. Dynamic response of continuum systems

    E-Print Network [OSTI]

    San Andres, Luis

    2008-01-01T23:59:59.000Z

    . For i=j, the i th natural frequency follows from () () 2 0 0 L ii i i L i ii EA dx A dx ?? ? ??? ?? ? == ? ? ? (3) Where , ii ??are the i th mode equivalent stiffness and mass coefficients. MEEN 617 ? HD#14 Vibrations of Continuous Systems...MEEN 617 ? HD#14 Vibrations of Continuous Systems. L. San Andr?s ? 2008 1 ME617 - Handout 14 Vibrations of Continuous Systems Axial vibrations of elastic bars The figure shows a uniform elastic bar of length L and cross section A. The bar...

  2. Dynamic simulation of a proposed ITER tritium processing system

    SciTech Connect (OSTI)

    Kuan, W.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States); Scott W.R. [Los Alamos National Lab., NM (United States)

    1995-10-01T23:59:59.000Z

    Dynamically simulating the fuel cycle in a fusion reactor is crucial to developing a better understanding of the safe and reliable operation of this complex system. In this work, we propose a tritium processing system for ITER`s plasma exhaust. The dynamic simulation of this proposed system is then performed with the TRUFFLES (TRitiUm Fusion Fuel cycLE dynamic Simulation) model. The fuel management, storage, and fueling operations are developed and coupled with previous cryopump and fuel cleanup unit subsystems to fully realize the complete torus exhaust flow cycle. Results show that tritium inventories will vary widely depending upon reactor operation, individual subsystem and unit operation designs. A diverse collection of batch-controlled subsystems with changes in their processing parameters are simulated in this work. In particular, the effects from the fuel management subsystem`s fuel reserve and tank switching times are quantified using sensitivity studies. 6 refs., 10 figs., 2 tabs.

  3. Quantifying sudden changes in dynamical systems using symbolic networks

    E-Print Network [OSTI]

    Masoller, Cristina; Ayad, Sarah; Gustave, Francois; Barland, Stephane; Pons, Antonio J; Gómez, Sergio; Arenas, Alex

    2015-01-01T23:59:59.000Z

    We characterise the evolution of a dynamical system by combining two well-known complex systems' tools, namely, symbolic ordinal analysis and networks. From the ordinal representation of a time-series we construct a network in which every node weights represents the probability of an ordinal patterns (OPs) to appear in the symbolic sequence and each edges weight represents the probability of transitions between two consecutive OPs. Several network-based diagnostics are then proposed to characterize the dynamics of different systems: logistic, tent and circle maps. We show that these diagnostics are able to capture changes produced in the dynamics as a control parameter is varied. We also apply our new measures to empirical data from semiconductor lasers and show that they are able to anticipate the polarization switchings, thus providing early warning signals of abrupt transitions.

  4. Quantifying sudden changes in dynamical systems using symbolic networks

    E-Print Network [OSTI]

    Cristina Masoller; Yanhua Hong; Sarah Ayad; Francois Gustave; Stephane Barland; Antonio J. Pons; Sergio Gómez; Alex Arenas

    2015-01-27T23:59:59.000Z

    We characterise the evolution of a dynamical system by combining two well-known complex systems' tools, namely, symbolic ordinal analysis and networks. From the ordinal representation of a time-series we construct a network in which every node weights represents the probability of an ordinal patterns (OPs) to appear in the symbolic sequence and each edges weight represents the probability of transitions between two consecutive OPs. Several network-based diagnostics are then proposed to characterize the dynamics of different systems: logistic, tent and circle maps. We show that these diagnostics are able to capture changes produced in the dynamics as a control parameter is varied. We also apply our new measures to empirical data from semiconductor lasers and show that they are able to anticipate the polarization switchings, thus providing early warning signals of abrupt transitions.

  5. Dynamics of harmonically-confined systems: Some rigorous results

    SciTech Connect (OSTI)

    Wu, Zhigang, E-mail: zwu@physics.queensu.ca; Zaremba, Eugene, E-mail: zaremba@sparky.phy.queensu.ca

    2014-03-15T23:59:59.000Z

    In this paper we consider the dynamics of harmonically-confined atomic gases. We present various general results which are independent of particle statistics, interatomic interactions and dimensionality. Of particular interest is the response of the system to external perturbations which can be either static or dynamic in nature. We prove an extended Harmonic Potential Theorem which is useful in determining the damping of the centre of mass motion when the system is prepared initially in a highly nonequilibrium state. We also study the response of the gas to a dynamic external potential whose position is made to oscillate sinusoidally in a given direction. We show in this case that either the energy absorption rate or the centre of mass dynamics can serve as a probe of the optical conductivity of the system. -- Highlights: •We derive various rigorous results on the dynamics of harmonically-confined atomic gases. •We derive an extension of the Harmonic Potential Theorem. •We demonstrate the link between the energy absorption rate in a harmonically-confined system and the optical conductivity.

  6. Effect of Fuel System Impedance Mismatch on Combustion Dynamics

    SciTech Connect (OSTI)

    Richards, G.A.; Robey, E.H.

    2008-01-01T23:59:59.000Z

    Combustion dynamics are a challenging problem in the design and operation of premixed gas turbine combustors. In premixed combustors, pressure oscillations created by the flame dynamic response can lead to damage. These dynamics are typically controlled by designing the combustor to achieve a stable operation for planned conditions, but dynamics may still occur with minor changes in ambient operating conditions or fuel composition. In these situations, pilot flames or adjustment to fuel flow splits can be used to stabilize the combustor, but often with a compromise in emission performance. As an alternative to purely passive design changes, prior studies have demonstrated that adjustment to the fuel system impedance can be used to stabilize combustion. Prior studies have considered just the response of an individual fuel injector and combustor. However, in practical combustion systems, multiple fuel injectors are used. In this situation, individual injector impedance can be modified to produce a different dynamic response from individual flames. The resulting impedance mismatch prevents all injectors from strongly coupling to the same acoustic mode. In principle, this mismatch should reduce the amplitude of dynamics and may expand the operating margin for stable combustion conditions. In this paper, a 30 kW laboratory combustor with two premixed fuel injectors is used to study the effect of impedance mismatch on combustion stability. The two fuel injectors are equipped with variable geometry resonators that allow a survey of dynamic stability while changing the impedance of the individual fuel systems. Results demonstrate that a wide variation in dynamic response can be achieved by combining different impedance fuel injectors. A base line 7% rms pressure oscillation was reduced to less than 3% by mismatching the fuel impedance.

  7. Long-term system dynamics simulation methods. Final report

    SciTech Connect (OSTI)

    Manke, J.W.; Pauly, W.R.; Hemmaplardh, K.

    1985-02-01T23:59:59.000Z

    The focus of long-term dynamic simulations is to analyze the effects of wide excursions of voltage, frequency and power flows for extended periods of time on the bulk power system. The emphasis on modeling the sequence of system events over an extended period of time that follows a major disturbance distinguishes long-term dynamics from transient and midterm stability analysis where the effects of inter-machine oscillations on synchronous machines is the primary focus. The assumption of a uniform system frequency during quiscent system conditions makes it possible to use a numerical stepsize of one or more seconds for long-term studies, as opposed to a fraction of a cycle for transient/midterm stability, and to simulate the voltage and frequency effects of such system events as automatic load shedding and unit tripping for long periods of time. Both the time frame and the type of system events of interest in long-term dynamic studies establish the modeling and simulation requirements for a long-term program and the need for system data to validate the models and program. The sequence of system events that occur during the long-term time frame may introduce step changes in the system, i.e., load shedding, which cause transients that must be modeled on the transient stability time scale. This is the basis for the requirements that a long-term program have an adequate interface with a transient stability program.

  8. Natural gas production from hydrate dissociation: An axisymmetric model

    SciTech Connect (OSTI)

    Ahmadi, G. (Clarkson Univ., Pottsdam, NY); Ji, Chuang (Clarkson Univ., Pottsdam, NY); Smith, D.H.

    2007-08-01T23:59:59.000Z

    This paper describes an axisymmetric model for natural gas production from the dissociation of methane hydrate in a confined reservoir by a depressurizing well. During the hydrate dissociation, heat and mass transfer in the reservoir are analyzed. The system of governing equations is solved by a finite difference scheme. For different well pressures and reservoir temperatures, distributions of temperature and pressure in the reservoir, as well as the natural gas production from the well are evaluated. The numerical results are compared with those obtained by a linearization method. It is shown that the gas production rate is a sensitive function of well pressure. The simulation results are compared with the linearization approach and the shortcomings of the earlier approach are discussed.

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

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01T23:59:59.000Z

    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. Quantum entropy dynamics for chaotic systems beyond the classical limit

    E-Print Network [OSTI]

    Arnaldo Gammal; Arjendu K. Pattanayak

    2007-02-15T23:59:59.000Z

    The entropy production rate for an open quantum system with a classically chaotic limit has been previously argued to be independent of $\\hbar$ and $D$, the parameter denoting coupling to the environment, and to be equal to the sum of generalized Lyapunov exponents, with these results applying in the near-classical regime. We present results for a specific system going well beyond earlier work, considering how these dynamics are altered for the Duffing problem by changing $\\hbar,D$ and show that the entropy dynamics have a transition from classical to quantum behavior that scales, at least for a finite time, as a function of $\\hbar^2/D$.

  11. STABILITY CONDITIONS IN PIECEWISE SMOOTH DYNAMICAL SYSTEMS

    E-Print Network [OSTI]

    Herrmann, Samuel

    -fold singularities. More specifically, we are interested in discussing stability problems of such systems around of those of Asymptotic and Lya- punov stability respectively. For technical reasons they will be presented in Subsection 2.6. Our main results exhibit conditions for the A- and L- stability of a two-fold singularity

  12. Optimal Control of Building HVAC Systems in the Presence of Imperfect Predictions, ASME Dynamic System Control Conference

    E-Print Network [OSTI]

    Maasoumy, Mehdi

    2012-01-01T23:59:59.000Z

    optimal control design for HVAC systems,” in Dynamic Systemalgorithm design for hvac systems in energy efficient build-OPTIMAL CONTROL OF BUILDING HVAC SYSTEMS IN THE PRESENCE OF

  13. Speeding up critical system dynamics through optimized evolution

    SciTech Connect (OSTI)

    Caneva, Tommaso [International School for Advanced Studies (SISSA), Via Beirut 2-4, I-34014 Trieste (Italy); Institut fuer Quanteninformationsverarbeitung, Universitaet Ulm, D-89069 Ulm (Germany); Calarco, Tommaso; Montangero, Simone [Institut fuer Quanteninformationsverarbeitung, Universitaet Ulm, D-89069 Ulm (Germany); Fazio, Rosario [NEST, Scuola Normale Superiore and Istituto di Nanoscienze-CNR, Piazza dei Cavalieri 7, I-56126 Pisa (Italy); Santoro, Giuseppe E. [International School for Advanced Studies (SISSA), Via Beirut 2-4, I-34014 Trieste (Italy); CNR-INFM Democritos National Simulation Center, Via Beirut 2-4, I-34014 Trieste (Italy); International Centre for Theoretical Physics (ICTP), P.O. Box 586, I-34014 Trieste (Italy)

    2011-07-15T23:59:59.000Z

    The number of defects which are generated upon crossing a quantum phase transition can be minimized by choosing properly designed time-dependent pulses. In this work we determine what are the ultimate limits of this optimization. We discuss under which conditions the production of defects across the phase transition is vanishing small. Furthermore we show that the minimum time required to enter this regime is T{approx}{pi}/{Delta}, where {Delta} is the minimum spectral gap, unveiling an intimate connection between an optimized unitary dynamics and the intrinsic measure of the Hilbert space for pure states. Surprisingly, the dynamics is nonadiabatic; this result can be understood by assuming a simple two-level dynamics for the many-body system. Finally we classify the possible dynamical regimes in terms of the action s=T{Delta}.

  14. Novel coupling scheme to control dynamics of coupled discrete systems

    E-Print Network [OSTI]

    Snehal M. Shekatkar; G. Ambika

    2014-11-05T23:59:59.000Z

    We present a new coupling scheme to control spatio-temporal patterns and chimeras on 1-d and 2-d lattices and random networks of discrete dynamical systems. The scheme involves coupling with an external lattice or network of damped systems. When the system network and external network are set in a feedback loop, the system network can be controlled to a homogeneous steady state or synchronized periodic state with suppression of the chaotic dynamics of the individual units. The control scheme has the advantage that its design does not require any prior information about the system dynamics or its parameters and works effectively for a range of parameters of the control network. We analyze the stability of the controlled steady state or amplitude death state of lattices using the theory of circulant matrices and Routh-Hurwitz's criterion for discrete systems and this helps to isolate regions of effective control in the relevant parameter planes. The conditions thus obtained are found to agree well with those obtained from direct numerical simulations in the specific context of lattices with logistic map and Henon map as on-site system dynamics. We show how chimera states developed in an experimentally realizable 2-d lattice can be controlled using this scheme. We propose this mechanism can provide a phenomenological model for the control of spatio-temporal patterns in coupled neurons due to non-synaptic coupling with the extra cellular medium. We extend the control scheme to regulate dynamics on random networks and adapt the master stability function method to analyze the stability of the controlled state for various topologies and coupling strengths.

  15. Ab initio studies of ionization potentials of hydrated hydroxide and hydronium

    E-Print Network [OSTI]

    Charles W. Swartz; Xifan Wu

    2013-06-04T23:59:59.000Z

    The ionization potential distributions of hydrated hydroxide and hydronium are computed with many-body approach for electron excitations with configurations generated by {\\it ab initio} molecular dynamics. The experimental features are well reproduced and found to be closely related to the molecular excitations. In the stable configurations, the ionization potential is mainly perturbed by water molecules within the first solvation shell. On the other hand, electron excitation is delocalized on both proton receiving and donating complex during proton transfer, which shifts the excitation energies and broadens the spectra for both hydrated ions.

  16. Nanomechanical properties of hydrated organic thin films

    E-Print Network [OSTI]

    Choi, Jae Hyeok

    2007-01-01T23:59:59.000Z

    Hydrated organic thin films are biological or synthetic molecularly thin coatings which impart a particular functionality to an underlying substrate and which have discrete water molecules associated with them. Such films ...

