Dynamics of Protein Hydration Water
M. Wolf; S. Emmert; R. Gulich; P. Lunkenheimer; A. Loidl
2014-12-08
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.
Gas hydrate cool storage system
Ternes, M.P.; Kedl, R.J.
1984-09-12
The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)
Curvature Dependence of Hydrophobic Hydration Dynamics
R. Gregor Weiß; Matthias Heyden; Joachim Dzubiella
2015-04-08
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.
Hydration water dynamics and instigation of protein structuralrelaxation
Russo, Daniela; Hura, Greg; Head-Gordon, Teresa
2003-09-01
Until a critical hydration level is reached, proteins do not function. This critical level of hydration is analogous to a similar lack of protein function observed for temperatures below a dynamical temperature range of 180-220K that also is connected to the dynamics of protein surface water. Restoration of some enzymatic activity is observed in partially hydrated protein powders, sometimes corresponding to less than a single hydration layer on the protein surface, which indicates that the dynamical and structural properties of the surface water is intimately connected to protein stability and function. Many elegant studies using both experiment and simulation have contributed important information about protein hydration structure and timescales. The molecular mechanism of the solvent motion that is required to instigate the protein structural relaxation above a critical hydration level or transition temperature has yet to be determined. In this work we use experimental quasi-elastic neutron scattering (QENS) and molecular dynamics simulation to investigate hydration water dynamics near a greatly simplified protein system. We consider the hydration water dynamics near the completely deuterated N-acetyl-leucine-methylamide (NALMA) solute, a hydrophobic amino acid side chain attached to a polar blocked polypeptide backbone, as a function of concentration between 0.5M-2.0M under ambient conditions. We note that roughly 50-60% of a folded protein's surface is equally distributed between hydrophobic and hydrophilic domains, domains whose lengths are on the order of a few water diameters, that justify our study of hydration dynamics of this simple model protein system. The QENS experiment was performed at the NIST Center for Neutron Research, using the disk chopper time of flight spectrometer (DCS). In order to separate the translational and rotational components in the spectra, two sets of experiments were carried out using different incident neutron wavelengths of 7.5{angstrom} and 5.5{angstrom} to give two different time resolutions. All the spectra have been measure at room temperature. The spectra were corrected for the sample holder contribution and normalized using the vanadium standard. The resulting data were analyzed with DAVE programs (http://www.ncnr.nist.gov/dave/). The AMBER force field and SPCE water model were used for modeling the NALMA solute and water, respectively. For the analysis of the water dynamics in the NALMA aqueous solutions, we performed simulations of a dispersed solute configuration consistent with our previous structural analysis, where we had primarily focused on the structural organization of these peptide solutions and their connection to protein folding. Further details of the QENS experiment and molecular dynamics simulations are reported elsewhere.
Time-dependent water dynamics in hydrated uranyl fluoride
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Miskowiec, Andrew J.; Anderson, Brian B.; Herwig, Kenneth W.; Huq, Ashfia; Mamontov, Eugene; Rondinone, Adam; Trowbridge, Lee D.
2015-09-15
In this study, uranyl fluoride is a three-layer, hexagonal structure with significant stacking disorder in the c-direction. It supports a range of unsolved ‘thermodynamic’ hydrates with 0–2.5 water molecules per uranium atom, and perhaps more. However, the relationship between water, hydrate crystal structures, and thermodynamic results, collectively representing the chemical pathway through these hydrate structures, has not been sufficiently elucidated. We used high-resolution quasielastic neutron scattering to study the dynamics of water in partially hydrated uranyl fluoride powder over the course of 4 weeks under closed conditions. The spectra are composed of two quasielastic components: one is associated with translationalmore »diffusive motion of water that is approximately five to six times slower than bulk water, and the other is a slow (on the order of 2–300 ps), spatially bounded water motion. The translational component represents water diffusing between the weakly bonded layers in the crystal, while the bounded component may represent water trapped in subnanometre ‘pockets’ formed by the space between uranium-centred polymerisation units. Complementary neutron diffraction measurements do not show any significant structural changes, suggesting that a chemical conversion of the material does not occur in the thermodynamically isolated system on this timescale.« less
Hydration water dynamics and instigation of protein structural relaxation
Russo, Daniela; Hura, Greg; Head-Gordon, Teresa
2008-01-01
the dipole vector of the water molecule at times t and 0.the rotational dynamics of water molecules that maintained aHydration Water Dynamics and Instigation of Protein
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 ...
Gas hydrate cool storage system
Ternes, Mark P. (Knoxville, TN); Kedl, Robert J. (Oak Ridge, TN)
1985-01-01
This invention is a process for formation of a gas hydrate to be used as a cool storage medium using a refrigerant in water. Mixing of the immiscible refrigerant and water is effected by addition of a surfactant and agitation. The difficult problem of subcooling during the process is overcome by using the surfactant and agitation and performance of the process significantly improves and approaches ideal.
Dynamics of lysozyme and its hydration water under electric field
P. M. Favi; Q. Zhang; H. O'Neill; E. Mamontov; S. O. Diallo
2013-12-06
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 $water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm (2 10$^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.
Dynamics of biopolymers and their hydration water studied by neutron and X-ray scattering
Chu, Xiang-qiang
2010-01-01
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 ...
Method for controlling clathrate hydrates in fluid systems
Sloan, Jr., Earle D. (Golden, CO)
1995-01-01
Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member and/or six member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone.
DPF -"Hydrated EGR" Fuel Saver System | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Publications GreenPower Trap Water-Muffler System GreenPowerTM Trap-Muffler System Diesel NOx-PM Reduction with Fuel Economy Increase by IMET-OBC-DPF + Hydrated-EGR System for...
Aalborg Universitet Modelling and Validation of Water Hydration of PEM Fuel Cell Membrane in Dynamic
Liso, Vincenzo
Aalborg Universitet Modelling and Validation of Water Hydration of PEM Fuel Cell Membrane of Water Hydration of PEM Fuel Cell Membrane in Dynamic Operations. In ECS Transactions. (Vol. 68). ECS from vbn.aau.dk on: november 29, 2015 #12;Modelling and Validation of Water Hydration of PEM Fuel Cell
The Dynamic Transition of Protein Hydration Water
W. Doster; S. Busch; A. M. Gaspar; M. -S. Appavou; J. Wuttke; H. Scheer
2010-02-12
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.
Metal halogen battery system with multiple outlet nozzle for hydrate
Bjorkman, Jr., Harry K. (Birmingham, MI)
1983-06-21
A metal halogen battery system, including at least one cell having a positive electrode and a negative electrode contacted by aqueous electrolyte containing the material of said metal and halogen, store means whereby halogen hydrate is formed and stored as part of an aqueous material, means for circulating electrolyte through the cell and to the store means, and conduit means for transmitting halogen gas formed in the cell to a hydrate former whereby the hydrate is formed in association with the store means, said store means being constructed in the form of a container which includes a filter means, said filter means being inoperative to separate the hydrate formed from the electrolyte, said system having, a hydrate former pump means associated with the store means and being operative to intermix halogen gas with aqueous electrolyte to form halogen hydrate, said hydrate former means including, multiple outlet nozzle means connected with the outlet side of said pump means and being operative to minimize plugging, said nozzle means being comprised of at least one divider means which is generally perpendicular to the rotational axes of gears within the pump means, said divider means acting to divide the flow from the pump means into multiple outlet flow paths.
Method for controlling clathrate hydrates in fluid systems
Sloan, E.D. Jr.
1995-07-11
Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.
Method for controlling clathrate hydrates in fluid systems
Sloan, Jr., Earle D. (Golden, CO)
1995-01-01
Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.
Molecular dynamics simulations of methane hydrate using polarizable force fields
Jiang, H.N.; Jordan, K.D.; Taylor, C.E.
2007-03-01
Molecular dynamics simulations of methane hydrate have been carried out using the AMOEBA and COS/G2 polarizable force fields. Properties examined include the temperature dependence of the lattice constant, the OC and OO radial distribution functions and the vibrational spectra. Both the AMOEBA and COS/G2 models are found to successfully account for the available experimental data, with overall slightly better agreement with experiment being found for the AMOEBA model. Several properties calculated using the AMOEBA and COS/G2 models differ appreciable from the corresponding results obtained previously using the polarizable TIP4P-FQ model. This appears to be due to the inadequacy of the treatment of polarization, especially, the restriction of polarization to in-plane only, in the TIP4P-FQ model.
Dynamic control of slow water transport by aquaporin 0: Implications for hydration
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
Methane escape from gas hydrate systems in marine environment, and methane-driven oceanic eruptions
Zhang, Youxue
Methane escape from gas hydrate systems in marine environment, and methane-driven oceanic eruptions quantities of CH4 are stored in marine sediment in the form of methane hydrate, bubbles, and dissolved CH4 in pore water. Here I discuss the various pathways for methane to enter the ocean and atmosphere
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chen, Sow-Hsin; Lagi, Marco; Chu, Xiang-qiang; Zhang, Yang; Kim, Chansoo; Faraone, Antonio; Fratini, Emiliano; Baglioni, Piero
2010-01-01
This review article describes our neutron scattering experiments made in the past four years for the understanding of the single-particle (hydrogen atom) dynamics of a protein and its hydration water and the strong coupling between them. We found that the key to this strong coupling is the existence of a fragile-to-strong dynamic crossover (FSC) phenomenon occurring at aroundTL= 225±5 K in the hydration water. On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the high density form (HDL), a more fluid state, to predominantly the low density form (LDL), a less fluidmore »state, derived from the existence of a liquid–liquid critical point at an elevated pressure. We show experimentally that this sudden switch in the mobility of hydration water on Lysozyme, B-DNA and RNA triggers the dynamic transition, at a temperatureTD= 220 K, for these biopolymers. In the glassy state, belowTD, the biopolymers lose their vital conformational flexibility resulting in a substantial diminishing of their biological functions. We also performed molecular dynamics (MD) simulations on a realistic model of hydrated lysozyme powder, which confirms the existence of the FSC and the hydration level dependence of the FSC temperature. Furthermore, we show a striking feature in the short time relaxation (?-relaxation) of protein dynamics, which is the logarithmic decay spanning 3 decades (from ps to ns). The long time?-relaxation shows instead a diffusive behavior, which supports the liquid-like motions of protein constituents. We then discuss our recent high-resolution X-ray inelastic scattering studies of globular proteins, Lysozyme and Bovine Serum Albumin. We were able to measure the dispersion relations of collective, intra-protein phonon-like excitations in these proteins for the first time. We found that the phonon energies show a marked softening and at the same time their population increases substantially in a certain wave vector range when temperature crosses over theTD. Thus the increase of biological activities aboveTDhas positive correlation with activation of slower and large amplitude collective motions of a protein.« less
Trueba, Alondra Torres; Kroon, Maaike C.; Peters, Cor J.; Moudrakovski, Igor L.; Ratcliffe, Christopher I.; Ripmeester, John A.; Alavi, Saman
2014-06-07
Prospective industrial applications of clathrate hydrates as materials for gas separation require further knowledge of cavity distortion, cavity selectivity, and defects induction by guest-host interactions. The results presented in this contribution show that under certain temperature conditions the guest combination of CH{sub 3}F and a large polar molecule induces defects on the clathrate hydrate framework that allow intercage guest dynamics. {sup 13}C NMR chemical shifts of a CH{sub 3}F/CH{sub 4}/TBME sH hydrate and a temperature analysis of the {sup 2}H NMR powder lineshapes of a CD{sub 3}F/THF sII and CD{sub 3}F/TBME sH hydrate, displayed evidence that the populations of CH{sub 4} and CH{sub 3}F in the D and D{sup ?} cages were in a state of rapid exchange. A hydrogen bonding analysis using molecular dynamics simulations on the TBME/CH{sub 3}F and TBME/CH{sub 4} sH hydrates showed that the presence of CH{sub 3}F enhances the hydrogen bonding probability of the TBME molecule with the water molecules of the cavity. Similar results were obtained for THF/CH{sub 3}F and THF/CH{sub 4} sII hydrates. The enhanced hydrogen bond formation leads to the formation of defects in the water hydrogen bonding lattice and this can enhance the migration of CH{sub 3}F molecules between adjacent small cages.
Not Available
1985-04-01
There is a definite need for the US government to provide leadership for research in gas hydrates and to coordinate its activities with academia, industry, private groups, federal agencies, and their foreign counterparts. In response to this need, the DOE Morgantown Energy Technology Center implemented a gas hydrates R and D program. Understanding the resource will be achieved through: assessment of current technology; characterization of gas hydrate geology and reservoir engineering; and development of diagnostic tools and methods. Research to date has focused on geology. As work progressed, areas where gas hydrates are likely to occur were identified, and specific high potential areas were targeted for future detailed investigation. Initial research activities involved the development of the Geologic Analysis System (GAS); which will provide, through approximately 30 software packages, the capability to manipulate and correlate several types of geologic and petroleum data into maps, graphics, and reports. Preliminary mapping of hydrate prospects for the Alaskan North Slope is underway. Geological research includes physical system characterization which focuses on creating synthetic methane hydrates and developing synthetic hydrate cores using tetrahydrofuran, consolidated rock cores, frost base mixtures, water/ice base mixtures, and water base mixtures. Laboratory work produced measurements of the sonic velocity and electrical resistivity of these synthetic hydrates. During 1983, a sample from a natural hydrate core recovered from the Pacific coast of Guatemala was tested for these properties by METC. More recently, a natural hydrate sample from the Gulf of Mexico was also acquired and testing of this sample is currently underway. In addition to the development of GAS, modeling and systems analysis work focused on the development of conceptual gas hydrate production models. 16 figs., 6 tabs.
Moridis, George; Moridis, George J.; Kowalsky, Michael B.; Pruess, Karsten
2008-03-01
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.
Product design and development of an aerodynamic hydration system for bicycling and triathlon
Cote, Mark (Mark Brian)
2007-01-01
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 ...
Quantum Chemical Analysis of the Excited State Dynamics of Hydrated Electrons
P. O. J. Scherer; Sighart F. Fischer
2006-02-01
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 .
Additives and method for controlling clathrate hydrates in fluid systems
Sloan, E.D. Jr.; Christiansen, R.L.; Lederhos, J.P.; Long, J.P.; Panchalingam, V.; Du, Y.; Sum, A.K.W.
1997-06-17
Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hindrance and/or charge repulsion. Also, polymers having an amide on which a C{sub 1}-C{sub 4} group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.
Additives and method for controlling clathrate hydrates in fluid systems
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)
1997-01-01
Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.
Faulting and hydration of the Juan de Fuca plate system Mladen R. Nedimovi a,c,
Bohnenstiehl, Delwayne
Available online xxxx Editor: R.D. van der Hilst Keywords: Juan de Fuca plate system seismic reflection imaging faulting hydration earthquakes Multichannel seismic observations provide the first direct images faulting within this young and sediment insulated oceanic plate is primarily limited to approximately Moho
S. A. Lusceac; C. R. Herbers; M. Vogel
2009-04-28
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.
Hydrate characterization research overview
Malone, R.D.
1993-06-01
Gas hydrate research has been focused primarily on the development of a basic understanding of hydrate formation and dissociation in the laboratory, as well as in the field. Laboratory research on gas hydrates characterized the physical system, which focused on creating methane hydrates samples, tetrahydrofuran (THF) hydrate samples, consolidated rock samples, frost base mixtures, water/ice-base mixtures, and water-base mixtures. Laboratory work produced measurements of sonic velocity and electrical resistivity of hydrates. As work progressed, areas, such as the Gulf of Mexico and the Guatemala Trench, where gas hydrates are likely to occur were identified, and specific high potential areas were targeted for detailed investigation. The testing of samples and recovered cores from such areas provided information for detection of hydrate formations in the natural environment. Natural gas hydrate samples have been tested for thermal properties, dissociation properties, fracture mechanics, and optical properties. Acoustical properties were investigated both in the laboratory and, as possible, in the field. Sonic velocity and electrical resistivity measurements will continue to be obtained. These activities have been undertaken in hydrate deposits on Alaska`s North Slope, the Gulf of Mexico and the US East coast offshore, as well as other gas hydrate target areas.
Chow, Aaron C. (Aaron Chunghin), 1978-
2008-01-01
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 ...
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
Categorical Introduction to Dynamical Systems Symbolic Dynamical Systems
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
Neil Dobbs; Mikko Stenlund
2015-04-08
We introduce the notion of a quasistatic dynamical system, which generalizes that of an ordinary dynamical system. Quasistatic dynamical systems are inspired by the namesake processes in thermodynamics, which are idealized processes where the observed system transforms (infinitesimally) slowly due to external influence, tracing out a continuous path of thermodynamic equilibria over an (infinitely) long time span. Time-evolution of states under a quasistatic dynamical system is entirely deterministic, but choosing the initial state randomly renders the process a stochastic one. In the prototypical setting where the time-evolution is specified by strongly chaotic maps on the circle, we obtain a description of the statistical behaviour as a stochastic diffusion process, under surprisingly mild conditions on the initial distribution, by solving a well-posed martingale problem. We also consider various admissible ways of centering the process, with the curious conclusion that the "obvious" centering suggested by the initial distribution sometimes fails to yield the expected diffusion.
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)
2014-09-14
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.
Singhose, William
Journal of Dynamic Systems, Measurement, and Control Technical Briefs Remote Vibration Control for Flexible Beams Subject to Harmonic Disturbances Shang-Teh Wu Department of Mechanical Engineering, National at the boundary are required in the control algorithm, which emulates the behavior of a set of mechanical spring
Moridis, George
2008-01-01
Hydrate saturation distribution in the reservoir at t = 2phase saturation distribution in the reservoir at t = 2 days12.23. Gas saturation distribution in the reservoir at t = 2
Gas hydrates: technology status report
Not Available
1986-01-01
The DOE Morgantown Energy Technology Center (METC) implemented a gas hydrates R and D program that emphasized an understanding of the resource through (1) an assessment of current technology, (2) the characterization of gas hydrate geology and reservoir engineering, and (3) the development of diagnostic tools and methods. Recovery of natural gas from gas hydrates will be made possible through (1) improved instrumentation and recovery methods, (2) developing the capability to predict production performance, and (3) field verification of recovery methods. Gas hydrates research has focused primarily on geology. As work progressed, areas where gas hydrates are likely to occur were identified, and specific high potential areas were targeted for detailed investigation. A Geologic Analysis System (GAS) was developed. GAS contains approximately 30 software packages and can manipulate and correlate several types of geologic and petroleum data into maps, graphics, and reports. The system also contains all well information currently available from the Alaskan North Slope area. Laboratory research on gas hydrates includes the characterization of the physical system, which focuses on creating synthetic methane hydrates and developing synthetic hydrate cores using tetrahydrofuran (THF), consolidated rock cores, frost base mixtures, water/ice-base mixtures, and water-base mixtures. Laboratory work produced measurements of the sonic velocity and electrical resistivity of these synthetic hydrates. During 1983, a sample from a natural hydrate core recovered from the Pacific coast of Guatemala was tested for these properties by DOE/METC. More recently, natural hydrate samples acquired from the Gulf of Mexico are being tested. Modeling and systems analysis work has focused on the development of GAS and preliminary gas hydrate production models. 23 refs., 18 figs., 6 tabs.
Broader source: Energy.gov [DOE]
Reports on truck fleet emission test results obtained from retrofitting in-use? old class-8 trucks with IMETs GreenPower? DPF-Hydrated-EGR system
Costandy, Joseph GN
2015-06-12
different molecules can form hydrates when mixed with water at relatively low temperatures and high pressures, including methane, ethane, propane, iso-butane, carbon dioxide, nitrogen and hydrogen. The accurate prediction of thermodynamic properties...
Entanglement dynamics in chaotic systems
Ghose, Shohini [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada); Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Sanders, Barry C. [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada); Centre for Quantum Computer Technology, Macquarie University, Sydney, New South Wales (Australia)
2004-12-01
We study quantum chaos for systems with more than one degree of freedom, for which we present an analysis of the dynamics of entanglement. Our analysis explains the main features of entanglement dynamics and identifies entanglement-based signatures of quantum chaos. We discuss entanglement dynamics for a feasible experiment involving an atom in a magneto-optical trap and compare the results with entanglement dynamics for the well-studied quantum kicked top.
Rack, Frank; Bohrmann, Gerhard; Trehu, Anne; Storms, Michael; Schroeder, Derryl
2002-09-30
The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the deployment of tools and measurement systems on ODP Leg 204 to study hydrate deposits on Hydrate Ridge, offshore Oregon from July through September, 2002. During Leg 204, we cored and logged 9 sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of hydrates in situ. A 3D seismic survey conducted in 2000 provided images of potential subsurface fluid conduits and indicated the position of the GHSZ throughout the survey region. After coring the first site, we acquired Logging-While-Drilling (LWD) data at all but one site to provide an overview of downhole physical properties. The LWD data confirmed the general position of key seismic stratigraphic horizons and yielded an initial estimate of hydrate concentration through the proxy of in situ electrical resistivity. These records proved to be of great value in planning subsequent coring. The second new hydrate proxy to be tested was infrared thermal imaging of cores on the catwalk as rapidly as possible after retrieval. The thermal images were used to identify hydrate samples and to map estimate the distribution and texture of hydrate within the cores. Geochemical analyses of interstitial waters and of headspace and void gases provide additional information on the distribution and concentration of hydrate within the stability zone, the origin and pathway of fluids into and through the GHSZ, and the rates at which the process of gas hydrate formation is occurring. Bio- and lithostratigraphic description of cores, measurement of physical properties, and in situ pressure core sampling and thermal measurements complement the data set, providing ground-truth tests of inferred physical and sedimentological properties. Among the most interesting preliminary results are: (1) the discovery that gas hydrates are distributed through a broad depth range within the GHSZ and that different physical and chemical proxies for hydrate distribution and concentration give generally consistent results; (2) evidence for the importance of sediment properties for controlling the migration of fluids in the accretionary complex; (3) geochemical indications that the gas hydrate system at Hydrate Ridge contains significant concentrations of higher order hydrocarbons and that fractionation and mixing signals will provide important constraints on gas hydrate dynamics; and (4) the discovery of very high chlorinity values that extend for at least 10 mbsf near the summit, indicating that hydrate formation here must be very rapid.
Connecting curves for dynamical systems
R. Gilmore; Jean-Marc Ginoux; Timothy Jones; C. Letellier; U. S. Freitas
2010-03-08
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.
Multiple stage multiple filter hydrate store
Bjorkman, Jr., Harry K. (Birmingham, MI)
1983-05-31
An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means or separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means.
Multiple stage multiple filter hydrate store
Bjorkman, H.K. Jr.
1983-05-31
An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means for separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means. 7 figs.
Hydrate Formation and Dissociation in Simulated and Field Samples
Pennycook, Steve
-Resolved 3-D temperature monitoring #12;Distributed Sensing System (DSS) The Luna® Distributed Sensing System-Situ Diffraction XRD Neutron · Hydrate synthesis capabilities · Seafloor Processing Simulator housed and temperatures where hydrates are stable Luna Distributed Sensing System (DSS) for observation of hydrate
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.
Nonequilibrium Dynamics in Lattice Systems
Steinhoff, Heinz-Jürgen
Nonequilibrium Dynamics in Lattice Systems: Epitaxial Growth and Time dependent Density Functional . . . . . . . . . . . . . . . . . . . . . 9 2.3.1 Island densities . . . . . . . . . . . . . . . . . . . . . . . . 9 2.3.2 Island size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2 Kinetic Monte Carlo Simulations . . . . . . . . . . . . . . . . . . 15 3.2.1 Multi-island
Cha, Jong-Ho [ORISE; Seol, Yongkoo [U.S. DOE
2013-01-01
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.
Smith, Jonathan David, S.M. Massachusetts Institute of Technology
2011-01-01
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 ...
Dynamical systems probabilistic risk assessment.
Denman, Matthew R.; Ames, Arlo Leroy
2014-03-01
Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.
Simulation and sequential dynamical systems
Mortveit, H.S.; Reidys, C.M.
1999-06-01
Computer simulations have a generic structure. Motivated by this the authors present a new class of discrete dynamical systems that captures this structure in a mathematically precise way. This class of systems consists of (1) a loopfree graph {Upsilon} with vertex set {l_brace}1,2,{hor_ellipsis},n{r_brace} where each vertex has a binary state, (2) a vertex labeled set of functions (F{sub i,{Upsilon}}:F{sub 2}{sup n} {yields} F{sub 2}{sup n}){sub i} and (3) a permutation {pi} {element_of} S{sub n}. The function F{sub i,{Upsilon}} updates the state of vertex i as a function of the states of vertex i and its {Upsilon}-neighbors and leaves the states of all other vertices fixed. The permutation {pi} represents the update ordering, i.e., the order in which the functions F{sub i,{Upsilon}} are applied. By composing the functions F{sub i,{Upsilon}} in the order given by {pi} one obtains the dynamical system (equation given in paper), which the authors refer to as a sequential dynamical system, or SDS for short. The authors will present bounds for the number of functionally different systems and for the number of nonisomorphic digraphs {Gamma}[F{sub {Upsilon}},{pi}] that can be obtained by varying the update order and applications of these to specific graphs and graph classes.
Dynamics of Triaxial Stellar Systems
David Merritt
1996-11-11
Recent work on the dynamics of triaxial stellar systems is reviewed. The motion of boxlike orbits in realistic triaxial potentials is generically stochastic. The degree to which the stochasticity manifests itself in the dynamics depends on the chaotic mixing timescale, which is a small multiple of the crossing time in triaxial models with steep cusps or massive central singularities. Low-luminosity ellipticals, which have the steepest cusps and the shortest dynamical times, are less likely than bright ellipticals to have strongly triaxial shapes. The observational evidence for triaxiality is reviewed; departures from axisymmetry in early-type galaxies are often found to be associated with evidence of recent interactions or with the presence of a bar.
Geometric control and dynamical systems Ludovic Rifford
Rifford, Ludovic
Geometric control and dynamical systems Ludovic Rifford Universit´e de Nice - Sophia Antipolis Equations and Applications Ludovic Rifford Geometric control and dynamical systems #12;Control of an inverted pendulum Ludovic Rifford Geometric control and dynamical systems #12;Control systems A general
Day, Sarah J; Evans, Aneurin; Parker, Julia E
2015-01-01
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...
Parameter Synthesis in Nonlinear Dynamical Systems: Application to Systems Biology
Langmead, Christopher James
Parameter Synthesis in Nonlinear Dynamical Systems: Application to Systems Biology Alexandre Donz. The dynamics of biological processes are often modeled as systems of nonlinear ordinary differential equations problem for nonlinear dynamical systems. That is, for systems of nonlinear ordinary differential equations
Computability and Dynamical Systems: a Perspective
Graça, Daniel S.
Computability and Dynamical Systems: a Perspective Daniel S. Gra¸ca SQIG - IT and DM In this paper we look at dynamical systems from a computability per- spective. We survey some topics and themes of research for dynamical systems and then see how they can be fitted in a computational frame- work. We
LANGUAGE LEARNING AND NONLINEAR DYNAMICAL SYSTEMS
Andrews, Mark W.
LANGUAGE LEARNING AND NONLINEAR DYNAMICAL SYSTEMS A Dissertation Presented to the Faculty LEARNING AND NONLINEAR DYNAMICAL SYSTEMS Mark William Andrews, Ph.D. Cornell University 2003 The thesis be provided by an better appreciation of the capacities of nonlinear dynamical systems to learn, rep- resent
Parameter and state estimation in nonlinear dynamical systems
Creveling, Daniel R.
2008-01-01
and J. Kurths. Nonlinear dynamical system identi?ca- tionEstimation In Nonlinear Dynamical Systems A dissertationState Estimation In Nonlinear Dynamical Systems by Daniel R.
Dynamical Systems and Applications of Nonlinear Functional Analysis to Dynamical Systems
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
2013-12-31
This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report. • Historical Methane Hydrate Project Review Report • Methane Hydrate Workshop Report • Topical Report: Marine Methane Hydrate Field Research Plan • Final Scientific/Technical Report
World-Systems as Dynamic Networks
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
Detection and Production of Methane Hydrate
George Hirasaki; Walter Chapman; Gerald Dickens; Colin Zelt; Brandon Dugan; Kishore Mohanty; Priyank Jaiswal
2011-12-31
This project seeks to understand regional differences in gas hydrate systems from the perspective of as an energy resource, geohazard, and long-term climate influence. Specifically, the effort will: (1) collect data and conceptual models that targets causes of gas hydrate variance, (2) construct numerical models that explain and predict regional-scale gas hydrate differences in 2-dimensions with minimal 'free parameters', (3) simulate hydrocarbon production from various gas hydrate systems to establish promising resource characteristics, (4) perturb different gas hydrate systems to assess potential impacts of hot fluids on seafloor stability and well stability, and (5) develop geophysical approaches that enable remote quantification of gas hydrate heterogeneities so that they can be characterized with minimal costly drilling. Our integrated program takes advantage of the fact that we have a close working team comprised of experts in distinct disciplines. The expected outcomes of this project are improved exploration and production technology for production of natural gas from methane hydrates and improved safety through understanding of seafloor and well bore stability in the presence of hydrates. The scope of this project was to more fully characterize, understand, and appreciate fundamental differences in the amount and distribution of gas hydrate and how this would affect the production potential of a hydrate accumulation in the marine environment. The effort combines existing information from locations in the ocean that are dominated by low permeability sediments with small amounts of high permeability sediments, one permafrost location where extensive hydrates exist in reservoir quality rocks and other locations deemed by mutual agreement of DOE and Rice to be appropriate. The initial ocean locations were Blake Ridge, Hydrate Ridge, Peru Margin and GOM. The permafrost location was Mallik. Although the ultimate goal of the project was to understand processes that control production potential of hydrates in marine settings, Mallik was included because of the extensive data collected in a producible hydrate accumulation. To date, such a location had not been studied in the oceanic environment. The project worked closely with ongoing projects (e.g. GOM JIP and offshore India) that are actively investigating potentially economic hydrate accumulations in marine settings. The overall approach was fivefold: (1) collect key data concerning hydrocarbon fluxes which is currently missing at all locations to be included in the study, (2) use this and existing data to build numerical models that can explain gas hydrate variance at all four locations, (3) simulate how natural gas could be produced from each location with different production strategies, (4) collect new sediment property data at these locations that are required for constraining fluxes, production simulations and assessing sediment stability, and (5) develop a method for remotely quantifying heterogeneities in gas hydrate and free gas distributions. While we generally restricted our efforts to the locations where key parameters can be measured or constrained, our ultimate aim was to make our efforts universally applicable to any hydrate accumulation.