  17. ConocoPhillips Gas Hydrate Production Test

    SciTech Connect (OSTI)

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

    2013-06-30T23:59:59.000Z

    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.

  18. A realistic molecular model of cement hydrates

    E-Print Network [OSTI]

    Ulm, Franz-Josef

    Despite decades of studies of calcium-silicate-hydrate (C-S-H), the structurally complex binder phase of concrete, the interplay between chemical composition and density remains essentially unexplored. Together these ...

  19. MethaneHydrateRD_FC.indd

    Office of Environmental Management (EM)

    source of natural gas in 1983. The Methane Hydrate Research and Development Act of 2000 established DOE as the lead U.S. agency for R&D in this fi eld. Early phases of...

  20. Metal-Catalyzed Hydration of 2-Pyridyloxirane

    E-Print Network [OSTI]

    Hanzlik, Robert P.; Michaely, William J.

    1975-01-01T23:59:59.000Z

    In the presence of CuII the hydration of 2-pyridyloxiran is accelerated 18,000-fold, and its reaction with Cl–, Br–, and MeO– becomes 100% regiospecific for ?-attack....

  1. Hydrate Control for Gas Storage Operations

    SciTech Connect (OSTI)

    Jeffrey Savidge

    2008-10-31T23:59:59.000Z

    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.

  2. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Donn McGuire; Thomas Williams; Bjorn Paulsson; Alexander Goertz

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a drilling hazard by the oil and gas industry for years. Drilling engineers working in Russia, Canada and the USA have documented numerous problems, including drilling 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 as a potential energy source agree that the resource potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained from physical samples taken from actual hydrate-bearing rocks. 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 identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The project team drilled and continuously cored the Hot Ice No. 1 well on Anadarko-leased acreage beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and used for determining physical characteristics of hydrates and surrounding rock. After the well was logged, a 3D vertical seismic profile (VSP) was recorded to calibrate the shallow geologic section with seismic data and to investigate techniques to better resolve lateral subsurface variations of potential hydrate-bearing strata. Paulsson Geophysical Services, Inc. deployed their 80 level 3C clamped borehole seismic receiver array in the wellbore to record samples every 25 ft. Seismic vibrators were successively positioned at 1185 different surface positions in a circular pattern around the wellbore. This technique generated a 3D image of the subsurface. Correlations were generated of these seismic data with cores, logging, and other well data. Unfortunately, the Hot Ice No. 1 well did not encounter hydrates in the reservoir sands, although brine-saturated sands containing minor amounts of methane were encountered within the hydrate stability zone (HSZ). Synthetic seismograms created from well log data were in agreement with reflectivity data measured by the 3D VSP survey. Modeled synthetic seismograms indicated a detectable seismic response would be expected in the presence of hydrate-bearing sands. Such a response was detected in the 3D VSP data at locations up-dip to the west of the Hot Ice No. 1 wellbore. Results of this project suggest that the presence of hydrate-bearing strata may not be related as simply to HSZ thickness as previously thought. Geological complications of reservoir facies distribution within fluvial-deltaic environments will require sophisticated detection technologies to assess the locations of recoverable volumes of methane contained in hydrates. High-resolution surface seismic data and more rigorous well log data analysis offer the best near-term potential. The hydrate resource potential is huge, but better tools are needed to accurately assess their location, distribution and economic recoverability.

  3. Weakening of ice by magnesium perchlorate hydrate

    E-Print Network [OSTI]

    Lenferink, Hendrik J., 1985-

    2012-01-01T23:59:59.000Z

    I show that perchlorate hydrates, which have been indirectly detected at high Martian circumpolar latitudes by the Phoenix Mars Lander, have a dramatic effect upon the rheological behavior of polycrystalline water ice under ...

  4. Modeling of gas hydrates from first principles

    E-Print Network [OSTI]

    Cao, Zhitao, 1974-

    2002-01-01T23:59:59.000Z

    Ab initio calculations were used to determine the H20-CH4 potential energy surface (PES) accurately for use in modeling gas hydrates. Electron correlation was found to be treated accurately by the second-order Moller-Plesset ...

  5. Electric Double-Layer Capacitor Based on an Ionic Clathrate Hydrate

    SciTech Connect (OSTI)

    Lee, Wonhee; Kwon, Minchul; Park, Seongmin; Lim, Dongwook Cha, Dr Jong-Ho; Lee, Dr. Huen

    2013-07-01T23:59:59.000Z

    Herein, we suggest a new approach to an electric double-layer capacitor (EDLC) that is based on a proton-conducting ionic clathrate hydrate (ICH). The ice-like structures of clathrate hydrates, which are comprised of host water molecules and guest ions, make them suitable for applications in EDLC electrolytes, owing to their high proton conductivities and thermal stabilities. The carbon materials in the ICH Me{sub 4}NOH[DOT OPERATOR]5?H{sub 2}O show a high specific capacitance, reversible charge–discharge behavior, and a long cycle life. The ionic-hydrate complex provides the following advantages in comparison with conventional aqueous and polymer electrolytes: 1)?The ICH does not cause leakage problems under normal EDLC operating conditions. 2)?The hydrate material can be utilized itself, without requiring any pre-treatments or activation for proton conduction, thus shortening the preparation procedure of the EDLC. 3)?The crystallization of the ICH makes it possible to tailor practical EDLC dimensions because of its fluidity as a liquid hydrate. 4)?The hydrate solid electrolyte exhibits more-favorable electrochemical stability than aqueous and polymer electrolytes. Therefore, ICH materials are expected to find practical applications in versatile energy devices that incorporate electrochemical systems.

  6. Estimating the amount of gas hydrate and free gas from marine seismic data

    SciTech Connect (OSTI)

    Ecker, C.; Dvorkin, J.; Nur, A.M.

    2000-04-01T23:59:59.000Z

    Marine seismic data and well-log measurements at the Blake Ridge offshore South Carolina show that prominent seismic bottom-simulating reflectors (BSRs) are caused by sediment layers with gas hydrate overlying sediments with free gas. The authors apply a theoretical rock-physics model to 2-D Blake Ridge marine seismic data to determine gas-hydrate and free-gas saturation. High-porosity marine sediment is modeled as a granular system where the elastic wave velocities are linked to porosity; effective pressure; mineralogy; elastic properties of the pore-filling material; and water, gas, and gas-hydrate saturation of the pore space. To apply this model to seismic data, the authors first obtain interval velocity using stacking velocity analysis. Next, all input parameters to the rock-physics model, except porosity and water, gas and gas hydrate saturation, are estimated from geologic information. To estimate porosity and saturation from interval velocity, they first assume that the entire sediment does not contain gas hydrate or free gas. Then they use the rock-physics model to calculate porosity directly from the interval velocity. Such porosity profiles appear to have anomalies where gas hydrate and free gas are present (as compared to typical profiles expected and obtained in sediment without gas hydrate of gas). Porosity is underestimated in the hydrate region and is overestimated in the free-gas region. The authors calculate the porosity residuals by subtracting a typical porosity profile (without gas hydrate and gas) from that with anomalies. Next they use the rock-physics model to eliminate these anomalies by introducing gas-hydrate of gas saturation. As a result, they obtain the desired 2-D saturation map. The maximum gas-hydrate saturation thus obtained is between 13% and 18% of the pore space (depending on the version of the model used). These saturation values are consistent with those measured in the Blake Ridge wells (away from the seismic line), which are about 12%. Free-gas saturation varies between 1% and 2%. The saturation estimates are extremely sensitive to the input velocity values. Therefore, accurate velocity determination is crucial for correct reservoir characterization.

  7. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

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

    2005-02-01T23:59:59.000Z

    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.

  8. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

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

    2005-02-01T23:59:59.000Z

    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.

  9. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-02-01T23:59:59.000Z

    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 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 a well (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 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. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in the project reports. Documenting the results of this effort are key to extracting lessons learned and maximizing the industry's benefits for future hydrate exploitation.

  10. Dynamic Modeling of Cascading Failure in Power Systems

    E-Print Network [OSTI]

    Song, Jiajia; Ghanavati, Goodarz; Hines, Paul D H

    2014-01-01T23:59:59.000Z

    The modeling of cascading failure in power systems is difficult because of the many different mechanisms involved; no single model captures all of these mechanisms. Understanding the relative importance of these different mechanisms is an important step in choosing which mechanisms need to be modeled for particular types of cascading failure analysis. This work presents a dynamic simulation model of both power networks and protection systems, which can simulate a wider variety of cascading outage mechanisms, relative to existing quasi-steady state (QSS) models. The model allows one to test the impact of different load models and protections on cascading outage sizes. This paper describes each module of the developed dynamic model and demonstrates how different mechanisms interact. In order to test the model we simulated a batch of randomly selected $N-2$ contingencies for several different static load configurations, and found that the distribution of blackout sizes and event lengths from the proposed dynamic...

  11. A Polynomial Chaos Approach to the Robust Analysis of the Dynamic Behaviour of Friction Systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . Key word: Dry friction systems, Nonlinear dynamic systems, stability, limit cycle, robustness, uncertainty propagation, polynomial chaos, Lyapunov function, SOS programming. 1. Introduction Dry friction1 A Polynomial Chaos Approach to the Robust Analysis of the Dynamic Behaviour of Friction Systems

  12. Thermal dissociation behavior and dissociation enthalpies of methane-carbon dioxide mixed hydrates

    E-Print Network [OSTI]

    Kwon, T.H.

    2012-01-01T23:59:59.000Z

    Dissociation heat of mixed-gas hydrate composed of methaneInternational Conference on Gas Hydrates (ICGH 2008), 2008,and specific heats of gas hydrates under submarine and

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

    E-Print Network [OSTI]

    Reagan, M. T.

    2010-01-01T23:59:59.000Z

    Spatial distributions of gas and hydrate phase saturations (from the Mallik 2002 Gas Hydrate Production Research Wellsimulating the behavior of gas hydrates, Energy Conversion

  14. Physical property changes in hydrate-bearing sediment due to depressurization and subsequent repressurization

    E-Print Network [OSTI]

    Waite, W.F.

    2008-01-01T23:59:59.000Z

    distribution of water, gas and hydrate within a core and thecontaining natural and laboratory-formed gas hydrate, inNatural Gas Hydrate In Oceanic and Permafrost Environments,

  15. Methane Hydrate Dissociation by Depressurization in a Mount Elbert Sandstone Sample: Experimental Observations and Numerical Simulations

    E-Print Network [OSTI]

    Kneafsey, T.

    2012-01-01T23:59:59.000Z

    DOE-USGS Mount Elbert gas hydrate stratigraphic test well:International Conference on Gas Hydrates, Vancouver, BritishGeologic controls on gas hydrate occurrence in the Mount

  16. Strategies for gas production from hydrate accumulations under various geologic conditions

    E-Print Network [OSTI]

    Moridis, G.; Collett, T.

    2003-01-01T23:59:59.000Z

    JNOC/GSC Mallik 2L- 38 Gas Hydrate Research Well, Mackenziedeposits. INTRODUCTION Gas hydrates are solid crystallinequantity of hydrocarbon gas hydrates range between 10 15 to

  17. Feasibility of monitoring gas hydrate production with time-lapse VSP

    E-Print Network [OSTI]

    Kowalsky, M.B.

    2010-01-01T23:59:59.000Z

    density of the aqueous, gas, and hydrate phases, which isfunction of the aqueous, gas and hydrate phase saturations;in Marine Sediments with Gas Hydrates: Effective Medium

  18. Gas production potential of disperse low-saturation hydrate accumulations in oceanic sediments

    E-Print Network [OSTI]

    Moridis, George J.; Sloan, E. Dendy

    2006-01-01T23:59:59.000Z

    EG. Formation of gas hydrates in natural gas transmissiongeology of natural gas hydrates. Amsterdam: Springer-Verlag;Soloviev, VA. Submarine gas hydrates. St. Petersburg;1998.

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

    E-Print Network [OSTI]

    Reagan, M. T.

    2010-01-01T23:59:59.000Z

    Spatial distributions of gas and hydrate phase saturations (Team, 2008, Investigation of gas hydrate bearing sandstoneInternational Conference on Gas Hydrates, July 6-10, 2008,

  20. Photoelectron Spectroscopy of Cold Hydrated Sulfate Clusters...

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

    sulfate clusters SO42-(H2O)n (n ) 4-7) at 12 K and ab initio studies to understand the structures and dynamics of these unique solvated systems. A significant increase of...

  1. DYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    (thermal, gas, diesel) and renewable (hydro, wind) power units. The objective is to assess the impact - that have a special dynamic behaviour, and the wind turbines. Detailed models for each one of the power system components are developed. Emphasis is given in the representation of different hydro power plant

  2. Nonlinear Dynamics and Structure Formation in Complex Systems

    E-Print Network [OSTI]

    Zonca, Fulvio

    Condition · In burning plasmas ignition condition is reached when local power density (self-heating the ignition condition (-particle self-heating) #12;Nonlinear Dynamics and Structure Formation in Complex of charged fusion products · -particle self-heating may be lost due to their transport out of the system

  3. Dynamic Interactions of PV units in Low Volatge Distribution Systems

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Dynamic Interactions of PV units in Low Volatge Distribution Systems M. J. Hossain, J. Lu Griffith. Abstract--Photovoltaic (PV) units along with other distributed energy resources (DERs) are located close, robust control, stability. I. Introduction The integration level of PV units in low and medium voltage

  4. Regulation and controlled synchronization for complex dynamical systems

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Regulation and controlled synchronization for complex dynamical systems H.J.C. Huijberts #3; H of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous of the problem where the standard solvability assumptions for the regulator problem are not met turn out to have

  5. The flashing ratchet: long time behavior and dynamical systems interpretation

    E-Print Network [OSTI]

    Dolbeault, Jean

    The flashing ratchet: long time behavior and dynamical systems interpretation Jean Dolbeault@mcs.kent.edu December 11, 2002 Abstract. The flashing ratchet is a model for certain types of molecular motors as well then study the long time behavior of the flashing ratchet model. By entropy methods, we prove the existence

  6. Innovation system dynamics and sustainable development Challenges for policy

    E-Print Network [OSTI]

    Innovation system dynamics and sustainable development ­ Challenges for policy Paper in progress Innovation, Sustainability and Policy Conference, 23-25 May 2004 Kloster Seeon, Germany Dr. Maj Munch, while market development perspectives are neglected. The NIS perspective forwarded in this paper has

  7. Vehicle System Dynamics Vol. 00, No. 00, April 2008, 129

    E-Print Network [OSTI]

    Brennan, Sean

    Vehicle System Dynamics Vol. 00, No. 00, April 2008, 1­29 Fidelity of using scaled vehicles (April 2008) There are many situations where physical testing of a vehicle or vehicle controller is necessary, yet use of a full-size vehicle is not practical. Some situations include implementation testing

  8. Movement Imitation with Nonlinear Dynamical Systems in Humanoid Robots

    E-Print Network [OSTI]

    Schaal, Stefan

    , as will be demonstrated later. We apply the CPs to a task involving the imitation of human movements by a humanoidMovement Imitation with Nonlinear Dynamical Systems in Humanoid Robots Auke Jan Ijspeert & Jun results demonstrate (a) that multi-joint human movements can be encoded successfully by the CPs, (b

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

    SciTech Connect (OSTI)

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

    2012-09-01T23:59:59.000Z

    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.

  10. Dynamics of a Simple Quantum System in a Complex Environment

    E-Print Network [OSTI]

    Aurel Bulgac; Gui DoDang; Dimitri Kusnezov

    1997-11-10T23:59:59.000Z

    We present a theory for the dynamical evolution of a quantum system coupled to a complex many-body intrinsic system/environment. By modelling the intrinsic many-body system with parametric random matrices, we study the types of effective stochastic models which emerge from random matrix theory. Using the Feynman-Vernon path integral formalism, we derive the influence functional and obtain either analytical or numerical solutions for the time evolution of the entire quantum system. We discuss thoroughly the structure of the solutions for some representative cases and make connections to well known limiting results, particularly to Brownian motion, Kramers classical limit and the Caldeira-Leggett approach.

  11. Notes 02. Dynamic response of second order mechanical systems

    E-Print Network [OSTI]

    San Andres, Luis

    2008-01-01T23:59:59.000Z

    Design Issues: SDOF FRF - Luis San Andr?s ? 2008 1 Important design issues and engineering applications of SDOF system Frequency response Functions The following descriptions show typical questions related to the design and dynamic performance... - Luis San Andr?s ? 2008 2 PROBLEM TYPE 1 Consider a system excited by a periodic force of magnitude F o with external frequency ?. a) Determine the damping ratio ? needed such that the amplitude of motion does not ever exceed (say) twice...

  12. Characterizing quantum dynamics with initial system-environment correlations

    E-Print Network [OSTI]

    Martin Ringbauer; Christopher J. Wood; Kavan Modi; Alexei Gilchrist; Andrew G. White; Alessandro Fedrizzi

    2014-10-21T23:59:59.000Z

    We fully characterize the reduced dynamics of an open quantum system initially correlated with its environment. Using a photonic qubit coupled to a simulated environment we tomographically reconstruct a superchannel---a generalised channel that treats preparation procedures as inputs---from measurement of the system alone, despite its coupling to the environment. We introduce novel quantitative measures for determining the strength of initial correlations, and to allow an experiment to be optimised in regards to its environment.

  13. Forward and adjoint sensitivity computation of chaotic dynamical systems

    SciTech Connect (OSTI)

    Wang, Qiqi, E-mail: qiqi@mit.edu [Department of Aeronautics and Astronautics, MIT, 77 Mass Ave., Cambridge, MA 02139 (United States)] [Department of Aeronautics and Astronautics, MIT, 77 Mass Ave., Cambridge, MA 02139 (United States)

    2013-02-15T23:59:59.000Z

    This paper describes a forward algorithm and an adjoint algorithm for computing sensitivity derivatives in chaotic dynamical systems, such as the Lorenz attractor. The algorithms compute the derivative of long time averaged “statistical” quantities to infinitesimal perturbations of the system parameters. The algorithms are demonstrated on the Lorenz attractor. We show that sensitivity derivatives of statistical quantities can be accurately estimated using a single, short trajectory (over a time interval of 20) on the Lorenz attractor.

  14. Simulation of methane production in a laboratory-scale reactor containing hydrate-bearing porous medium

    SciTech Connect (OSTI)

    Gamwo, I.K.; Myshakin, E.M.; Zhang, Wu; Warzinski, R.P.

    2008-01-01T23:59:59.000Z

    Production of methane, induced by depressurization of hydrate sediment in a reactor, was investigated by numerical simulations using a computational fluid dynamics code TOUGH+/Hydrate. The methane production rates were computed at well-pressure drops of 4.2, 14.7, and 29.5 MPa and at a reactor temperature of 21 0C. The predicted behavior of methane production from the reactor is consistent with field-scale simulations and observations. The production rate increases with pressure drop at the well. Evolution patterns of gas and hydrate distributions are similar to those obtained in field-scale simulations. These preliminary results clearly indicate that numerical simulators can be applied to laboratory-scale reactors to anticipate scenarios observed in field experiments.

  15. Study of the Natural Gas Hydrate 'Trap Zone' and the Methane Hydrate Potential in the Sverdrup Basin, Canada

    SciTech Connect (OSTI)

    Majorowicz, J. A. [Northern Geothermal Consult. (Canada)], E-mail: majorowi@show.ca; Hannigan, P. K.; Osadetz, K. G. [Geological Survey of Canada, Calgary (Canada)

    2002-06-15T23:59:59.000Z

    The methane hydrate stability zone beneath Sverdrup Basin has developed to a depth of 2 km underneath the Canadian Arctic Islands and 1 km below sea level under the deepest part of the inter-island sea channels. It is not, however, a continuous zone. Methane hydrates are detected in this zone, but the gas hydrate/free gas contact occurs rarely. Interpretation of well logs indicate that methane hydrate occurs within the methane stability zone in 57 of 150 analyzed wells. Fourteen wells show the methane hydrate/free gas contact. Analysis of the distribution of methane hydrate and hydrate/gas contact occurrences with respect to the present methane hydrate stability zone indicate that, in most instances, the detected methane hydrate occurs well above the base of methane hydrate stability. This relationship suggests that these methane hydrates were formed in shallower strata than expected with respect to the present hydrate stability zone from methane gases which migrated upward into hydrate trap zones. Presently, only a small proportion of gas hydrate occurrences occur in close proximity to the base of predicted methane hydrate stability. The association of the majority of detected hydrates with deeply buried hydrocarbon discoveries, mostly conventional natural gas accumulations, or mapped seismic closures, some of which are dry, located in structures in western and central Sverdrup Basin, indicate the concurring relationship of hydrate occurrence with areas of high heat flow. Either present-day or paleo-high heat flows are relevant. Twenty-three hydrate occurrences coincide directly with underlying conventional hydrocarbon accumulations. Other gas hydrate occurrences are associated with structures filled with water with evidence of precursor hydrocarbons that were lost because of upward leakage.

  16. ENG ME 404: Dynamics and control Fall 2011 ENG ME 404: Dynamics and Control of Mechanical Systems, Fall 2011

    E-Print Network [OSTI]

    Systems and control theory plays a vital role across most aspects of modern life. Control systemsENG ME 404: Dynamics and control Fall 2011 ENG ME 404: Dynamics and Control of Mechanical Systems and provide you a set of tools to analyze and design controllers. Elements of both state-space (modern

  17. Relativistic Quantum Metrology in Open System Dynamics

    E-Print Network [OSTI]

    Zehua Tian; Jieci Wang; Heng Fan; Jiliang Jing

    2015-01-27T23:59:59.000Z

    Quantum metrology studies the ultimate limit of precision in estimating a physical quantity if quantum strategies are exploited. Here we investigate the evolution of a two-level atom as a detector which interacts with a massless scalar field using the master equation approach for open quantum system. We employ local quantum estimation theory to estimate the Unruh temperature when probed by a uniformly accelerated detector in the Minkowski vacuum. In particular, we evaluate the Fisher information (FI) for population measurement, maximize its value over all possible detector preparations and evolution times, and compare its behavior with that of the quantum Fisher information (QFI). We find that the optimal precision of estimation is achieved when the detector evolves for a long enough time. Furthermore, we find that in this case the FI for population measurement is independent of initial preparations of the detector and is exactly equal to the QFI, which means that population measurement is optimal. This result demonstrates that the achievement of the ultimate bound of precision imposed by quantum mechanics is possible. Finally, we note that the same configuration is also available to the maximum of the QFI itself.

  18. Power Systems Frequency Dynamic Monitoring System Design and Applications

    E-Print Network [OSTI]

    Schrijver, Karel

    Disturbance Recorder (FDR), Phasor Measurement Unit (PMU), Wide Area Measurement System, Under Frequency Load for the first time. The FNET system consists of Frequency Disturbance Recorders (FDR), which work as the sensor to process event detection, localization and unbalanced power estimation during frequency disturbances

  19. The percolation transition of hydration water: from planar hydrophilic surfaces to proteins

    E-Print Network [OSTI]

    Alla Oleinikova; Ivan Brovchenko; Nikolai Smolin; Aliaksei Krukau; Alfons Geiger; Roland Winter

    2005-08-05T23:59:59.000Z

    The formation of a spanning hydrogen-bonded network of hydration water is found to occur via a 2D percolation transition in various systems: smooth hydrophilic surfaces, the surface of a single protein molecule, protein powder and diluted peptide solution. The average number of water-water hydrogen bonds nH at the percolation threshold varies from 2.0 to 2.3, depending on temperature, system size and surface properties. Calculation of nH allows an easy estimation of the percolation threshold of hydration water in various systems, including biomolecules.

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

    SciTech Connect (OSTI)

    Torres, Marta

    2014-01-31T23:59:59.000Z

    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.

  1. Econophysical Dynamics of Market-Based Electric Power Distribution Systems

    E-Print Network [OSTI]

    Nicolas Ho; David P. Chassin

    2006-02-09T23:59:59.000Z

    As energy markets begin clearing at sub-hourly rates, their interaction with load control systems becomes a potentially important consideration. A simple model for the control of thermal systems using market-based power distribution strategies is proposed, with particular attention to the behavior and dynamics of electric building loads and distribution-level power markets. Observations of dynamic behavior of simple numerical model are compared to that of an aggregate continuous model. The analytic solution of the continuous model suggests important deficiencies in each. The continuous model provides very valuable insights into how one might design such load control system and design the power markets they interact with. We also highlight important shortcomings of the continuous model which we believe must be addressed using discrete models.

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

    SciTech Connect (OSTI)

    Sherman, Max H.; Walker, Iain S.

    2011-04-01T23:59:59.000Z

    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).

  3. Pressure-induced Hydration in Zeolite Tetranatrolite

    SciTech Connect (OSTI)

    Lee,Y.; Hriljac, J.; Parise, J.; Vogt, T.

    2006-01-01T23:59:59.000Z

    The tetranatrolite-paranatrolite transformation has remained a key problem in understanding the paragenesis of zeolites in the natrolite family. It is accepted that when paranatrolite, approximate formula Na{sub 16-x}Ca{sub x}Al{sub 16+x}Si{sub 24-x}O{sub 80}{center_dot}24H{sub 2}O, is removed from an aqueous environment and exposed to the atmosphere, it loses water and transforms to tetranatrolite, Na{sub 16-x}Ca{sub x}Al{sub 16+x}Si{sub 24-x}O{sub 80}{center_dot}nH{sub 2}O (n {le} 24). Here we show that this transformation is not only reversible, but that tetranatrolite exhibits two sequential pressure-induced hydrations leading first to paranatrolite and then to a superhydrated tetranatrolite above 0.2 and 3.0 GPa, respectively. We have previously reported similar behavior for the corresponding system with an ordered Si/Al distribution, i.e., natrolite itself, however the ordered version of paranatrolite exists over a much smaller pressure range. The pressure-induced transformations of natrolite and tetranatrolite thus further supports the supposition that paranatrolite is a distinct mineral species, with a pressure-stability field dependent upon composition.

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

    DOE Patents [OSTI]

    Simmons, Blake A. (San Francisco, CA); Bradshaw, Robert W. (Livermore, CA); Dedrick, Daniel E. (Berkeley, CA); Anderson, David W. (Riverbank, CA)

    2009-07-14T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Rissanou, Anastassia N.; Harmandaris, Vagelis [Department of Mathematics and Applied Mathematics, University of Crete, GR-71409, Heraklion, Crete, Greece and Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), GR-71110, Heraklion, Cret (Greece)

    2014-05-15T23:59:59.000Z

    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.

  6. POWER GRID DYNAMICS: ENHANCING POWER SYSTEM OPERATION THROUGH PRONY ANALYSIS

    SciTech Connect (OSTI)

    Ray, C.; Huang, Z.

    2007-01-01T23:59:59.000Z

    Prony Analysis is a technique used to decompose a signal into a series consisting of weighted complex exponentials and promises to be an effi cient way of recognizing sensitive lines during faults in power systems such as the U.S. Power grid. Positive Sequence Load Flow (PSLF) was used to simulate the performance of a simple two-area-four-generator system and the reaction of the system during a line fault. The Dynamic System Identifi cation (DSI) Toolbox was used to perform Prony analysis and use modal information to identify key transmission lines for power fl ow adjustment to improve system damping. The success of the application of Prony analysis methods to the data obtained from PSLF is reported, and the key transmission line for adjustment is identifi ed. Future work will focus on larger systems and improving the current algorithms to deal with networks such as large portions of the Western Electricity Coordinating Council (WECC) power grid.