Dynamics and architectures of innovation systems
Chen, Po Chia, S.M. Massachusetts Institute of Technology
2011-01-01
Innovation processes are multifaceted. Different studies usually focus on different facets of innovations without being integrated into a complete innovation system. In this thesis, system dynamics and system architecture ...
Transport in Transitory Dynamical Systems
B. A. Mosovsky; J. D. Meiss
2010-08-10
We introduce the concept of a "transitory" dynamical system---one whose time-dependence is confined to a compact interval---and show how to quantify transport between two-dimensional Lagrangian coherent structures for the Hamiltonian case. This requires knowing only the "action" of relevant heteroclinic orbits at the intersection of invariant manifolds of "forward" and "backward" hyperbolic orbits. These manifolds can be easily computed by leveraging the autonomous nature of the vector fields on either side of the time-dependent transition. As illustrative examples we consider a two-dimensional fluid flow in a rotating double-gyre configuration and a simple one-and-a-half degree of freedom model of a resonant particle accelerator. We compare our results to those obtained using finite-time Lyapunov exponents and to adiabatic theory, discussing the benefits and limitations of each method.
A Dynamical Systems Approach to Turbulence
This talk will discuss a general software framework for the computation of periodic orbits of high-dimensional dynamical systems, that is based on a matrix-
ME 413 Systems Dynamics & Control Chapter 1: Introduction to System Dynamics CChhaapptteerr 11
Al-Qahtani, Hussain M.
heat) when excited by temperature or heat flow. A heating system warming a house has a dynamic response
Nonlinear and Complex Dynamics in Real Systems
Barnett, William A.; Serletis, Apostolos; Serletis, Demitre
2006-06-01
In this article we provide a review of the literature with respect to fluctuations in real systems and chaos. In doing so, we contrast the order and organization hypothesis of real systems to nonlinear chaotic dynamics and discuss some techniques...
Oil & Natural Gas Technology Temporal Characterization of Hydrates System Dynamics beneath Seafloor
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access toOctober 1996 -Workers'OfficialSan Miguel CountyOklahoma City,Oil
Effect of under-inhibition with methanol and ethylene glycol on the hydrate control process
Yousif, M.H.
1996-12-31
Hydrate control can be achieved by chemical injection. Currently, methanol and ethylene glycol are the most widely used inhibitors in offshore hydrate control operations. To achieve effective hydrate inhibition, a sufficient amount of inhibitor must be injected to shift the thermodynamic equilibrium condition for hydrate formation outside the pipeline operating pressure and temperature. Recently published field experiments showed that hydrate blockages form more readily in under-inhibited systems than in systems completely without inhibitor. A laboratory study is conducted to determine the effect of low concentration (1--5wt%) methanol and ethylene glycol on the hydrate formation process. The results show that, although these chemicals are effective hydrate inhibitors when added in sufficient quantities, they actually enhance the rate of hydrate formation when added at low concentrations to the water. Furthermore, the presence of these chemicals seems to affect the size of the forming hydrate particles.
Casey, Jennifer Ryan
2014-01-01
Cavity and Non-cavity Hydrated Elec- tron at the Air/Waterrelaxation dynamics at water/air interfaces. J. Chem.Electronic states at the water/air interface. J. Phys. Chem.
A Study of Formation and Dissociation of Gas Hydrate
Badakhshan Raz, Sadegh
2012-07-16
The estimation of gas hydrate volume in closed systems such as pipelines during shut-in time has a great industrial importance. A method is presented to estimate the volume of formed or decomposed gas hydrate in closed systems. The method was used...
Computability in planar dynamical systems Daniel Graca
Lisboa, Universidade Técnica de
Computability in planar dynamical systems Daniel Gra¸ca DM/FCT, Universidade do Algarve, C undecidable, even for analytic systems and (b) the attractors are semi-computable for stable systems. We also show that the basins of attraction are semi-computable if and only if the system is stable. Keywords
control and Dynamic Systems Decentralized Control
Moore, John Barratt
control and Dynamic Systems BR Departn Decentralized Control Using Time-Varying Feedback AN D. O controller one connects to the system, so long as the controller has available to it the system inputs of the closed-loop system. If the controller CopyrightO 1985 by Academic Pres, inc. 85 Allrightsofreproductjon
Symmetries and dynamics in constrained systems
Xavier Bekaert; Jeong-Hyuck Park
2009-04-03
We review in detail the Hamiltonian dynamics for constrained systems. Emphasis is put on the total Hamiltonian system rather than on the extended Hamiltonian system. We provide a systematic analysis of (global and local) symmetries in total Hamiltonian systems. In particular, in analogue to total Hamiltonians, we introduce the notion of total Noether charges. Grassmannian degrees of freedom are also addressed in details.
Epstein, Irving R.
FOCUS ISSUE: Nonlinear dynamics related to polymeric systems Overview: Nonlinear dynamics related is another promising practical application of nonlinear chemical dynamics. In this issue we focus on non is known about nonlinear phenom- ena in polymeric systems. One reason for the lack of interest in nonlinear
SIAM conference on applications of dynamical systems
Not Available
1992-01-01
A conference (Oct.15--19, 1992, Snowbird, Utah; sponsored by SIAM (Society for Industrial and Applied Mathematics) Activity Group on Dynamical Systems) was held that highlighted recent developments in applied dynamical systems. The main lectures and minisymposia covered theory about chaotic motion, applications in high energy physics and heart fibrillations, turbulent motion, Henon map and attractor, integrable problems in classical physics, pattern formation in chemical reactions, etc. The conference fostered an exchange between mathematicians working on theoretical issues of modern dynamical systems and applied scientists. This two-part document contains abstracts, conference program, and an author index.
Protein viscoelastic dynamics: a model system
Craig Fogle; Joseph Rudnick; David Jasnow
2015-02-02
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.
Parallel Implementation of Power System Dynamic Simulation
Jin, Shuangshuang; Huang, Zhenyu; Diao, Ruisheng; Wu, Di; Chen, Yousu
2013-07-21
Dynamic simulation of power system transient stability is important for planning, monitoring, operation, and control of electrical power systems. However, modeling the system dynamics and network involves the computationally intensive time-domain solution of numerous differential and algebraic equations (DAE). This results in a transient stability implementation that may not maintain the real-time constraints of an online security assessment. This paper presents a parallel implementation of the dynamic simulation on a high-performance computing (HPC) platform using parallel simulation algorithms and computation architectures. It enables the simulation to run even faster than real time, enabling the “look-ahead” capability of upcoming stability problems in the power grid.
Scalable Support for Multithreaded Applications on Dynamic Binary Instrumentation Systems
Hazelwood, Kim
Scalable Support for Multithreaded Applications on Dynamic Binary Instrumentation Systems Kim Dynamic binary instrumentation systems are used to inject or mod- ify arbitrary instructions in existing for supporting large, multithreaded applications on JIT-based dynamic instrumentation systems. While implementing
System Dynamics and Vibration Lab Dept. of Mechanical Engineering
Shaw, Steven W.
System Dynamics and Vibration Lab Dept. of Mechanical Engineering Component Mode Synthesis Using #12;System Dynamics and Vibration Lab Dept. of Mechanical Engineering Outline · Motivation · Conclusions #12;System Dynamics and Vibration Lab Dept. of Mechanical Engineering Complex Structures
Vegetation Dynamics in Seasonally Grazed Upland Systems
Pollock, Meg L
This thesis addresses the effects of seasonality of grazing on vegetation dynamics. Background to the thesis is provided by the Hill Sheep and Native Woodland (HSNW) project, a system-scale experiment with the long-term ...
Dynamic modeling issues for power system applications
Song, Xuefeng
2005-02-17
Power system dynamics are commonly modeled by parameter dependent nonlinear differential-algebraic equations (DAE) x ???p y x f ) and 0 = p y x g ) . Due to (,, (,, the algebraic constraints, we cannot directly perform...
System dynamics, market microstructure and asset pricing
Leika, Mindaugas
2013-01-01
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 ...
Fuel cell membrane hydration and fluid metering
Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)
2003-01-01
A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).
Fuel cell membrane hydration and fluid metering
Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)
1999-01-01
A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).
Computation with perturbed dynamical systems Olivier Bournez
GraÃ§a, 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
Dynamical Systems with Delays Benefits and Detriments
to what the system has exhibited in the past, and current information signals actually are not available Geographical Location 1 Production DELAY Headquarters Ordering Information Exchanging Decision Making DELAY1 Dynamical Systems with Delays Benefits and Detriments I. INTRODUCTION A feedback control system
Sorin A. Lusceac; Markus Rosenstihl; Michael Vogel; Catalin Gainaru; Ariane Fillmer; Roland Böhmer
2010-04-23
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 {\
Dynamic Logics of Dynamical Systems ANDR E PLATZER, Carnegie Mellon University
Platzer, AndrÃ©
. Dynamical systems are mathematical models describing how the state of a system evolves over time. They are important for modeling and understanding many applications, including embedded systems and cyber of differential equations. We explain the dynamical system models, dynamic logics of dynamical systems
Formation of porous gas hydrates
Salamatin, Andrey N
2015-01-01
Gas hydrates grown at gas-ice interfaces are examined by electron microscopy and found to have a submicron porous texture. Permeability of the intervening hydrate layers provides the connection between the two counterparts (gas and water molecules) of the clathration reaction and makes further hydrate formation possible. The study is focused on phenomenological description of principal stages and rate-limiting processes that control the kinetics of the porous gas hydrate crystal growth from ice powders. Although the detailed physical mechanisms involved in the porous hydrate formation still are not fully understood, the initial stage of hydrate film spreading over the ice surface should be distinguished from the subsequent stage which is presumably limited by the clathration reaction at the ice-hydrate interface and develops after the ice grain coating is finished. The model reveals a time dependence of the reaction degree essentially different from that when the rate-limiting step of the hydrate formation at...
Geographical Information Systems and Dynamic Modeling via Agent Based Systems
de Figueiredo, Luiz Henrique
Geographical Information Systems and Dynamic Modeling via Agent Based Systems Cláudio Antônio da fariasol@eng.uerj.br ABSTRACT A full integration among Geographical Information Systems and Agent Based integrated with Geographical Information Systems (GIS). The first one is the movement of pedestrians
Sanov, Andrei
Photoelectron Imaging of Hydrated Carbon Dioxide Cluster Anions Eric Surber, Richard Mabbs, Terefe solvation on the electronic structure and photodetachment dynamics of hydrated carbon dioxide cluster anions and carbon dioxide. The effect of hydration on the electronic structure of ions has far- reaching
Prediction of gas-hydrate formation conditions in production and surface facilities
Ameripour, Sharareh
2006-10-30
.2 Phase diagram for natural gas hydrocarbons which form hydrates .............9 Fig. 2.3 Formation of gas hydrate plugs a subsea hydrocarbon pipeline................11 Fig. 2.4 Experimental hydrate equilibrium conditions for the ternary... exploration and production operations. Hydrate clathrates can plug gas gathering systems and transmission pipelines subsea and on the surface. In offshore explorations, the main concern is the multiphase transfer lines from the wellhead...
Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments [Part 2 of 2
Bryant, Steven; Juanes, Ruben
2011-12-31
In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate saturations. Large volumes (of order one pore volume) of gaseous and aqueous phases must be transported into the gas hydrate stability zone. The driver for this transport is the pressure sink induced by a reduction in occupied pore volume that accompanies the formation of hydrate from gas and water. Pore-scale imbibition models and bed-scale multiphase flow models indicate that the rate-limiting step in converting gas to hydrate is the supply of water to the hydrate stability zone. Moreover, the water supply rate is controlled by capillarity-driven flux for conditions typical of the Alaska North Slope. A meter-scale laboratory experiment confirms that significant volumes of fluid phases move into the hydrate stability zone and that capillarity is essential for the water flux. The model shows that without capillarity-driven flux, large saturations of hydrate cannot form. The observations of thick zones of large saturation at Mallik and Mt Elbert thus suggest that the primary control on these systems is the rate of transport of gaseous and aqueous phases, driven by the pressure sink at the base of the gas hydrate stability zone. A key finding of our project is the elucidation of ?capillary fracturing? as a dominant gas transport mechanism in low-permeability media. We initially investigate this phenomenon by means of grain-scale simulations in which we extended a discrete element mechanics code (PFC, by Itasca) to incorporate the dynamics of first singlephase and then multiphase flow. A reductionist model on a square lattice allows us to determine some of the fundamental dependencies of the mode of gas invasion (capillary fingering, viscous fingering, and fracturing) on the parameters of the system. We then show that the morphology of the gas-invaded region exerts a fundamental control on the fabric of methane hydrate formation, and on the overpressures caused by methane hydrate dissociation. We demonstrate the existence of the different invasion regimes by means of controlled laboratory experiments in a radial cell. We collapse the behavior in the form of a phase dia
Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments [Part 1 of 2
Bryant, Steven; Juanes, Ruben
2011-12-31
In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate saturations. Large volumes (of order one pore volume) of gaseous and aqueous phases must be transported into the gas hydrate stability zone. The driver for this transport is the pressure sink induced by a reduction in occupied pore volume that accompanies the formation of hydrate from gas and water. Pore-scale imbibition models and bed-scale multiphase flow models indicate that the rate-limiting step in converting gas to hydrate is the supply of water to the hydrate stability zone. Moreover, the water supply rate is controlled by capillarity-driven flux for conditions typical of the Alaska North Slope. A meter-scale laboratory experiment confirms that significant volumes of fluid phases move into the hydrate stability zone and that capillarity is essential for the water flux. The model shows that without capillarity-driven flux, large saturations of hydrate cannot form. The observations of thick zones of large saturation at Mallik and Mt Elbert thus suggest that the primary control on these systems is the rate of transport of gaseous and aqueous phases, driven by the pressure sink at the base of the gas hydrate stability zone. A key finding of our project is the elucidation of ?capillary fracturing? as a dominant gas transport mechanism in low-permeability media. We initially investigate this phenomenon by means of grain-scale simulations in which we extended a discrete element mechanics code (PFC, by Itasca) to incorporate the dynamics of first single-phase and then multiphase flow. A reductionist model on a square lattice allows us to determine some of the fundamental dependencies of the mode of gas invasion (capillary fingering, viscous fingering, and fracturing) on the parameters of the system. We then show that the morphology of the gas-invaded region exerts a fundamental control on the fabric of methane hydrate formation, and on the overpressures caused by methane hydrate dissociation. We demonstrate the existence of the different invasion regimes by means of controlled laboratory experiments in a radial cell. We collapse the behavior in the form of a phase di
Reaction dynamics in polyatomic molecular systems
Miller, W.H. [Lawrence Berkeley Laboratory, CA (United States)
1993-12-01
The goal of this program is the development of theoretical methods and models for describing the dynamics of chemical reactions, with specific interest for application to polyatomic molecular systems of special interest and relevance. There is interest in developing the most rigorous possible theoretical approaches and also in more approximate treatments that are more readily applicable to complex systems.
Dynamical Systems with Delays Benefits and Detriments
delays arise Manufacturer Geographical Location 1 Production DELAY Headquarters Ordering Information1 Dynamical Systems with Delays Benefits and Detriments I. INTRODUCTION A feedback control system is composed of a process to be controlled, a set of sensors with access to information signals from the plant
Control Theory of Digitally Networked Dynamic Systems
Knobloch,JÃ¼rgen
Control Theory of Digitally Networked Dynamic Systems #12;Jan Lunze Editor Control Theory control technology for mobile objects. Due to this flexibility, a new challenge for control theory about networked control systems as a new area of control theory. This book gives a concise introduc
INFORMATION THEORY AND DYNAMICAL SYSTEM PREDICTABILITY
such as the atmosphere and ocean as well as earthquake prediction for which the system can be considered even more nonINFORMATION THEORY AND DYNAMICAL SYSTEM PREDICTABILITY RICHARD KLEEMAN Abstract. Predicting of obtaining practical results for prediction also guides the development presented. 1. Introduction Prediction
Diffusion motions in hydrated sodium alginate by QENS
Tripadus, V.; Statescu, M.; Aranghel, D.; Gugiu, M.; Petre, M.; Precup, I. [Institute of Physics and Nuclear Engineerig, Bucuresti (Romania); Zanotti, J. M.; Mitra, S. [Laboratoire Leon Brillouin, CEA Saclay (France)
2010-01-21
QENS experiments are very suitable for the study of water-polysaccharides systems both for slow polymer chains dynamics as well as for faster solvent molecules dynamics. By a suitable choice of experimental conditions as well as a properly data processing we can get information about the motion modes of various molecular groups of polymer chains in aqueous solutions presumes. Virtually we can distinguish the polymer protons motions at nanosecond time scale by choosing a narrow energy resolution window. The present work presents the QENS measurements performed at LLB, MIBEMOL neutron spectrometer on sodium alginate hydrated samples. The experimental spectra were fitted using one lorentzian fit. At high polymer concentration the quasielastic part of the line is given by the translational-rotational diffusion performed by heavy water molecules in confined spaces created by the polymer coils. The experimental data are well described by Chudley Elliot and Hall-Ross models.
Site Selection for DOE/JIP Gas Hydrate Drilling in the Northern Gulf of Mexico
Collett, T.S.; Riedel, M.; Cochran, J.R.; Boswell, R.M.; Kumar, Pushpendra; Sathe, A.V.
2008-07-01
Studies of geologic and geophysical data from the offshore of India have revealed two geologically distinct areas with inferred gas hydrate occurrences: the passive continental margins of the Indian Peninsula and along the Andaman convergent margin. The Indian National Gas Hydrate Program (NGHP) Expedition 01 was designed to study the occurrence of gas hydrate off the Indian Peninsula and along the Andaman convergent margin with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. NGHP Expedition 01 established the presence of gas hydrates in Krishna- Godavari, Mahanadi and Andaman basins. The expedition discovered one of the richest gas hydrate accumulations yet documented (Site 10 in the Krishna-Godavari Basin), documented the thickest and deepest gas hydrate stability zone yet known (Site 17 in Andaman Sea), and established the existence of a fully-developed gas hydrate system in the Mahanadi Basin (Site 19).
Learning Nonlinear Dynamical Systems using an EM Algorithm
Edinburgh, University of
Learning Nonlinear Dynamical Systems using an EM Algorithm Zoubin Ghahramani and Sam T. Roweis present a generalization of the EM algorithm for parameter estimation in nonlinear dynamical systems Nonlinear Dynamical Systems We examine inference and learning in discrete-time dynamical systems with hidden
Logistic maps General systems Motivating examples in dynamical systems
Climenhaga, Vaughn
Logistic maps General systems Motivating examples in dynamical systems Vaughn Climenhaga University of Houston October 16, 2012 Vaughn Climenhaga (University of Houston) October 16, 2012 1 / 7 #12;Logistic #12;Logistic maps General systems The logistic map Logistic map: f (x) = x(1 - x) 0 4 x f(x) = 0
Investigating the Metastability of Clathrate Hydrates for Energy Storage
Koh, Carolyn Ann
2014-11-18
Important breakthrough discoveries have been achieved from the DOE award on the key processes controlling the synthesis and structure-property relations of clathrate hydrates, which are critical to the development of clathrate hydrates as energy storage materials. Key achievements include: (i) the discovery of key clathrate hydrate building blocks (stable and metastable) leading to clathrate hydrate nucleation and growth; (ii) development of a rapid clathrate hydrate synthesis route via a seeding mechanism; (iii) synthesis-structure relations of H2 + CH4/CO2 binary hydrates to control thermodynamic requirements for energy storage and sequestration applications; (iv) discovery of a new metastable phase present during clathrate hydrate structural transitions. The success of our research to-date is demonstrated by the significant papers we have published in high impact journals, including Science, Angewandte Chemie, J. Am. Chem. Soc. Intellectual Merits of Project Accomplishments: The intellectual merits of the project accomplishments are significant and transformative, in which the fundamental coupled computational and experimental program has provided new and critical understanding on the key processes controlling the nucleation, growth, and thermodynamics of clathrate hydrates containing hydrogen, methane, carbon dioxide, and other guest molecules for energy storage. Key examples of the intellectual merits of the accomplishments include: the first discovery of the nucleation pathways and dominant stable and metastable structures leading to clathrate hydrate formation; the discovery and experimental confirmation of new metastable clathrate hydrate structures; the development of new synthesis methods for controlling clathrate hydrate formation and enclathration of molecular hydrogen. Broader Impacts of Project Accomplishments: The molecular investigations performed in this project on the synthesis (nucleation & growth)-structure-stability relations of clathrate hydrate systems are pivotal in the fundamental understanding of crystalline clathrate hydrates and the discovery of new clathrate hydrate properties and novel materials for a broad spectrum of energy applications, including: energy storage (hydrogen, natural gas); carbon dioxide sequestration; controlling hydrate formation in oil/gas transportation in subsea pipelines. The Project has also enabled the training of undergraduate, graduate and postdoctoral students in computational methods, molecular spectroscopy and diffraction, and measurement methods at extreme conditions of high pressure and low temperature.
Jagannathan, Deepak
2013-01-01
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 ...
Identification of Hybrid Dynamical Models of Human Movement via Switched System Optimal Control
Vasudevan, Ramanarayan
2012-01-01
of constrained nonlinear switched dynamical systems. Inconstrained nonlinear switched dynamical systems is devised.
Chaos in Nonlinear Dynamical Systems Helicopter Flight-data Analysis
Taylor, James H.
Chaos in Nonlinear Dynamical Systems Helicopter Flight-data Analysis James H. Taylor1 and S of chaos in nonlinear dynamical systems is discussed, and approaches for the identification of chaos can only occur in systems with nonlinear dynamics. The recognition of chaos in a complex dynamical
A dynamically reconfigurable data stream processing system
Nogiec, J.M.; Trombly-Freytag, K.; /Fermilab
2004-11-01
This paper describes a component-based framework for data stream processing that allows for configuration, tailoring, and runtime system reconfiguration. The system's architecture is based on a pipes and filters pattern, where data is passed through routes between components. A network of pipes and filters can be dynamically reconfigured in response to a preplanned sequence of processing steps, operator intervention, or a change in one or more data streams. This framework provides several mechanisms supporting dynamic reconfiguration and can be used to build static data stream processing applications such as monitoring or data acquisition systems, as well as self-adjusting systems that can adapt their processing algorithm, presentation layer, or data persistency layer in response to changes in input data streams.
Design tools for complex dynamic security systems.
Byrne, Raymond Harry; Rigdon, James Brian; Rohrer, Brandon Robinson; Laguna, Glenn A.; Robinett, Rush D. III; Groom, Kenneth Neal; Wilson, David Gerald; Bickerstaff, Robert J.; Harrington, John J.
2007-01-01
The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systems are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle.
Dynamical systems techniques for enhancing microfluidic mixing
Balasuriya, Sanjeeva
Dynamical systems techniques for enhancing microfluidic mixing Sanjeeva Balasuriya School@yahoo.com 17 March 2015 Abstract. Achieving rapid mixing is often desirable in microfluidic devices microfluidic situations (e.g., best cross-flow positioning in cross- channel micromixers, usage of channel
Dynamical real numbers and living systems
Dhurjati Prasad Datta
2010-01-11
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.
On sequential dynamical systems and simulation
Barrett, C.L.; Mortveit, H.S.; Reidys, C.M.
1999-06-01
The generic structure of computer simulations motivates a new class of discrete dynamical systems that captures this structure in a mathematically precise way. This class of systems consists of (1) a loopfree graph {Upsilon} with vertex set {l_brace}1,2,{hor_ellipsis},n{r_brace} where each vertex has a binary state, (2) a vertex labeled set of functions (F{sub i,{Upsilon}}:F{sub 2}{sup n} {r_arrow} F{sub 2}{sup n}){sub i} and (3) a permutation {pi} {element_of} S{sub n}. The function F{sub i,{Upsilon}} updates the state of vertex i as a function of the states of vertex i and its {Upsilon}-neighbors and leaves the states of all other vertices fixed. The permutation {pi} represents the update ordering, i.e., the order in which the functions F{sub i,{Upsilon}} are applied. By composing the functions F{sub i,{Upsilon}} in the order given by {pi} one obtains the dynamical system (equation given in paper) which the authors refer to as a sequential dynamical system, or SDS for short. The authors will present bounds for the number of functionally different systems and for the number of nonisomorphic digraphs {Gamma}[F{sub {Upsilon}},{pi}] that can be obtained by varying the update order and applications of these to specific graphs and graph classes. This will be done using both combinatorial/algebraic techniques and probabilistic techniques. Finally the authors give results on dynamical system properties for some special systems.
Hofer, T.S.; Randolf, B.R.; Shah, S.Adnan Ali; Rode, B.M.; Persson, I.
2009-06-01
The pharmacologically and industrially important palladium(II) ion is usually characterised as square-planar structure in aqueous solution, similar to the platinum(II) ion. Our investigations by means of the most modern experimental and theoretical methods give clear indications, however, that the hydrated palladium(II) ion is hexa-coordinated, with four ligands arranged in a plane at 2.0 {angstrom} plus two additional ligands in axial positions showing an elongated bond distance of 2.7-2.8 A. The second shell consists in average of 8.0 ligands at a mean distance of 4.4 {angstrom}. This structure provides a new basis for the interpretation of the kinetic properties of palladium(II) complexes.
Nonlinear dynamical system approaches towards neural prosthesis
Torikai, Hiroyuki; Hashimoto, Sho [Graduate School of Engineering Science, Osaka University (Japan)
2011-04-19
An asynchronous discrete-state spiking neurons is a wired system of shift registers that can mimic nonlinear dynamics of an ODE-based neuron model. The control parameter of the neuron is the wiring pattern among the registers and thus they are suitable for on-chip learning. In this paper an asynchronous discrete-state spiking neuron is introduced and its typical nonlinear phenomena are demonstrated. Also, a learning algorithm for a set of neurons is presented and it is demonstrated that the algorithm enables the set of neurons to reconstruct nonlinear dynamics of another set of neurons with unknown parameter values. The learning function is validated by FPGA experiments.
Rapid gas hydrate formation process
Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.
2013-01-15
The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.
Dynamics of heat transfer between nano systems
Svend-Age Biehs; Girish S. Agarwal
2012-10-18
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.
Delone dynamical systems and associated random operators
Daniel Lenz; Peter Stollmann
2002-05-13
We carry out a careful study of basic topological and ergodic features of Delone dynamical systems. We then investigate the associated topological groupoids and in particular their representations on certain direct integrals with non constant fibres. Via non-commutative-integration theory these representations give rise to von Neumann algebras of random operators. Features of these algebras and operators are discussed. Restricting our attention to a certain subalgebra of tight binding operators, we then discuss a Shubin trace formula.
System Dynamics and Vibration Lab Dept. of Mechanical Engineering
Shaw, Steven W.
System Dynamics and Vibration Lab Dept. of Mechanical Engineering Finite-Element-Based Modal Response --Recent Results · Conclusions #12;System Dynamics and Vibration Lab Dept. of Mechanical and Vibration Lab Dept. of Mechanical Engineering Motivation · Motivation --Flexible Structure, Complex Geometry
A Chaotic Dynamical System that Paints
Tuhin Sahai; George Mathew; Amit Surana
2015-04-08
Can a dynamical system paint masterpieces such as Da Vinci's Mona Lisa or Monet's Water Lilies? Moreover, can this dynamical system be chaotic in the sense that although the trajectories are sensitive to initial conditions, the same painting is created every time? Setting aside the creative aspect of painting a picture, in this work, we develop a novel algorithm to reproduce paintings and photographs. Combining ideas from ergodic theory and control theory, we construct a chaotic dynamical system with predetermined statistical properties. If one makes the spatial distribution of colors in the picture the target distribution, akin to a human, the algorithm first captures large scale features and then goes on to refine small scale features. Beyond reproducing paintings, this approach is expected to have a wide variety of applications such as uncertainty quantification, sampling for efficient inference in scalable machine learning for big data, and developing effective strategies for search and rescue. In particular, our preliminary studies demonstrate that this algorithm provides significant acceleration and higher accuracy than competing methods for Markov Chain Monte Carlo (MCMC).
Microsoft Word - NETL-TRS-6-2015 Detection of Hydrates on Gas...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
hydrate nucleation elsewhere in the system. By accurately controlling the pressure, temperature, and aqueous-phase hydrocarbon concentration, the thermodynamic state of the...
Analysis of Power System Dynamics Subject to Stochastic Power Injections
DeVille, Lee
of the system dynamic states, e.g., synchronous machines angles and speeds, and algebraic states, e.g., bus
Reduction of dimension for nonlinear dynamical systems
Heather A. Harrington; Robert A. Van Gorder
2015-08-24
We consider reduction of dimension for nonlinear dynamical systems. We demonstrate that in some cases, one can reduce a nonlinear system of equations into a single equation for one of the state variables, and this can be useful for computing the solution when using a variety of analytical approaches. In the case where this reduction is possible, we employ differential elimination to obtain the reduced system. While analytical, the approach is algorithmic, and is implemented in symbolic software such as {\\sc MAPLE} or {\\sc SageMath}. In other cases, the reduction cannot be performed strictly in terms of differential operators, and one obtains integro-differential operators, which may still be useful. In either case, one can use the reduced equation to both approximate solutions for the state variables and perform chaos diagnostics more efficiently than could be done for the original higher-dimensional system, as well as to construct Lyapunov functions which help in the large-time study of the state variables. A number of chaotic and hyperchaotic dynamical systems are used as examples in order to motivate the approach.