  7. SystemC Analysis of a new Dynamic Power Management Architecture Massimo Conti

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    SystemC Analysis of a new Dynamic Power Management Architecture Massimo Conti Università dynamic power management architecture of a System on Chip. The Power State Machine describing the status Power Management Architecture Dynamic Power Management (DPM) is a design methodology that dynamically

  8. Numerical, Laboratory And Field Studies of Gas Production From Natural Hydrate Accumulations in Geologic Media

    E-Print Network [OSTI]

    Moridis, George J.; Kneafsey, Timothy J.; Kowalsky, Michael; Reagan, Matthew

    2006-01-01T23:59:59.000Z

    hydrate (Class 1W) or gas and hydrate (Class 1G). In Class 1Economic Geology of Natural Gas Hydrates, M. Max, A.H. John-of the thermal test of gas hydrate dissociation in the

  9. Depressurization-induced gas production from Class 1 and Class 2 hydrate deposits

    E-Print Network [OSTI]

    Moridis, George J.; Kowalsky, Michael

    2006-01-01T23:59:59.000Z

    hydrate (Class 1W) or gas and hydrate (Class 1G). In Class 1Class 1G (involving gas and hydrate in the HBL). In Class 2JNOC/GSC Mallik 2L-38 Gas Hydrate Research Well, Mackenzie

  10. 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

    2005-02-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Frank Rack; Michael Storms; Derryl Schroeder; Brandon Dugan; Peter Schultheiss; ODP Leg 204 Shipboard Scientific Party

    2002-12-31T23:59:59.000Z

    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.

  12. Generalized Performance of Concatenated Quantum Codes -- A Dynamical Systems Approach

    E-Print Network [OSTI]

    Jesse Fern; Julia Kempe; Slobodan Simic; Shankar Sastry

    2006-03-15T23:59:59.000Z

    We apply a dynamical systems approach to concatenation of quantum error correcting codes, extending and generalizing the results of Rahn et al. [1] to both diagonal and nondiagonal channels. Our point of view is global: instead of focusing on particular types of noise channels, we study the geometry of the coding map as a discrete-time dynamical system on the entire space of noise channels. In the case of diagonal channels, we show that any code with distance at least three corrects (in the infinite concatenation limit) an open set of errors. For Calderbank-Shor-Steane (CSS) codes, we give a more precise characterization of that set. We show how to incorporate noise in the gates, thus completing the framework. We derive some general bounds for noise channels, which allows us to analyze several codes in detail.

  13. Quench Dynamics of Isolated Many-Body Quantum Systems

    E-Print Network [OSTI]

    E. J. Torres-Herrera; Lea F. Santos

    2014-04-29T23:59:59.000Z

    We study isolated quantum systems with two-body interactions after a quench. In these systems, the energy shell is a Gaussian of width $\\sigma$, and it gives the maximum possible spreading of the energy distribution of the initial states. When the distribution achieves this shape, the fidelity decay can be Gaussian until saturation. This establishes a lower bound for the fidelity decay in realistic systems. An ultimate bound for systems with many-body interactions is also derived based on the analysis of full random matrices. We find excellent agreement between numerical and analytical results. We also provide the conditions under which the short-time dynamics of few-body observables is controlled by $\\sigma$. The analyses are developed for systems, initial states, and observables accessible to experiments.

  14. Reduced Measurement-space Dynamic State Estimation (ReMeDySE) for Power Systems

    SciTech Connect (OSTI)

    Zhang, Jinghe; Welch, Greg; Bishop, Gary; Huang, Zhenyu

    2011-06-19T23:59:59.000Z

    Abstract- Applying Kalman filtering techniques to dynamic state estimation is a developing research area in modern power systems.

  15. Characterization of NOx Species in Dehydrated and Hydrated Na...

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

    NOx Species in Dehydrated and Hydrated Na- and Ba-Y, FAU Zeolites Formed in NO Adsorption. Characterization of NOx Species in Dehydrated and Hydrated Na- and Ba-Y, FAU Zeolites...

  16. ENG ME 404: Dynamics and control Fall 2014 ENG ME 404: Dynamics and Control of Mechanical Systems, Fall 2014

    E-Print Network [OSTI]

    Lin, Xi

    and control theory plays a vital role across most aspects of modern life. Control systems are found in yourENG ME 404: Dynamics and control Fall 2014 ENG ME 404: Dynamics and Control of Mechanical Systems a set of tools to analyze and design controllers. Elements of both state-space (modern) and frequency

  17. Method for production of hydrocarbons from hydrates

    DOE Patents [OSTI]

    McGuire, Patrick L. (Los Alamos, NM)

    1984-01-01T23:59:59.000Z

    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.

  18. Best practices for system dynamics model design and construction with powersim studio.

    SciTech Connect (OSTI)

    Malczynski, Leonard A.

    2011-06-01T23:59:59.000Z

    This guide addresses software quality in the construction of Powersim{reg_sign} Studio 8 system dynamics simulation models. It is the result of almost ten years of experience with the Powersim suite of system dynamics modeling tools (Constructor and earlier Studio versions). It is a guide that proposes a common look and feel for the construction of Powersim Studio system dynamics models.

  19. Effect of Large Dynamic Loads on Interconnected Power Systems with Power Oscillation Damping

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Effect of Large Dynamic Loads on Interconnected Power Systems with Power Oscillation Damping.hossain and H.Pota)@adfa.edu.au Abstract--Power systems are composed of dynamic loads. In this paper presents an analysis to investigate the effects of large dynamic loads on interconnected power systems

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

    SciTech Connect (OSTI)

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

    2006-03-01T23:59:59.000Z

    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.

  1. A study of the sensitivity of topological dynamical systems and the Fourier spectrum of chaotic interval maps

    E-Print Network [OSTI]

    Roque Sol, Marco A.

    2009-06-02T23:59:59.000Z

    We study some topological properties of dynamical systems. In particular the rela- tionship between spatio-temporal chaotic and Li-Yorke sensitive dynamical systems establishing that for minimal dynamical systems those properties are equivalent...

  2. Liquid-state polaron theory of the hydrated electron revisited

    E-Print Network [OSTI]

    James P. Donley; David R. Heine; Caleb A. Tormey; David T. Wu

    2014-12-25T23:59:59.000Z

    The quantum path integral/classical liquid-state theory of Chandler and co-workers, created to describe an excess electron in solvent, is re-examined for the hydrated electron. The portion that models electron-water density correlations is replaced by two equations: the range optimized random phase approximation (RO-RPA), and the DRL approximation to the "two-chain" equation, both shown previously to describe accurately the static structure and thermodynamics of strongly charged polyelectrolyte solutions. The static equilibrium properties of the hydrated electron are analyzed using five different electron-water pseudopotentials. The theory is then compared with data from mixed quantum/classical Monte Carlo and molecular dynamics simulations using these same pseudopotentials. It is found that the predictions of the RO-RPA and DRL-based polaron theories are similar and improve upon previous theory, with values for almost all properties analyzed in reasonable quantitative agreement with the available simulation data. Also, it is found using the Larsen, Glover and Schwartz pseudopotential that the theories give values for the solvation free energy that are at least three times larger than that from experiment.

  3. Hydration of non-polar anti-parallel ?-sheets

    SciTech Connect (OSTI)

    Urbic, Tomaz [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ašker?eva 5, SI-1000 Ljubljana (Slovenia)] [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ašker?eva 5, SI-1000 Ljubljana (Slovenia); Dias, Cristiano L., E-mail: cld@njit.edu [Physics Department, New Jersey Institute of Technology, Newark, New Jersey 07102-1982 (United States)

    2014-04-28T23:59:59.000Z

    In this work we focus on anti-parallel ?-sheets to study hydration of side chains and polar groups of the backbone using all-atom molecular dynamics simulations. We show that: (i) water distribution around the backbone does not depend significantly on amino acid sequence, (ii) more water molecules are found around oxygen than nitrogen atoms of the backbone, and (iii) water molecules around nitrogen are highly localized in the planed formed by peptide backbones. To study hydration around side chains we note that anti-parallel ?-sheets exhibit two types of cross-strand pairing: Hydrogen-Bond (HB) and Non-Hydrogen-Bond (NHB) pairing. We show that distributions of water around alanine, leucine, and valine side chains are very different at HB compared to NHB faces. For alanine pairs, the space between side chains has a higher concentration of water if residues are located in the NHB face of the ?-sheet as opposed to the HB face. For leucine residues, the HB face is found to be dry while the space between side chains at the NHB face alternates between being occupied and non-occupied by water. Surprisingly, for valine residues the NHB face is dry, whereas the HB face is occupied by water. We postulate that these differences in water distribution are related to context dependent propensities observed for ?-sheets.

  4. Dehydration of plutonium or neptunium trichloride hydrate

    DOE Patents [OSTI]

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

    1992-03-24T23:59:59.000Z

    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.

  5. 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)

    1992-01-01T23:59:59.000Z

    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.

  6. Gas hydrates in the Gulf of Mexico

    E-Print Network [OSTI]

    Cox, Henry Benjamin

    1986-01-01T23:59:59.000Z

    GAS HYDRATES IN THE GULF OF MEXICO A Thesis by HENRY BENJAMIN COX Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1986 Major Subject...: Oceanography GAS HYDRATES IN THE GULF OF MEXICO A Thesis by HENRY BENJAMIN COX Approved as to style and content by: James M. Brooks (Chair of Committee) Leis M. Jef e (Member) Andre M. Landry, J (Member) Roger R. Fay (Member) Robert 0. Reid (Head...

  7. Power-laws in recurrence networks from dynamical systems

    E-Print Network [OSTI]

    Y. Zou; J. Heitzig; R. V. Donner; J. F. Donges; J. D. Farmer; R. Meucci; S. Euzzor; N. Marwan; J. Kurths

    2012-03-15T23:59:59.000Z

    Recurrence networks are a novel tool of nonlinear time series analysis allowing the characterisation of higher-order geometric properties of complex dynamical systems based on recurrences in phase space, which are a fundamental concept in classical mechanics. In this Letter, we demonstrate that recurrence networks obtained from various deterministic model systems as well as experimental data naturally display power-law degree distributions with scaling exponents $\\gamma$ that can be derived exclusively from the systems' invariant densities. For one-dimensional maps, we show analytically that $\\gamma$ is not related to the fractal dimension. For continuous systems, we find two distinct types of behaviour: power-laws with an exponent $\\gamma$ depending on a suitable notion of local dimension, and such with fixed $\\gamma=1$.

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

    SciTech Connect (OSTI)

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

    1985-06-01T23:59:59.000Z

    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.

  9. ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS

    SciTech Connect (OSTI)

    Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.; Bryson, Stephen T.; Howell, Steve B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ragozzine, Darin; Holman, Matthew J.; Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Fabrycky, Daniel C.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, Batavia, IL 60510 (United States); Ford, Eric B. [211 Bryant Space Science Center, University of Florida, Gainesville, FL 32611 (United States); Shporer, Avi [Las Cumbres Observatory Global Telescope Network, Santa Barbara, CA 93117 (United States); Rowe, Jason F.; Quintana, Elisa V.; Caldwell, Douglas A. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Ciardi, David [Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Dunham, Edward W. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Gautier, Thomas N. III, E-mail: Jack.Lissauer@nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); and others

    2011-11-01T23:59:59.000Z

    About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.

  10. MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE

    E-Print Network [OSTI]

    Meyer, Christian

    MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE Feng Lin Submitted in partial and Sciences COLUMBIA UNIVERSITY 2006 #12;MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE;ABSTRACT MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE Feng Lin A mathematical

  11. Dynamical resonance locking in tidally interacting binary systems

    E-Print Network [OSTI]

    Joshua Burkart; Eliot Quataert; Phil Arras

    2014-10-25T23:59:59.000Z

    We examine the dynamics of resonance locking in detached, tidally interacting binary systems. In a resonance lock, a given stellar or planetary mode is trapped in a highly resonant state for an extended period of time, during which the spin and orbital frequencies vary in concert to maintain the resonance. This phenomenon is qualitatively similar to resonance capture in planetary dynamics. We show that resonance locks can accelerate the course of tidal evolution in eccentric systems and also efficiently couple spin and orbital evolution in circular binaries. Previous analyses of resonance locking have not treated the mode amplitude as a fully dynamical variable, but rather assumed the adiabatic (i.e. Lorentzian) approximation valid only in the limit of relatively strong mode damping. We relax this approximation, analytically derive conditions under which the fixed point associated with resonance locking is stable, and further check these analytic results using numerical integrations of the coupled mode, spin, and orbital evolution equations. These show that resonance locking can sometimes take the form of complex limit cycles or even chaotic trajectories. We provide simple analytic formulae that define the binary and mode parameter regimes in which resonance locks of some kind occur (stable, limit cycle, or chaotic). We briefly discuss the astrophysical implications of our results for white dwarf and neutron star binaries as well as eccentric stellar binaries.

  12. In-situ early-age hydration study of sulfobelite cements by synchrotron powder diffraction

    SciTech Connect (OSTI)

    Álvarez-Pinazo, G.; Cuesta, A.; García-Maté, M.; Santacruz, I.; Losilla, E.R. [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain)] [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain); Sanfélix, S.G. [Unidad Técnica de Investigación de Materiales, AIDICO, Avda. Benjamín Franklin, 17 Paterna, Valencia (Spain)] [Unidad Técnica de Investigación de Materiales, AIDICO, Avda. Benjamín Franklin, 17 Paterna, Valencia (Spain); Fauth, F. [CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain)] [CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); Aranda, M.A.G. [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain) [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain); CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); De la Torre, A.G., E-mail: mgd@uma.es [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain)

    2014-02-15T23:59:59.000Z

    Eco-friendly belite calcium sulfoaluminate (BCSA) cement hydration behavior is not yet well understood. Here, we report an in-situ synchrotron X-ray powder diffraction study for the first hours of hydration of BCSA cements. Rietveld quantitative phase analysis has been used to establish the degree of reaction (?). The hydration of a mixture of ye'elimite and gypsum revealed that ettringite formation (? ? 70% at 50 h) is limited by ye'elimite dissolution. Two laboratory-prepared BCSA cements were also studied: non-active-BCSA and active-BCSA cements, with ?- and ??{sub H}-belite as main phases, respectively. Ye'elimite, in the non-active-BCSA system, dissolves at higher pace (? ? 25% at 1 h) than in the active-BCSA one (? ? 10% at 1 h), with differences in the crystallization of ettringite (? ? 30% and ? ? 5%, respectively). This behavior has strongly affected subsequent belite and ferrite reactivities, yielding stratlingite and other layered phases in non-active-BCSA. The dissolution and crystallization processes are reported and discussed in detail. -- Highlights: •Belite calcium sulfoaluminate cements early hydration mechanism has been determined. •Belite hydration strongly depends on availability of aluminum hydroxide. •Orthorhombic ye’elimite dissolved at a higher pace than cubic one. •Ye’elimite larger reaction degree yields stratlingite formation by belite reaction. •Rietveld method quantified gypsum, anhydrite and bassanite dissolution rates.