Quantitative Adaptation Analytics for Assessing Dynamic Systems of Systems.
Gauthier, John H.; Miner, Nadine E.; Wilson, Michael L.; Le, Hai D.; Kao, Gio K; Melander, Darryl J.; Longsine, Dennis Earl; Vander Meer, Robert Charles,
2015-01-01
Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combining the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.
Modular Dynamical Semigroups for Quantum Dissipative Systems
David Taj; Hans Christian Öttinger
2015-03-10
We introduce a class of Markovian quantum master equations, able to describe the dissipative dynamics of a quantum system weakly coupled to one or several heat baths. The dissipative structure is driven by an entropic operator, the so called modular Hamiltonian, which makes it nonlinear. The generated Modular Dynamical Semigroup (MDS) is not, in general, a Quantum Dynamical Semigroup (QDS), whose dynamics is of the popular Lindblad type. The MDS has a robust thermodynamic structure, which guarantees for the positivity of the time evolved state, the correct steady state properties, the positivity of the entropy production, a positive Onsager matrix and Onsager symmetry relations (arising from Green-Kubo formulas). We show that the celebrated Davies generator, obtained through the Born and the secular approximations, generates a MDS. By unravelling the modular structure of the former, we provide a different and genuinely nonlinear MDS, not of QDS type, which is free from the severe spectral restrictions of the Davies generator, while still being supported by a weak coupling limit argument. With respect to the latter, the present work is a substantial extension of \\cite{Ottinger2011_GEO,Ottinger2010_TLS_DHO}
Obstacle penetrating dynamic radar imaging system
Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)
2006-12-12
An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.
Empirical Dynamical System Reduction I: Global Nonlinear Transformations
Miranda, Rick
Empirical Dynamical System Reduction I: Global Nonlinear Transformations Michael Kirby and Rick (CNLKL) for the data reduction and semianalytical remodeling of dynamical systems. The unconstrainedLo`eve (CNLKL) 12 5. Reduction and Semianalytic Remodeling of Dynamical Systems 17 6. Summary and Directions
Nonlinear Hybrid Dynamical Systems: Modeling, Optimal Control, and Applications
Stryk, Oskar von
Nonlinear Hybrid Dynamical Systems: Modeling, Optimal Control, and Applications Martin Buss1¨unchen, Germany Abstract. Nonlinear hybrid dynamical systems are the main focus of this paper. A modeling Introduction The recent interest in nonlinear hybrid dynamical systems has forced the merger of two very
Novel approximations for inference and learning in nonlinear dynamical systems
Heskes, Tom
Novel approximations for inference and learning in nonlinear dynamical systems Alexander Ypma #3 from marketing research. 1 Introduction Many real-world systems are nonlinear, dynamical and stochastic in nature. Inference and learning of nonlinear system models with hidden dynamics is a diÆcult task, which
2. Nonlinear Dynamical Systems 2014 January 17 February 12
Pulfrey, David L.
MATH 552 2. Nonlinear Dynamical Systems 2014 January 17 February 12 1. Existence, Uniqueness flows and flows are also called continuous-time dynamical systems, but often we will call them flows on Rn x g(x), also written xk+1 = g(xk), generates a discrete-time dynamical system consisting
Wadley, Haydn
to investigate the dynamic performance of truss panel systems. Two configurations were computer simulated to correlate experimental system failure limits under dynamic load. The computer code matched the experimental was the only trusted metric of dynamic performance of system. Computer codes were too inaccurate
Heat flux dynamics in dissipative cascaded systems
Salvatore Lorenzo; Alessandro Farace; Francesco Ciccarello; G. Massimo Palma; Vittorio Giovannetti
2015-03-24
We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of $S$ and show that the presence of correlations at the beginning can considerably affect the heat flux rate. We carry out our study in two paradigmatic cases -- a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes -- and compare the corresponding behaviours. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total heat flux.
Dynamically stable magnetic suspension/bearing system
Post, R.F.
1996-02-27
A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw`s Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements. 32 figs.
Dynamically stable magnetic suspension/bearing system
Post, Richard F. (Walnut Creek, CA)
1996-01-01
A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw's Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements.
Information flow within stochastic dynamical systems
X. San Liang
2007-10-05
Information flow or information transfer is an important concept in dynamical systems which has applications in a wide variety of scientific disciplines. In this study, we show that a rigorous formalism can be established in the context of a generic stochastic dynamical system. The resulting measure of of information transfer possesses a property of transfer asymmetry and, when the stochastic perturbation to the receiving component does not rely on the giving component, has a form same as that for the corresponding deterministic system. An application with a two-dimensional system is presented, and the resulting transfers are just as expected. A remarkable observation is that, for two highly correlated time series, there could be no information transfer from one certain series, say $x_2$, to the other ($x_1$). That is to say, the evolution of $x_1$ may have nothing to do with $x_2$, even though $x_1$ and $x_2$ are highly correlated. Information transfer analysis thus extends the traditional notion of correlation analysis by providing a quantitative measure of causality between time series.
Wax and hydrate control with electrical power
1997-08-01
Electrical heating of subsea flowlines is an effective way to prevent wax and hydrate information, especially for long transportation distances and in low-temperature deep water. Systems are available for use in conjunction with bundles, pipe-in-pipe, and wet-thermal-insulation systems. These systems provide environmentally friendly fluid-temperature control without chemicals or flaring for pipeline depressurizing. Enhanced production is achieved because no time is lost by unnecessary depressurizing, pigging, heating-medium circulation, or removal of hydrate and wax blockages. The seabed temperature at 100-m and greater water depths may range from 7 to {minus}1.5 C, causing a rapid cooling of the hot well streams being transported in subsea flowlines. Under these supercooling conditions, vulnerable crude oils and multiphase compositions will deposit wax and asphalts; also the gas/water phase may freeze solid with hydrate particles. The paper discusses thermal-insulated flowlines, heat-loss compensation with electrical power, electrical power consumption and operation, and subsea electrical-power distribution system.
Dynamic data filtering system and method
Bickford, Randall L; Palnitkar, Rahul M
2014-04-29
A computer-implemented dynamic data filtering system and method for selectively choosing operating data of a monitored asset that modifies or expands a learned scope of an empirical model of normal operation of the monitored asset while simultaneously rejecting operating data of the monitored asset that is indicative of excessive degradation or impending failure of the monitored asset, and utilizing the selectively chosen data for adaptively recalibrating the empirical model to more accurately monitor asset aging changes or operating condition changes of the monitored asset.
Dynamics of two-dimensional dipole systems
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)
2010-09-15
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.
Goldfinger, Chris
SUESS ET AL.: SEA FLOOR METHANE HYDRATES AT HYDRATE RIDGE, CASCADIA MARGIN 1 Sea Floor Methane are exposed at the sea floor. A methane-oxidizing bacterial consortium populates the exposures of hydrate; colonies of vent macro-fauna are abundant as well. Discharge of methane from destabilized hydrate
Response of oceanic hydrate-bearing sediments to thermalstresses
Moridis, G.J.; Kowalsky, M.B.
2006-05-01
In this study, we evaluate the response of oceanicsubsurface systems to thermal stresses caused by the flow of warm fluidsthrough noninsulated well systems crossing hydrate-bearing sediments.Heat transport from warm fluids, originating from deeper reservoirs underproduction, into the geologic media can cause dissociation of the gashydrates. The objective of this study is to determine whether gasevolution from hydrate dissociation can lead to excessive pressurebuildup, and possibly to fracturing of hydrate-bearing formations andtheir confining layers, with potentially adverse consequences on thestability of the suboceanic subsurface. This study also aims to determinewhether the loss of the hydrate--known to have a strong cementing effecton the porous media--in the vicinity of the well, coupled with thesignificant pressure increases, can undermine the structural stability ofthe well assembly.Scoping 1D simulations indicated that the formationintrinsic permeability, the pore compressibility, the temperature of theproduced fluids andthe initial hydrate saturation are the most importantfactors affecting the system response, while the thermal conductivity andporosity (above a certain level) appear to have a secondary effect.Large-scale simulations of realistic systems were also conducted,involving complex well designs and multilayered geologic media withnonuniform distribution of properties and initial hydrate saturationsthat are typical of those expected in natural oceanic systems. Theresults of the 2D study indicate that although the dissociation radiusremains rather limited even after long-term production, low intrinsicpermeability and/or high hydrate saturation can lead to the evolution ofhigh pressures that can threaten the formation and its boundaries withfracturing. Although lower maximum pressures are observed in the absenceof bottom confining layers and in deeper (and thus warmer and morepressurized) systems, the reduction is limited. Wellbore designs withgravel packs that allow gas venting and pressure relief result insubstantially lower pressures.
Evaluation of the thermodynamic properties of hydrated metal oxide nanoparticles by INS techniques
Spencer, Elinor; Ross, Dr. Nancy; Parker, Stewart F.; Kolesnikov, Alexander I
2013-01-01
In this contribution we will present a detailed methodology for the elucidation of the following aspects of the thermodynamic properties of hydrated metal oxide nanoparticles from high-resolution, low-temperature inelastic neutron scattering (INS) data: (i) the isochoric heat capacity and entropy of the hydration layers both chemi- and physisorbed to the particle surface; (ii) the magnetic contribution to the heat capacity of the nanoparticles. This will include the calculation of the vibrational density of states (VDOS) from the raw INS spectra, and the subsequent extraction of the thermodynamic data from the VDOS. This technique will be described in terms of a worked example namely, cobalt oxide (Co3O4 and CoO). To complement this evaluation of the physical properties of metal oxide nanoparticle systems, we will emphasise the importance of high-resolution, high-energy INS for the determination of the structure and dynamics of the water species, namely molecular (H2O) and dissociated water (OH, hydroxyl), confined to the oxide surfaces. For this component of the chapter we will focus on INS investigations of hydrated isostructural rutile (a-TiO2) and cassiterite (SnO2) nanoparticles. We will complete this discussion of nanoparticle analysis by including an appraisal of the INS instrumentation employed in such studies with particular focus on TOSCA [ISIS, Rutherford Appleton Laboratory (RAL), U.K.] and the newly developed spectrometer SEQUOIA [SNS, Oak Ridge National Laboratory (ORNL), U.S.A].
Approximate Method To Determine The Worst Case Performance Of A Nonlinear Dynamical System
Tongue, Benson H.; Packard, Andrew
1998-01-01
Case Performance of a Nonlinear Dynamical System Benson H.Case Performance of a Nonlinear Dynamical System Benson H.
Impact of Hydrated Cement Paste Quality and Entrained Air-Void
Impact of Hydrated Cement Paste Quality and Entrained Air-Void System on the Durability of Concrete the characteristics of the entrained air-void system #12;Objectives · Review the current accepted relationship between is affected by the quality of the hydrated cement paste (HCP) and the presence of a properly entrained air
Quantum Dynamics of Nonlinear Cavity Systems
Paul D. Nation
2010-09-16
We investigate the quantum dynamics of three different configurations of nonlinear cavity systems. To begin, we carry out a quantum analysis of a dc superconducting quantum interference device (SQUID) mechanical displacement detector comprised of a SQUID with a mechanically compliant loop segment. The SQUID is approximated by a nonlinear current-dependent inductor, inducing a flux tunable nonlinear Duffing term in the cavity equation of motion. Expressions are derived for the detector signal and noise response where it is found that a soft-spring Duffing self-interaction enables a closer approach to the displacement detection standard quantum limit, as well as cooling closer to the ground state. Next, we make use of a superconducting transmission line formed from an array of dc-SQUIDs for investigating analogue Hawking radiation. Biasing the array with a space-time varying flux modifies the propagation velocity of the transmission line, leading to an effective metric with a horizon. This setup allows for quantum effects such as backreaction and analogue space-time fluctuations on the Hawking process. Finally, we look at a quantum parametric amplifier with dynamical pump mode, viewed as a zero-dimensional model of Hawking radiation from an evaporating black hole. The conditions are derived under which the spectrum of particles generated from vacuum fluctuations deviates from the thermal spectrum predicted for the conventional parametric amplifier. We find that significant deviation occurs once the pump mode (black hole) has released nearly half of its initial energy in the signal (Hawking radiation) and idler (in-falling particle) modes. As a model of black hole dynamics, this finding lends support to the view that late-time Hawking radiation contains information about the quantum state of the black hole and is entangled with the black hole's quantum gravitational degrees of freedom.
Non-Isothermal, Multi-phase, Multi-component Flows through Deformable Methane Hydrate Reservoirs
Gupta, Shubhangi; Wohlmuth, Barbara
2015-01-01
We present a hydro-geomechanical model for subsurface methane hydrate systems. Our model considers kinetic hydrate phase change and non-isothermal, multi-phase, multi-component flow in elastically deforming soils. The model accounts for the effects of hydrate phase change and pore pressure changes on the mechanical properties of the soil, and also for the effect of soil deformation on the fluid-solid interaction properties relevant to reaction and transport processes (e.g., permeability, capillary pressure, reaction surface area). We discuss a 'cause-effect' based decoupling strategy for the model and present our numerical discretization and solution scheme. We then identify the important model components and couplings which are most vital for a hydro-geomechanical hydrate simulator, namely, 1) dissociation kinetics, 2) hydrate phase change coupled with non-isothermal two phase two component flow, 3) two phase flow coupled with linear elasticity (poroelasticity coupling), and finally 4) hydrate phase change c...
Challenges, uncertainties and issues facing gas production from gas hydrate deposits
Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswell, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.
2010-11-01
The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas hydrate petroleum system, to discuss advances, requirement and suggested practices in gas hydrate (GH) prospecting and GH deposit characterization, and to review the associated technical, economic and environmental challenges and uncertainties, including: the accurate assessment of producible fractions of the GH resource, the development of methodologies for identifying suitable production targets, the sampling of hydrate-bearing sediments and sample analysis, the analysis and interpretation of geophysical surveys of GH reservoirs, well testing methods and interpretation of the results, geomechanical and reservoir/well stability concerns, well design, operation and installation, field operations and extending production beyond sand-dominated GH reservoirs, monitoring production and geomechanical stability, laboratory investigations, fundamental knowledge of hydrate behavior, the economics of commercial gas production from hydrates, and the associated environmental concerns.
Methods and systems for combustion dynamics reduction
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)
2009-08-25
Methods and systems for combustion dynamics reduction are provided. A combustion chamber may include a first premixer and a second premixer. Each premixer may include at least one fuel injector, at least one air inlet duct, and at least one vane pack for at least partially mixing the air from the air inlet duct or ducts and fuel from the fuel injector or injectors. Each vane pack may include a plurality of fuel orifices through which at least a portion of the fuel and at least a portion of the air may pass. The vane pack or packs of the first premixer may be positioned at a first axial position and the vane pack or packs of the second premixer may be positioned at a second axial position axially staggered with respect to the first axial position.
RAPID DYNAMICAL CHAOS IN AN EXOPLANETARY SYSTEM
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)
2012-08-10
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.
Stochastic Embedding of Dynamical Systems Jacky CRESSON and Sebastien DARSES
Stochastic Embedding of Dynamical Systems Jacky CRESSON and SÂ´ebastien DARSES Institut des Hautes;Stochastic embedding of dynamical systems Jacky CRESSON SÂ´ebastien DARSES UniversitÂ´e de Pau et des Pays de l for the stochastic embedding of ordinary differential equations. We apply this method to Lagrangian systems
Hybrid Dynamical Systems, or HDS: The Ultimate Switching Experience
Branicky, Michael S.
Hybrid Dynamical Systems, or HDS: The Ultimate Switching Experience Michael S. Branicky Laboratory concentrated on formalizing the notion of a hybrid system as switching among an indexed collection of dynamical give a quick overview of the area of hybrid systems. I also briefly review the formal definition
Distributed Control of Networked Dynamical Systems: Static Feedback,
Dimarogonas, Dimos
1 Distributed Control of Networked Dynamical Systems: Static Feedback, Integral Action--This paper analyzes distributed control protocols for first- and second-order networked dynamical systems. We systems. The PI controllers successfully attenuate constant disturbances in the network. We prove
Phase control of intermittency in dynamical systems Samuel Zambrano,1
Rey Juan Carlos, Universidad
Phase control of intermittency in dynamical systems Samuel Zambrano,1 Inés P. Mariño,1 Francesco has been proved in periodically driven chaotic systems is phase control of chaos 10 that the intermittency at an interior crisis in a dynamical system can be controlled by a phase control scheme. We give
Robustness of Supersensitivity to Small Signals in Nonlinear Dynamical Systems
Changsong Zhou; C. -H. Lai
2000-05-08
Nonlinear dynamical systems possessing an invariant subspace can display interesting dynamical behavior, such as on-off intermittency and bubbling. This letter shows that a class of such systems have amazing features of (1) supersensitivity to small input signals and (2) robustness of the supersensitivity in the presence of noise. These features make the systems very promising as small signal detectors.
Title of dissertation: NONLINEAR DYNAMICS IN BIOLOGICAL SYSTEMS
Anlage, Steven
ABSTRACT Title of dissertation: NONLINEAR DYNAMICS IN BIOLOGICAL SYSTEMS: ACTIN NETWORKS AND GENE in several cases. #12;NONLINEAR DYNAMICS IN BIOLOGICAL SYSTEMS: ACTIN NETWORKS AND GENE NETWORKS by Andrew Department of Physics Two problems in biological systems are studied: (i) experiments in microscale
Hydration of ions in two dimensional water
S. Dutta; Yongjin Lee; Y. S. Jho
2015-11-11
We present a 2D lattice model of water to study the effects of ion hydration on the properties of water. We map the water molecules as lattice particles consisting of a single Oxygen at the center of a site and two Hydrogen atoms on each side. The internal state of the system, such as the dipole moment at a site, is defined with respect to the location of the Hydrogen atoms at the site depending on their role in Hydrogen bonds (H-bonds) being a donor or an acceptor. We study the influence of the charge and the radius of the ion on the insertion energy and on the H-bonds in the first and second hydration layers around the ion and in the bulk. In particular we analyze how the competing interactions of the short-ranged H-bonds and the long-ranged electrostatics influence the hydration properties. The role of the ion both as a source of the electrostatic interactions as well as a defect is also discussed. Our model also shows the well known fact that the polarizability of the water molecules destroys the hydrogen bond network and increases the dipole moment of the molecules near the ion.
Hydration of ions in two dimensional water
Dutta, S; Jho, Y S
2015-01-01
We present a 2D lattice model of water to study the effects of ion hydration on the properties of water. We map the water molecules as lattice particles consisting of a single Oxygen at the center of a site and two Hydrogen atoms on each side. The internal state of the system, such as the dipole moment at a site, is defined with respect to the location of the Hydrogen atoms at the site depending on their role in Hydrogen bonds (H-bonds) being a donor or an acceptor. We study the influence of the charge and the radius of the ion on the insertion energy and on the H-bonds in the first and second hydration layers around the ion and in the bulk. In particular we analyze how the competing interactions of the short-ranged H-bonds and the long-ranged electrostatics influence the hydration properties. The role of the ion both as a source of the electrostatic interactions as well as a defect is also discussed. Our model also shows the well known fact that the polarizability of the water molecules destroys the hydrogen...
Thermodynamics of quantum systems under dynamical control
D. Gelbwaser-Klimovsky; Wolfgang Niedenzu; Gershon Kurizki
2015-03-04
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.
Chu, Xiang-Qiang [ORNL; Ehlers, Georg [ORNL; Mamontov, Eugene [ORNL; Podlesnyak, Andrey A [ORNL; Wang, Wei [ORNL; Wesolowski, David J [ORNL
2011-01-01
Quasielastic neutron scattering (QENS) was used to investigate the diffusion dynamics of hydration water on the surface of rutile (TiO{sub 2}) nanopowder. The dynamics measurements utilizing two inelastic instruments, a backscattering spectrometer and a disk chopper spectrometer, probed the fast, intermediate, and slow motions of the water molecules on the time scale of picoseconds to more than a nanosecond. We employed a model-independent analysis of the data collected at each value of the scattering momentum transfer to investigate the temperature dependence of several diffusion components. All of the probed components were present in the studied temperature range of 230-320 K, providing, at a first sight, no evidence of discontinuity in the hydration water dynamics. However, a qualitative change in the elastic scattering between 240 and 250 K suggested a surface freezing-melting transition, when the motions that were localized at lower temperatures became delocalized at higher temperatures. On the basis of our previous molecular dynamics simulations of this system, we argue that interpretation of QENS data from such a complex interfacial system requires at least qualitative input from simulations, particularly when comparing results from spectrometers with very different energy resolutions and dynamic ranges.
Dynamics and Coordinate Systems in Skilled Sensorimotor Elliot L. Saltzman .
Contents Dynamics and Coordinate Systems in Skilled Sensorimotor Activity Elliot L. Saltzman John Hogden, Philip Rubin, and Elliot Saltzman .. Prosodic Patterns in the Coordination of Vowel
Dynamics of micelle-nanoparticle systems undergoing shear: a...
Office of Scientific and Technical Information (OSTI)
results based on a coarse-grained molecular dynamics (CGMD) model of a solventpolymernanoparticle system. Our results demonstrate the importance of polymer concentration...
Movement Imitation with Nonlinear Dynamical Systems in Humanoid Robots
Baltes, Jacky
Movement Imitation with Nonlinear Dynamical Systems in Humanoid Robots Auke Jan Ijspeert & Jun movement plans based on a set of nonlinear differential equations with well-defined attrac- tor dynamics of an adjustable pattern generator built from simple nonlinear autonomous dynamical sys- tems. The desired
Dynamic Positioning System as Dynamic Energy Storage on Diesel-Electric Ships
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
Dynamic Object Oriented Requirements System (DOORS) System Test Plan
JOHNSON, A.L.
2000-04-01
The U. S. Department of Energy, Office of River Protection (ORP) will use the Dynamic Object Oriented Requirements System (DOORS) as a tool to assist in identifying, capturing, and maintaining the necessary and sufficient set of requirements for accomplishing the ORP mission. By managing requirements as one integrated set, the ORP will be able to carry out its mission more efficiently and effectively. DOORS is a Commercial-Off-The-Shelf (COTS) requirements management tool. The tool has not been customized for the use of the PIO, at this time.
Lyapunov Mode Dynamics in Hard-Disk Systems
D. J. Robinson; G. P. Morriss
2007-09-20
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.
Dunbar, John
2012-12-31
Electrical methods offer a geophysical approach for determining the sub-bottom distribution of hydrate in deep marine environments. Methane hydrate is essentially non-conductive. Hence, sediments containing hydrate are more resistive than sediments without hydrates. To date, the controlled source electromagnetic (CSEM) method has been used in marine hydrates studies. This project evaluated an alternative electrical method, direct current resistivity (DCR), for detecting marine hydrates. DCR involves the injection of direct current between two source electrodes and the simultaneous measurement of the electric potential (voltage) between multiple receiver electrodes. The DCR method provides subsurface information comparable to that produced by the CSEM method, but with less sophisticated instrumentation. Because the receivers are simple electrodes, large numbers can be deployed to achieve higher spatial resolution. In this project a prototype seafloor DCR system was developed and used to conduct a reconnaissance survey at a site of known hydrate occurrence in Mississippi Canyon Block 118. The resulting images of sub-bottom resistivities indicate that high-concentration hydrates at the site occur only in the upper 50 m, where deep-seated faults intersect the seafloor. Overall, there was evidence for much less hydrate at the site than previously thought based on available seismic and CSEM data alone.
Sources of biogenic methane to form marine gas hydrates: In situ production or upward migration?
Paull, C.K.; Ussler, W. III; Borowski, W.S.
1993-09-01
Potential sources of biogenic methane in the Carolina Continental Rise -- Blake Ridge sediments have been examined. Two models were used to estimate the potential for biogenic methane production: (1) construction of sedimentary organic carbon budgets, and (2) depth extrapolation of modern microbial production rates. While closed-system estimates predict some gas hydrate formation, it is unlikely that >3% of the sediment volume could be filled by hydrate from methane produced in situ. Formation of greater amounts requires migration of methane from the underlying continental rise sediment prism. Methane may be recycled from below the base of the gas hydrate stability zone by gas hydrate decomposition, upward migration of the methane gas, and recrystallization of gas hydrate within the overlying stability zone. Methane bubbles may also form in the sediment column below the depth of gas hydrate stability because the methane saturation concentration of the pore fluids decreases with increasing depth. Upward migration of methane bubbles from these deeper sediments can add methane to the hydrate stability zone. From these models it appears that recycling and upward migration of methane is essential in forming significant gas hydrate concentrations. In addition, the depth distribution profiles of methane hydrate will differ if the majority of the methane has migrated upward rather than having been produced in situ.
McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.
2007-09-01
Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate
Applications of axial and radial compressor dynamic system modeling
Spakovszky, Zoltán S. (Zoltán Sándor), 1972-
2001-01-01
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. ...
Model reduction for nonlinear dynamical systems with parametric uncertainties
Zhou, Yuxiang Beckett
2012-01-01
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 ...
15.872 System Dynamics II, Fall 2010
Sterman, John
15.872 is a continuation of 15.871 Introduction to System Dynamics. It emphasizes tools and methods needed to apply systems thinking and simulation modeling successfully in complex real-world settings. The course uses ...
Dynamics of a neural system with a multiscale architecture
Breakspear, Michael
Dynamics of a neural system with a multiscale architecture Michael Breakspear1,2,3,* and Cornelis J of Clinical Neurophysiology, VU University Medical Centre, Amsterdam, The Netherlands The architecture for neural systems in which the dynamics are nested within a multiscale architecture. In essence
Dynamical Systems Analysis of Various Dark Energy Models
Nandan Roy
2015-11-25
In this thesis, we used dynamical systems analysis to find the qualitative behaviour of some dark energy models. Specifically, dynamical systems analysis of quintessence scalar field models, chameleon scalar field models and holographic models of dark energy are discussed in this thesis.
Dynamic wind turbine models in power system simulation tool
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
Analysis of Dynamic Task Allocation in Multi-Robot Systems
Southern California, University of
Analysis of Dynamic Task Allocation in Multi-Robot Systems Kristina Lerman1 , Chris Jones2 , Aram of Southern California, Los Angeles, CA 90089-0781, USA {lerman|galstyan}@isi.edu, {cvjones|maja}@robotics.usc.edu Abstract Dynamic task allocation is an essential requirement for multi-robot systems operating in unknown
Analysis of Dynamic Task Allocation in Multi-Robot Systems
Galstyan, Aram
Analysis of Dynamic Task Allocation in Multi-Robot Systems Kristina Lerman1 , Chris Jones2 , Aram of Southern California, Los Angeles, CA 90089-0781, USA {lerman|galstyan}@isi.edu, {cvjones|maja}@robotics.usc.edu Abstract Dynamic task allocation is an essential requirement for multi-robot systems functioning in unknown
OBSERVING LYAPUNOV EXPONENTS OF INFINITE-DIMENSIONAL DYNAMICAL SYSTEMS
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
CULTURE, ECONOMIC STRUCTURE, AND THE DYNAMICS OF ECOLOGICAL ECONOMIC SYSTEMS
Fournier, John J.F.
CULTURE, ECONOMIC STRUCTURE, AND THE DYNAMICS OF ECOLOGICAL ECONOMIC SYSTEMS By John M. Anderies B are developed and analyzed in an attempt to better un- derstand the interaction of culture, economic structure, and the dynamics of human ecological economic systems. Speci cally, how does the ability of humans to change
Hybrid Renewable Energy Systems for a Dynamically Positioned Buoy
Wood, Stephen L.
i Hybrid Renewable Energy Systems for a Dynamically Positioned Buoy by Robert Sean Pagliari ________________________ #12; ii We the undersigned committee hereby approve the attached thesis Hybrid Renewable Energy, College of Engineering #12; iii Abstract Hybrid Renewable Energy Systems for a Dynamically Positioned
Dynamical Systems Analysis of Various Dark Energy Models
Roy, Nandan
2015-01-01
In this thesis, we used dynamical systems analysis to find the qualitative behaviour of some dark energy models. Specifically, dynamical systems analysis of quintessence scalar field models, chameleon scalar field models and holographic models of dark energy are discussed in this thesis.
Natural Gas Hydrates Update 1998-2000
Reports and Publications (EIA)
2001-01-01
Significant events have transpired on the natural gas hydrate research and development front since "Future Supply Potential of Natural Gas Hydrates" appeared in Natural Gas 1998 Issues and Trends and in the Potential Gas Committee's 1998 biennial report.
Marine Electromagnetic Methods for Gas Hydrate Characterization
Weitemeyer, Karen A
2008-01-01
data: an electromagnetic survey at Hydrate Ridge, Oregon made possible by funding from Exxon MobilExxon Mobil and from GERD, Japan to study gas hydrates. We only had 3 days of data
Marine electromagnetic methods for gas hydrate characterization
Weitemeyer, Karen Andrea
2008-01-01
data: an electromagnetic survey at Hydrate Ridge, Oregon made possible by funding from Exxon MobilExxon Mobil and from GERD, Japan to study gas hydrates. We only had 3 days of data
Natural Gas Hydrates Update 2000-2002
Reports and Publications (EIA)
2003-01-01
Natural gas hydrates research and development (R&D) activity expanded significantly during the 2000-2002.