  13. Medium-pressure clathrate hydrate/membrane hybrid process for postcombustion capture of carbon dioxide

    SciTech Connect (OSTI)

    Praveen Linga; Adebola Adeyemo; Peter Englezos [University of British Columbia, Vancouver, BC (Canada). Department of Chemical and Biological Engineering

    2008-01-01T23:59:59.000Z

    This study presents a medium-pressure CO{sub 2} capture process based on hydrate crystallization in the presence of tetrahydrofuran (THF). THF reduces the incipient equilibrium hydrate formation conditions from a CO{sub 2}/N{sub 2} gas mixture. Relevant thermodynamic data at 0.5, 1.0, and 1.5 mol % THF were obtained and reported. In addition, the kinetics of hydrate formation from the CO{sub 2}/N{sub 2}/THF system as well as the CO{sub 2} recovery and separation efficiency were also determined experimentally at 273.75 K. The above data were utilized to develop the block flow diagram of the proposed process. The process involves three hydrate stages coupled with a membrane-based gas separation process. The three hydrate stages operate at 2.5 MPa and 273.75 K. This operating pressure is substantially less than the pressure required in the absence of THF and hence the compression costs are reduced from 75 to 53% of the power produced for a typical 500 MW power plant. 21 refs., 8 figs., 4 tabs.

  14. Composite Thermal Conductivity in a Large Heterogeneous PorousMethane Hydrate Sample

    SciTech Connect (OSTI)

    Gupta, Arvind; Kneafsey, Timothy J.; Moridis George J.; Seol,Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

    2006-08-01T23:59:59.000Z

    By employing inverse modeling to analyze the laboratorydata, we determined the composite thermal conductivity (k theta W/m/K) ofa porous methane hydrate sample ranged between 0.25 and 0.58 W/m/K as afunction of density. The calculated composite thermal diffusivities ofporous hydrate sample ranged between 2.59x10-7 m2/s and 3.71x10-7 m2/s.The laboratory study involved a large heterogeneous sample (composed ofhydrate, water, and methane gas). The measurements were conductedisobarically at 4.98 MPa over a temperature range of 277.3-279.1 K.Pressure and temperature were monitored at multiple locations in thesample. X-ray computed tomography (CT) was used to visualize and quantifythe density changes that occurred during hydrate formation from granularice. CT images showed that methane hydrate formed from granular ice washeterogeneous and provided an estimate of the sample density variation inthe radial direction. This facilitated quantifying the density effect oncomposite thermal conductivity. This study showed that the sampleheterogeneity should be considered in thermal conductivity measurementsof hydrate systems. Mixing models (i.e., arithmetic, harmonic, geometricmean, and square root models) were compared to the estimated compositethermal conductivity determined by inverse modeling. The results of thearithmetic mean model showed the best agreement with the estimatedcomposite thermal conductivity.

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

    DOE Patents [OSTI]

    Fong, Walter L. (Royal Oak, MI); Catherino, Henry A. (Rochester, MI); Kotch, Richard J. (Mt. Clemens, MI)

    1983-01-01T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    2013-08-20T23:59:59.000Z

    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.

  17. Extended space expectation values in quantum dynamical system evolutions

    SciTech Connect (OSTI)

    Demiralp, Metin [Istanbul Technical University, Informatics Institute, Maslak, 34469, Istanbul (Turkey)

    2014-10-06T23:59:59.000Z

    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 Hamiltonian’s 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.

  18. Dynamic Simulation and Optimization of Nuclear Hydrogen Production Systems

    SciTech Connect (OSTI)

    Paul I. Barton; Mujid S. Kaximi; Georgios Bollas; Patricio Ramirez Munoz

    2009-07-31T23:59:59.000Z

    This project is part of a research effort to design a hydrogen plant and its interface with a nuclear reactor. This project developed a dynamic modeling, simulation and optimization environment for nuclear hydrogen production systems. A hybrid discrete/continuous model captures both the continuous dynamics of the nuclear plant, the hydrogen plant, and their interface, along with discrete events such as major upsets. This hybrid model makes us of accurate thermodynamic sub-models for the description of phase and reaction equilibria in the thermochemical reactor. Use of the detailed thermodynamic models will allow researchers to examine the process in detail and have confidence in the accurary of the property package they use.

  19. Multipole Electrostatics in Hydration Free Energy Calculations

    E-Print Network [OSTI]

    Ponder, Jay

    Multipole Electrostatics in Hydration Free Energy Calculations YUE SHI,1 CHUANJIE WU,2 JAY W Acceptance Ratio method. We have compared two approaches to derive the atomic multipoles from quantum mechanical calculations: one directly from the new distributed multipole analysis and the other involving

  20. Dynamic Systems Analysis Report for Nuclear Fuel Recycle

    SciTech Connect (OSTI)

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

    2008-12-01T23:59:59.000Z

    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.

  1. StreamWorks - A system for Dynamic Graph Search

    SciTech Connect (OSTI)

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

    2013-06-11T23:59:59.000Z

    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.

  2. Comparative Assessment of Advanced Gay Hydrate Production Methods

    SciTech Connect (OSTI)

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

    2009-06-30T23:59:59.000Z

    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.

  3. Rapid Gas Hydrate Formation Processes: Will They Work?

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

    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. 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 (see Figure 1).

  4. 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.

    2010-06-01T23:59:59.000Z

    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. Results from this work demonstrate that the rapid and continuous formationmore »of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.« less

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

    SciTech Connect (OSTI)

    Sinha, Sudipta Kumar; Chakraborty, Kausik; Bandyopadhyay, Sanjoy, E-mail: sanjoy@chem.iitkgp.ernet.in [Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur - 721302 (India); Jana, Madhurima [Molecular Simulation Laboratory, Department of Chemistry, National Institute of Technology, Rourkela - 769008 (India)

    2014-12-14T23:59:59.000Z

    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.

  6. Dynamical Friction and Resonance Trapping in Planetary Systems

    E-Print Network [OSTI]

    Nader Haghighipour

    1998-12-05T23:59:59.000Z

    A restricted planar circular three-body system, consisting of the Sun and two planets, is studied as a simple model for a planetary system. The mass of the inner planet is considered to be larger and the system is assumed to be moving in a uniform interplanetary medium with constant density. Numerical integrations of this system indicate a resonance capture when the dynamical friction of the interplanetary medium is taken into account. As a result of this resonance trapping, the ratio of orbital periods of the two planets becomes nearly commensurate and the eccentricity and semimajor axis of the orbit of the outer planet and also its angular momentum and total energy become constant. It appears from the numerical work that the resulting commensurability and also the resonant values of the orbital elements of the outer planet are essentially independent of the initial relative positions of the two bodies. The results of numerical integrations of this system are presented and the first-order partially averaged equations are studied in order to elucidate the behavior of the system while captured in resonance.

  7. Dynamic self-assembly in living systems as computation.

    SciTech Connect (OSTI)

    Bouchard, Ann Marie; Osbourn, Gordon Cecil

    2004-06-01T23:59:59.000Z

    Biochemical reactions taking place in living systems that map different inputs to specific outputs are intuitively recognized as performing information processing. Conventional wisdom distinguishes such proteins, whose primary function is to transfer and process information, from proteins that perform the vast majority of the construction, maintenance, and actuation tasks of the cell (assembling and disassembling macromolecular structures, producing movement, and synthesizing and degrading molecules). In this paper, we examine the computing capabilities of biological processes in the context of the formal model of computing known as the random access machine (RAM) [Dewdney AK (1993) The New Turing Omnibus. Computer Science Press, New York], which is equivalent to a Turing machine [Minsky ML (1967) Computation: Finite and Infinite Machines. Prentice-Hall, Englewood Cliffs, NJ]. When viewed from the RAM perspective, we observe that many of these dynamic self-assembly processes - synthesis, degradation, assembly, movement - do carry out computational operations. We also show that the same computing model is applicable at other hierarchical levels of biological systems (e.g., cellular or organism networks as well as molecular networks). We present stochastic simulations of idealized protein networks designed explicitly to carry out a numeric calculation. We explore the reliability of such computations and discuss error-correction strategies (algorithms) employed by living systems. Finally, we discuss some real examples of dynamic self-assembly processes that occur in living systems, and describe the RAM computer programs they implement. Thus, by viewing the processes of living systems from the RAM perspective, a far greater fraction of these processes can be understood as computing than has been previously recognized.

  8. Neutron scattering evidence of a boson peak in protein hydration water Alessandro Paciaroni,1

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    Neutron scattering evidence of a boson peak in protein hydration water Alessandro Paciaroni,1 Anna Viterbo, Italy Received 24 February 1999 Measurement of the low temperature neutron excess of scattering, has been detected by neutron scattering and Raman spectros- copy in a large variety of glassy systems

  9. Fiber Optic Sensing Technology for Detecting Gas Hydrate Formation and Decomposition

    SciTech Connect (OSTI)

    Rawn, Claudia J [ORNL; Leeman, John R [University of Oklahoma, Norman; Ulrich, Shannon M [ORNL; Alford, Jonathan E [ORNL; Phelps, Tommy Joe [ORNL; Madden, Megan Elwood [University of Oklahoma, Norman

    2011-01-01T23:59:59.000Z

    A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 L) pressure vessel providing high spatial resolution, time resolved, 3-D measurement of hybrid temperature-strain (TS) values within experimental sediment gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data is visualized as a 'movie' of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Processing Simulator (SPS) at Oak Ridge National Laboratory show clear indications of hydrate formation and dissociation events at expected P-T conditions given the thermodynamics of the CH4-H2O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time resolved formation and dissociation of gas hydrates in large-scale sediment experiments.

  10. Detailed Hydration Maps of Benzene and Cyclohexane Reveal Distinct Water Structures Tanya M. Raschke* and Michael Levitt

    E-Print Network [OSTI]

    Raschke, Tanya M.

    Detailed Hydration Maps of Benzene and Cyclohexane Reveal Distinct Water Structures Tanya M of the hydrophobic solutes benzene and cyclohexane were investigated using molecular dynamics (MD) simulations O and H atoms surrounding either benzene or cyclohexane were generated from the simulation data. MD

  11. The Center for Control, Dynamical Systems, and Computation University of California at Santa Barbara

    E-Print Network [OSTI]

    Akhmedov, Azer

    The Center for Control, Dynamical Systems, and Computation University of California at Santa, the system dynamics involve significant nonlinear forces as well as model uncertainty, leading to interesting and chaos. He has studied applications in electric power systems, mechanical and aerospace systems

  12. New methods for estimation, modeling and validation of dynamical systems using automatic differentiation 

    E-Print Network [OSTI]

    Griffith, Daniel Todd

    2005-02-17T23:59:59.000Z

    The main objective of this work is to demonstrate some new computational methods for estimation, optimization and modeling of dynamical systems that use automatic differentiation. Particular focus will be upon dynamical ...

  13. Thermoacoustic instability - a dynamical system and time domain analysis

    E-Print Network [OSTI]

    Sayadi, Taraneh; Schmid, Peter; Richecoeur, Franck; Massot, Marc

    2013-01-01T23:59:59.000Z

    This study focuses on the Rijke tube problem, which includes features relevant to the modeling of thermoacoustic coupling in reactive flows: a compact acoustic source, an empirical model for the heat source, and nonlinearities. This system features both linear and nonlinear flow regimes with complex dynamical behavior. In order to synthesize accurate time-series, we tackle this problem from a numerical point-of-view, and start by proposing a dedicated solver designed for dealing with the underlying stiffness, in particular, the retarded time and the discontinuity at the location of the heat source. Stability analysis is performed on the limit of the low amplitude perturbations by means of the projection method proposed by Jarlebring (2008), which alleviates the linearization of the retarded term. The results are then compared to the analytical solution of the undamped system, in addition to the analysis based on Galerkin projection. The method provides insight into the consequence of the simplification due to...

  14. What can one learn about Self-Organized Criticality from Dynamical Systems theory ?

    E-Print Network [OSTI]

    Ph. Blanchard; B. Cessac; T. Krueger

    1999-12-06T23:59:59.000Z

    We develop a dynamical system approach for the Zhang's model of Self-Organized Criticality, for which the dynamics can be described either in terms of Iterated Function Systems, or as a piecewise hyperbolic dynamical system of skew-product type. In this setting we describe the SOC attractor, and discuss its fractal structure. We show how the Lyapunov exponents, the Hausdorff dimensions, and the system size are related to the probability distribution of the avalanche size, via the Ledrappier-Young formula.

  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.

    2013-09-05T23:59:59.000Z

    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 Péclet 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. 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

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    and Englezos, P. , 2009. Gas hydrate formation in a variable1999. Formation of natural gas hydrates in marine sediments.1. Conceptual model of gas hydrate growth conditioned by

  17. Coalbed Methane Procduced Water Treatment Using Gas Hydrate Formation at the Wellhead

    SciTech Connect (OSTI)

    BC Technologies

    2009-12-30T23:59:59.000Z

    Water associated with coalbed methane (CBM) production is a significant and costly process waste stream, and economic treatment and/or disposal of this water is often the key to successful and profitable CBM development. In the past decade, advances have been made in the treatment of CBM produced water. However, produced water generally must be transported in some fashion to a centralized treatment and/or disposal facility. The cost of transporting this water, whether through the development of a water distribution system or by truck, is often greater than the cost of treatment or disposal. To address this economic issue, BC Technologies (BCT), in collaboration with Oak Ridge National Laboratory (ORNL) and International Petroleum Environmental Consortium (IPEC), proposed developing a mechanical unit that could be used to treat CBM produced water by forming gas hydrates at the wellhead. This process involves creating a gas hydrate, washing it and then disassociating hydrate into water and gas molecules. The application of this technology results in three process streams: purified water, brine, and gas. The purified water can be discharged or reused for a variety of beneficial purposes and the smaller brine can be disposed of using conventional strategies. The overall objectives of this research are to develop a new treatment method for produced water where it could be purified directly at the wellhead, to determine the effectiveness of hydrate formation for the treatment of produced water with proof of concept laboratory experiments, to design a prototype-scale injector and test it in the laboratory under realistic wellhead conditions, and to demonstrate the technology under field conditions. By treating the water on-site, producers could substantially reduce their surface handling costs and economically remove impurities to a quality that would support beneficial use. Batch bench-scale experiments of the hydrate formation process and research conducted at ORNL confirmed the feasibility of the process. However, researchers at BCT were unable to develop equipment suitable for continuous operation and demonstration of the process in the field was not attempted. The significant achievements of the research area: Bench-scale batch results using carbon dioxide indicate >40% of the feed water to the hydrate formation reactor was converted to hydrate in a single pass; The batch results also indicate >23% of the feed water to the hydrate formation reactor (>50% of the hydrate formed) was converted to purified water of a quality suitable for discharge; Continuous discharge and collection of hydrates was achieved at atmospheric pressure. Continuous hydrate formation and collection at atmospheric conditions was the most significant achievement and preliminary economics indicate that if the unit could be made operable, it is potentially economic. However, the inability to continuously separate the hydrate melt fraction left the concept not ready for field demonstration and the project was terminated after Phase Two research.

  18. Coupled multiphase fluid flow and wellbore stability analysis associated with gas production from oceanic hydrate-bearing sediments

    E-Print Network [OSTI]

    Rutqvist, J.

    2014-01-01T23:59:59.000Z

    Toward Production from Gas Hydrates: Current Status,Facing Gas Production From Gas-Hydrate Deposits. Society ofConference on Gas Hydrates (ICGH 2011), Edinburgh, Scotland,

  19. Evaluation of the Gas Production Potential of Marine Hydrate Deposits in the Ulleung Basin of the Korean East Sea

    E-Print Network [OSTI]

    Moridis, George J.; Reagan, Matthew T.; Kim, Se-Joon; Seol, Yongkoo; Zhang, Keni

    2007-01-01T23:59:59.000Z

    indicators for natural gas hydrates in shallow sediments ofInternational Symposium on Gas Hydrate Technology, Seoul,International Symposium on Gas Hydrate Technology, Seoul,

  20. Numerical studies of gas production from several CH4-hydrate zones at the Mallik Site, Mackenzie Delta, Canada

    E-Print Network [OSTI]

    Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Steven; Weatherill, Brian

    2002-01-01T23:59:59.000Z

    JNOC/GSC Mallik 2L-38 Gas Hydrate Research Well, Mackenziepermafrost- associated gas hydrate accumulation in theTerritories, Canada. A gas hydrate research well was drilled

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

    E-Print Network [OSTI]

    Seol, Yongkoo

    2010-01-01T23:59:59.000Z

    Formation of natural gas hydrates in marine sediments 1.Conceptual model of gas hydrate growth conditioned by hostPotential effects of gas hydrate on human welfare, Proc.

  2. Comparison of Kinetic and Equilibrium Reaction Models in Simulating the Behavior of Gas Hydrates in Porous Media

    E-Print Network [OSTI]

    Kowalsky, Michael B.; Moridis, George J.

    2006-01-01T23:59:59.000Z

    rate constant of methane gas hydrate decomposition, CanadianAdvances in the Study of Gas Hydrates, C. Taylor , J. Qwan,International Conference on Gas Hydrates, Trondheim, Norway,

  3. Gas Production From a Cold, Stratigraphically Bounded Hydrate Deposit at the Mount Elbert Site, North Slope, Alaska

    E-Print Network [OSTI]

    Moridis, G.J.

    2010-01-01T23:59:59.000Z

    of P, T, and gas and hydrate phase saturations (S G and SInternational Conference on Gas Hydrates, Vancouver, Britishinterrelations relative to gas hydrates within the North

  4. Ab initio study of the structure and dynamics of solvated highly charged metal ions

    E-Print Network [OSTI]

    Bogatko, Stuart A.

    2008-01-01T23:59:59.000Z

    Study of the Structure and Dynamics of Solvated Highly27 Chapter 3 Structure and Dynamics of the High Spin Fe 3+66 Chapter 4 Structure and Dynamics of the Hydrated Ca 2+

  5. THERMODYNAMIC MODELLING OF GAS SEMI-CLATHRATE HYDRATES USING THE ELECTROLYTE NRTL MODEL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    THERMODYNAMIC MODELLING OF GAS SEMI-CLATHRATE HYDRATES USING THE ELECTROLYTE NRTL MODEL Matthias. For the description of the gas semiclathrate hydrate phase a combination of the salt hydrate model of Paricaud the applicability of the approach presented. Keywords: modeling, semiclathrate hydrate, gas semiclathrate hydrate, e

  6. International Conference on Gas Hydrates May 19-23, 2002, Yokohama

    E-Print Network [OSTI]

    Gudmundsson, Jon Steinar

    4th International Conference on Gas Hydrates May 19-23, 2002, Yokohama Cold Flow Hydrate Technology an opportunity for flow assurance in deepwater production of oil and gas. Hydrate R&D in the Natural Gas Hydrate exchange and reactor units. Introduction Hydrates form when liquid water and natural gas are in contact

  7. Behavioral interpretation of the object-oriented paradigm for interconnected dynamic system

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -oriented language Modelica is finally presented. 1 Keywords Object-modeling techniques, mathematical models, dynamic, published in "International Journal of Systems Science 38, 4 (2007) 319-326" #12;language: Modelica [Tiller dynamic systems, e.g. the language Modelica, lead to handle differential algebraic equation systems

  8. Real Time Dynamic Wind Calculation for a Pressure Driven Wind System Criss Martin

    E-Print Network [OSTI]

    Parberry, Ian

    for controllable real time dynamic wind cal- culation for a pressure driven wind system. Our method allows re to specify the positions and pressure val- ues of a high and a low pressure system to drive the wind. SetupReal Time Dynamic Wind Calculation for a Pressure Driven Wind System Criss Martin Dept. of Computer

  9. Impact of Dynamic PHEVs Load on Renewable Sources based Distribution System

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Impact of Dynamic PHEVs Load on Renewable Sources based Distribution System F. R. Islam, H. R. Pota.Roy@student.adfa.edu.au Abstract--In this paper, charging effect of dynamic Plug in Hybrid Electric Vehicle (PHEV) is presented in a renewable energy based electricity distribution system. For planning and designing a distribution system

  10. Dynamic Power Management in a Mobile Multimedia System with Guaranteed Quality-of-Service*

    E-Print Network [OSTI]

    Qiu, Qinru

    Dynamic Power Management in a Mobile Multimedia System with Guaranteed Quality-of-Service* Qinru address the problem of dynamic power management in a distributed multimedia system with a required quality of the power-managed multimedia system under general QoS constraints. Based on this mathematical model

  11. Dynamic Power Management of Complex Systems Using Generalized Stochastic Petri Nets *

    E-Print Network [OSTI]

    Qiu, Qinru

    Dynamic Power Management of Complex Systems Using Generalized Stochastic Petri Nets * Qinru Qiu introduce a new technique for modeling and solving the dynamic power management (DPM) problem for systems model a power-managed distributed computing system as a controllable Generalized Stochastic Petri Net

  12. Dynamic Power Management of Complex Systems Using Generalized Stochastic Petri Nets*

    E-Print Network [OSTI]

    Pedram, Massoud

    Dynamic Power Management of Complex Systems Using Generalized Stochastic Petri Nets* Qinru Qiu introduce a new technique for modeling and solving the dynamic power management (DPM) problem for systems model a power-managed distributed computing system as a controllable Generalized Stochastic Petri Net

  13. Power-system dynamic equivalents:coherency recognition via the rate of change of

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    .F.I.M.A. Indexing terms: Power systems and plant, Simulation, Time-varying parameters, Dynamic equivalents AbstractPower-system dynamic equivalents:coherency recognition via the rate of change of kinetic energy H of sections of a power system, its main drawback being the extensive computation times required to recognise

  14. Impact of Wind Turbine Penetration on the Dynamic Performance of Interconnected Power Systems

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Impact of Wind Turbine Penetration on the Dynamic Performance of Interconnected Power Systems M. J School of S ~ao Carlos, Brazil. Email: ramos@sel.eese.usp.br Abstract--The complexity of power systems, such as wind generators. This changing nature of power systems has considerable effect on its dynamic behaviour

  15. Dynamic behaviour of a DFIG wind turbine subjected to power system faults

    E-Print Network [OSTI]

    Dynamic behaviour of a DFIG wind turbine subjected to power system faults Gabriele Michalke+, Anca, Institute for Electrical Power Systems, Landgraf-Georg-Straße 4, 64283 Darmstadt, Germany * Risø National of the dynamic interaction between variable speed DFIG wind turbines and the power system subjected

  16. Investigation of Critical Parameters for Power Systems Stability with Dynamic Loads

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Investigation of Critical Parameters for Power Systems Stability with Dynamic Loads M. A. Mahmud, M. J. Hossain, and H. R. Pota Abstract--Most of the power system networks have significant dynamic problems in power systems. This paper presents an analysis to investigate the critical parameters of power

  17. Nonlinear Excitation Controller for Power Systems using Zero Dynamic Design Approach

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Nonlinear Excitation Controller for Power Systems using Zero Dynamic Design Approach M. A. Mahmud controller design technique for interconnected power systems. A zero dynamic design approach is used of power systems, regardless of operating points and the performance is very similar to that of exactly

  18. Dynamic evidential networks in system reliability analysis: A Dempster Shafer Approach

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Dynamic evidential networks in system reliability analysis: A Dempster Shafer Approach Philippe for modeling and analyzing the system reliability based on Dynamic Evidential Networks (DEN). This method. The current system state determine the probability distribution over the next states. In the work reported

  19. Exploring dynamics of unstable many-body systems

    SciTech Connect (OSTI)

    Volya, Alexander [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States); Zelevinsky, Vladimir [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States)

    2014-10-15T23:59:59.000Z

    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.

  20. Quantum tomography meets dynamical systems and bifurcations theory

    SciTech Connect (OSTI)

    Goyeneche, D., E-mail: dardo.goyeneche@cefop.udec.cl [Departamento de Fisíca, Universidad de Concepción, Casilla 160-C, Concepción, Chile and Center for Optics and Photonics, Universidad de Concepción, Casilla 4012, Concepción (Chile); Torre, A. C. de la [Departamento de Física, Universidad Nacional de Mar del Plata, IFIMAR-CONICET, Dean Funes 3350, 7600 Mar del Plata (Argentina)

    2014-06-15T23:59:59.000Z

    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.

  1. Quantum Dynamical Behaviour in Complex Systems - A Semiclassical Approach

    SciTech Connect (OSTI)

    Gliebe, Cheryn E; Ananth, Nandini

    2008-05-22T23:59:59.000Z

    One of the biggest challenges in Chemical Dynamics is describing the behavior of complex systems accurately. Classical MD simulations have evolved to a point where calculations involving thousands of atoms are routinely carried out. Capturing coherence, tunneling and other such quantum effects for these systems, however, has proven considerably harder. Semiclassical methods such as the Initial Value Representation (SC-IVR) provide a practical way to include quantum effects while still utilizing only classical trajectory information. For smaller systems, this method has been proven to be most effective, encouraging the hope that it can be extended to deal with a large number of degrees of freedom. Several variations upon the original idea of the SCIVR have been developed to help make these larger calculations more tractable; these range from the simplest, classical limit form, the Linearized IVR (LSC-IVR) to the quantum limit form, the Exact Forward-Backward version (EFB-IVR). In this thesis a method to tune between these limits is described which allows us to choose exactly which degrees of freedom we wish to treat in a more quantum mechanical fashion and to what extent. This formulation is called the Tuning IVR (TIVR). We further describe methodology being developed to evaluate the prefactor term that appears in the IVR formalism. The regular prefactor is composed of the Monodromy matrices (jacobians of the transformation from initial to finial coordinates and momenta) which are time evolved using the Hessian. Standard MD simulations require the potential surfaces and their gradients, but very rarely is there any information on the second derivative. We would like to be able to carry out the SC-IVR calculation without this information too. With this in mind a finite difference scheme to obtain the Hessian on-the-fly is proposed. Wealso apply the IVR formalism to a few problems of current interest. A method to obtain energy eigenvalues accurately for complex systems is described. We proposed the use of a semiclassical correction term to a preliminary quantum calculation using, for instance, a variational approach. This allows us to increase the accuracy significantly. Modeling Nonadiabatic dynamics has always been a challenge to classical simulations because the multi-state nature of the dynamics cannot be described accurately by the time evolution on a single average surface, as is the classical approach. We show that using the Meyer-Miller-Stock-Thoss (MMST) representation of the exact vibronic Hamiltonian in combination with the IVR allows us to accurately describe dynamics where the non Born-Oppenheimer regime. One final problem that we address is that of extending this method to the long time regime. We propose the use of a time independent sampling function in the Monte Carlo integration over the phase space of initial trajectory conditions. This allows us to better choose the regions of importance at the various points in time; by using more trajectories in the important regions, we show that the integration can be converged much easier. An algorithm based loosely on the methods of Diffusion Monte Carlo is developed that allows us to carry out this time dependent sampling in a most efficient manner.

  2. Structure-dynamics relationship in coherent transport through disordered systems

    E-Print Network [OSTI]

    Stefano Mostarda; Federico Levi; Diego Prada-Gracia; Florian Mintert; Francesco Rao

    2013-07-17T23:59:59.000Z

    Quantum transport is strongly influenced by interference with phase relations that depend sensitively on the scattering medium. Since even small changes in the geometry of the medium can turn constructive interference to destructive, a clear relation between structure and fast, efficient transport is difficult to identify. Here we present a complex network analysis of quantum transport through disordered systems to elucidate the relationship between transport efficiency and structural organization. Evidence is provided for the emergence of structural classes with different geometries but similar high efficiency. Specifically, a structural motif characterised by pair sites which are not actively participating to the dynamics renders transport properties robust against perturbations. Our results pave the way for a systematic rationalization of the design principles behind highly efficient transport which is of paramount importance for technological applications as well as to address transport robustness in natural light harvesting complexes.