Solubility of Hematite Revisited: Effects of Hydration
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
Multipole Electrostatics in Hydration Free Energy Calculations
Ponder, Jay
Multipole Electrostatics in Hydration Free Energy Calculations YUE SHI,1 CHUANJIE WU,2 JAY W: Hydration free energy (HFE) is generally used for evaluating molecular solubility, which is an important interactions. The effect of long-range correction to van der Waals interaction on the hydration free energies
Generic solar photovoltaic system dynamic simulation model specification.
Ellis, Abraham; Behnke, Michael Robert; Elliott, Ryan Thomas
2013-10-01
This document is intended to serve as a specification for generic solar photovoltaic (PV) system positive-sequence dynamic models to be implemented by software developers and approved by the WECC MVWG for use in bulk system dynamic simulations in accordance with NERC MOD standards. Two specific dynamic models are included in the scope of this document. The first, a Central Station PV System model, is intended to capture the most important dynamic characteristics of large scale (> 10 MW) PV systems with a central Point of Interconnection (POI) at the transmission level. The second, a Distributed PV System model, is intended to represent an aggregation of smaller, distribution-connected systems that comprise a portion of a composite load that might be modeled at a transmission load bus.
Non-Classical Computation: a Dynamical Systems Perspective
Stepney, Susan
Non-Classical Computation: a Dynamical Systems Perspective Susan Stepney Department of Computer. In a classical computational system, that rule is given explicitly by the computer program; in a physical system approach to computation allows us to take a unified view of computation in classical discrete systems
Dynamics of a Gear System with Faults in Meshing Stiffness
Grzegorz Litak; Michael I. Friswell
2004-05-23
Gear box dynamics is characterised by a periodically changing stiffness. In real gear systems, a backlash also exists that can lead to a loss in contact between the teeth. Due to this loss of contact the gear has piecewise linear stiffness characteristics, and the gears can vibrate regularly and chaotically. In this paper we examine the effect of tooth shape imperfections and defects. Using standard methods for nonlinear systems we examine the dynamics of gear systems with various faults in meshing stiffness.
Coherence resonance near blowout bifurcation in nonlinear dynamical systems
Bambi Hu; Changsong Zhou
2000-05-29
Previous studies have shown that noise can induce coherence resonance in some nonlinear dynamical systems close to a bifurcation of a periodic motion, such as in excitable systems. We demonstrate that coherence resonance can be observed in systems close to a {\\sl blowout bifurcation}. It is shown that for dynamical systems with an invariant subspace in which there is a phase-coherent chaotic attractor, the interplay among the oscillation of local transverse stability, noise and nonlinearity can lead to coherence resonance phenomenon. The mechanism of coherence resonance in this type of system is different from that in previously studied systems.
Protein structure and hydration probed by SANS and osmotic stress
Rau, Dr. Donald [National Institutes of Health
2008-01-01
Interactions governing protein folding, stability, recognition, and activity are mediated by hydration. Here, we use small-angle neutron scattering coupled with osmotic stress to investigate the hydration of two proteins, lysozyme and guanylate kinase (GK), in the presence of solutes. By taking advantage of the neutron contrast variation that occurs upon addition of these solutes, the number of protein-associated (solute-excluded) water molecules can be estimated from changes in both the zero-angle scattering intensity and the radius of gyration. Poly(ethylene glycol) exclusion varies with molecular weight. This sensitivity can be exploited to probe structural features such as the large internal GK cavity. For GK, small-angle neutron scattering is complemented by isothermal titration calorimetry with osmoticstress to also measure hydration changes accompanying ligand binding. These results provide a framework for studying other biomolecular systems and assemblies using neutron scattering together with osmotic stress.
Basin scale assessment of gas hydrate dissociation in response to climate change
Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M.; Cameron-Smith, P.
2011-07-01
Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenarios, has only recently been investigated. Field investigations have discovered substantial methane gas plumes exiting the seafloor along the Arctic Ocean margin, and the plumes appear at depths corresponding to the upper limit of a receding gas hydrate stability zone. It has been suggested that these plumes may be the first visible signs of the dissociation of shallow hydrate deposits due to ongoing climate change in the arctic. We simulate the release of methane from oceanic deposits, including the effects of fully-coupled heat transfer, fluid flow, hydrate dissociation, and other thermodynamic processes, for systems representative of segments of the Arctic Ocean margins. The modeling encompasses a range of shallow hydrate deposits from the landward limit of the hydrate stability zone down to water depths beyond the expected range of century-scale temperature changes. We impose temperature changes corresponding to predicted rates of climate change-related ocean warming and examine the possibility of hydrate dissociation and the release of methane. The assessment is performed at local-, regional-, and basin-scales. The simulation results are consistent with the hypothesis that dissociating shallow hydrates alone can result in significant methane fluxes at the seafloor. However, the methane release is likely to be confined to a narrow region of high dissociation susceptibility, defined by depth and temperature, and that any release will be continuous and controlled, rather than explosive. This modeling also establishes the first realistic bounds for methane release along the arctic continental shelf for potential hydrate dissociation scenarios, and ongoing work may help confirm whether climate change is already impacting the stability of the vast oceanic hydrate reservoir.
Al-Qahtani, Hussain M.
ME 413 Systems Dynamics & Control Chapter 6: Electrical Systems and Electromechanical Systems 1SystemsSystemsSystems andandandand Electromechanical SystemsElectromechanical SystemsElectromechanical SystemsElectromechanical and Electromechanical Systems 2/20 Current Source and Voltage Source A voltage source is a device that causes
Fluid transport properties by equilibrium molecular dynamics. II. Multicomponent systems
Dysthe, Dag Kristian
Fluid transport properties by equilibrium molecular dynamics. II. Multicomponent systems D. K than 25 years molecular dynamics has been used to study fluid transport properties. Such MD studies and multicenter molecular models.816 d The study of transport properties of certain fluids and classes of fluids
MATH3395: Dynamical Systems Dr A.M. Rucklidge
Rucklidge, Alastair
MATH3395: Dynamical Systems Dr A.M. Rucklidge 8.18g, Department of Applied Mathematics A.M.Rucklidge at leeds.ac.uk This course continues the study of nonlinear dynamics begun in MATH2390/2391, but for maps example) MATH2390/2391. Basic linear algebra is required, and there will be some use of the notion
Handbook of gas hydrate properties and occurrence
Kuustraa, V.A.; Hammershaimb, E.C.
1983-12-01
This handbook provides data on the resource potential of naturally occurring hydrates, the properties that are needed to evaluate their recovery, and their production potential. The first two chapters give data on the naturally occurring hydrate potential by reviewing published resource estimates and the known and inferred occurrences. The third and fourth chapters review the physical and thermodynamic properties of hydrates, respectively. The thermodynamic properties of hydrates that are discussed include dissociation energies and a simplified method to calculate them; phase diagrams for simple and multi-component gases; the thermal conductivity; and the kinetics of hydrate dissociation. The final chapter evaluates the net energy balance of recovering hydrates and shows that a substantial positive energy balance can theoretically be achieved. The Appendices of the Handbook summarize physical and thermodynamic properties of gases, liquids and solids that can be used in designing and evaluating recovery processes of hydrates. 158 references, 67 figures, 47 tables.
Allen, Matthew S.
Identifying parameters of nonlinear structural dynamic systems using linear time- periodic nonlinearity. 1. Introduction Most dynamical systems behave nonlinearly in the most general scenario. This can point bifurcation [1], in rotor dynamic systems with bearing contact nonlinearities [2], in biomechanics
Brain Prostheses as a Dynamic System (Immortalizing the Human Brain?)
Vadim Astakhov; Tamara Astakhova
2007-05-17
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.
Validated global multiobjective optimization of trajectories in nonlinear dynamical systems
Coffee, Thomas Merritt
2015-01-01
We introduce a new approach for global multiobjective optimization of trajectories in continuous nonlinear dynamical systems that can provide rigorous, arbitrarily tight bounds on the objective values and state paths ...
Simulation Algorithms in Vehicle System Dynamics MARTIN ARNOLD
be considered as integration platform for simulation in vehicle system dynamics. In the present report we report the analysis of distributed physical phenomena like the elastic deformation of car components
Approximate dynamic programming with applications in multi-agent systems
Valenti, Mario J. (Mario James), 1976-
2007-01-01
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 ...
Fast Concurrent Dynamic Linking for an Adaptive Operating System
Walpole, Jonathan
Fast Concurrent Dynamic Linking for an Adaptive Operating System Crispin Cowan, Tito Autrey operating system is one that can adapt to some particular circumstance to gain some functional or perfor due to the cost of inter-process protection barriers. Commercial operating systems that can e ciently
Computational Chemical Dynamics of Complex Systems University of Minnesota
Truhlar, Donald G
Computational Chemical Dynamics of Complex Systems University of Minnesota Accuracy of density functionals for Pd(PH3)2L complexes where L is ethene or a conjugated CnHn+2 system (n = 4, 6, 8, and 10) Pd large when the size of the conjugated system is increased. We carried out accurate benchmark
Parameterized Model Order Reduction of Nonlinear Dynamical Systems
Reif, Rafael
Parameterized Model Order Reduction of Nonlinear Dynamical Systems Brad Bond Research Laboratory reduction technique for non-linear systems. Our approach combines an existing non-parameterized trajectory piecewise linear method for non-linear systems, with an existing moment matching param- eterized technique
Dynamic Agents Command and Control System (DACCS)
Fitzgerald, John J
2007-01-01
the movement of MSA compliant mobile devices, such as cell phones, and dynamically display the device locations on maps in real time. It is intended for use in command and dispatch type applications such as controlling mobile resources in the deployment...
Distributed Termination Detection for Dynamic Systems
Dhamdhere, Dhananjay Madhav
systems, Termination detection. \\Lambda Address all correspondence to this author. 1 #12; Distributed
High-surface-area hydrated lime for SO2 control
Rostam-Abadi, M.; Moran, D.L. (Illinois State Geological Survey, Champaign, IL (United States). Minerals Engineering Section)
1993-03-01
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.
STRUCTURAL VALIDATION OF SYSTEM DYNAMICS AND AGENT-BASED SIMULATION MODELS
Tesfatsion, Leigh
, population dynamics, energy systems, and urban planning. The usefulness of these models is predicated including global warming, population dynamics, energy systems, and urban planning simply defy a face
Editorial Comment on the Special Issue of "Information in Dynamical Systems and Complex Systems"
Erik M. Bollt; Jie Sun
2015-05-16
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.
THE DYNAMICS OF THREE-PLANET SYSTEMS: AN APPROACH FROM A DYNAMICAL SYSTEM
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)
2010-04-01
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.
Dynamic Algorithm for Space Weather Forecasting System
Fischer, Luke D.
2011-08-08
.............................................................................................9 Task 1: Developing a database of solar weather data ...............................9 Task 2: Developing the ?dynamic analysis? process .............................. 10 Task 3: Developing a Java applet that presents real-time solar...-computing resources have been recently discovered. Software materials include the programming language ?Java?, the Graphical-User-Interface ?JCreator?, and Rapid Miner. We also make use of publicly available scientific databases that contain a vast plethora...
Partial dynamical symmetries in quantum systems
A. Leviatan
2011-12-22
We discuss the the notion of a partial dynamical symmetry (PDS), for which a prescribed symmetry is obeyed by only a subset of solvable eigenstates, while other eigenstates are strongly mixed. We present an explicit construction of Hamiltonians with this property, including higher-order terms, and portray their significance for spectroscopy and shape-phase transitions in nuclei. The occurrence of both a single PDS, relevant to stable structures, and of several PDSs, relevant to coexistence phenomena, are considered.
Dynamic thermal management in chip multiprocessor systems
Liu, Chih-Chun
2009-05-15
Application test scenarios : : : : : : : : : : : : : : : : : : : : : : : : 45 VIII Experimental results compared to Linux Standard Scheduler in System I (4-core system): (R.P.T. : Reduced Peak Temperature; P.O. : Performance Overhead...) : : : : : : : : : : : : : : : : : : : : : : 51 IX Experimental results compared to Linux Standard Scheduler in System II (8-core system): (R.P.T. : Reduced Peak Temperature; P.O. : Performance Overhead) : : : : : : : : : : : : : : : : : : : : : : 54 viii LIST OF FIGURES FIGURE Page 1 Real...
Non-Markovian dynamics in open quantum systems
Heinz-Peter Breuer; Elsi-Mari Laine; Jyrki Piilo; Bassano Vacchini
2015-05-06
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.
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
2011-01-01
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).
Upayan Baul; Satyavani Vemparala
2014-12-18
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.
Gas hydrates: Technology status report
Not Available
1987-01-01
In 1983, the US Department of Energy (DOE) assumed the responsibility for expanding the knowledge base and for developing methods to recover gas from hydrates. These are ice-like mixtures of gas and water where gas molecules are trapped within a framework of water molecules. This research is part of the Unconventional Gas Recovery (UGR) program, a multidisciplinary effort that focuses on developing the technology to produce natural gas from resources that have been classified as unconventional because of their unique geologies and production mechanisms. Current work on gas hydrates emphasizes geological studies; characterization of the resource; and generic research, including modeling of reservoir conditions, production concepts, and predictive strategies for stimulated wells. Complementing this work is research on in situ detection of hydrates and field tests to verify extraction methods. Thus, current research will provide a comprehensive technology base from which estimates of reserve potential can be made, and from which industry can develop recovery strategies. 7 refs., 3 figs., 6 tabs.
Hydrate-phobic surfaces: fundamental studies in clathrate hydrate adhesion reduction
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 ...
Development of Alaskan gas hydrate resources
Kamath, V.A.; Sharma, G.D.; Patil, S.L.
1991-06-01
The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.
Dynamics of quasi-stationary systems: Finance as an example
Rinn, Philip; Peinke, Joachim; Guhr, Thomas; Schäfer, Rudi
2015-01-01
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.
Dynamics of an Open System for Repeated Harmonic Perturbation
Hiroshi Tamura; Valentin A. Zagrebnov
2015-06-18
We use the Kossakowski-Lindblad-Davies formalism to consider an open system defined as the Markovian extension of one-mode quantum oscillator S, perturbed by a piecewise stationary harmonic interaction with a chain of oscillators C. The long-time asymptotic behaviour of various subsystems of S+C are obtained in the framework of the dual W-dynamical system approach.
Robust computations with dynamical systems Olivier Bournez1
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
Toward Standards for Dynamics in Electric Energy Systems
conducting research on challenges facing the electric power industry and educating the next generation in complex electric power systems; and to, eventually utilize these for proposing principles for standardsToward Standards for Dynamics in Electric Energy Systems Future Grid Initiative White Paper Power
Dynamic Optimization for Optimal Control of Water Distribution Systems
Ertin, Emre
Dynamic Optimization for Optimal Control of Water Distribution Systems Emre Ertin, Anthony N. Dean Columbus OH 43201 ABSTRACT In this paper we consider the design of intelligent control policies for water as a controller for a water distribution system. In the example presented we obtain a 12.5 percent reduction
Modeling Combined Time-and Event-Driven Dynamic Systems
Baclawski, Kenneth B.
such as logistical systems, distributed sensor sys- tems and intelligent highway vehicle systems, are complex dynamic. In this approach, future behaviors are generated through quantitative simulation which "executes" a simulation model, typically at fixed time steps, to obtain quantitative values of state and/or output variables. 1
Energy-Efficient Adaptive MIMO Systems Leveraging Dynamic Spare Capacity
de Veciana, Gustavo
Energy-Efficient Adaptive MIMO Systems Leveraging Dynamic Spare Capacity Hongseok Kim, Chan, energy conservation, spare capacity I. INTRODUCTION Wireless cellular systems such as WiMAX are evolving capacity, it is achieved in most cases at the expense of much higher energy consumption resulting
Quantifying the Objective Cost of Uncertainty in Complex Dynamical Systems
Yoon, Byung-Jun
in translational genomics. Index Terms Mean objective cost of uncertainty (MOCU), objective-based uncertaintyQuantifying the Objective Cost of Uncertainty in Complex Dynamical Systems Byung-Jun Yoon, Senior quantifies the uncertainty in a given system based on the expected increase of the operational cost
Lessons Learned from Quantitative Dynamical Modeling in Systems Biology
Timmer, Jens
Lessons Learned from Quantitative Dynamical Modeling in Systems Biology Andreas Raue1,2 *. , Marcel of Physics, University of Freiburg, Freiburg, Germany, 2 Institute of Computational Biology, Helmholtz Center, Munich, Germany, 3 Systems Biology of Signal Transduction, German Cancer Research Center
Optimal PMU Placement Evaluation for Power System Dynamic State Estimation
Pollefeys, Marc
Optimal PMU Placement Evaluation for Power System Dynamic State Estimation Jinghe Zhang, Student--The synchronized phasor measurement unit (PMU), developed in the 1980s, is considered to be one of the most important devices in the future of power systems. The recent development of PMU technology provides high
Seol, Yongkoo Choi, Jeong-Hoon; Dai, Sheng
2014-08-01
With the increase in the interest of producing natural gas from methane hydrates as well as potential risks of massive hydrate dissociation in the context of global warming, studies have recently shifted from pure hydrate crystals to hydrates in sediments. Such a research focus shift requires a series of innovative laboratory devices that are capable of investigating various properties of hydrate-bearing sediments (HBS). This study introduces a newly developed high pressure testing chamber, i.e., multi-property characterization chamber (MPCC), that allows simultaneous investigation of a series of fundamental properties of HBS, including small-strain stiffness (i.e., P- and S-waves), shear strength, large-strain deformation, stress-volume responses, and permeability. The peripheral coolant circulation system of the MPCC permits stable and accurate temperature control, while the core holder body, made of aluminum, enables X-ray computer tomography scanning to be easily employed for structural and morphological characterization of specimens. Samples of hydrate-bearing sediments are held within a rubber sleeve inside the chamber. The thick sleeve is more durable and versatile than thin membranes while also being much softer than oedometer-type chambers that are incapable of enabling flow tests. Bias introduced by the rubber sleeve during large deformation tests are also calibrated both theoretically and experimentally. This system provides insight into full characterization of hydrate-bearing sediments in the laboratory, as well as pressure core technology in the field.
Dynamic Positioning Systems Usability and Interaction Styles
Dunlop, Mark D.
manually by manipulating the propulsion system, which included different types of thrusters and propellers position, a system was developed which automatically compensated to natural forces such as waves, wind, position reference sensors, gyro compasses (detects true north by using an electrically powered fast
Fusion dynamics of symmetric systems near barrier energies
Zhao-Qing Feng; Gen-Ming Jin
2009-09-06
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.
Computational dynamics of acoustically-driven microsphere systems
Glosser, Connor A; Dault, Daniel L; Piermarocchi, Carlo; Shanker, Balasubramaniam
2015-01-01
We propose a computational framework for the self-consistent dynamics of a microsphere system driven by a pulsed acoustic field in an ideal fluid. Our framework combines a molecular dynamics integrator describing the dynamics of the microsphere system with a time-dependent integral equation solver for the acoustic field that makes use of fields represented as surface expansions in spherical harmonic basis functions. The presented approach allows us to describe the inter-particle interaction induced by the field as well as the dynamics of trapping in counter-propagating acoustic pulses. The integral equation formulation leads to equations of motion for the microspheres describing the effect of non-dissipative drag forces. We show (1) that the field-induced interactions between the microspheres give rise to effective dipolar interactions, with effective dipoles defined by their velocities, and (2) that the dominant effect of an ultrasound pulse through a cloud of microspheres gives rise mainly to a translation ...
The Structure and Transport of Water and Hydrated Ions Within Hydrophobic, Nanoscale Channels
Holt, J K; Herberg, J L; Wu, Y; Schwegler, E; Mehta, A
2009-06-15
The purpose of this project includes an experimental and modeling investigation into water and hydrated ion structure and transport at nanomaterials interfaces. This is a topic relevant to understanding the function of many biological systems such as aquaporins that efficiently shuttle water and ion channels that permit selective transport of specific ions across cell membranes. Carbon nanotubes (CNT) are model nanoscale, hydrophobic channels that can be functionalized, making them artificial analogs for these biological channels. This project investigates the microscopic properties of water such as water density distributions and dynamics within CNTs using Nuclear Magnetic Resonance (NMR) and the structure of hydrated ions at CNT interfaces via X-ray Absorption Spectroscopy (XAS). Another component of this work is molecular simulation, which can predict experimental measurables such as the proton relaxation times, chemical shifts, and can compute the electronic structure of CNTs. Some of the fundamental questions this work is addressing are: (1) what is the length scale below which nanoscale effects such as molecular ordering become important, (2) is there a relationship between molecular ordering and transport?, and (3) how do ions interact with CNT interfaces? These are questions of interest to the scientific community, but they also impact the future generation of sensors, filters, and other devices that operate on the nanometer length scale. To enable some of the proposed applications of CNTs as ion filtration media and electrolytic supercapacitors, a detailed knowledge of water and ion structure at CNT interfaces is critical.
Physical Properties of Gas Hydrates: A Review
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gabitto, Jorge F.; Tsouris, Costas
2010-01-01
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 10 16 ? m 3 of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detectedmore »by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed. « less
Robust control of redundantly actuated dynamical systems
Majji, Manoranjan
2006-08-16
mechanical systems. A methodology for coordinated actuation of redundant actuator sets by a trained weighted minimum norm solution is presented. To apply the methodology to hyper-redundant actuator arrays, for application to smart actuator arrays, a novel...
Dynamically reconfigurable systems offer the potential for realising efficient systems as well as
Havinga, Paul J.M.
mobile multimedia systems that have limited battery resources, must handle diverse data types, and must operate in dynamic application and communication environments. We propose an approach in which reconfiguration is applied dynamically at various levels of a mobile system, whereas traditionally, reconfigurable
Verification of Relational Data-Centric Dynamic Systems with External Services
Calvanese, Diego
Verification of Relational Data-Centric Dynamic Systems with External Services Babak Bagheri Hariri@cs.ucsd.edu ABSTRACT Data-centric dynamic systems are systems where both the process controlling the dynamics relational data-centric dynamic systems, where data are main- tained in a relational database
Selection of hydrate suppression methods for gas streams
Behrens, S.D.; Covington, K.K.; Collie, J.T. III
1999-07-01
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.
Dynamics of non-Markovian open quantum systems
Inés de Vega; Daniel Alonso
2015-11-22
Open quantum systems (OQS) cannot always be described with the Markov approximation, which requires a large separation of system and environment time scales. Here, we give an overview of some of the most important techniques available to tackle the dynamics of an OQS beyond the Markov approximation. Some of these techniques, such as master equations, Heisenberg equations and stochastic methods, are based on solving the reduced OQS dynamics, while others, such as path integral Monte Carlo or chain mapping approaches, are based on solving the dynamics of the full system. We emphasize the physical interpretation and derivation of the various approaches, explore how they are connected and examine how different methods may be suitable for solving different problems.
Notes 14. Dynamic response of continuum systems
San Andres, Luis
2008-01-01
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...(x,t) ? x L Fig. Schematic view of elastic bar undergoing axial motions From elementary strength of materials consider a) Cross-sections A remain plane and perpendicular to the main axis (x) of the bar. b) Material is linearly elastic c) Material...
Paris-Sud XI, Université de
)-liquid ( wL )-gas (G)-phase equilibria of selected ternary {water + salt + gas} and quaternary {water + salt1 + salt2 + gas} systems (salt = NaCl, KCl, CaCl2; gas = CH4, CO2) comprising a gas clathrate hydrate phase.g. pipeline blockages by hydrates in drilling applications or gas pipelines) [6]. Species being capable
Dynamical system theory of periodically collapsing bubbles
Yukalov, V I; Sornette, D
2015-01-01
We propose a reduced form set of two coupled continuous time equations linking the price of a representative asset and the price of a bond, the later quantifying the cost of borrowing. The feedbacks between asset prices and bonds are mediated by the dependence of their "fundamental values" on past asset prices and bond themselves. The obtained nonlinear self-referencing price dynamics can induce, in a completely objective deterministic way, the appearance of periodically exploding bubbles ending in crashes. Technically, the periodically explosive bubbles arise due to the proximity of two types of bifurcations as a function of the two key control parameters $b$ and $g$, which represent, respectively, the sensitivity of the fundamental asset price on past asset and bond prices and of the fundamental bond price on past asset prices. One is a Hopf bifurcation, when a stable focus transforms into an unstable focus and a limit cycle appears. The other is a rather unusual bifurcation, when a stable node and a saddle...
Global Energy Management System Implementation: General Dynamics...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Erie I Furnace 19 BBtu, 20,000 GJ 175,000 1.0M Heat Treat Furnace Holcroft 1 BurnersRecoup 14 BBtu, 15,000 GJ 132,000 276,000 Boiler Systems Installed new 500 HP...
Dynamic Simulation of Nuclear Hydrogen Production Systems
in a hydrogen plant. The resulting system is tightly interconnected and operates at very high temperature connecting a nuclear reactor and a hydrogen production plant. This heat transfer loop uses helium as the heat scenarios. The first contribution of this thesis is a novel equation-based model for the heat transfer loop
Model Based Safety Assessment Dynamic System
Grigoras, .Romulus
Assessment Techniques ·Failure mode and effect analysis (FMEA) Model: from a local failure to its system chain .... 2 Functional FMEA template FT unannunciated loss of wheel braking #12;Drawbacks of the Classical Safety Assessment Techniques · Fault Tree, FMEA Give failure propagation paths without referring
Low Power Dynamic Scheduling for Computing Systems
Neely, Michael J
2011-01-01
This paper considers energy-aware control for a computing system with two states: "active" and "idle." In the active state, the controller chooses to perform a single task using one of multiple task processing modes. The controller then saves energy by choosing an amount of time for the system to be idle. These decisions affect processing time, energy expenditure, and an abstract attribute vector that can be used to model other criteria of interest (such as processing quality or distortion). The goal is to optimize time average system performance. Applications of this model include a smart phone that makes energy-efficient computation and transmission decisions, a computer that processes tasks subject to rate, quality, and power constraints, and a smart grid energy manager that allocates resources in reaction to a time varying energy price. The solution methodology of this paper uses the theory of optimization for renewal systems developed in our previous work. This paper is written in tutorial form and devel...
Strategies for gas production from oceanic Class 3 hydrate accumulations
Moridis, George J.; Reagan, Matthew T.
2007-01-01
during production from the Class 3 oceanic hydrate depositProduction From Oceanic Class 3 Hydrate Accumulations GeorgeAccumulations Houston, Texas, Class 3 May 2007. presented,
Modeling mesoscopic phenomena in extended dynamical systems
Bishop, A.; Lomdahl, P.; Jensen, N.G.; Cai, D.S. [Los Alamos National Lab., NM (United States); Mertenz, F. [Bayreuth Univ. (Germany); Konno, Hidetoshi [Tsukuba Univ., Ibaraki (Japan); Salkola, M. [Stanford Univ., CA (United States)
1997-08-01
This is the final report of a three-year, Laboratory-Directed Research and Development project at the Los Alamos National Laboratory (LANL). We have obtained classes of nonlinear solutions on curved geometries that demonstrate a novel interplay between topology and geometric frustration relevant for nanoscale systems. We have analyzed the nature and stability of localized oscillatory nonlinear excitations (multi-phonon bound states) on discrete nonlinear chains, including demonstrations of successful perturbation theories, existence of quasiperiodic excitations, response to external statistical time-dependent fields and point impurities, robustness in the presence of quantum fluctuations, and effects of boundary conditions. We have demonstrated multi-timescale effects for nonlinear Schroedinger descriptions and shown the success of memory function approaches for going beyond these approximations. In addition we have developed a generalized rate-equation framework that allows analysis of the important creation/annihilation processes in driven nonlinear, nonequilibiium systems.
Dynamical Modelling of Hot Stellar Systems
David Merritt
1995-10-30
Estimation of the distribution function f and potential Phi of hot stellar systems from kinematical data is discussed. When the functional forms of f and Phi are not specified a priori, accurate estimation of either function requires very high quality data: either accurate ``line profiles'' at radii extending well beyond an effective radius, or large samples of discrete radial velocities. Estimates of Phi(r) based on much smaller data sets can be very strongly influenced by assumptions, explicit or implicit, about the form of f. The importance of casting the estimation problem into a mathematically determined form is stressed. Some techniques for nonparametric estimation are presented, with some preliminary results of their application to real stellar systems.
Novel coupling scheme to control dynamics of coupled discrete systems
Snehal M. Shekatkar; G. Ambika
2015-08-08
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.
Particle Motion and Perturbed Dynamical System in Warped Product Spacetimes
Pinaki Bhattacharya; Sarbari Guha
2015-06-01
In this paper we have used the dynamical systems analysis to study the dynamics of a five-dimensional universe in the form of a warped product spacetime with a spacelike dynamic extra dimension. We have decomposed the geodesic equations to get the motion along the extra dimension and have studied the associated dynamical system when the cross-diagonal element of the Einstein tensor vanishes, and also when it is non-vanishing. In the first case, introducing the concept of an energy function along the phase path in terms of the extra-dimensional coordinate, we have examined how the energy function depends on the warp factor. The energy function has been used as a measure of the amount of perturbation caused by a brane displacement. Geometrically the effect of brane displacement is manifested in terms of a coordinate translation along the extra dimension, thereby producing a change in the geodesic motion along the extra dimension in the region close to the brane. Then we studied the geodesic motion under a conventional metric perturbation in the form of homothetic motion and conformal motion and examined the nature of critical points for a Mashhoon-Wesson-type metric. Finally we investigated the motion for null and timelike geodesics under the condition when the cross-diagonal element of the Einstein tensor is non-vanishing and examined the effects of perturbation on the critical points of the dynamical system.
Reaction dynamics and photochemistry of divalent systems
Davis, H.F.
1992-05-01
Results are presented of molecular beam studies of bimolecular and unimolecular reactions of Ba. Chapter 1 discusses the reaction Ba + NO{sub 2}. Formation of the dominant BaO({sup 1}{Sigma}) + NO products resulted primarily from decay of long-lived Ba{sup +}NO{sub 2}{sup {minus}} collision complexes. Secondary mechanisms led to formation of forward scattered, internally excited BaO, and BaNO + O. D{sub o}(Ba-NO) = 65{plus_minus}20 kcal/mol. Reactions of ground state and electronically excited Ba with water and alcohols are examined in Chapter 2. Reaction of Ba({sup 1}S) + H{sup 2}O led to BaO + H{sub 2}, whereas excited state Ba({sup 1}D) + H{sub 2}O reacted to form BaOH + H. Collisions between Ba and CH{sub 3}OH led to BaOCH{sub 3} + H. Radical channels involve H-atom migration and are promoted by excitation of the incident Ba atom. In Chapter 3, reactions of Ba({sup 1}S) with ClO{sub 2}2 and O{sub 3} are discussed. Again, direct and complex mechanisms were observed. Formation of BaCl + O{sub 2} from decomposition of Ba{sup +}ClO{sub 2}{sup {minus}} accounted for 10% of total reaction crass section. Although Ba + O{sub 3} {yields} BaO + 0{sub 2} occurs primarily by direct reaction mechanisms, the secondary channel Ba + 0{sub 3} {yields} BaO{sub 2} + 0 involved decay of long lived Ba{sup +}O{sub 3}{sup {minus}} intermediates. D{sub o}(Ba{minus}O{sub 2}) = 120 {plus_minus}20 kcal/mol. Photodissociation dynamics of NO{sub 3} is explored in chapter 4. Visible excitation leads to formation of NO + 0{sub 2} and NO{sub 2} + O. Wavelength dependence of branching ratios is investigated. D{sub o}(O-NO{sub 2}) = 48.55 kcal/mole ;and calculate {Delta}H{sub f}(NO{sub 3}) = 17.75 kcal/mole (298K). Chapter 5 discusses the photodissociation of OClO in a molecular beam. Although ClO({sup 2}II) + O({sup 3}P) is dominant, Cl({sup 2}P) + O{sub 2} also forms, with a max yield of 3.9{plus_minus}0.8% near 404nm.
Dynamic Boosting Systems | Open Energy Information
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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EA Jump to:of the National ClimateDongyingOpenDukeLLCBoosting Systems
METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST
Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis
2005-02-01
Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the revolutionary and new Arctic Drilling Platform in search of gas hydrate and free gas accumulations at depths of approximately 1200 to 2500 ft MD. A secondary objective was the gas-charged sands of the uppermost Campanian interval at approximately 3000 ft. Summary results of geophysical analysis of the well are presented in this report.
Deshmukh, Venkatesh
Dynamical Systems Venkatesh Deshmukh Center for Nonlinear Dynamics and Control Department of Mechanical dynamic system models to be constructed from available data. The parameters to be estimated are assumed in the dynamic system models are assumed to have a known form, and the models are assumed to be parameter affine
Stability of an Euler-Bernoulli beam with a nonlinear dynamic feedback system
Arnold, Anton
Stability of an Euler-Bernoulli beam with a nonlinear dynamic feedback system M. Mileti´ca , D. St to a nonlinear dynamic feedback system. This setup comprises nonlinear dynamic boundary controllers satisfying with the interaction of the Euler-Bernoulli beam (1.1) - (1.3) with a dynamic nonlinear feedback system. In particular
Dynamics in hybrid complex systems of switches and oscillators
Dane Taylor; Elana J. Fertig; Juan G. Restrepo
2013-08-09
While considerable progress has been made in the analysis of large systems containing a single type of coupled dynamical component (e.g., coupled oscillators or coupled switches), systems containing diverse components (e.g., both oscillators and switches) have received much less attention. We analyze large, hybrid systems of interconnected Kuramoto oscillators and Hopfield switches with positive feedback. In this system, oscillator synchronization promotes switches to turn on. In turn, when switches turn on they enhance the synchrony of the oscillators to which they are coupled. Depending on the choice of parameters, we find theoretically coexisting stable solutions with either (i) incoherent oscillators and all switches permanently off, (ii) synchronized oscillators and all switches permanently on, or (iii) synchronized oscillators and switches that periodically alternate between the on and off states. Numerical experiments confirm these predictions. We discuss how transitions between these steady state solutions can be onset deterministically through dynamic bifurcations or spontaneously due to finite-size fluctuations.
METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST
Thomas E. Williams; Keith Millheim; Bill Liddell
2005-03-01
Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in the project reports.
Overview on Hydrate Coring, Handling and Analysis
Jon Burger; Deepak Gupta; Patrick Jacobs; John Shillinglaw
2003-06-30
Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Worldwide, gas hydrate is estimated to hold about 1016 kg of organic carbon in the form of methane (Kvenvolden et al., 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In June 2002, Westport Technology Center was requested by the Department of Energy (DOE) to prepare a ''Best Practices Manual on Gas Hydrate Coring, Handling and Analysis'' under Award No. DE-FC26-02NT41327. The scope of the task was specifically targeted for coring sediments with hydrates in Alaska, the Gulf of Mexico (GOM) and from the present Ocean Drilling Program (ODP) drillship. The specific subjects under this scope were defined in 3 stages as follows: Stage 1: Collect information on coring sediments with hydrates, core handling, core preservation, sample transportation, analysis of the core, and long term preservation. Stage 2: Provide copies of the first draft to a list of experts and stakeholders designated by DOE. Stage 3: Produce a second draft of the manual with benefit of input from external review for delivery. The manual provides an overview of existing information available in the published literature and reports on coring, analysis, preservation and transport of gas hydrates for laboratory analysis as of June 2003. The manual was delivered as draft version 3 to the DOE Project Manager for distribution in July 2003. This Final Report is provided for records purposes.
System Dynamics and the Electric Power Industry Andrew Forda
Ford, Andrew
by John Wiley & Sons, Ltd. Syst. Dyn. Rev. 13, 5785, 1997 (No. of Figures: 9 No. of Tables: 4 No. of Refs historical developments that gave rise to a capital intensive, price regulated power sector in the United. System dynamics applications to electric power Table 1 lists 33 publications on the applications
Stability Monitoring of Rotorcraft Systems: A Dynamic Data-Driven
Ray, Asok
. For example, unstable vibratory oscillations in the rotor system may lead to component failures, while low-frequency instabilities due to the coupled pilot- vehicle dynamics may cause loss of control. There are numerous other cycling as an equilibrium point becomes unstable at large- torque flight conditions [1]. (2) Ground
Regulation and controlled synchronization for complex dynamical systems
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
MAT656 --Topics in Dynamical Systems: Introduction to Quantum Chaos
Sutherland, Scott
MAT656 -- Topics in Dynamical Systems: Introduction to Quantum Chaos Spring 2011 Shimon Brooks MWF mainly on simpler "toy models" of quantum chaos, that capture many of the ideas, without much conventions and notations! Â· Quantum Chaos: a Brief First Visit, by Stephan De Bi`evre. Good intro- ductory
Dynamic Interactions of PV units in Low Volatge Distribution Systems
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
EECS 598 Special Topic Power System Dynamics and Control
Cafarella, Michael J.
for enabling aggregate load to track fluctuations in renewable generation, and the use of model predictive-disruptive load control, model predictive control. Prerequisites: EECS 463 (or Permission of Instructor). CourseEECS 598 Special Topic Power System Dynamics and Control Wednesday and Friday, 10:30am-12:00pm Fall
MATH2390: Dynamical Systems Dr A.M. Rucklidge
Rucklidge, Alastair
MATH2390: Dynamical Systems Dr A.M. Rucklidge 8.18g, Department of Applied Mathematics A familiarity with ordinary dif- ferential equations, at the level of (for example) MATH1932, MATH1400 or MATH2450. MATH2360 or MATH2420 would be helpful but are not essential, as would some famil- iarity
Dynamics of Satellites in Binary Near-Earth Asteroid Systems: A Study Based on Radar Observations
Naidu, Shantanu
2015-01-01
Murray and S.F. Dermott. Solar System Dynamics. CambridgeMurray and S.F. Dermott. Solar System Dynamics. Cambridgea wide range of important solar system processes that shape
Dynamic Reconfiguration of Photovoltaic Energy Harvesting System in Hybrid Electric Vehicles
Pedram, Massoud
Dynamic Reconfiguration of Photovoltaic Energy Harvesting System in Hybrid Electric Vehicles Yanzhi, xuelin, pedram}@usc.edu, 2 {naehyuck}@elpl.snu.ac.kr ABSTRACT Photovoltaic (PV) energy harvesting system. Keywords Photovoltaic System, Hybrid Electric Vehicle, Photovoltaic Array Reconfiguration, Dynamic
Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities
Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina
2012-09-01
The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.
Determining the role of hydration forces in protein folding
Sorenson, J.M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry] [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Hura, G. [Univ. of California, Berkeley, CA (United States)] [Univ. of California, Berkeley, CA (United States); [Lawrence Berkeley National Lab., CA (United States). Life Sciences Div.; Soper, A.K. [Rutherford Appleton Lab., Didcot (United Kingdom). ISIS Facility] [Rutherford Appleton Lab., Didcot (United Kingdom). ISIS Facility; Pertsemlidis, A. [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Biochemistry] [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Biochemistry; Head-Gordon, T. [Lawrence Berkeley National Lab., CA (United States)] [Lawrence Berkeley National Lab., CA (United States)
1999-07-01
One of the primary issues in protein folding is determining what forces drive folding and eventually stabilize the native state. A delicate balance exists between electrostatic forces such as hydrogen bonding and salt bridges, and the hydrophobic effect, which are present for both intramolecular protein interactions and intermolecular contributions with the surrounding aqueous environment. This article describes a combined experimental, theoretical, and computational effort to show how the complexity of aqueous hydration can influence the structure, folding and aggregation, and stability of model protein systems. The unification of the theoretical and experimental work is the development or discovery of effective amino acid interactions that implicitly include the effects of aqueous solvent. The authors show that consideration of the full range of complexity of aqueous hydration forces such as many-body effects, long-ranged character of aqueous solvation, and the assumptions made about the degree of protein hydrophobicity can directly impact the observed structure, folding, and stability of model protein systems.
Forward and adjoint sensitivity computation of chaotic dynamical systems
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)
2013-02-15
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.
Methane Recovery from Hydrate-bearing Sediments
J. Carlos Santamarina; Costas Tsouris
2011-04-30
Gas hydrates are crystalline compounds made of gas and water molecules. Methane hydrates are found in marine sediments and permafrost regions; extensive amounts of methane are trapped in the form of hydrates. Methane hydrate can be an energy resource, contribute to global warming, or cause seafloor instability. This study placed emphasis on gas recovery from hydrate bearing sediments and related phenomena. The unique behavior of hydrate-bearing sediments required the development of special research tools, including new numerical algorithms (tube- and pore-network models) and experimental devices (high pressure chambers and micromodels). Therefore, the research methodology combined experimental studies, particle-scale numerical simulations, and macro-scale analyses of coupled processes. Research conducted as part of this project started with hydrate formation in sediment pores and extended to production methods and emergent phenomena. In particular, the scope of the work addressed: (1) hydrate formation and growth in pores, the assessment of formation rate, tensile/adhesive strength and their impact on sediment-scale properties, including volume change during hydrate formation and dissociation; (2) the effect of physical properties such as gas solubility, salinity, pore size, and mixed gas conditions on hydrate formation and dissociation, and it implications such as oscillatory transient hydrate formation, dissolution within the hydrate stability field, initial hydrate lens formation, and phase boundary changes in real field situations; (3) fluid conductivity in relation to pore size distribution and spatial correlation and the emergence of phenomena such as flow focusing; (4) mixed fluid flow, with special emphasis on differences between invading gas and nucleating gas, implications on relative gas conductivity for reservoir simulations, and gas recovery efficiency; (5) identification of advantages and limitations in different gas production strategies with emphasis; (6) detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2; (7) the relevance of fines in otherwise clean sand sediments on gas recovery and related phenomena such as fines migration and clogging, vuggy structure formation, and gas-driven fracture formation during gas production by depressurization.
The Quantum-Classical Transition in Nonlinear Dynamical Systems
Salman Habib; Kurt Jacobs; Hideo Mabuchi; Robert Ryne; Kosuke Shizume; Bala Sundaram
2000-10-26
Viewed as approximations to quantum mechanics, classical evolutions can violate the positive-semidefiniteness of the density matrix. The nature of this violation suggests a classification of dynamical systems based on classical-quantum correspondence; we show that this can be used to identify when environmental interaction (decoherence) will be unsuccessful in inducing the quantum-classical transition. In particular, the late-time Wigner function can become positive without any corresponding approach to classical dynamics. In the light of these results, we emphasize key issues relevant for experiments studying the quantum-classical transition.
Econophysical Dynamics of Market-Based Electric Power Distribution Systems
Nicolas Ho; David P. Chassin
2006-02-09
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.
An Optimization Framework for Dynamic Hybrid Energy Systems
Wenbo Du; Humberto E Garcia; Christiaan J.J. Paredis
2014-03-01
A computational framework for the efficient analysis and optimization of dynamic hybrid energy systems (HES) is developed. A microgrid system with multiple inputs and multiple outputs (MIMO) is modeled using the Modelica language in the Dymola environment. The optimization loop is implemented in MATLAB, with the FMI Toolbox serving as the interface between the computational platforms. Two characteristic optimization problems are selected to demonstrate the methodology and gain insight into the system performance. The first is an unconstrained optimization problem that optimizes the dynamic properties of the battery, reactor and generator to minimize variability in the HES. The second problem takes operating and capital costs into consideration by imposing linear and nonlinear constraints on the design variables. The preliminary optimization results obtained in this study provide an essential step towards the development of a comprehensive framework for designing HES.
Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems
Sherman, Max H.; Walker, Iain S.
2011-04-01
Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).
Power Systems Frequency Dynamic Monitoring System Design and Applications
Schrijver, Karel
Disturbance Recorder (FDR), Phasor Measurement Unit (PMU), Wide Area Measurement System, Under Frequency Load between FDR and commercial PMU (Phasor Measurement Unit) demonstrate the advantage of FNET. The web
Gas Hydrates Research Programs: An International Review
Jorge Gabitto; Maria Barrufet
2009-12-09
Gas hydrates sediments have the potential of providing a huge amount of natural gas for human use. Hydrate sediments have been found in many different regions where the required temperature and pressure conditions have been satisfied. Resource exploitation is related to the safe dissociation of the gas hydrate sediments. Basic depressurization techniques and thermal stimulation processes have been tried in pilot efforts to exploit the resource. There is a growing interest in gas hydrates all over the world due to the inevitable decline of oil and gas reserves. Many different countries are interested in this valuable resource. Unsurprisingly, developed countries with limited energy resources have taken the lead in worldwide gas hydrates research and exploration. The goal of this research project is to collect information in order to record and evaluate the relative strengths and goals of the different gas hydrates programs throughout the world. A thorough literature search about gas hydrates research activities has been conducted. The main participants in the research effort have been identified and summaries of their past and present activities reported. An evaluation section discussing present and future research activities has also been included.
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
Notes 02. Dynamic response of second order mechanical systems
San Andres, Luis
2008-01-01
: Handout 2a ? Luis San Andr?s (2008) 2-1 Handout #2a (pp. 1-39) Dynamic Response of Second Order Mechanical Systems with Viscous Dissipation forces 2 () 2 ext t dX dX MDKXF dt dt ++= Free Response to initial conditions and F (t) = 0..., Underdamped, Critically Damped and Overdamped Systems Free Response for system with Coulomb (Dry) friction Forced Response for Step Loading F (t) = F o MEEN 617 Notes: Handout 2a ? Luis San Andr?s (2008) 2-2 Second Order Mechanical...
Simulating the Dynamic Coupling of Market and Physical System Operations
Widergren, Steven E.; Roop, Joseph M.; Guttromson, Ross T.; Huang, Zhenyu
2004-06-01
Abstract-As energy trading products cover shorter time periods and demand response programs move toward real-time pricing, financial market-based activity impacts ever more directly the physical operation of the system. To begin to understand the complex interactions between the market-driven operation signals, the engineered controlled schemes, and the laws of physics, new system modeling and simulation techniques must be explored. This discussion describes requirements for new simulation tools to address such market transaction control interactions and an approach to capture the dynamic coupling between energy markets and the physical operation of the power system appropriate for dispatcher reaction time frames.
A molecular dynamics study of polymer/graphene interfacial systems
Rissanou, Anastassia N.; Harmandaris, Vagelis
2014-05-15
Graphene based polymer nanocomposites are hybrid materials with a very broad range of technological applications. In this work, we study three hybrid polymer/graphene interfacial systems (polystyrene/graphene, poly(methyl methacrylate)/graphene and polyethylene/graphene) through detailed atomistic molecular dynamics (MD) simulations. Density profiles, structural characteristics and mobility aspects are being examined at the molecular level for all model systems. In addition, we compare the properties of the hybrid systems to the properties of the corresponding bulk ones, as well as to theoretical predictions.
POWER GRID DYNAMICS: ENHANCING POWER SYSTEM OPERATION THROUGH PRONY ANALYSIS
Ray, C.; Huang, Z.
2007-01-01
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.
CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Li, Qinfei; Ge, Yong; Geng, Guoqing; Bae, Sungchul; Monteiro, Paulo J. M.
2015-01-01
The effect of calcium chloride (CaCl 2 ) on tricalcium silicate (C 3 S) hydration was investigated by scanning transmission X-ray microscopy (STXM) with Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra and 29 Si MAS NMR. STXM is demonstrated to be a powerful tool for studying the chemical composition of a cement-based hydration system. The Ca L 3,2 -edge NEXAFS spectra obtained by examining C 3 S hydration in the presence of CaCl 2 showed that this accelerator does not change the coordination of calcium in the calcium silicate hydrate (C-S-H), which is the primary hydration product. Omore »K-edge NEXAFS is also very useful in distinguishing the chemical components in hydrated C 3 S. Based on the Ca L 3,2 -edge spectra and chemical component mapping, we concluded that CaCl 2 prefers to coexist with unhydrated C 3 S instead of C-S-H. In Si K-edge NEXAFS analysis, CaCl 2 increases the degree of silicate polymerization of C-S-H in agreement with the 29 Si CP/MAS NMR results, which show that the presence of CaCl 2 in hydrated C 3 S considerably accelerates the formation of middle groups ( Q 2 ) and branch sites ( Q 3 ) in the silicate chains of C-S-H gel at 1-day hydration. « less
Seol, Yongkoo; Kneafsey, Timothy J.
2009-06-01
We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.
Stochastic dynamics of a delayed bistable system with multiplicative noise
Dung, Nguyen Tien E-mail: dungnt@fpt.edu.vn
2014-05-15
In this paper we investigate the properties of a delayed bistable system under the effect of multiplicative noise. We first prove the existence and uniqueness of the positive solution and show that its moments are uniformly bounded. Then, we study stochastic dynamics of the solution in long time, the lower and upper bounds for the paths and an estimate for the average value are provided.
Controlling quantum systems by embedded dynamical decoupling schemes
Oliver Kern; Gernot Alber
2005-06-05
A dynamical decoupling method is presented which is based on embedding a deterministic decoupling scheme into a stochastic one. This way it is possible to combine the advantages of both methods and to increase the suppression of undesired perturbations of quantum systems significantly even for long interaction times. As a first application the stabilization of a quantum memory is discussed which is perturbed by one-and two-qubit interactions.
A simple correlation to predict the hydrate quadruple point temperature for LPG mixtures
Yousif, M.H.
1997-12-31
A simple correlation to predict the hydrate upper quadruple point temperature, T{sub Q2B} for liquefied petroleum gas (LPG) mixtures was developed. It was developed for use as a part of a modeling and control system for a LPG pipeline in Russia. For performance reasons, a simple hydrate prediction correlation was required that could be incorporated into the real-time and predictive pipeline simulation models. The operating company required both real time and predictive simulation tools be developed to assist in preventing hydrate blockages while minimizing the use of methanol. In this particular pipeline, LPG fluid moves through the pipeline as a single phase liquid above its bubble point pressure. Because of the very low flow rates, the trace amount of water present in the LPG drops out and creates water pools at low points in the pipeline. The pipeline pressure and seasonal temperatures are conducive for hydrate formation in these pools. Methanol and monoethylene glycol (MEG) are injected in the pipeline to help prevent hydrate formation. The newly developed correlation predicts the hydrate quadruple point temperature using only the composition and the molecular weight of the LPG mixture while retaining an accuracy comparable to the statistical thermodynamic models throughout the range of normal operating conditions.
Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics...
Office of Scientific and Technical Information (OSTI)
Water Usage for In-Situ Oil Shale Retorting - A Systems Dynamics Model Earl D. Mattson; Larry Hull; Kara Cafferty 02 PETROLEUM Water Water A system dynamic model was construction...
A realistic molecular model of cement hydrates
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 ...
Weakening of ice by magnesium perchlorate hydrate
Lenferink, Hendrik J., 1985-
2012-01-01
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 ...
Overview: Gas hydrate geology and geography
Malone, R.D.
1993-01-01
Several geological factors which are directly responsible for the presence or absence of gas hydrates have been reviewed and are: tectonic position of the region; sedimentary environments; structural deformation; shale diapirism; hydrocarbon generation and migration; thermal regime in the hydrate formation zone (HFZ); pressure conditions; and hydrocarbon gas supply to the HFZ. Work on gas hydrate formation in the geological environment has made significant advances, but there is still much to be learned. Work is continuing in the deeper offshore areas through the Ocean Drilling Program, Government Agencies, and Industry. The pressure/temperature conditions necessary for formation has been identified for various compositions of natural gas through laboratory investigations and conditions for formation are being advanced through drilling in areas where gas hydrates exist.
Overview: Gas hydrate geology and geography
Malone, R.D.
1993-06-01
Several geological factors which are directly responsible for the presence or absence of gas hydrates have been reviewed and are: tectonic position of the region; sedimentary environments; structural deformation; shale diapirism; hydrocarbon generation and migration; thermal regime in the hydrate formation zone (HFZ); pressure conditions; and hydrocarbon gas supply to the HFZ. Work on gas hydrate formation in the geological environment has made significant advances, but there is still much to be learned. Work is continuing in the deeper offshore areas through the Ocean Drilling Program, Government Agencies, and Industry. The pressure/temperature conditions necessary for formation has been identified for various compositions of natural gas through laboratory investigations and conditions for formation are being advanced through drilling in areas where gas hydrates exist.
Nanomechanical properties of hydrated organic thin films
Choi, Jae Hyeok
2007-01-01
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 ...
ConocoPhillips Gas Hydrate Production Test
Schoderbek, David; Farrell, Helen; Howard, James; Raterman, Kevin; Silpngarmlert, Suntichai; Martin, Kenneth; Smith, Bruce; Klein, Perry
2013-06-30
Work began on the ConocoPhillips Gas Hydrates Production Test (DOE award number DE-NT0006553) on October 1, 2008. This final report summarizes the entire project from January 1, 2011 to June 30, 2013.
Methane Hydrate Advisory Committee (MHAC) Meeting
Broader source: Energy.gov (indexed) [DOE]
to establish the resource potential of methane hydrates via a sustained, long-term production test in the Arctic. DFO Gant reminded the Committee that on May 1, the MHAC members...
METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST
Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr
2005-02-01
Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models and to research teams for developing future gas-hydrate projects. No gas hydrates were encountered in this well; however, a wealth of information was generated and has been documented by the project team. This Topical Report documents drilling and coring operations and other daily activities.
METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST
Steve Runyon; Mike Globe; Kent Newsham; Robert Kleinberg; Doug Griffin
2005-02-01
Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists planning hydrate exploration and development projects. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this and other project reports. This Topical Report contains details describing logging operations.
Gas hydrates in the Gulf of Mexico
Cox, Henry Benjamin
1986-01-01
OCE-8020560. Additional funding and the majority of sample collection was done on geochemical survey cruises in 1983, 1984 and 1985 through the participation of the aforementioned oil companies. Finally, I'd like to thank Kathy York for her love... the sediment. Some hydrates were found associated with oil stained sediments while others were interspersed with carbonate rubble. These hydrated cores represent less than 1% of the approximately 1000 piston cores that have been taken in the Gulf of Mexico...
Presentations from the March 27th - 28th Methane Hydrates Advisory...
Office of Environmental Management (EM)
the March 27th - 28th Methane Hydrates Advisory Committee Meeting Presentations from the March 27th - 28th Methane Hydrates Advisory Committee Meeting International Gas Hydrate...
Dynamics of Josephson junction systems in the computational subspace
Wang Xiang-Bin; Matsumoto Keiji; Fan Heng; Y. Nakamura
2001-12-05
The quantum dynamics of the Josephson junction system in the computational subspace is investigated. A scheme for the controlled not operation is given for two capasitively coupled SQUIDs. In this system, there is no systematic error for the two qubit operation. For the inductively coupled SQUIDs, the effective Hamiltonian causes systematic errors in the computational subspace for the two qubit operation. Using the purterbation theory, we construct a more precise effective Hamiltonian. This new effective Hamiltonian reduces the systematic error to the level much lower than the threshold of the fault resilent quantum computation.
Nonlinear Dynamics of Quantum Systems and Soliton Theory
Eldad Bettelheim; Alexander G. Abanov; Paul Wiegmann
2006-10-26
We show that space-time evolution of one-dimensional fermionic systems is described by nonlinear equations of soliton theory. We identify a space-time dependence of a matrix element of fermionic systems related to the {\\it Orthogonality Catastrophe} or {boundary states} with the $\\tau$-function of the modified KP-hierarchy. The established relation allows to apply the apparatus of soliton theory to the study of non-linear aspects of quantum dynamics. We also describe a {\\it bosonization in momentum space} - a representation of a fermion operator by a Bose field in the presence of a boundary state.
Kneafsey, T.J.
2012-01-01
temperature to 4°C with the pore pressure of the system atby increasing the pore pressure to 4.8MPa and the confiningto a drop in pore pressure of 0.07MPa. Additional hydrate
Dynamical Interactions of Planetary Systems in Dense Stellar Environments
John M. Fregeau; Sourav Chatterjee; Frederic A. Rasio
2005-11-23
We study dynamical interactions of star--planet binaries with other single stars. We derive analytical cross sections for all possible outcomes, and confirm them with numerical scattering experiments. We find that a wide mass ratio in the binary introduces a region in parameter space that is inaccessible to comparable-mass systems, in which the nature of the dynamical interaction is fundamentally different from what has traditionally been considered in the literature on binary scattering. We study the properties of the planetary systems that result from the scattering interactions for all regions of parameter space, paying particular attention to the location of the "hard--soft" boundary. The structure of the parameter space turns out to be significantly richer than a simple statement of the location of the "hard--soft" boundary would imply. We consider the implications of our findings, calculating characteristic lifetimes for planetary systems in dense stellar environments, and applying the results to previous analytical studies, as well as past and future observations. Recognizing that the system PSR B1620-26 in the globular cluster M4 lies in the "new" region of parameter space, we perform a detailed analysis quantifying the likelihood of different scenarios in forming the system we see today.
Self-Interacting Electron as a Nonlinear Dynamical System
Vladimir A. Manasson
2006-09-15
We have proposed a simple one-dimensional model of internal particle dynamics. The model is based on the assumption that self-interaction can be represented by a nonlinear feedback and described by a quadratic recurrent map. Charge plays the role of a generalized dynamical variable and a feedback coupling parameter. The model suggests that charge and action quantization stem from the system's dissipative quality and from a hierarchy of supercycle orbits located between period-doubling bifurcations on the Feigenbaum tree. Among the numerical results, we have discovered a link between the quantum of action and the elementary charge. We also found that the fine structure constant can with a good accuracy be expressed exclusively through mathematical constants, including the Feigenbaum delta. We have introduced dimensionless numbers that describe the relative role of the internal particle dynamics when both internal and external dynamics are taken into consideration. We have found these numbers to be close to the electron, proton, and neutron g-factors known from the experiment.
Power-laws in recurrence networks from dynamical systems
Y. Zou; J. Heitzig; R. V. Donner; J. F. Donges; J. D. Farmer; R. Meucci; S. Euzzor; N. Marwan; J. Kurths
2012-03-15
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 $\\gamma=1$.
Verification of Relational Data-Centric Dynamic Systems with External Services
Calvanese, Diego
Verification of Relational Data-Centric Dynamic Systems with External Services Babak Bagheri Hariri@cs.ucsd.edu ABSTRACT Data-centric dynamic systems are systems where both the process controlling the dynamics processes. In this paper we study verification of (first-order) µ-calculus variants over relational data-centric
Mixtures of Predictive Linear Gaussian Models for Nonlinear Stochastic Dynamical Systems
Baveja, Satinder Singh
Mixtures of Predictive Linear Gaussian Models for Nonlinear Stochastic Dynamical Systems David dynamical systems. The primary contribution of this work is to extend the PLG to nonlinear, stochastic- proves upon traditional linear dynamical system mod- els by using a predictive representation of state
Title of Dissertation: NONLINEAR DYNAMICS OF EXTENDED SYSTEMS: CHAOS FRONTS, RARE INTENSE EVENTS,
Anlage, Steven
ABSTRACT Title of Dissertation: NONLINEAR DYNAMICS OF EXTENDED SYSTEMS: CHAOS FRONTS, RARE INTENSE Edward Ott Department of Physics We investigate the nonlinear dynamics of three extended systems: chaos considered as nodes and actors as links. #12;NONLINEAR DYNAMICS OF EXTENDED SYSTEMS: CHAOS FRONTS, RARE
GLOMAP Approach for Nonlinear System Identification of Aircraft Dynamics Using Flight Data
Valasek, John
GLOMAP Approach for Nonlinear System Identification of Aircraft Dynamics Using Flight Data Monika model dynamics are assumed to be perturbed by a nonlinear term which represents the system accurate behavior. Nonlinear system identification of aircraft dynamics is a comparitively new and still
Nonlinear Dynamics and Quantum Entanglement in Optomechanical Systems Guanglei Wang,1
Lai, Ying-Cheng
Nonlinear Dynamics and Quantum Entanglement in Optomechanical Systems Guanglei Wang,1 Liang Huang,2, is nonlinear. A nonlinear dynamical system can exhibit all kinds of interesting phenomena such as periodic at the other. In view of the ubiquity of nonlinear dynamics in physical systems and of the funda- mental
Future Directions in Control, Dynamics, and Systems: Overview, Grand Challenges, and New Courses
Murray, Richard M.