  3. Development of Alaskan gas hydrate resources. Final report

    SciTech Connect (OSTI)

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

    1991-06-01T23:59:59.000Z

    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.

  4. System vulnerability as a concept to assess power system dynamic security

    SciTech Connect (OSTI)

    Fouad, A.A.; Qin Zhou; Vittal, V. (Iowa State Univ., Ames, IA (United States))

    1994-05-01T23:59:59.000Z

    The concept of system vulnerability is introduced as a new framework for power system dynamic security assessment. This new concept combines information on the level of security and its trend with changing system condition. In this paper the transient energy function (TEF) method is used as a tool of analysis. The energy margin [Delta]V is used as an indicator of the level of security, and its sensitivity ([partial derivative][Delta]V/[partial derivative]p) to a changing system parameter p as an indicator of its trend. The thresholds for acceptable levels of the security indicator ([Delta]V) and its trend ([partial derivative][Delta]V/[partial derivative]p) are related to the stability limits of a critical system parameter. A method is proposed to determine these thresholds using heuristic techniques derived from operating practices and policies for a change in plant generation. Results from the IEEE 50 generator test system are presented to illustrate the procedure.

  5. 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 (University of Chicago, Chicago, IL); Hanson, Jason (University of New Mexico, Albuquerque, NM); Grimsrud, Kristine (University of New Mexico, Albuquerque, NM); Thacher, Jennifer (University of New Mexico, Albuquerque, NM); Broadbent, Craig (University of New Mexico, Albuquerque, NM); Brookshire, David (University of New Mexico, Albuquerque, NM); Chemak, Janie (University of New Mexico, Albuquerque, NM); Cockerill, Kristan (Cockeril Consulting, Boone, NC); Aragon, Carlos (New Mexico Univeristy of Technology and Mining (NM-TECH), Socorro, NM); Hallett, Heather (New Mexico Univeristy of Technology and Mining (NM-TECH), Socorro, NM); Vivoni, Enrique (New Mexico Univeristy of Technology and Mining (NM-TECH), Socorro, NM); Roach, Jesse

    2006-12-01T23:59:59.000Z

    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.

  6. Ultrafast Structural Dynamics in Combustion Relevant Model Systems

    SciTech Connect (OSTI)

    Weber, Peter M. [Brown University

    2014-03-31T23:59:59.000Z

    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 molecule’s 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 molecule’s 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 electron’s 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 molecule’s 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

  7. Universal Science of Complexity: Consistent Understanding of Ecological, Living and Intelligent System Dynamics

    E-Print Network [OSTI]

    Andrei P. Kirilyuk

    2014-05-26T23:59:59.000Z

    A major challenge of interdisciplinary description of complex system behaviour is whether real systems of higher complexity levels can be understood with at least the same degree of objective, "scientific" rigour and universality as "simple" systems of classical, Newtonian science paradigm. The problem is reduced to that of arbitrary, many-body interaction (unsolved in standard theory). Here we review its causally complete solution, the ensuing concept of complexity and applications. The discovered key properties of dynamic multivaluedness and entanglement give rise to a qualitatively new kind of mathematical structure providing the exact version of real system behaviour. The extended mathematics of complexity contains the truly universal definition of dynamic complexity, randomness (chaoticity), classification of all possible dynamic regimes, and the unifying principle of any system dynamics and evolution, the universal symmetry of complexity. Every real system has a non-zero (and actually high) value of unreduced dynamic complexity determining, in particular, "mysterious" behaviour of quantum systems and relativistic effects causally explained now as unified manifestations of complex interaction dynamics. The observed differences between various systems are due to different regimes and levels of their unreduced dynamic complexity. We outline applications of universal concept of dynamic complexity emphasising cases of "truly complex" systems from higher complexity levels (ecological and living systems, brain operation, intelligence and consciousness, autonomic information and communication systems) and show that the urgently needed progress in social and intellectual structure of civilisation inevitably involves qualitative transition to unreduced complexity understanding (we call it "revolution of complexity").

  8. Dynamics and control of the system of a 2-D rigid circular cylinder and point vortices

    E-Print Network [OSTI]

    Shashikanth, Banavara N.

    Dynamics and control of the system of a 2-D rigid circular cylinder and point vortices Zhanhua Ma dynamically interacting with N point vortices in its vicinity [16] is an idealized example of coupled solid from a fluid mechanics viewpoint as well as a dynamics and control viewpoint. The problem has many

  9. Thwarting systems and institutional dynamics, or how to stabilize an unstable economy.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Thwarting systems and institutional dynamics, or how to stabilize an unstable economy. Eric Nasica contained in Minsky's approach, namely that the economy is subject to "financial dynamics", insofar of institutional mechanisms and of the interventions of public authorities on the dynamics of market economies

  10. DHARMA: A Tool for Evaluating Dynamic Scheduling Algorithms for Realtime Multiprocessor Systems

    E-Print Network [OSTI]

    Manimaran, Govindarasu

    ­tolerance and resource reclaiming. Section 3 reviews the earlier work on dynamic scheduling algorithms. In Section 4, we discuss our dynamic scheduling and reclaiming algorithms. Section 5 discusses the software architectureDHARMA: A Tool for Evaluating Dynamic Scheduling Algorithms for Real­time Multiprocessor Systems G

  11. Marine Protists : : Distributions, Diversity and Dynamics

    E-Print Network [OSTI]

    Pasulka, Alexis Leah

    2013-01-01T23:59:59.000Z

    and sulfide flux at gas hydrate deposits from the Cascadiaoxidation of methane above gas hydrates at Hydrate Ridge, NEoxidation of methane above gas hydrate at Hydrate Ridge, NE

  12. Marine Protists : : Distributions, Diversity and Dynamics

    E-Print Network [OSTI]

    Pasulka, Alexis Leah

    2013-01-01T23:59:59.000Z

    oxidation of methane above gas hydrates at Hydrate Ridge, NEoxidation of methane above gas hydrate at Hydrate Ridge, NEand sulfide flux at gas hydrate deposits from the Cascadia

  13. Local Dynamic Reactive Power for Correction of System Voltage Problems

    SciTech Connect (OSTI)

    Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

    2008-12-01T23:59:59.000Z

    Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.

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

    SciTech Connect (OSTI)

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

    2008-03-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    Methods: Trying to Create Representative Samples Timothy J.Methods: Trying to Create Representative Samples Timothy J.Introduction Forming representative gas hydrate-bearing

  16. Method for the photocatalytic conversion of gas hydrates

    DOE Patents [OSTI]

    Taylor, Charles E. (Pittsburg, PA); Noceti, Richard P. (Pittsburg, PA); Bockrath, Bradley C. (Bethel Park, PA)

    2001-01-01T23:59:59.000Z

    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.

  17. Energy Department Expands Research into Methane Hydrates, a Vast...

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

    of methane in shallow subsurface and water columns, and the role gas hydrates play in carbon cycling. DOE Investment: approximately 650,000 Massachusetts Institute of...

  18. air clathrate hydrates: Topics by E-print Network

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

    the extent of hydration can be determined. In order to achieve this, development of a new pellet production method was essential. This technique facilitates the elimination of...

  19. airway surface hydration: Topics by E-print Network

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

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 200 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  20. angiogenesis vascularity hydration: Topics by E-print Network

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

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 177 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  1. alaskan gas hydrate: Topics by E-print Network

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

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 224 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  2. aluminum hydration effects: Topics by E-print Network

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

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 258 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  3. Hydration of Clays at the Molecular Scale: The Promising Perspective of Classical Density Functional Theory

    E-Print Network [OSTI]

    Jeanmairet, Guillaume; Levesque, Maximilien; Rotenberg, Benjamin; Borgis, Daniel

    2014-01-01T23:59:59.000Z

    We report here how the hydration of complex surfaces can be efficiently studied thanks to recent advances in classical molecular density functional theory. This is illustrated on the example of the pyrophylite clay. After presenting the most recent advances, we show that the strength of this implicit method is that (i) it is in quantitative or semi-quantitative agreement with reference all-atoms simulations (molecular dynamics here) for both the solvation structure and energetics, and that (ii) the computational cost is two to three orders of magnitude less than in explicit methods. The method remains imperfect, in that it locally overestimates the polarization of water close to hydrophylic sites of the clay. The high numerical efficiency of the method is illustrated and exploited to carry a systematic study of the electrostatic and van der Waals components of the surface-solvant interactions within the most popular force field for clays, CLAYFF. Hydration structure and energetics are found to weakly depend u...

  4. MATH3395: Dynamical Systems Dr A.M. Rucklidge

    E-Print Network [OSTI]

    Rucklidge, Alastair

    dynamics, which arise in a variety of contexts in biology, chemistry, physics, economics and engineering example) MATH2390/2391. Basic linear algebra is required, and there will be some use of the notion An Introduction to Economic Dynamics Cambridge University Press 2001; R. Stone Economic Dynamics Cambridge

  5. Logarithmic decay in single-particle relaxations of hydrated lysozyme powder

    E-Print Network [OSTI]

    Marco Lagi; Piero Baglioni; Sow-Hsin Chen

    2009-08-13T23:59:59.000Z

    We present the self-dynamics of protein amino acids of hydrated lysozyme powder around the physiological temperature by means of molecular dynamics (MD) simulations. The self-intermediate scattering functions (SISF) of the amino acid residue center-of-mass and of the protein hydrogen atoms display a logarithmic decay over 3 decades of time, from 2 picoseconds to 2 nanoseconds, followed by an exponential alpha-relaxation. This kind of slow dynamics resembles the relaxation scenario within the beta-relaxation time range predicted by the mode coupling theory (MCT) in the vicinity of higher-order singularities. These results suggest a strong analogy between the single-particle dynamics of the protein and the dynamics of colloidal, polymeric and molecular glass-forming liquids.

  6. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    E-Print Network [OSTI]

    Boswell, R.D.

    2010-01-01T23:59:59.000Z

    Advances in the Study of Gas Hydrates. Kluwer, New York, pp.and quantification of gas hydrates using rock physics andand Salt Inhibition of Gas Hydrate Formation in the Northern

  7. Estimation of composite thermal conductivity of a heterogeneous methane hydrate sample using iTOUGH2

    E-Print Network [OSTI]

    Gupta, Arvind; Kneafsey, Timothy J.; Moridis, George J.; Seol, Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

    2006-01-01T23:59:59.000Z

    International Conference on Gas Hydrates, Trondheim, Norway,Challenges for the future/gas hydrates, NYAS 912, 304, 2000.C. , Thermal state of the gas hydrate reservoir, natural gas

  8. Development of a Numerical Simulator for Analyzing the Geomechanical Performance of Hydrate-Bearing Sediments

    E-Print Network [OSTI]

    Rutqvist, J.

    2008-01-01T23:59:59.000Z

    J. Mienert. 2004. Effect of gas hydrates melting on seafloorInternational Conference on Gas Hydrates, Trondheim, Norway,A Documented Example of Gas Hydrate Saturated Sand in the

  9. Sensitivity Analysis of Gas Production from Class 2 and Class 3 Hydrate Deposits

    E-Print Network [OSTI]

    Reagan, Matthew

    2009-01-01T23:59:59.000Z

    a) temperature, (b) gas and hydrate phase saturations, and (A Documented Example of Gas Hydrate Saturated Sand in theMakogon, Y.F. , “Gas hydrates: frozen energy,” Recherche 18(

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

    E-Print Network [OSTI]

    Kowalsky, Michael B.; Moridis, George J.

    2006-01-01T23:59:59.000Z

    with Diapirism and Gas Hydrates at the Head of the Cape FearSea-Level Low Stands Above Gas Hydrate-Bearing Sediments.rate constant of methane gas hydrate decomposition. Canadian

  11. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

    E-Print Network [OSTI]

    Rutqvist, J.

    2009-01-01T23:59:59.000Z

    Conference on Gas Hydrates (ICGH 2008), Vancouver, BritishGSC et al. Mallik 5L-38 gas hydrate production research wellfrom the Mallik 2002 Gas Hydrate Production Research Well

  12. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    E-Print Network [OSTI]

    Boswell, R.D.

    2010-01-01T23:59:59.000Z

    and quantification of gas hydrates using rock physics andAdvances in the Study of Gas Hydrates. Kluwer, New York, pp.and Salt Inhibition of Gas Hydrate Formation in the Northern

  13. Contribution of oceanic gas hydrate dissociation to the formation of Arctic Ocean methane plumes

    E-Print Network [OSTI]

    Reagan, M.

    2012-01-01T23:59:59.000Z

    V.A. Soloviev, Submarine Gas Hydrates. St. Petersburg, 1998.and stability of gas hydrate-related bottom-simulatingPotential effects of gas hydrate on human welfare, Proc.

  14. The Use of Horizontal Wells in Gas Production from Hydrate Accumulations

    E-Print Network [OSTI]

    Moridis, George J.

    2008-01-01T23:59:59.000Z

    E.D. Toward Production From Gas Hydrates: Current Status,International Conference on Gas Hydrates, Trondheim, Norway,for Gas Production from Gas Hydrate Reservoirs, J. Can. Pet.

  15. 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.

    2014-02-26T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Everett, Susan M [ORNL; Rawn, Claudia J [ORNL; Chakoumakos, Bryan C [ORNL; Keffer, David J. [University of Tennessee, Knoxville (UTK); Huq, Ashfia [ORNL; Phelps, Tommy Joe [ORNL

    2015-01-01T23:59:59.000Z

    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.

  17. Ultrafast dynamics of strongly coupled quantum dot-nanocavity systems

    E-Print Network [OSTI]

    Kai Müller; Kevin A. Fischer; Armand Rundquist; Constantin Dory; Konstantinos G. Lagoudakis; Tomas Sarmiento; Victoria Borish; Yousif A. Kelaita; Jelena Vu?kovi?