Future Directions in Control, Dynamics, and Systems: Overview, Grand Challenges, and New Courses and recommendations of a recent panel on Future Di- rections in Control, Dynamics, and Systems, sponsored by the US on Future Directions in Control and Dynamical Systems was formed to prepare a report to provide a renewed
Assessment of dynamic energy conversion systems for radioisotope heat sources
Thayer, G.R.; Mangeng, C.A.
1985-06-01
The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.
Daniel Liberzon and A. Stephen Morse y a switched system, we mean a hybrid dynamical system
Morse, A. Stephen
. This article surveys recent developments in three basic problems regarding stability and design of switched industry, aircraft and air traffic control, switching power converters, and many other fields. The book 18C s Daniel Liberzon and A. Stephen Morse y a switched system, we mean a hybrid dynamical system
Entanglement dynamics in a model tripartite quantum system
Pradip Laha; B. Sudarsan; S. Lakshmibala; V. Balakrishnan
2015-09-23
A system comprising a $\\Lambda$-type or V-type atom interacting with two radiation fields exhibits, during its dynamical evolution, interesting optical phenomena such as electromagnetically-induced transparency (EIT) and a variety of nonclassical effects. Signatures of the latter are seen in the entanglement dynamics of the atomic subsystem and in appropriate field observables. Some of these effects have been experimentally detected, and have even been used to change the nonlinear optical properties of certain atomic media. It is therefore useful to investigate the roles played by specific initial states of the radiation fields, detuning parameters, field nonlinearities and the nature of field-atom couplings on EIT and on the entanglement between subsystems. We investigate these aspects in the framework of a simple model that captures the salient features of such tripartite entangled systems. Entanglement dynamics is shown to be very sensitive to the intensity-dependent atom-field couplings. Unexpected interesting features pertaining to the collapses and revivals of the atomic subsystem von Neumann entropy appear. These features could, in principle, be useful in enabling entanglement.
Torres, Marta
2014-01-31
In November 2012, Oregon State University initiated the project entitled: Application of Crunch-Flow routines to constrain present and past carbon fluxes at gas-hydrate bearing sites. Within this project we developed Crunch-Flow based modeling modules that include important biogeochemical processes that need to be considered in gas hydrate environments. Our modules were applied to quantify carbon cycling in present and past systems, using data collected during several DOE-supported drilling expeditions, which include the Cascadia margin in US, Ulleung Basin in South Korea, and several sites drilled offshore India on the Bay of Bengal and Andaman Sea. Specifically, we completed modeling efforts that: 1) Reproduce the compositional and isotopic profiles observed at the eight drilled sites in the Ulleung Basin that constrain and contrast the carbon cycling pathways at chimney (high methane flux) and non-chimney sites (low methane, advective systems); 2) Simulate the Ba record in the sediments to quantify the past dynamics of methane flux in the southern Hydrate Ridge, Cascadia margin; and 3) Provide quantitative estimates of the thickness of individual mass transport deposits (MTDs), time elapsed after the MTD event, rate of sulfate reduction in the MTD, and time required to reach a new steady state at several sites drilled in the Krishna-Godavari (K-G) Basin off India. In addition we developed a hybrid model scheme by coupling a home-made MATLAB code with CrunchFlow to address the methane transport and chloride enrichment at the Ulleung Basins chimney sites, and contributed the modeling component to a study focusing on pore-scale controls on gas hydrate distribution in sediments from the Andaman Sea. These efforts resulted in two manuscripts currently under review, and contributed the modeling component of another pare, also under review. Lessons learned from these efforts are the basis of a mini-workshop to be held at Oregon State University (Feb 2014) to instruct graduate students (OSU and UW) as well as DOE staff from the NETL lab in Albany on the use of Crunch Flow for geochemical applications.
Novel Dynamics and Thermodynamics in systems with long range interactions
Atenas, Boris
2015-01-01
Systems with long range interactions display some anomalies when its dynamics and thermodynamics are studied below certain conditions. Among these anomalies are the quasi- stationary states, which are exacerbated because of special initial conditions that are used here. We present in this letter a new Hamiltonian whose potential is inspired in the two-dipole interaction. An analytical solution is obtained for the equilibrium in the canonical ensemble that is coincident with the one obtained from computational simulations. However, results from this model presents a kind of nonequivalence of ensembles in long-living states before arriving to equilibrium. Thus, a complete characterization is made for the nonequilibrium through molecular dynamics. In which, novel quasi-stationary states are observed due to the long range interactions.
Extended space expectation values in quantum dynamical system evolutions
Demiralp, Metin
2014-10-06
The time variant power series expansion for the expectation value of a given quantum dynamical operator is well-known and well-investigated issue in quantum dynamics. However, depending on the operator and Hamiltonian singularities this expansion either may not exist or may not converge for all time instances except the beginning of the evolution. This work focuses on this issue and seeks certain cures for the negativities. We work in the extended space obtained by adding all images of the initial wave function under the system 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.
System and method for reducing combustion dynamics in a combustor
Uhm, Jong Ho; Johnson, Thomas Edward; Zuo, Baifang; York, William David
2013-08-20
A system for reducing combustion dynamics in a combustor includes an end cap having an upstream surface axially separated from a downstream surface, and tube bundles extend through the end cap. A diluent supply in fluid communication with the end cap provides diluent flow to the end cap. Diluent distributors circumferentially arranged inside at least one tube bundle extend downstream from the downstream surface and provide fluid communication for the diluent flow through the end cap. A method for reducing combustion dynamics in a combustor includes flowing fuel through tube bundles that extend axially through an end cap, flowing a diluent through diluent distributors into a combustion chamber, wherein the diluent distributors are circumferentially arranged inside at least one tube bundle and each diluent distributor extends downstream from the end cap, and forming a diluent barrier in the combustion chamber between at least one pair of adjacent tube bundles.
Polar rotation angle identifies elliptic islands in unsteady dynamical systems
Mohammad Farazmand; George Haller
2015-03-20
We propose rotation inferred from the polar decomposition of the flow gradient as a diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical systems. We consider here two- and three-dimensional systems, in which polar rotation can be characterized by a single angle. For this polar rotation angle (PRA), we derive explicit formulas using the singular values and vectors of the flow gradient. We find that closed level sets of the PRA reveal elliptic islands in great detail, and singular level sets of the PRA uncover centers of such islands. Both features turn out to be objective (frame-invariant) for two-dimensional systems. We illustrate the diagnostic power of PRA for elliptic structures on several examples.
Polar rotation angle identifies elliptic islands in unsteady dynamical systems
Farazmand, Mohammad
2015-01-01
We propose rotation inferred from the polar decomposition of the flow gradient as a diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical systems. We consider here two- and three-dimensional systems, in which polar rotation can be characterized by a single angle. For this polar rotation angle (PRA), we derive explicit formulas using the singular values and vectors of the flow gradient. We find that closed level sets of the PRA reveal elliptic islands in great detail, and singular level sets of the PRA uncover centers of such islands. Both features turn out to be objective (frame-invariant) for two-dimensional systems. We illustrate the diagnostic power of PRA for elliptic structures on several examples.
Complex admixtures of clathrate hydrates in a water desalination method
Simmons, Blake A. (San Francisco, CA); Bradshaw, Robert W. (Livermore, CA); Dedrick, Daniel E. (Berkeley, CA); Anderson, David W. (Riverbank, CA)
2009-07-14
Disclosed is a method that achieves water desalination by utilizing and optimizing clathrate hydrate phenomena. Clathrate hydrates are crystalline compounds of gas and water that desalinate water by excluding salt molecules during crystallization. Contacting a hydrate forming gaseous species with water will spontaneously form hydrates at specific temperatures and pressures through the extraction of water molecules from the bulk phase followed by crystallite nucleation. Subsequent dissociation of pure hydrates yields fresh water and, if operated correctly, allows the hydrate-forming gas to be efficiently recycled into the process stream.
Numerical tests of dynamical friction in gravitational inhomogeneous systems
A. Del Popolo
2003-05-05
In this paper, I test by numerical simulations the results of Del Popolo & Gambera (1998),dealing with the extension of Chandrasekhar and von Neumann's analysis of the statistics of the gravitational field to systems in which particles (e.g., stars, galaxies) are inhomogeneously distributed. The paper is an extension of that of Ahmad & Cohen (1974), in which the authors tested some results of the stochastic theory of dynamical friction developed by Chandrasekhar & von Neumann (1943) in the case of homogeneous gravitational systems. It is also a continuation of the work developed in Del Popolo (1996a,b), which extended the results of Ahmad & Cohen (1973), (dealing with the study of the probability distribution of the stochastic force in homogeneous gravitational systems) to inhomogeneous gravitational systems. Similarly to what was done by Ahmad & Cohen (1974) in the case of homogeneous systems, I test, by means of the evolution of an inhomogeneous system of particles, that the theoretical rate of force fluctuation d F/dt describes correctly the experimental one, I find that the stochastic force distribution obtained for the evolved system is in good agreement with the Del Popolo & Gambera (1998) theory. Moreover, in an inhomogeneous background the friction force is actually enhanced relative to the homogeneous case.
Dynamic Load Balancing on Single- and Multi-GPU Systems
Chen, Long; Villa, Oreste; Krishnamoorthy, Sriram; Gao, Guang R.
2010-04-19
The computational power provided by many-core graphics processing units (GPUs) has been exploited in many applications. The programming techniques supported and employed on these GPUs are not sufficient to address problems exhibiting irregular, and unbalanced workload. The problem is exacerbated when trying to effectively exploit multiple GPUs, which are commonly available in many modern systems. In this paper, we propose a task-based dynamic load-balancing solution for single- and multi-GPU systems. The solution allows load balancing at a finer granularity than what is supported in existing APIs such as NVIDIA’s CUDA. We evaluate our approach using both micro-benchmarks and a molecular dynamics application that exhibits significant load imbalance. Experimental results with a single-GPU configuration show that our fine-grained task solution can utilize the hardware more efficiently than the CUDA scheduler for unbalanced workload. On multi-GPU systems, our solution achieves near-linear speedup, load balance, and significant performance improvement over techniques based on standard CUDA APIs.
Dynamic Systems Analysis Report for Nuclear Fuel Recycle
Brent Dixon; Sonny Kim; David Shropshire; Steven Piet; Gretchen Matthern; Bill Halsey
2008-12-01
This report examines the time-dependent dynamics of transitioning from the current United States (U.S.) nuclear fuel cycle where used nuclear fuel is disposed in a repository to a closed fuel cycle where the used fuel is recycled and only fission products and waste are disposed. The report is intended to help inform policy developers, decision makers, and program managers of system-level options and constraints as they guide the formulation and implementation of advanced fuel cycle development and demonstration efforts and move toward deployment of nuclear fuel recycling infrastructure.
Critical dynamics in systems controlled by fractional kinetic equations
L. A. Batalov; A. A. Batalova
2012-05-23
The article is devoted to the dynamics of systems with an anomalous scaling near a critical point. The fractional stochastic equation of a Lanvevin type with the $\\varphi^3$ nonlinearity is considered. By analogy with the model A the field theoretic model is built, and its propagators are calculated. The nonlocality of the new action functional in the coordinate representation is caused by the involving of the fractional spatial derivative. It is proved that the new model is multiplicatively renormalizable, the Gell-Man-Low function in the one-loop approximation is evaluted. The existence of the scaling behavior in the framework of the $\\varepsilon$-expansion for a superdiffusion is established.
Probing quantum many-body dynamics in nuclear systems
C. Simenel; M. Dasgupta; D. J. Hinde; A. Kheifets; A. Wakhle
2013-08-31
Quantum many-body nuclear dynamics is treated at the mean-field level with the time-dependent Hartree-Fock (TDHF) theory. Low-lying and high-lying nuclear vibrations are studied using the linear response theory. The fusion mechanism is also described for light and heavy systems. The latter exhibit fusion hindrance due to quasi-fission. Typical characteristics of quasi-fission, such as contact time and partial symmetrisation of the fragments mass in the exit channel, are reproduced by TDHF calculations. The (multi-)nucleon transfer at sub-barrier energies is also discussed.
METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST
Richard Sigal; Kent Newsham; Thomas Williams; Barry Freifeld; Timothy Kneafsey; Carl Sondergeld; Shandra Rai; Jonathan Kwan; Stephen Kirby; Robert Kleinberg; Doug Griffin
2005-02-01
Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu Formation and approximately 215 ft of porous sandstone were recovered in the West Sak Formation. There were gas shows in the bottom part of the Ugnu and throughout the West Sak. No hydrate-bearing zones were identified either in recovered core or on well logs. The base of the permafrost was found at about 1260 ft. With the exception of the deepest sands in the West Sak and some anomalous thin, tight zones, all sands recovered (after thawing) are unconsolidated with high porosity and high permeability. At 800 psi, Ugnu sands have an average porosity of 39.3% and geometrical mean permeability of 3.7 Darcys. Average grain density is 2.64 g/cc. West Sak sands have an average porosity of 35.5%, geometrical mean permeability of 0.3 Darcys, and average grain density of 2.70 g/cc. There were several 1-2 ft intervals of carbonate-cemented sandstone recovered from the West Sak. These intervals have porosities of only a few percent and very low permeability. On a well log they appear as resistive with a high sonic velocity. In shallow sections of other wells these usually are the only logs available. Given the presence of gas in Hot Ice No. 1, if only resistivity and sonic logs and a mud log had been available, tight sand zones may have been interpreted as containing hydrates. Although this finding does not imply that all previously mapped hydrate zones are merely tight sands, it does add a note of caution to the practice of interpreting the presence of hydrates from old well information. The methane hydrate stability zone below the Hot Ice No. 1 location includes thick sections of sandstone and conglomerate which would make excellent reservoir rocks for hydrates and below the permafrost zone shallow gas. The Ugnu formation comprises a more sand-rich section than does the West Sak formation, and the Ugnu sands when cleaned and dried are slightly more porous and significantly more permeable than the West Sak.
Rack, Frank; Storms, Michael; Schroeder, Derryl; Dugan, Brandon; Schultheiss, Peter
2002-12-31
The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were (1) the preliminary postcruise evaluation of the tools and measurement systems that were used during ODP Leg 204 to study hydrate deposits on Hydrate Ridge, offshore Oregon from July through September 2002; and (2) the preliminary study of the hydrate-bearing core samples preserved in pressure vessels and in liquid nitrogen cryofreezers, which are now stored at the ODP Gulf Coast Repository in College Station, TX. During ODP Leg 204, several newly modified downhole tools were deployed to better characterize the subsurface lithologies and environments hosting microbial populations and gas hydrates. A preliminary review of the use of these tools is provided herein. The DVTP, DVTP-P, APC-methane, and APC-Temperature tools (ODP memory tools) were used extensively and successfully during ODP Leg 204 aboard the D/V JOIDES Resolution. These systems provided a strong operational capability for characterizing the in situ properties of methane hydrates in subsurface environments on Hydrate Ridge during ODP Leg 204. Pressure was also measured during a trial run of the Fugro piezoprobe, which operates on similar principles as the DVTP-P. The final report describing the deployments of the Fugro Piezoprobe is provided in Appendix A of this report. A preliminary analysis and comparison between the piezoprobe and DVTP-P tools is provided in Appendix B of this report. Finally, a series of additional holes were cored at the crest of Hydrate Ridge (Site 1249) specifically geared toward the rapid recovery and preservation of hydrate samples as part of a hydrate geriatric study partially funded by the Department of Energy (DOE). In addition, the preliminary results from gamma density non-invasive imaging of the cores preserved in pressure vessels are provided in Appendix C of this report. An initial visual inspection of the samples stored in liquid nitrogen is provided in Appendix D of this report.
Enderlein, Jörg
Changing the Dynamical Behavior of Nonlinear Reaction Diffusion Systems by Stochastic Electric fields on the dynamics of the nonlinear system was extensively studied by several authors. Initial on the dynamical behavior of the Belouzov-Zhabotinsky reaction is theoretically studied and discussed. 1
Dynamical Robust Nonlinear H Filtering for Lipschitz Descriptor Systems with Parametric and
Marquez, Horacio J.
Dynamical Robust Nonlinear H Filtering for Lipschitz Descriptor Systems with Parametric and filtering of nonlinear dynamical systems has been a subject of extensive research during the recent decays and Nonlinear Uncertainties Masoud Abbaszadeh and Horacio J. Marquez Abstract-- In this paper, a dynamical
Der, Ralf
Contingent robot behaviors from self-referential dynamical systems Ralf Der, Frank Hesse and Ren and a challenging objective for autonomous robots. In our earlier work we introduced homeokinesis the dynamical-regulating dynamical system. Mathematical arguments show that the robot behaviors emerging from this are both
The Momentum Cloud Method for Dynamic Simulation of Rigid Body Systems
Sweetman, Bert
is presented for a 6-body floating wind turbine system. CE Database subject headings: Simulation, Structural dynamics, Rigid-body dynamics, Wind power, Floating structures 1. Introduction and Background A multibody. Featherstone (Featherstone, 2008) investigates the dynamics formulation of a floating-base rigid-body system
A computational method to extract macroscopic variables and their dynamics in multiscale systems
Gary Froyland; Georg A. Gottwald; Andy Hammerlindl
2014-09-29
This paper introduces coordinate-independent methods for analysing multiscale dynamical systems using numerical techniques based on the transfer operator and its adjoint. In particular, we present a method for testing whether an arbitrary dynamical system exhibits multiscale behaviour and for estimating the time-scale separation. For systems with such behaviour, we establish techniques for analysing the fast dynamics in isolation, extracting slow variables for the system, and accurately simulating these slow variables at a large time step. We illustrate our method with numerical examples and show how the reduced slow dynamics faithfully represents statistical features of the full dynamics which are not coordinate dependent.
Complex Systems Dynamics (CoSyDy) Meeting, Leeds 5th "Complexity in Economics and Social Dynamics"
Wirosoetisno, Djoko
Complex Systems Dynamics (CoSyDy) Meeting, Leeds 5th June 2013 "Complexity in Economics and Social Dynamics" Organiser: Dr. Mauro Mobilia (Applied Maths, Leeds) Directions: http://www.maths.leeds.ac.uk/home/visit-us.html and http://www.maths.leeds.ac.uk/fileadmin/user_upload/directions_2011-12.pdf Tentative programme All talks
Thermoacoustic instability - a dynamical system and time domain analysis
Sayadi, Taraneh; Schmid, Peter; Richecoeur, Franck; Massot, Marc
2013-01-01
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...
Dynamics of a Two-Dimensional System of Quantum Dipoles
Mazzanti, F.; Astrakharchik, G. E.; Boronat, J.; Zillich, R. E.
2009-03-20
A detailed microscopic analysis of the dynamic structure function S(k,{omega}) of a two-dimensional Bose system of dipoles polarized along the direction perpendicular to the plane is presented and discussed. Starting from ground-state quantities obtained using a quantum diffusion Monte Carlo algorithm, the density-density response is evaluated in the context of the correlated basis functions (CBF) theory. CBF predicts a sharp peak and a multiexcitation component at higher energies produced by the decay of excitations. We discuss the structure of the phonon-roton peak and show that the Feynman and Bogoliubov predictions depart from the CBF result already at low densities. We finally discuss the emergence of a roton in the spectrum, but find the roton energy not low enough to make the system unstable under density fluctuations up to the highest density considered that is close to the freezing point.
Resonances of Dynamical Systems and Fredholm-Riesz Operators on Rigged
Bandtlow, Oscar
Resonances of Dynamical Systems and Fredholm-Riesz Operators on Rigged, of certain chaotic dynamical systems can be described by suitably chosen evolution operators of these systems systems are defined as the singularities of the analytically continued resolvent of the restriction
On the linear operation of cloned dynamical systems and its Lyapunov exponents
Pengfei Wang
2014-03-16
The cloned dynamical system theory is introduced and the Lyapunov exponents of this system are qualitatively proven to be same as the original dynamical system. This property indicates that these two systems have the same error propagation speed in the phase space, and thus we can interpret the phenomenon as why the ensemble mean method sometimes is not effective.
Nerukh, Dmitry
Computational mechanics of molecular systems: Quantifying high- dimensional dynamics computational mechanics as a bridge between deterministic chaos in nonlinear dynamical systems with few degrees-Hakodate, School of Systems Information Science, Department of Complex System, 116-2 Kamedanakano-cho, Hakodate
Approximate Bisimulations for Nonlinear Dynamical Systems Antoine Girard and George J. Pappas
Pappas, George J.
Approximate Bisimulations for Nonlinear Dynamical Systems Antoine Girard and George J. Pappas generalization of the exact notions of bisimulation of nonlinear dynamical systems [9], [20], [22]. Furthermore nonlinear systems. This is achieved by requiring that a distance between system observations starts
Quantum speed-up transition in open system dynamics
Xiang Hao; Wenjiong Wu
2015-10-20
The rate of the trace distance is used to evaluate quantum speed-up for arbitrary mixed states. Compared with some present methods, the approach based on trace distance can provide an optimal bound to the speed of the evolution. The dynamical transition from no speed-up region to speed-up region takes on in the spontaneous decay of an two-level atom with detuning. The evolution is characteristic of the alternating behavior between quantum speed-up and speed-down in the strong system-reservoir coupling regime. Under the o?ff-resonance condition, the dynamical evolution can be accelerated for short previous times and then decelerated to a normal process either in the weak or strong coupling regime. From the time-energy uncertainty relation, we demonstrate that the potential capacity for quantum speed-up evolution is closely related to the energy flow-back from the reservoir to the system. The negative decay rate for short time intervals leads to the speed-up process where the photons previously emitted by the atom are reabsorbed at a later time. The values of the spontaneous decay rate becomes positive after a long enough time, which results in the normal evolution with no speed-up potential.
Preliminary relative permeability estimates of methane hydrate-bearing sand
Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.
2006-01-01
through methane hydrate-bearing sand. X-ray CT was usedin partially saturated sand, 229th ACS National Meeting, SanOF METHANE HYDRATE- BEARING SAND Yongkoo Seol, Timothy J.
Method for production of hydrocarbons from hydrates
McGuire, Patrick L. (Los Alamos, NM)
1984-01-01
A method of recovering natural gas entrapped in frozen subsurface gas hydrate formations in arctic regions. A hot supersaturated solution of CaCl.sub.2 or CaBr.sub.2, or a mixture thereof, is pumped under pressure down a wellbore and into a subsurface hydrate formation so as to hydrostatically fracture the formation. The CaCl.sub.2 /CaBr.sub.2 solution dissolves the solid hydrates and thereby releases the gas entrapped therein. Additionally, the solution contains a polymeric viscosifier, which operates to maintain in suspension finely divided crystalline CaCl.sub.2 /CaBr.sub.2 that precipitates from the supersaturated solution as it is cooled during injection into the formation.
Griffith, Daniel Todd
2005-02-17
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 ...
Nonlinear dynamics of a self-excited thermoacoustic system subjected to acoustic forcing
Balusamy, Saravanan; Li, Larry K. B.; Han, Zhiyi; Juniper, Matthew P.; Hochgreb, Simone
2014-06-25
We experimentally study the nonlinear dynamics of a self-excited thermoacoustic system subjected to acoustic forcing. Our aim is to relate these dynamics to the behavior of universal model oscillators subjected to external forcing. The self...
Nonlinear dynamics of a self-excited thermoacoustic system subjected to acoustic forcing
Balusamy, Saravanan; Li, Larry K.B.; Han, Zhiyi; Juniper, Matthew P.; Hochgreb, Simone
2014-06-25
We experimentally study the nonlinear dynamics of a self-excited thermoacoustic system subjected to acoustic forcing. Our aim is to relate these dynamics to the behavior of universal model oscillators subjected to external forcing. The self...
A high dynamic range data acquisition system for a solid-state...
Office of Scientific and Technical Information (OSTI)
A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment Citation Details In-Document Search Title: A high dynamic range data...
Su, Zhiyong
2012-10-19
Response and stability of vessel rolling motion with strongly nonlinear softening stiffness will be studied in this dissertation using the methods of stochastic dynamical systems. As one of the most classic stability failure modes of vessel dynamics...
Natural gas hydrates - issues for gas production and geomechanical stability
Grover, Tarun
2008-10-10
gases, some liquids like tetrahydrofuran (THF) can also react with water to form hydrates. The formation of natural gas hydrates depends on pressure, temperature, gas composition, and presence of inhibitors such as salts. NGHs are found... deposits constitute the bulk of natural hydrates (Sloan and Koh, 2008). In offshore environments, hydrates are stable in water depths greater than 200 to 600 meters depending on the gas composition and seafloor temperatures (Milkov and Sassen, 2002). Fig...
Dehydration of plutonium or neptunium trichloride hydrate
Foropoulos, J. Jr.; Avens, L.R.; Trujillo, E.A.
1992-03-24
A process is described for preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride.
Dehydration of plutonium or neptunium trichloride hydrate
Foropoulos, Jr., Jerry (Los Alamos, NM); Avens, Larry R. (Los Alamos, NM); Trujillo, Eddie A. (Espanola, NM)
1992-01-01
A process of preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride is provided.
Dynamic analysis methods for detecting anomalies in asynchronously interacting systems.
Kumar, Akshat; Solis, John Hector; Matschke, Benjamin
2014-01-01
Detecting modifications to digital system designs, whether malicious or benign, is problematic due to the complexity of the systems being analyzed. Moreover, static analysis techniques and tools can only be used during the initial design and implementation phases to verify safety and liveness properties. It is computationally intractable to guarantee that any previously verified properties still hold after a system, or even a single component, has been produced by a third-party manufacturer. In this paper we explore new approaches for creating a robust system design by investigating highly-structured computational models that simplify verification and analysis. Our approach avoids the need to fully reconstruct the implemented system by incorporating a small verification component that dynamically detects for deviations from the design specification at run-time. The first approach encodes information extracted from the original system design algebraically into a verification component. During run-time this component randomly queries the implementation for trace information and verifies that no design-level properties have been violated. If any deviation is detected then a pre-specified fail-safe or notification behavior is triggered. Our second approach utilizes a partitioning methodology to view liveness and safety properties as a distributed decision task and the implementation as a proposed protocol that solves this task. Thus the problem of verifying safety and liveness properties is translated to that of verifying that the implementation solves the associated decision task. We develop upon results from distributed systems and algebraic topology to construct a learning mechanism for verifying safety and liveness properties from samples of run-time executions.
MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE
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
Ensemble Kalman filters for dynamical systems with unresolved turbulence
Grooms, Ian; Lee, Yoonsang; Majda, Andrew J.
2014-09-15
Ensemble Kalman filters are developed for turbulent dynamical systems where the forecast model does not resolve all the active scales of motion. Coarse-resolution models are intended to predict the large-scale part of the true dynamics, but observations invariably include contributions from both the resolved large scales and the unresolved small scales. The error due to the contribution of unresolved scales to the observations, called ‘representation’ or ‘representativeness’ error, is often included as part of the observation error, in addition to the raw measurement error, when estimating the large-scale part of the system. It is here shown how stochastic superparameterization (a multiscale method for subgridscale parameterization) can be used to provide estimates of the statistics of the unresolved scales. In addition, a new framework is developed wherein small-scale statistics can be used to estimate both the resolved and unresolved components of the solution. The one-dimensional test problem from dispersive wave turbulence used here is computationally tractable yet is particularly difficult for filtering because of the non-Gaussian extreme event statistics and substantial small scale turbulence: a shallow energy spectrum proportional to k{sup ?5/6} (where k is the wavenumber) results in two-thirds of the climatological variance being carried by the unresolved small scales. Because the unresolved scales contain so much energy, filters that ignore the representation error fail utterly to provide meaningful estimates of the system state. Inclusion of a time-independent climatological estimate of the representation error in a standard framework leads to inaccurate estimates of the large-scale part of the signal; accurate estimates of the large scales are only achieved by using stochastic superparameterization to provide evolving, large-scale dependent predictions of the small-scale statistics. Again, because the unresolved scales contain so much energy, even an accurate estimate of the large-scale part of the system does not provide an accurate estimate of the true state. By providing simultaneous estimates of both the large- and small-scale parts of the solution, the new framework is able to provide accurate estimates of the true system state.
Quantum tomography meets dynamical systems and bifurcations theory
Goyeneche, D.; Torre, A. C. de la
2014-06-01
A powerful tool for studying geometrical problems in Hilbert spaces is developed. We demonstrate the convergence and robustness of our method in every dimension by considering dynamical systems theory. This method provides numerical solutions to hard problems involving many coupled nonlinear equations in low and high dimensions (e.g., quantum tomography problem, existence and classification of Pauli partners, mutually unbiased bases, complex Hadamard matrices, equiangular tight frames, etc.). Additionally, this tool can be used to find analytical solutions and also to implicitly prove the existence of solutions. Here, we develop the theory for the quantum pure state tomography problem in finite dimensions but this approach is straightforwardly extended to the rest of the problems. We prove that solutions are always attractive fixed points of a nonlinear operator explicitly given. As an application, we show that the statistics collected from three random orthonormal bases is enough to reconstruct pure states from experimental (noisy) data in every dimension d ? 32.