    2015-03-18T23:59:59.000Z

    We investigate the influence of exciton-phonon coupling on the dynamics of a strongly coupled quantum dot-photonic crystal cavity system and explore the effects of this interaction on different schemes for non-classical light generation. By performing time-resolved measurements, we map out the detuning-dependent polariton lifetime and extract the spectrum of the polariton-to-phonon coupling. Photon-blockade experiments are presented for different pulse-length and detuning conditions that are in very good agreement with quantum-optical simulations; we demonstrate that achieving high-fidelity photon blockade requires an intricate understanding of this parameter space. Furthermore, we show that detuned photon blockade, which is more efficient than resonant photon blockade, is also more dramatically affected by phonons. Finally, we achieve coherent control of the polariton states of a strongly coupled system and demonstrate that their efficient coupling to phonons can be exploited for novel concepts in high-fidelity single photon generation.

  18. Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

    E-Print Network [OSTI]

    Rees, E.V.L.

    2012-01-01T23:59:59.000Z

    K. and McDonald, T. , Gas Hydrates of the Middle Americaet al. , Indian National Gas Hydrate Program Expedition 01et al. , Drilling Gas Hydrates on Hydrate Ridge, Cascadia

  19. Regular and Chaotic Dynamics of Triaxial Stellar Systems

    E-Print Network [OSTI]

    Monica Valluri; David Merritt

    1998-06-01T23:59:59.000Z

    We use Laskar's frequency mapping technique to study the dynamics of triaxial galaxies with central density cusps and nuclear black holes. For ensembles of 10^4 orbits, we numerically compute the three fundamental frequencies of the motion, allowing us to map out the Arnold web. We also compute diffusion rates of stochastic orbits in frequency space. The objects of fundamental importance in structuring phase space are found to be the 3-dimensional resonant tori; even when stable, such tori are not necessarily associated with periodic orbits as in systems with only two degrees of freedom. Boxlike orbits are generically stochastic, but some tube orbits are stochastic as well. The spectrum of diffusion rates for box-like orbits at a given energy is well approximated as a power law over at least six decades. Models with high central concentrations -- steep central cusps or massive black holes -- exhibit the most stochasticity. A black hole with a mass of 0.3% the mass of the galaxy is as effective as the steepest central density cusp at inducing stochastic diffusion. There is a transition to global stochasticity in box-like phase space when the mass of a central black hole exceeds 2% the galaxy mass. We predict a greater average degree of dynamical evolution in faint ellipticals, due to their high central densities and short crossing times. The evolution time is estimated to be shorter than a galaxy lifetime for absolute magnitudes fainter than about -19 or -20, consistent with the observed change in many elliptical galaxy properties at this luminosity.

  20. Augmenting Trust Establishment in Dynamic Systems with Social Networks

    SciTech Connect (OSTI)

    Lagesse, Brent J [ORNL] [ORNL; Kumar, Mohan [University of Texas, Arlington] [University of Texas, Arlington; Venkatesh, Svetha [Curtin University of Technology, Perth, Australia] [Curtin University of Technology, Perth, Australia; Lazarescu, Mihai [Curtin University of Technology, Perth, Australia] [Curtin University of Technology, Perth, Australia

    2010-01-01T23:59:59.000Z

    Social networking has recently flourished in popularity through the use of social websites. Pervasive computing resources have allowed people stay well-connected to each other through access to social networking resources. We take the position that utilizing information produced by relationships within social networks can assist in the establishment of trust for other pervasive computing applications. Furthermore, we describe how such a system can augment a sensor infrastructure used for event observation with information from mobile sensors (ie, mobile phones with cameras) controlled by potentially untrusted third parties. Pervasive computing systems are invisible systems, oriented around the user. As a result, many future pervasive systems are likely to include a social aspect to the system. The social communities that are developed in these systems can augment existing trust mechanisms with information about pre-trusted entities or entities to initially consider when beginning to establish trust. An example of such a system is the Collaborative Virtual Observation (CoVO) system fuses sensor information from disaparate sources in soft real-time to recreate a scene that provides observation of an event that has recently transpired. To accomplish this, CoVO must efficently access services whilst protecting the data from corruption from unknown remote nodes. CoVO combines dynamic service composition with virtual observation to utilize existing infrastructure with third party services available in the environment. Since these services are not under the control of the system, they may be unreliable or malicious. When an event of interest occurs, the given infrastructure (bus cameras, etc.) may not sufficiently cover the necessary information (be it in space, time, or sensor type). To enhance observation of the event, infrastructure is augmented with information from sensors in the environment that the infrastructure does not control. These sensors may be unreliable, uncooperative, or even malicious. Additionally, to execute queries in soft real-time, processing must be distributed to available systems in the environment. We propose to use information from social networks to satisfy these requirements. In this paper, we present our position that knowledge gained from social activities can be used to augment trust mechanisms in pervasive computing. The system uses social behavior of nodes to predict a subset that it wants to query for information. In this context, social behavior such as transit patterns and schedules (which can be used to determine if a queried node is likely to be reliable) or known relationships, such as a phone's address book, that can be used to determine networks of nodes that may also be able to assist in retrieving information. Neither implicit nor explicit relationships necessarily imply that the user trusts an entity, but rather will provide a starting place for establishing trust. The proposed framework utilizes social network information to assist in trust establishment when third-party sensors are used for sensing events.

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

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

    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.

  2. Dynamics of Poisson-Nernst-Planck systems and applications to ionic channels

    E-Print Network [OSTI]

    Zhang, Mingji

    2013-08-31T23:59:59.000Z

    Dynamics of Poisson-Nernst-Planck systems and its applications to ion channels are studied in this dissertation. The Poisson-Nernst-Planck systems serve as basic electro-diffusion equations modeling, for example, ion flow ...

  3. Modeling the resource consumption of Housing in New Orleans using System Dynamics

    E-Print Network [OSTI]

    Quinn, David James, Ph. D. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    This work uses Systems Dynamics as a methodology to analyze the resource requirements of New Orleans as it recovers from Hurricane Katrina. It examines the behavior of the city as a system of stocks, flows and time delays ...

  4. Dynamic Code Overlay of SDF-Modeled Programs on Low-end Embedded Systems

    E-Print Network [OSTI]

    Ha, Soonhoi

    Dynamic Code Overlay of SDF-Modeled Programs on Low-end Embedded Systems Hae-woo Park Kyoungjoo Oh of synchronous data-flow (SDF) ­modeled program for low-end embedded systems which lack MMU- support-program code, dynamic loader and linker script files from the given SDF- modeled blocks and schematic, so we

  5. Design of piecewise linear hybrid dynamical systems using a control regulator approach

    E-Print Network [OSTI]

    Antsaklis, Panos

    Design of piecewise linear hybrid dynamical systems using a control regulator approach X This paper presents a novel framework for hierarchical control of piecewise linear hybrid dynamical systems the continuous and the discrete part is defined by piecewise linear maps. Control design is formulated

  6. On the dynamics of lattice systems with unbounded on-site terms in the Hamiltonian

    E-Print Network [OSTI]

    Bruno Nachtergaele; Robert Sims

    2014-10-29T23:59:59.000Z

    We supply the mathematical arguments required to complete the proofs of two previously published results: Lieb-Robinson bounds for the dynamics of quantum lattice systems with unbounded on-site terms in the Hamiltonian and the existence of the thermodynamic limit of the dynamics of such systems.

  7. Optimal Supervisory Control of Discrete Event Dynamical Systems 1,2

    E-Print Network [OSTI]

    Kumar, Ratnesh

    Optimal Supervisory Control of Discrete Event Dynamical Systems 1,2 Ratnesh Kumar Department;Abstract We formalize the notion of optimal supervisory control of discrete event dynamical sys- tems (DEDS some undesired states, or not reaching some desired states in the controlled system. The control

  8. Structure and dynamics affect the controllability of complex systems: a Preliminary Study

    E-Print Network [OSTI]

    Menczer, Filippo

    well does network structure represent the multivariate dynamics of the underlying complex sys- tem- linear multivariate systems. Their organization and behavior are commonly modeled by representations the structure or or- ganization of complex systems. The simplest way to study multi-variate dynamics

  9. Dynamic Power Management in a Mobile Multimedia System with Guaranteed Quality-of-Service

    E-Print Network [OSTI]

    Pedram, Massoud

    1 Dynamic Power Management in a Mobile Multimedia System with Guaranteed Quality-of-Service Abstract ­ In this paper we address the problem of dynamic power management in a distributed multimedia, we provide a detailed model of the power-managed multimedia system under general QoS constraints

  10. The Center for Control, Dynamical Systems, and Computation University of California at Santa Barbara

    E-Print Network [OSTI]

    Akhmedov, Azer

    for applications of dynamic systems modelling, and non-linear and adaptive control. Egardt is a Fellow of the IEEEThe Center for Control, Dynamical Systems, and Computation University of California at Santa (e.g. an ICE engine) and power from the buffer. This additional degree of freedom in the control

  11. THEORY OF DYNAMICAL SYSTEMS AND GENERAL TRANSFORMATION GROUPS WITH INVARIANT MEASURE

    E-Print Network [OSTI]

    Katok, Svetlana

    THEORY OF DYNAMICAL SYSTEMS AND GENERAL TRANSFORMATION GROUPS WITH INVARIANT MEASURE A. B. Katok, Ya. G. Sinai, and A. M. Stepin UDC 513.83:513.88+517.9+519.4 INTRODUCTION The theory of dynamical systems with invariant measure, or ergodic theory, is one of those domains of mathematics whose form

  12. Lyapunov Analysis Captures the Collective Dynamics of Large Chaotic Systems Kazumasa A. Takeuchi,1,2

    E-Print Network [OSTI]

    Sano, Masaki

    Lyapunov Analysis Captures the Collective Dynamics of Large Chaotic Systems Kazumasa A. Takeuchi,1, that the collective dynamics of large chaotic systems is encoded in their Lyapunov spectra: most modes are typically numbers: 05.45.Àa, 05.70.Ln, 05.90.+m A common way of characterizing chaos is to measure Lyapunov

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

    Office of Environmental Management (EM)

    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,...

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

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    collection of additional reservoir data to support reservoirflow (drawdown) data for those hydrate reservoirs that aregeologic data on gas-hydrate-bearing sand reservoirs in the

  15. Fundamental measure theory of hydrated hydrocarbons

    E-Print Network [OSTI]

    Victor F. Sokolov; Gennady N. Chuev

    2006-04-13T23:59:59.000Z

    To calculate the solvation of hydrophobic solutes we have developed the method based on the fundamental measure treatment of the density functional theory. This method allows us to carry out calculations of density profiles and the solvation energy for various hydrophobic molecules with a high accuracy. We have applied the method to the hydration of various hydrocarbons (linear, branched and cyclic). The calculations of the entropic and the enthalpic parts are also carried out. We have examined a question about temperature dependence of the entropy convergence. Finally, we have calculated the mean force potential between two large hydrophobic nanoparticles immersed in water.

  16. methane_hydrates | netl.doe.gov

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires mayYuan T.External Links ExternalMethane Hydrates Special

  17. Methane Hydrates R&D Program

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from aRodMIT-Harvard Center forMetallicH.Gas Hydrates

  18. Phase space theory of quantum–classical systems with nonlinear and stochastic dynamics

    SciTech Connect (OSTI)

    Buri?, Nikola, E-mail: buric@ipb.ac.rs; Popovi?, Duška B.; Radonji?, Milan; Prvanovi?, Slobodan

    2014-04-15T23:59:59.000Z

    A novel theory of hybrid quantum–classical systems is developed, utilizing the mathematical framework of constrained dynamical systems on the quantum–classical phase space. Both, the quantum and classical descriptions of the respective parts of the hybrid system are treated as fundamental. Therefore, the description of the quantum–classical interaction has to be postulated, and includes the effects of neglected degrees of freedom. Dynamical law of the theory is given in terms of nonlinear stochastic differential equations with Hamiltonian and gradient terms. The theory provides a successful dynamical description of the collapse during quantum measurement. -- Highlights: •A novel theory of quantum–classical systems is developed. •Framework of quantum constrained dynamical systems is used. •A dynamical description of the measurement induced collapse is obtained.

  19. Dissolved carbonic anhydrase for enhancing post-combustion carbon dioxide hydration in aqueous ammonia

    SciTech Connect (OSTI)

    Collett, James R.; Heck, Robert W.; Zwoster, Andy

    2011-04-01T23:59:59.000Z

    Aqueous ammonia solvents that capture CO2 as ionic complexes of carbonates with ammonium have recently been advanced as alternatives to amine-based solvents due to their lower energy requirements for thermal regeneration. In ammonia based solvents, the hydration of CO2 to form bicarbonate may become a rate-limiting step as the CO2 loading increases and the resulting pH level of the solvent decreases. Variants of the enzyme carbonic anhydrase can accelerate the reversible hydration of CO2 to yield bicarbonate by more than 10(6)-fold. The possible benefit of bovine carbonic anhydrase (BCA) addition to solutions of aqueous ammonia to enhance CO2 hydration was investigated in semi-batch reactions within continuously stirred tank reactors or in a bubble column gas-liquid contactor. Adding 154 mg/liter of BCA to 2 M aqueous ammonia provided a 34.1% overall increase in the rate of CO2 hydration (as indicated by the production of [H+]) as the pH declined from 9.6 to 8.6 during sparging with a 15% CO2, 85% N-2 gas at a flow rate of 3 lpm. The benefits of adding BCA to enhance CO2 hydration were only discernable below similar to pH 9. The implications of the apparent pH limitations on the utility of BCA are discussed in the context of absorber unit operation design. Possible embodiments of carbonic anhydrase as either an immobilized catalyst or as a dissolved, recirculating catalyst in potential plant scale aqueous ammonia systems are considered as well. (C) 2010 Published by Elsevier Ltd.

  20. CHARACTERIZATION OF MIXED CO2-TBPB HYDRATE FOR REFRIGERATION APPLICATIONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    CHARACTERIZATION OF MIXED CO2-TBPB HYDRATE FOR REFRIGERATION APPLICATIONS Pascal Clain , Anthony storage and distribution in refrigeration applications. Previous studies show that these hydrates are able.s] INTRODUCTION Secondary refrigeration is a method using a neutral fluid for cold distribution in order