Evaluation of mutual information estimators on nonlinear dynamic systems
A. Papana; D. Kugiumtzis
2008-09-12
Mutual information is a nonlinear measure used in time series analysis in order to measure the linear and non-linear correlations at any lag $\\tau$. The aim of this study is to evaluate some of the most commonly used mutual information estimators, i.e. estimators based on histograms (with fixed or adaptive bin size), $k$-nearest neighbors and kernels. We assess the accuracy of the estimators by Monte-Carlo simulations on time series from nonlinear dynamical systems of varying complexity. As the true mutual information is generally unknown, we investigate the existence and rate of consistency of the estimators (convergence to a stable value with the increase of time series length), and the degree of deviation among the estimators. The results show that the $k$-nearest neighbor estimator is the most stable and less affected by the method-specific parameter.
Swarming behaviors in multi-agent systems with nonlinear dynamics
Yu, Wenwu; School of Electrical and Computer Engineering, RMIT University, Melbourne VIC 3001 ; Chen, Guanrong; Cao, Ming; Lü, Jinhu; Zhang, Hai-Tao
2013-12-15
The dynamic analysis of a continuous-time multi-agent swarm model with nonlinear profiles is investigated in this paper. It is shown that, under mild conditions, all agents in a swarm can reach cohesion within a finite time, where the upper bounds of the cohesion are derived in terms of the parameters of the swarm model. The results are then generalized by considering stochastic noise and switching between nonlinear profiles. Furthermore, swarm models with limited sensing range inducing changing communication topologies and unbounded repulsive interactions between agents are studied by switching system and nonsmooth analysis. Here, the sensing range of each agent is limited and the possibility of collision among nearby agents is high. Finally, simulation results are presented to demonstrate the validity of the theoretical analysis.
Quantum Dynamical Behaviour in Complex Systems - A Semiclassical Approach
Gliebe, Cheryn E; Ananth, Nandini
2008-05-22
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.
Nonlinear dynamics of a system of particle-like wavepackets
A. Babin; A. Figotin
2007-08-13
This work continues our studies of nonlinear evolution of a system of wavepackets. We study a wave propagation governed by a nonlinear system of hyperbolic PDE's with constant coefficients with the initial data being a multi-wavepacket. By definition a general wavepacket has a well defined principal wave vector, and, as we proved in previous works, the nonlinear dynamics preserves systems of wavepackets and their principal wave vectors. Here we study the nonlinear evolution of a special class of wavepackets, namely particle-like wavepackets. A particle-like wavepacket is of a dual nature: on one hand, it is a wave with a well defined principal wave vector, on the other hand, it a particle in the sense that it can be assigned a well defined position in the space. We prove that under the nonlinear evolution a generic multi-particle wavepacket remains to be a multi-particle wavepacket with a high accuracy, and every constituting single particle-like wavepacket not only preserves its principal wave number but also it has a well-defined space position evolving with a constant velocity which is its group velocity. Remarkably the described properties hold though the involved single particle-like wavepackets undergo nonlinear interactions and multiple collisions in the space. We also prove that if principal wavevectors of multi-particle wavepacket are generic, the result of nonlinear interactions between different wavepackets is small and the approximate linear superposition principle holds uniformly with respect to the initial spatial positions of wavepackets.
Dynamic Power Management in a Mobile Multimedia System with Guaranteed Quality-of-Service*
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 Qiu, Qing Wu, and Massoud Pedram Department of Electrical Engineering-Systems University of Southern
Xu, Haiping
that DRBD provides a powerful tool for system reliability modeling, and our proposed verification approachFORMAL SEMANTICS AND VERIFICATION OF DYNAMIC RELIABILITY BLOCK DIAGRAMS FOR SYSTEM RELIABILITY-scale computer-based systems. KEY WORDS Reliability modeling, dynamic reliability block diagrams (DRBD), Object
A SIMPLE CLOSURE APPROXIMATION FOR SLOW DYNAMICS OF A MULTISCALE SYSTEM: NONLINEAR AND
Abramov, Rafail
A SIMPLE CLOSURE APPROXIMATION FOR SLOW DYNAMICS OF A MULTISCALE SYSTEM: NONLINEAR response, multiscale systems, nonlinear coupling AMS subject classifications. 37M, 37N 1. Introduction slow and fast variables of the system. Many closure methods were designed for multiscale dynamical
Integrated system dynamics toolbox for water resources planning.
Reno, Marissa Devan; Passell, Howard David; Malczynski, Leonard A.; Peplinski, William J.; Tidwell, Vincent Carroll; Coursey, Don; Hanson, Jason; Grimsrud, Kristine; Thacher, Jennifer; Broadbent, Craig; Brookshire, David; Chemak, Janie; Cockerill, Kristan; Aragon, Carlos , Socorro, NM); Hallett, Heather , Socorro, NM); Vivoni, Enrique , Socorro, NM); Roach, Jesse
2006-12-01
Public mediated resource planning is quickly becoming the norm rather than the exception. Unfortunately, supporting tools are lacking that interactively engage the public in the decision-making process and integrate over the myriad values that influence water policy. In the pages of this report we document the first steps toward developing a specialized decision framework to meet this need; specifically, a modular and generic resource-planning ''toolbox''. The technical challenge lies in the integration of the disparate systems of hydrology, ecology, climate, demographics, economics, policy and law, each of which influence the supply and demand for water. Specifically, these systems, their associated processes, and most importantly the constitutive relations that link them must be identified, abstracted, and quantified. For this reason, the toolbox forms a collection of process modules and constitutive relations that the analyst can ''swap'' in and out to model the physical and social systems unique to their problem. This toolbox with all of its modules is developed within the common computational platform of system dynamics linked to a Geographical Information System (GIS). Development of this resource-planning toolbox represents an important foundational element of the proposed interagency center for Computer Aided Dispute Resolution (CADRe). The Center's mission is to manage water conflict through the application of computer-aided collaborative decision-making methods. The Center will promote the use of decision-support technologies within collaborative stakeholder processes to help stakeholders find common ground and create mutually beneficial water management solutions. The Center will also serve to develop new methods and technologies to help federal, state and local water managers find innovative and balanced solutions to the nation's most vexing water problems. The toolbox is an important step toward achieving the technology development goals of this center.
Ultrafast Structural Dynamics in Combustion Relevant Model Systems
Weber, Peter M.
2014-03-31
The research project explored the time resolved structural dynamics of important model reaction system using an array of novel methods that were developed specifically for this purpose. They include time resolved electron diffraction, time resolved relativistic electron diffraction, and time resolved Rydberg fingerprint spectroscopy. Toward the end of the funding period, we also developed time-resolved x-ray diffraction, which uses ultrafast x-ray pulses at LCLS. Those experiments are just now blossoming, as the funding period expired. In the following, the time resolved Rydberg Fingerprint Spectroscopy is discussed in some detail, as it has been a very productive method. The binding energy of an electron in a Rydberg state, that is, the energy difference between the Rydberg level and the ground state of the molecular ion, has been found to be a uniquely powerful tool to characterize the molecular structure. To rationalize the structure sensitivity we invoke a picture from electron diffraction: when it passes the molecular ion core, the Rydberg electron experiences a phase shift compared to an electron in a hydrogen atom. This phase shift requires an adjustment of the binding energy of the electron, which is measurable. As in electron diffraction, the phase shift depends on the molecular, geometrical structure, so that a measurement of the electron binding energy can be interpreted as a measurement of the 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
Behavioral/Systems/Cognitive Inhibition Determines Membrane Potential Dynamics and
Destexhe, Alain
with computational models to investi- gate subthreshold dynamics of conductances and how conductance dynamics contribution to membrane potential fluctuations. Computational models predict that in such inhibition and unconscious cortical states. Key words: intracellular recordings; conductance analysis; cerebral cortex
Rapid gas hydrate formation processes: Will they work?
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.
2010-06-07
Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETL’s 15-Liter Hydrate Cell. The results from this work demonstrate that the rapid and continuousmore »formation of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.« less
Rapid Gas Hydrate Formation Processes: Will They Work?
Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.
2010-06-01
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.
In silico studies of the properties of water hydrating a small protein
Sinha, Sudipta Kumar; Chakraborty, Kausik; Bandyopadhyay, Sanjoy; Jana, Madhurima
2014-12-14
Atomistic molecular dynamics simulation of an aqueous solution of the small protein HP-36 has been carried out with explicit solvent at room temperature. Efforts have been made to explore the influence of the protein on the relative packing and ordering of water molecules around its secondary structures, namely, three ?-helices. The calculations reveal that the inhomogeneous water ordering and density distributions around the helices are correlated with their relative hydrophobicity. Importantly, we have identified the existence of a narrow relatively dehydrated region containing randomly organized “quasi-free” water molecules beyond the first layer of “bound” waters at the protein surface. These water molecules with relatively weaker binding energies form the transition state separating the “bound” and “free” water molecules at the interface. Further, increased contribution of solid-like caging motions of water molecules around the protein is found to be responsible for reduced fluidity of the hydration layer. Interestingly, we notice that the hydration layer of helix-3 is more fluidic with relatively higher entropy as compared to the hydration layers of the other two helical segments. Such characteristics of helix-3 hydration layer correlate well with the activity of HP-36, as helix-3 contains the active site of the protein.
Neutron scattering evidence of a boson peak in protein hydration water Alessandro Paciaroni,1
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
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
On theoretical issues of computer simulations sequential dynamical systems
Barrett, C.L.; Mortveit, H.S.; Reidys, C.M.
1998-12-01
The authors study a class of discrete dynamical systems that is motivated by the generic structure of simulations. The systems consist of the following data: (a) a finite graph Y with vertex set {l_brace}1,...,n{r_brace} where each vertex has a binary state, (b) functions F{sub i}:F{sub 2}{sup n} {r_arrow} F{sub 2}{sup n} and (c) an update ordering {pi}. The functions F{sub i} update the binary state of vertex i as a function of the state of vertex i and its Y-neighbors and leave the states of all other vertices fixed. The update ordering is a permutation of the Y-vertices. They derive a decomposition result, characterize invertible SDS and study fixed points. In particular they analyze how many different SDS that can be obtained by reordering a given multiset of update functions and give a criterion for when one can derive concentration results on this number. Finally, some specific SDS are investigated.
1992-12-31
Natural gas hydrates are solid crystalline compounds which form when molecules smaller than n-butane contact molecules of water at elevated pressures and reduced temperatures, both above and below the ice point. Because these crystalline compounds plug flow channels, they are undesirable. In this project the authors proposed an alternate approach of controlling hydrate formation by preventing hydrate growth into a sizeable mass which could block a flow channel. The authors call this new technique kinetic inhibition, because while it allows the system to exist in the hydrate domain, it prevents the kinetic agglomeration of small hydrate crystals to the point of pluggage of a flow channel. In order to investigate the kinetic means of inhibiting hydrate formation, they held two consortium meetings, on June 1, 1990 and on August 31, 1990. At subsequent meetings, the authors determined the following four stages of the project, necessary to reach the goal of determining a new hydrate field inhibitor: (1) a rapid screening method was to be determined for testing the hydrate kinetic formation period of many surfactants and polymer candidates (both individually and combined), the present report presents the success of two screening apparatuses: a multi-reactor apparatus which is capable of rapid, high volume screening, and the backup screening method--a viscometer for testing with gas at high pressure; (2) the construction of two high, constant pressure cells were to experimentally confirm the success of the chemicals in the rapid screening apparatus; (3) in the third phase of the work, Exxon volunteered to evaluate the performance of the best chemicals from the previous two stages in their 4 inch I.D. Multiphase flow loop in Houston; (4) in the final phase of the work, the intention was to take the successful kinetic inhibition chemicals from the previous three stages and then test them in the field in gathering lines and wells from member companies.
Dutta, Parikshit
2012-10-19
Recently there has been growing interest to characterize and reduce uncertainty in stochastic dynamical systems. This drive arises out of need to manage uncertainty in complex, high dimensional physical systems. Traditional ...
Butcher, Eric A.
2005-01-01
coefficients such as the dynamics of rotating systems, like helicopter blades, asymmetric rotor-bearing systems and structures subjected to periodic loadings, etc. For the purpose of modal analysis, control and model test
Modeling the resource consumption of Housing in New Orleans using System Dynamics
Quinn, David James, Ph. D. Massachusetts Institute of Technology
2008-01-01
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 ...
Dynamic Modeling and Wavelet-Based Multi-Parametric Tuning and Validation for HVAC Systems
Liang, Shuangshuang
2014-07-10
Dynamic Heating, Ventilation, and Air-Conditioning (HVAC) system models are used for the purpose of control design, fault detection and diagnosis, system analysis, design and optimization. Therefore, ensuring the accuracy ...
An innovative dynamic bus lane system and its simulation-based performance investigation
Yang, Hong
The strategy of exempting bus from other traffic through exclusive bus lanes (XBL) is prevalent. Rather than just deploying the XBL system, in this study, a new innovative dynamic bus lane (DBL) operation system which is ...
Real-Time Trajectory Generation for Constrained Nonlinear Dynamical Systems Using
Murray, Richard M.
Systems, California Institute of Technology, · John Doyle, Control and Dynamical Systems, Electrical possible without the love and support of my wife. Mali, you are by far the best thing that has ever
A Self-Repairing Peer-to-Peer System Resilient to Dynamic Adversarial Churn
A Self-Repairing Peer-to-Peer System Resilient to Dynamic Adversarial Churn Fabian Kuhn, Stefan at any time. Such peers join and leave the P2P system at high rates ("churn"), a problem
A Self-Repairing Peer-to-Peer System Resilient to Dynamic Adversarial Churn
A Self-Repairing Peer-to-Peer System Resilient to Dynamic Adversarial Churn Fabian Kuhn, Stefan rates ("churn"), a problem that is not existent in orthodox distributed systems. In other words, a P2P
Coalbed Methane Procduced Water Treatment Using Gas Hydrate Formation at the Wellhead
BC Technologies
2009-12-30
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.
State-Boundedness in Data-Aware Dynamic Systems Babak Bagheri Hariri
Calvanese, Diego
relaxations of the sufficient conditions proposed in the concrete setting of Data-Centric Dynamic Systems, such as data-centric workflows (Vianu 2009) and business artifacts (Hull 2008), where the static (i.e., data for the verification of state-bounded Data-Centric Dynamic Systems (DCDSs) against a first-order variant of the µ
Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting
Qiu, Qinru
Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting}@binghamton.edu Abstract In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm energy and the harvested energy in a future duration. Specifically, if the system has sufficient energy
Dang, Zhe
Bond Computing Systems: a Biologically Inspired and High-level Dynamics Model for Pervasive. Targeting at modeling the high-level dynamics of pervasive comput- ing systems, we introduce Bond Computing are regular, and study their computation power and verification problems. Among other results, we show
Dynamic behaviour of a DFIG wind turbine subjected to power system faults
Dynamic behaviour of a DFIG wind turbine subjected to power system faults Gabriele Michalke+, Anca Laboratory, Wind Energy Department, P.O. Box 49, DK-4000 Roskilde, Denmark Email: gmichalke of the dynamic interaction between variable speed DFIG wind turbines and the power system subjected
Using System Dynamics to Extend Real Options Use: Insights from the Oil & Gas Industry
Ford, David N.
Using System Dynamics to Extend Real Options Use: Insights from the Oil & Gas Industry Scott to real options through work with a major energy firm to apply real options. Five key challenges facing the real options community are presented and potential system dynamics contributions to these challenges
A COMPUTATIONAL METHOD TO EXTRACT MACROSCOPIC VARIABLES AND THEIR DYNAMICS IN MULTISCALE SYSTEMS
Gottwald, Georg A.
A COMPUTATIONAL METHOD TO EXTRACT MACROSCOPIC VARIABLES AND THEIR DYNAMICS IN MULTISCALE SYSTEMS-independent methods for analysing multiscale dy- namical systems using numerical techniques based on the transfer operator and its adjoint. In particular, we present a method for testing whether an arbitrary dynamical
Lyapunov Analysis Captures the Collective Dynamics of Large Chaotic Systems Kazumasa A. Takeuchi,1,2
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
Operator renewal theory and mixing rates for dynamical systems with infinite measure
Operator renewal theory and mixing rates for dynamical systems with infinite measure Ian Melbourne renewal sequences in the context of infinite ergodic theory. For large classes of dynamical systems technique, operator renewal theory, to obtain precise asymptotics and hence sharp mixing rates
Zheng, M.; Kong, F.; Han, Z.; Liu, W.
2006-01-01
expansion dynamic ice-on-coil storage system that overcame the disadvantages of static and dynamic ice-storage system. It is concluded that periodic ice moving avoids the increased heat resistance that creates a decreased evaporating temperature. Due to a...
Obradovic, Zoran
Towards understanding dominant processes in complex dynamical systems: Case of precipitation.obradovic@temple.edu ABSTRACT Complex dynamical systems like precipitation extremes under climate variability or change to characterize the effect of dominant processes on precipitation extremes, annually and seasonally, and from
Moridis, G.J.
2010-01-01
Mallik 2002 Gas Hydrate Production Research Well Program,Of Methane Hydrate Production Methods To Reservoirs WithNumerical Studies of Gas Production From Methane Hydrates,
Moridis, George J.
2008-01-01
Mallik Gas Hydrate Production Research Program, Northwestof Depressurization for Gas Production from Gas Hydrate5L-38 Gas Hydrate Thermal Production Test Through Numerical
Temperature and Tidal Dynamics in a Branching Estuarine System
Wagner, Richard Wayne
2012-01-01
Migrating through the Sacramento-San-Joaquin River Delta ofEnvisioning Futures for the Sacramento-San Joaquin Delta (Population Dynamics of Sacramento Splittail (Pogonichthys
Atomistic Simulation of Nafion Membrane: 2. Dynamics of Water Molecules and Hydronium Ions
Devanathan, Ram; Venkatnathan, Arun; Dupuis, Michel
2007-10-20
We have performed a detailed and comprehensive analysis of the dynamics of water molecules and hydronium ions in hydrated Nafion using classical molecular dynamics simulations with the DREIDING force field. In addition to calculating diffusion coefficients as a function of hydration level, we have also determined mean residence time of H2O molecules and H3O+ ions in the first solvation shell of SO3- groups. The diffusion coefficient of H2O molecules increases with increasing hydration level and is in good agreement with experiment. The mean residence time of H2O molecules decreases with increasing membrane hydration from 1 ns at a low hydration level to 75 ps at the highest hydration level studied. These dynamical changes are related to the changes in membrane nanostructure reported in the first part of this work. Our results provide insights into slow proton dynamics observed in neutron scattering experiments and are consistent with the Gebel model of Nafion structure.
Quantum extensions of dynamical systems and of Markov semigroups
Ivan Bardet
2015-09-16
We investigate some particular completely positive maps which admit a stable commutative Von Neumann subalgebra. The restriction of such maps to the stable algebra is then a Markov operator. In the first part of this article, we propose a recipe in order to find a quantum extension of a given Markov operator in the above sense. We show that the existence of such an extension is linked with the existence of a special form of dilation for the Markov operator studied by Attal in \\cite{Att1}, reducing the problem to the extension of dynamical system. We then apply our method to the same problem in continuous time, proving the existence of a quantum extension for L\\'evy processes. In the second part of this article, we focus on the case where the commutative algebra is isomorphic to $\\Acal=l^\\infty(1,...,N)$ with $N$ either finite or infinite. We propose a classification of the CP maps leaving $\\Acal$ stable, producing physical examples of each classes.
Description of waste pretreatment and interfacing systems dynamic simulation model
Garbrick, D.J.; Zimmerman, B.D.
1995-05-01
The Waste Pretreatment and Interfacing Systems Dynamic Simulation Model was created to investigate the required pretreatment facility processing rates for both high level and low level waste so that the vitrification of tank waste can be completed according to the milestones defined in the Tri-Party Agreement (TPA). In order to achieve this objective, the processes upstream and downstream of the pretreatment facilities must also be included. The simulation model starts with retrieval of tank waste and ends with vitrification for both low level and high level wastes. This report describes the results of three simulation cases: one based on suggested average facility processing rates, one with facility rates determined so that approximately 6 new DSTs are required, and one with facility rates determined so that approximately no new DSTs are required. It appears, based on the simulation results, that reasonable facility processing rates can be selected so that no new DSTs are required by the TWRS program. However, this conclusion must be viewed with respect to the modeling assumptions, described in detail in the report. Also included in the report, in an appendix, are results of two sensitivity cases: one with glass plant water recycle steams recycled versus not recycled, and one employing the TPA SST retrieval schedule versus a more uniform SST retrieval schedule. Both recycling and retrieval schedule appear to have a significant impact on overall tank usage.
Extreme event statistics of daily rainfall: Dynamical systems approach
G. Cigdem Yalcin; Pau Rabassa; Christian Beck
2015-08-15
We analyse the probability densities of daily rainfall amounts at a variety of locations on the Earth. The observed distributions of the amount of rainfall fit well to a q-exponential distribution with exponent q close to q=1.3. We discuss possible reasons for the emergence of this power law. On the contrary, the waiting time distribution between rainy days is observed to follow a near-exponential distribution. A careful investigation shows that a q-exponential with q=1.05 yields actually the best fit of the data. A Poisson process where the rate fluctuates slightly in a superstatistical way is discussed as a possible model for this. We discuss the extreme value statistics for extreme daily rainfall, which can potentially lead to flooding. This is described by Frechet distributions as the corresponding distributions of the amount of daily rainfall decay with a power law. On the other hand, looking at extreme event statistics of waiting times between rainy days (leading to droughts for very long dry periods) we obtain from the observed near-exponential decay of waiting times an extreme event statistics close to Gumbel distributions. We discuss superstatistical dynamical systems as simple models in this context.
Methane Hydrate Program Annual Report to Congress
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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPAEnergy May 28 WebinarProtectMessageFY 2010 Methane Hydrate
Development of Alaskan gas hydrate resources. Final report
Kamath, V.A.; Sharma, G.D.; Patil, S.L.
1991-06-01
The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.
Method for the photocatalytic conversion of gas hydrates
Taylor, Charles E. (Pittsburg, PA); Noceti, Richard P. (Pittsburg, PA); Bockrath, Bradley C. (Bethel Park, PA)
2001-01-01
A method for converting methane hydrates to methanol, as well as hydrogen, through exposure to light. The process includes conversion of methane hydrates by light where a radical initiator has been added, and may be modified to include the conversion of methane hydrates with light where a photocatalyst doped by a suitable metal and an electron transfer agent to produce methanol and hydrogen. The present invention operates at temperatures below 0.degree. C., and allows for the direct conversion of methane contained within the hydrate in situ.
Geomechanical Performance of Hydrate-Bearing Sediment in Offshore Environments
Stephen Holditch; Tad Patzek; Jonny Rutqvist; George Moridis; Richard Plumb
2008-03-31
The objective of this multi-year, multi-institutional research project was to develop the knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate-bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus was on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. We have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. We also investigated the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. The objective of the UC Berkeley work was to develop a grain-scale model of hydrate-bearing sediments. Hydrate dissociation alters the strength of HBS. In particular, transformation of hydrate clusters into gas and liquid water weakens the skeleton and, simultaneously, reduces the effective stress by increasing the pore pressure. The large-scale objective of the study is evaluation of geomechanical stability of offshore oil and gas production infrastructure. At Lawrence Berkeley National Laboratory (LBNL), we have developed the numerical model TOUGH + Hydrate + FLAC3D to evaluate how the formation and disassociation of hydrates in seafloor sediments affects seafloor stability. Several technical papers were published using results from this model. LBNL also developed laboratory equipment and methods to produce realistic laboratory samples of sediments containing gas hydrates so that mechanical properties could be measured in the laboratory. These properties are required to run TOUGH + Hydrate + FLAC3D to evaluate seafloor stability issues. At Texas A&M University we performed a detailed literature review to determine what gas hydrate formation properties had been measured and reported in the literature. We then used TOUGH + Hydrate to simulate the observed gas production and reservoir pressure field data at Messoyakha. We simulated various scenarios that help to explain the field behavior. We have evaluated the effect of reservoir parameters on gas recovery from hydrates. Our work should be beneficial to others who are investigating how to produce gas from a hydrate capped gas reservoir. The results also can be used to better evaluate the process of producing gas from offshore hydrates. The Schlumberger PETREL model is used in industry to the description of geologic horizons and the special distribution of properties. An interface between FLAC3D and Petrel was built by Schlumberger to allow for efficient data entry into TOUGH + Hydrate + FLAC3D.
Oil & Natural Gas Technology Temporal Characterization of Hydrates...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
controlled by both deep and near- surface structure. Results have been integrated with seismic data from the area and show correspondence in space of hydrate and structures,...
On the dynamics near the Lagrangian points of the real Earth-Moon system
Barcelona, Universitat de
On the dynamics near the Lagrangian points of the real Earth-Moon system #3; Enric Castell#18;a particle near the equi- lateral points of the real Earth-Moon system. We use, as real system, the one hand, we can consider one of the most accurate models of the Solar system now available, which
DYNAMIC MANAGEMENT OF NETWORK SYSTEMS Syed Yousaf Shah
Linhardt, Robert J.
OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi LIST OF FIGURES . . . . . . . . . . . . . 16 3.3 Dynamic Price Based Routing (PBR) . . . . . . . . . . . . . . . . . . . . 17 3 . . . . . . . . . . . . . . . . . . . . 29 3.5 Price Based Routing for Network Resource Management . . . . . . . . . 33 3.6 Concluding
Human Growth and Body Weight Dynamics: An Integrative Systems Model
Rahmandad, Hazhir
Quantifying human weight and height dynamics due to growth, aging, and energy balance can inform clinical practice and policy analysis. This paper presents the first mechanism-based model spanning full individual life and ...
Piepenbrock, Theodore F. (Theodore Frederick), 1965-
2004-01-01
As the business world is neither linear nor static, the mastery of its "chaotic" nonlinear dynamics lies at the heart of finding high-leverage policies that return uncommon benefits for marginal costs. Today's global ...
Kneafsey, T.
2012-01-01
S.S.H. , 1987. Kinetics of Methane Hydrate Decomposition,T. J. , et al. (2007), Methane Hydrate Formation andCharting the future of methane hydrate research in the
Contribution of oceanic gas hydrate dissociation to the formation of Arctic Ocean methane plumes
Reagan, M.
2012-01-01
Potential distribution of methane hydrate in the world'sisotopic evidence for methane hydrate instability duringHendy, L.L. , and R.J. Behl, Methane hydrates in quaternary
Insights into the structure of mixed CO2/CH4 in gas hydrates
Everett, Susan M; Rawn, Claudia J; Chakoumakos, Bryan C; Keffer, David J.; Huq, Ashfia; Phelps, Tommy Joe
2015-01-01
The exchange of CO2 for CH4 in natural gas hydrates is an attractive approach to methane for energy production while simultaneously sequestering CO2. In addition to the energy and environmental implications, the solid solution of clathrate hydrate (CH4)1-x(CO2)x 5.75H2O provides a model system to study how the distinct bonding and shapes of CH4 and CO2 influence the structure and properties of the compound. High-resolution neutron diffraction was used to examine mixed CO2/CH4 gas hydrates. CO2-rich hydrates had smaller lattice parameters, which were attributed to the higher affinity of the CO2 molecule interacting with H2O molecules that form the surrounding cages, and resulted in a reduction in the unit cell volume. Experimental nuclear scattering densities illustrate how the cage occupants and energy landscape change with composition. These results provide important insights on the impact and mechanisms for exchanging CH4 and CO2.
Electron beam dynamics for the ISIS bremsstrahlung beam generation system
Block, Robert E. (Robert Edward)
2011-01-01
An electron beam transport system was designed for use in the Bremsstrahlung Beam Generation System of the Integrated Stand-off Inspection System (ISIS). The purpose of this electron transport system was to provide for ...
Guo, Yi
BULK POWER SYSTEM DYNAMICS AND CONTROL V, AUGUST 26-31, 2001, ONOMICHI, JAPAN Global Hybrid Control| This paper presents an overview of recent results on an ap- proach to total control of power systems con- trol for voltage security of power systems, and same ideas for general control [1{6]. In arriving
Quantum diffusion dynamics in nonlinear systems: A modified kicked-rotor model
Gong Jiangbin [Department of Physics and Centre of Computational Science and Engineering, National University of Singapore, 117542 (Singapore); Wang Jiao [Temasek Laboratories and Beijing-Hong Kong-Singapore Joint Center for Nonlinear and Complex Systems (Singapore), National University of Singapore, 117542 (Singapore)
2007-09-15
Using a simple method analogous to a quantum rephasing technique, a simple modification to a paradigm of classical and quantum chaos is proposed. The interesting quantum maps thus obtained display remarkably rich quantum dynamics. Emphasis is placed on the destruction of dynamical localization without breaking periodicity, unbounded quantum anomalous diffusion in integrable systems, and transient dynamical localization. Experimental realizations of this work are also discussed.
SIAM conference on applications of dynamical systems. Abstracts and author index
Not Available
1992-12-31
A conference (Oct.15--19, 1992, Snowbird, Utah; sponsored by SIAM (Society for Industrial and Applied Mathematics) Activity Group on Dynamical Systems) was held that highlighted recent developments in applied dynamical systems. The main lectures and minisymposia covered theory about chaotic motion, applications in high energy physics and heart fibrillations, turbulent motion, Henon map and attractor, integrable problems in classical physics, pattern formation in chemical reactions, etc. The conference fostered an exchange between mathematicians working on theoretical issues of modern dynamical systems and applied scientists. This two-part document contains abstracts, conference program, and an author index.
Surfactant process for promoting gas hydrate formation and application of the same
Rogers, Rudy E. (Starkville, MS); Zhong, Yu (Brandon, MS)
2002-01-01
This invention relates to a method of storing gas using gas hydrates comprising forming gas hydrates in the presence of a water-surfactant solution that comprises water and surfactant. The addition of minor amounts of surfactant increases the gas hydrate formation rate, increases packing density of the solid hydrate mass and simplifies the formation-storage-decomposition process of gas hydrates. The minor amounts of surfactant also enhance the potential of gas hydrates for industrial storage applications.
Banaszuk, Andrzej; Frewen, Thomas A; Kobilarov, Marin; Mathew, George; Mezic, Igor; Pinto, Alessandro; Sahai, Tuhin; Sane, Harshad; Speranzon, Alberto; Surana, Amit
2011-01-01
Development of robust dynamical systems and networks such as autonomous aircraft systems capable of accomplishing complex missions faces challenges due to the dynamically evolving uncertainties coming from model uncertainties, necessity to operate in a hostile cluttered urban environment, and the distributed and dynamic nature of the communication and computation resources. Model-based robust design is difficult because of the complexity of the hybrid dynamic models including continuous vehicle dynamics, the discrete models of computations and communications, and the size of the problem. We will overview recent advances in methodology and tools to model, analyze, and design robust autonomous aerospace systems operating in uncertain environment, with stress on efficient uncertainty quantification and robust design using the case studies of the mission including model-based target tracking and search, and trajectory planning in uncertain urban environment. To show that the methodology is generally applicable to...
CO{sub 2} HYDRATE PROCESS FOR GAS SEPARATION
G. Deppe; R. Currier; D. Spencer
2004-01-01
Modifications were implemented to the hydrogen flow test rig per safety review comments, and the apparatus was tested for leaks. Tests were then done using Helium/CO{sub 2} mixtures to re-verify performance prior to hydrogen testing. It was discovered that hydrate formation was more difficult to initiate, and new initiation methods were developed to improve the tests. Delivery of ETM hardware continued and buildup of the ETM system continued, the ETM is now mechanically complete. The STU (pilot plant) site selection process was resumed because Tennessee Eastman declined to participate in the program. Two potential sites were visited: The Global Energy/Conoco-Phillips Wabash River Plant, and the Tampa Electric Polk Power Plant.
P. H. Chavanis
2006-02-20
We complete previous investigations on the dynamical stability of barotropic stars and collisionless stellar systems. A barotropic star that minimizes the energy functional at fixed mass is a nonlinearly dynamically stable stationary solution of the Euler-Poisson system. Formally, this minimization problem is similar to a condition of ``canonical stability'' in thermodynamics. A stellar system that maximizes an H-function at fixed mass and energy is a nonlinearly dynamically stable stationary solution of the Vlasov-Poisson system. Formally, this maximization problem is similar to a condition of ``microcanonical stability'' in thermodynamics. Using a thermodynamical analogy, we provide a derivation and an interpretation of the nonlinear Antonov first law in terms of ``ensembles inequivalence'': a spherical stellar system with f=f(epsilon) and f'(epsilon)nonlinearly dynamically stable with respect to the Vlasov-Poisson system if the corresponding barotropic star with the same equilibrium density distribution is nonlinearly dynamically stable with respect to the Euler-Poisson system. This is similar to the fact that ``canonical stability implies microcanonical stability'' in thermodynamics. The converse is wrong in case of ``ensembles inequivalence'' which is generic for systems with long-range interactions like gravity. We show that criteria of nonlinear dynamical stability can be obtained very simply from purely graphical constructions by using the method of series of equilibria and the turning point argument of Poincare, as in thermodynamics.
Natural gas hydrates on the North Slope of Alaska
Collett, T.S.
1991-01-01
Gas hydrates are crystalline substances composed of water and gas, mainly methane, in which a solid-water lattice accommodates gas molecules in a cage-like structure, or clathrate. These substances often have been regarded as a potential (unconventional) source of natural gas. Significant quantities of naturally occurring gas hydrates have been detected in many regions of the Arctic including Siberia, the Mackenzie River Delta, and the North Slope of Alaska. On the North Slope, the methane-hydrate stability zone is areally extensive beneath most of the coastal plain province and has thicknesses as great as 1000 meters in the Prudhoe Bay area. Gas hydrates have been identified in 50 exploratory and production wells using well-log responses calibrated to the response of an interval in one well where gas hydrates were recovered in a core by ARCO Alaska and EXXON. Most of these gas hydrates occur in six laterally continuous Upper Cretaceous and lower Tertiary sandstone and conglomerate units; all these gas hydrates are geographically restricted to the area overlying the eastern part of the Kuparuk River Oil Field and the western part of the Prudhoe Bay Oil Field. The volume of gas within these gas hydrates is estimated to be about 1.0 {times} 10{sup 12} to 1.2 {times} 10{sup 12} cubic meters (37 to 44 trillion cubic feet), or about twice the volume of conventional gas in the Prudhoe Bay Field. Geochemical analyses of well samples suggest that the identified hydrates probably contain a mixture of deep-source thermogenic gas and shallow microbial gas that was either directly converted to gas hydrate or first concentrated in existing traps and later converted to gas hydrate. The thermogenic gas probably migrated from deeper reservoirs along the same faults thought to be migration pathways for the large volumes of shallow, heavy oil that occur in this area. 51 refs., 11 figs., 3 tabs.
Lai, Ying-Cheng
Predicting Catastrophes in Nonlinear Dynamical Systems by Compressive Sensing Wen-Xu Wang,1,* Rui that on the attractor before the crisis. Suppose that, for a nonlinear dynamical system, the state before the crisis the problem of predicting catastrophes in nonlinear dynamical systems. We assume that an accurate model
Lai, Ying-Cheng
2015-01-01
bifurcation of a nonlinear dynamical system can be unequivocally uncovered through adiabatic parameter of nonlinear dynamical systems. DOI: 10.1103/PhysRevE.91.022906 PACS number(s): 05.45.-a I. INTRODUCTION Fundamental to nonlinear dynamical systems is a rich variety of bifurcation phenomena. As a control parameter
Coupling neural networks to incomplete dynamical systems via variational data assimilation
Hsieh, William
Coupling neural networks to incomplete dynamical systems via variational data assimilationforward neural network (NN) model opens the possibility of hybrid neuraldynamical models via variational data value decomposition (SVD) (Syu and Neelin 1995), or by a neural network (Tang et al. 1999). While
Real Time Dynamic Wind Calculation for a Pressure Driven Wind System Criss Martin
Parberry, Ian
Real Time Dynamic Wind Calculation for a Pressure Driven Wind System Criss Martin Dept. of Computer University of North Texas Abstract We describe real time dynamic wind calculation for a pressure driven wind fraction of the CPU's processing power over and above what is required for static wind. Experiments were
Integration and Dynamics of a Renewable Regenerative Hydrogen Fuel Cell System
Victoria, University of
Integration and Dynamics of a Renewable Regenerative Hydrogen Fuel Cell System by Alvin Peter, hydrogen and electricity storage, and fuel cells. A special design feature of this test bed is the ability of the author. #12;ii Supervisory Committee Integration and Dynamics of a Renewable Regenerative Hydrogen Fuel
Microfluidic systems for single DNA dynamics Danielle J. Mai,a
Schroeder, Charles
Microfluidic systems for single DNA dynamics Danielle J. Mai,a Christopher Brockmana and Charles M in microfluidics have enabled the molecular-level study of polymer dynamics using single DNA chains. Single polymer. Microfluidic devices have enabled the precise control of model flow fields to study the non
Berning, Torsten
Aalborg Universitet Dynamic Modeling of a Reformed Methanol Fuel Cell System using Empirical Data Reza Published in: Journal of Fuel Cell Science and Technology DOI (link to publication from Publisher. K., Andreasen, S. J., & Shaker, H. R. (2014). Dynamic Modeling of a Reformed Methanol Fuel Cell
VIRTUAL TIME BASED DYNAMIC LOAD MANAGEMENT IN THE TIME WARP OPERATING SYSTEM
California at Los Angeles, University of
VIRTUAL TIME BASED DYNAMIC LOAD MANAGEMENT IN THE TIME WARP OPERATING SYSTEM Peter L. Reiher Jet on parallel machines. Recently TWOS has been substantially improved by the addition of dynamic load management to processors. Because TWOS uses optimistic synchronization, existing load management theory, which tends
Dynamic online optimization of a house heating system in a fluctuating energy price
Skogestad, Sigurd
Dynamic online optimization of a house heating system in a fluctuating energy price scenario in this problem is the time- varying nature of the main disturbances, which are the energy price and outdoor that there is a great economical gain in using dynamic optimization for the case of variable energy price. 1
PreDVS: Preemptive Dynamic Voltage Scaling for Real-time Systems using Approximation Scheme
Mishra, Prabhat
, dynamic voltage scal- ing, approximation algorithm 1. INTRODUCTION Energy conservation has been the main to save energy is that linear reduction in the supply voltage leads to approximately linear slow downPreDVS: Preemptive Dynamic Voltage Scaling for Real-time Systems using Approximation Scheme Weixun
Operator renewal theory and mixing rates for dynamical systems with in nite measure
Operator renewal theory and mixing rates for dynamical systems with in#12;nite measure Ian of operator renewal sequences in the context of in#12;nite ergodic theory. For large classes of dynamical for mixing rates. Sarig [37] introduced a powerful new technique, operator renewal theory, to obtain precise
Sensitivity Analysis of Gas Production from Class 2 and Class 3 Hydrate Deposits
Reagan, Matthew
2009-01-01
during production from a Class 2 oceanic deposit withinduced gas production from Class 1 hydrate deposits,” (Gas Production From Oceanic Class 3 Hydrate Accumulations”
Kneafsey, T.
2012-01-01
in a Mount Elbert Sandstone Sample: Experimentalsample of hydrate-bearing sandstone from the Mount Elbertsample of hydrate-bearing sandstone from the Mount Elbert
Dynamical formulations and control of an automatic retargeting system
Sovinsky, Michael Charles
2007-04-25
will not greatly increase the workload of the weapon systems. The first step of this new algorithm is the same as the last method, a weapon systems will find their priority target. Now, during the weapon system?s the initial movement, the weapon systems...
Fundamental measure theory of hydrated hydrocarbons
Victor F. Sokolov; Gennady N. Chuev
2006-04-13
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.
Broader source: Energy.gov (indexed) [DOE]
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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOE Safetyof Methane Hydrate Program Annual Report to Congress
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matter ByMentor-ProtegeFromGas Hydrates R&D Program Gas
Boutchko, R.
2014-01-01
emission tomography systems and computational fluid dynamicsa computational ?uid dynamics (CFD) model of the systemthe computational domain. A Cartesian coordinate system was
Lai, Ying-Cheng
2013-01-01
730000, China 2 School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe in complex dynamical systems with significant applications to social, economical, and political systems. DOI
Jordan, Rhonda LeNai
2013-01-01
This research develops a novel approach to long-term power system capacity expansion planning for developing countries by incorporating endogenous demand dynamics resulting from social processes of technology adoption. ...
Stochastic Stabilization of Dynamical Systems using Levy David Applebaum and Michailina Siakalli
Applebaum, David
Stochastic Stabilization of Dynamical Systems using LÂ´evy Noise David Applebaum and Michailina is a Carr-Geman-Madan-Yor (or CGMY) process. In section 6 we examine the special case where an unstable
Using System Dynamics to Analyze the Effect of Funding Fluctuations on Software Development
Trammell, Travis
Almost everyone understands that budget fluctuations have an impact on software development, but it is difficult to estimate the magnitude of the impact and all the causes. This paper uses System Dynamics modeling to examine ...
From population dynamics to ecoinformatics: Ecosystems as multilevel information processing systems
Utrecht, Universiteit
From population dynamics to ecoinformatics: Ecosystems as multilevel information processing systems which lead to viewing ecosystems in terms of local multilevel information processing and evolution. We of information processing, and under which circumstances these modes may be favored. Ecosystem diversity
Networking technology adoption : system dynamics modeling of fiber-to-the-home
Kelic, Andjelka, 1972-
2005-01-01
A system dynamics model is developed and run to study the adoption of fiber-to-the-home as a residential broadband technology. Communities that currently do not have broadband in the United States are modeled. This case ...
An Analysis of the Dynamics of the US Commercial Air Transportation System
Tam, Ryan
Major trends in the airline industry are analyzed to highlight key dynamics that govern the US domestic air transportation system. The hypothesis is that air travel supply and demand equilibriums, a reliance on outside ...
Oladokun, M.; Motawa, I.; Banfill, P.
2012-01-01
The purpose of this paper is to propose and demonstrate the application of system dynamics modeling approach to analyze and study the behavior the complex interrelationships among the different policies/interventions aimed ...
RHEOLOGICAL STUDY OF AN HYDRATE SLURRY FOR AIR CONDITIONNING APPLICATION
Boyer, Edmond
Saint-Etienne France ABSTRACT Under atmospheric pressure condition and temperatures between 0°C and +12 behaviour. The experimental device is made up of a brushed surface heat exchanger in which the hydrates flow rates and pressure drops measurements. We obtain flow curves of hydrates slurries depending
Ice method for production of hydrogen clathrate hydrates
Lokshin, Konstantin (Santa Fe, NM); Zhao, Yusheng (Los Alamos, NM)
2008-05-13
The present invention includes a method for hydrogen clathrate hydrate synthesis. First, ice and hydrogen gas are supplied to a containment volume at a first temperature and a first pressure. Next, the containment volume is pressurized with hydrogen gas to a second higher pressure, where hydrogen clathrate hydrates are formed in the process.
Climate Dynamics Diagnosis of the Marine Low Cloud Simulation in the NCAR Community Earth System
Bretherton, Chris
-of-the-art coupled atmosphere-ocean models: the NCAR Community Earth System Model (CESM) and the NCEP Global of the Marine Low Cloud Simulation in the NCAR1 Community Earth System Model (CESM) and the NCEP Global2Climate Dynamics Diagnosis of the Marine Low Cloud Simulation in the NCAR Community Earth System
A Dynamical Systems Analysis of the Data Assimilation Linked Ecosystem Carbon (DALEC) Models
Skeldon, Anne C.
A Dynamical Systems Analysis of the Data Assimilation Linked Ecosystem Carbon (DALEC) Models Anna M make it ever more important to understand the processes involved in Earth systems, such as the carbon with it the ability to perform ever- more detailed studies of the Earth system and its components. Such studies help
The potential for dynamic distribution systems to create a new energy marketplace
Bohnhoff, David
Berkeley National Laboratory and the National Renewable Energy Laboratory, the price of installedJuly 2014 The potential for dynamic distribution systems to create a new energy marketplace Transforming the Grid from the Distribution System Out Part of a continuing series on energy systems
Shen, Jinglai
DYNAMIC SECURITY ANALYSIS OF ELECTRIC POWER SYSTEMS: PASSIVITY-BASED APPROACH AND POSITIVE power system to supply electricity. By nature, a power system is continually experiencing disturbances through the electric power grid is modeled by a set of nonlinear differential/algebraic equations. These n
Comparison of Price-based Static and Dynamic Job Allocation Schemes for Grid Computing Systems
Chronopoulos, Anthony T.
Comparison of Price-based Static and Dynamic Job Allocation Schemes for Grid Computing Systems Antonio San Antonio, TX 78249, USA Email: atc@cs.utsa.edu Abstract--Grid computing systems are a cost-effective al- ternative to traditional high-performance computing systems. However, the computing resources
Stabilization of Linear Dynamical Systems with Scalar Quantizers under Communication Constraints
Reissig, Gunther
Stabilization of Linear Dynamical Systems with Scalar Quantizers under Communication Constraints for stabilizing the system at reduced data rates. I. INTRODUCTION Historically, communication and control have been an increasing demand on networks consisting of control and communication systems which are subject
Modeling and Dynamic Management of 3D Multicore Systems with Liquid Cooling
Simunic, Tajana
Modeling and Dynamic Management of 3D Multicore Systems with Liquid Cooling Ayse K. Coskun , Jos liquid cooling. Furthermore, for systems capable of varying the coolant flow rate at runtime, our University of Madrid, Spain. Embedded Systems Laboratory (ESL), Ecole Polytechnique FÂ´edÂ´erale de Lausanne
Cool and Save: Cooling Aware Dynamic Workload Scheduling in Multi-socket CPU Systems
Simunic, Tajana
Cool and Save: Cooling Aware Dynamic Workload Scheduling in Multi-socket CPU Systems Raid Ayoub, dissipating the high temper- ature requires a large and energy hungry cooling system which increases the cost and fan control in multi-socket systems have been designed sep- arately leading to less efficient
Butcher, Eric A.
) of structural dynamic systems with isolated nonlinearities. The POD method requires that the solution response Systems with Isolated Nonlinearities Mohammad A. AL-Shudeifat Eric A. Butcher Thomas D. Burton Department NNMs of large-order systems with isolated nonlinearities. In addition, LELSM and POD are compared
How Dynamic is the Grid? Towards a Quality Metric for Grid Information Systems
Sakellariou, Rizos
How Dynamic is the Grid? Towards a Quality Metric for Grid Information Systems Laurence Field CERN rizos@cs.man.ac.uk Abstract--Grid information systems play a core role in today's production Grid. Quality metrics for Grid information systems are required in order to compare different implementations
School of Mechanical Engineering and Computer Science Mech 348: Dynamic Systems and Control
, including mechanical, electrical, fluid, and thermal systems. Fundamentals of vibration analysis, controlSchool of Mechanical Engineering and Computer Science Mech 348: Dynamic Systems and Control Catalog mechanical, electrical, thermal and fluid engineering systems 3. To introduce students to the analysis
Exploring the Dynamic Costs of Process-aware Information Systems through Simulation
Ulm, Universität
Exploring the Dynamic Costs of Process-aware Information Systems through Simulation Bela Mutschler systems, case handling systems) is associated with high costs. Though cost evaluation has received utilizes si- mulation models for investigating costs related to PAIS engineering projects. We motivate
Electronic power conditioning for dynamic power conversion in high-power space systems
Hansen, James Michael
1991-01-01
power conversion allows for improved methods of power conditioning. A block diagram of one such system that uses dynamic power conversion is shown in Fig. 4. The blocks labeled Energy Source, Primary Heat Rejection, snd User's Load are the same...ELECTRONIC POWER CONDITIONING FOR DYNAMIC POWER CONVERSION IN HIGH ? POWER SPACE SYSTEMS A Thesis by JAMES MICHAEL HANSEN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...
STABILITY ANALYSIS OF INTERCONNECTED POWER SYSTEMS COUPLED WITH MARKET DYNAMICS
and Computer Engineering 2Department of Electrical Engineering University of Wisconsin-Madison Federal through numeric tests using various mar- ket update models, with detailed generator. The work by Mota and Alvarado [4] gives the basic modeling for full, two-way dynamic coupling between
International Symposium on Structure and Dynamics of Heterogeneous Systems
Duisburg-Essen, Universität
on light-activated proteins, water, melting and transport Chairman: P. Entel 13:3014:10 Norbert Hampp (Chemistry Department, Nagoya University, Nagoya, Japan) Water dynamics, fluctuation, freezing and chemical transport in single-molecule junctions 19:0021:00 SNACKS, BEVERAGES AND POSTER SHOW Friday, November 29
Seismic-Scale Rock Physics of Methane Hydrate
Amos Nur
2009-01-08
We quantify natural methane hydrate reservoirs by generating synthetic seismic traces and comparing them to real seismic data: if the synthetic matches the observed data, then the reservoir properties and conditions used in synthetic modeling might be the same as the actual, in-situ reservoir conditions. This approach is model-based: it uses rock physics equations that link the porosity and mineralogy of the host sediment, pressure, and hydrate saturation, and the resulting elastic-wave velocity and density. One result of such seismic forward modeling is a catalogue of seismic reflections of methane hydrate which can serve as a field guide to hydrate identification from real seismic data. We verify this approach using field data from known hydrate deposits.
Wang, Shaobu; Lu, Shuai; Zhou, Ning; Lin, Guang; Elizondo, Marcelo A.; Pai, M. A.
2014-09-04
In interconnected power systems, dynamic model reduction can be applied on generators outside the area of interest to mitigate the computational cost with transient stability studies. This paper presents an approach of deriving the reduced dynamic model of the external area based on dynamic response measurements, which comprises of three steps, dynamic-feature extraction, attribution and reconstruction (DEAR). In the DEAR approach, a feature extraction technique, such as singular value decomposition (SVD), is applied to the measured generator dynamics after a disturbance. Characteristic generators are then identified in the feature attribution step for matching the extracted dynamic features with the highest similarity, forming a suboptimal ‘basis’ of system dynamics. In the reconstruction step, generator state variables such as rotor angles and voltage magnitudes are approximated with a linear combination of the characteristic generators, resulting in a quasi-nonlinear reduced model of the original external system. Network model is un-changed in the DEAR method. Tests on several IEEE standard systems show that the proposed method gets better reduction ratio and response errors than the traditional coherency aggregation methods.
Complex Systems Dynamics (CoSyDy) Meeting, Leeds 2nd "Evolution and Diversity in Complex Systems"
Wirosoetisno, Djoko
Complex Systems Dynamics (CoSyDy) Meeting, Leeds 2nd March 2012 "Evolution and Diversity in Complex Systems" Organiser: Mauro Mobilia (Leeds); Network coordinator: Robert MacKay (Warwick) Directions: http://www.maths.leeds.ac.uk/home/visit-us.html and http://www.maths.leeds.ac.uk/fileadmin/user_upload/directions_2011-12.pdf Programme All talks
Parameterized model order reduction for nonlinear dynamical systems
Bond, Bradley N. (Bradley Neil)
2006-01-01
The presence of several nonlinear analog circuits and Micro-Electro-Mechanical (MEM) components in modern mixed signal System-on-Chips (SoC) makes the fully automatic synthesis and optimization of such systems an extremely ...
The dynamics and kinematics of bio-in swimming systems
Burton, Lisa Janelle
2013-01-01
The motion of biological systems in fluids is inherently complex, even for the simplest organisms. In this thesis, we develop methods of analyzing locomotion of both mechanical and biological systems with the aim of ...
Structural dynamics and synaptic development in the visual system
Oray, Serkan, 1974-
2004-01-01
This thesis takes as its subject three model systems which exhibit interesting properties in the developing nervous system. The first study details the developmental properties of dendritic spines, the principle sites of ...
Gedeon, Tomas
, from those appearing in physiology and ecology to Earth systems modeling, often experience critical
Study the vibration and dynamic response of the dipole girder system for CSNS/RCS
Liu Renhong; Wang Min; Zhang JunSong; Wang GuangYuan
2015-06-24
China Spallation Neutron Source is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts an H- linac and a rapid cycling synchrotron. The RCS accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25Hz. The dipole of the CSNS RCS is operated at a 25 Hz sinusoidal alternating current which causes severe vibrate. The vibration will influence the long term safety and reliable operation of the magnet. The dipole of the CSNS RCS is an active vibration equipment which is different from the ground vibration accelerator. It is very important to design and study the dynamic characteristics of the dipole girder system. This paper takes the dipole and girder as a specific model system, a method for studying the dynamic characteristics of the system is put forward by combining theoretical calculation with experimental testing. The modal parameters with and without vibration isolator of the dipole girder system are obtain through ANSYS simulation and testing. Then the dynamic response of the system is calculated with modal analysis and vibration testing data. The dipole girder takes four-point support system which maybe appears over constrained in the progress of adjustment. The dynamic characteristics and dynamic response of the three point girder system were studied with the same method.
Nakagawa, S.; Kneafsey, T.J.
2011-05-03
Conventional resonant bar tests allow the measurement of seismic properties of rocks and sediments at low frequencies (several kilohertz). However, the tests require a long, slender sample which is often difficult to obtain from the deep subsurface and weak and fractured formations. We present an alternative low-frequency measurement technique to the conventional resonant bar tests. This technique involves a jacketed core sample placed between a pair of long, metal extension rods with attached seismic source and receiver—the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the added length and mass to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The proposed “Split Hopkinson Resonant Bar (SHRB)” test is applied in two steps. In the first step, extension and torsion-mode resonance frequencies and attenuation of the system are measured. Then, numerical inversions for the compressional and shear wave velocities and attenuation are performed. We initially applied the SHRB test to synthetic materials (plastics) for testing its accuracy, then used it for measuring the seismic velocities and attenuation of a rock core containing supercritical CO{sub 2}, and a sediment core while methane hydrate formed in the pore space.
E ects of the Driving Force on the Composition of Natural Gas Hydrates
Gudmundsson, Jon Steinar
E ects of the Driving Force on the Composition of Natural Gas Hydrates Odd I. Levik(1) , Jean for storage and transport of natural gas. Storage of natural gas in the form of hydrate at elevated pressure concept) (Gud- mundsson et al. 1998). Natural gas hydrate contains up to 182 Sm3 gas per m3 hydrate
Kowalsky, Michael B.; Moridis, George J.
2006-01-01
hydrocarbons residing in hydrate deposits is estimated to substantially exceed all known conventional
Rutqvist, J.
2009-01-01
hydrocarbons) trapped in hydrates is enormous, and easily exceeds the equivalent of all the known conventional
Energy management in wireless healthcare systems using dynamic task assignment
Aghera, Priti
2010-01-01
in wireless channel conditions: System energy consumption2007: Microleap: Energy-aware wireless sensor platform forresults in a more energy efficient wireless transmission for
A Generalized Recursive Coordinate Reduction Method for Multibody System Dynamics
Anderson, Kurt S.
of multibody systems. Application of these techniques are further illustrated with a special five-bar linkage & K. S. Anderson Department of Mechanical, Aeronautical, and Nuclear Engineering, Rensselaer
PMU Placement for Dynamic State Tracking of Power Systems
Sun, Yannan; Du, Pengwei; Huang, Zhenyu; Kalsi, Karanjit; Diao, Ruisheng; Anderson, Kevin K.; Li, Yulan; Lee, Barry
2011-08-04
Accurately tracking the state variables (rotor angle and speed) is a necessity for monitoring system stability conditions and assessing the risks of large-scale system collapse. This paper explores how the number and locations of PMUs installed in the system are determined to ensure satisfactory state tracking performance. A search algorithm is presented for determining PMU placement (location and quantity). The algorithm determines a placement that gives small tracking error in polynomial time. A modified, scalable algorithm is also presented. Observability in the presence of faults is considered. Simulation results for a 16-machine and a 50-machine system are provided.
Intrinsic decoherence dynamics in smooth Hamiltonian systems: Quantum-classical correspondence
Gong, Jiangbin; Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Canada M5S 3H6 (Canada)
2003-08-01
A direct classical analog of the quantum dynamics of intrinsic decoherence in Hamiltonian systems, characterized by the time dependence of the linear entropy of the reduced density operator, is introduced. The similarities and differences between the classical and quantum decoherence dynamics of an initial quantum state are exposed using both analytical and computational results. In particular, the classicality of early-time intrinsic decoherence dynamics is explored analytically using a second-order perturbative treatment, and an interesting connection between decoherence rates and the stability nature of classical trajectories is revealed in a simple approximate classical theory of intrinsic decoherence dynamics. The results offer deeper insights into decoherence, dynamics of quantum entanglement, and quantum chaos.
Optimal system size for complex dynamics in random neural networks near criticality
Wainrib, Gilles, E-mail: wainrib@math.univ-paris13.fr [Laboratoire Analyse Géométrie et Applications, Université Paris XIII, Villetaneuse (France)] [Laboratoire Analyse Géométrie et Applications, Université Paris XIII, Villetaneuse (France); García del Molino, Luis Carlos, E-mail: garciadelmolino@ijm.univ-paris-diderot.fr [Institute Jacques Monod, Université Paris VII, Paris (France)
2013-12-15
In this article, we consider a model of dynamical agents coupled through a random connectivity matrix, as introduced by Sompolinsky et al. [Phys. Rev. Lett. 61(3), 259–262 (1988)] in the context of random neural networks. When system size is infinite, it is known that increasing the disorder parameter induces a phase transition leading to chaotic dynamics. We observe and investigate here a novel phenomenon in the sub-critical regime for finite size systems: the probability of observing complex dynamics is maximal for an intermediate system size when the disorder is close enough to criticality. We give a more general explanation of this type of system size resonance in the framework of extreme values theory for eigenvalues of random matrices.
Alternative to the Well-known Statistical Dynamics of Linear Systems
V. N. Tibabishev
2013-01-22
The problem of determining the mathematical model of the dynamics of multi-dimensional control systems in the presence of noise under the condition that the correlation functions cannot be found. Known statistical dynamics of linear systems is a more effective alternative. Background information is presented in the form of individual implementations nonergodic stochastic processes. Such a realization is deterministic functions. We introduce the concept of systems of sets of signals for the components on the semiring. For the system of sets of linearly dependent and linearly independent of the measured signals of a certain frequency properties. Frequency method is designed to deal with the noise on the set of deterministic functions. Example is the determination of the dynamic characteristics of the aircraft in accordance with the data obtained in one automatic landing.
Controlling Quantum Systems by Embedded Dynamical Decoupling Schemes O. Kern and G. Alber
Controlling Quantum Systems by Embedded Dynamical Decoupling Schemes O. Kern and G. Alber Institut on embedding a deterministic decoupling scheme into a stochastic one. This way it is possible to combine the advantages of both methods and to increase the suppression of undesired perturbations of quantum systems
A dynamical systems approach for the station keeping of a Solar Sail
Barcelona, Universitat de
A dynamical systems approach for the station keeping of a Solar Sail Ariadna Farr´es and `Angel considered the movement of a solar sail in the Sun - Earth system. As a model we have used the RTBP adding the solar radiation pressure. It can be seen that we have a 2D family of equilibria parametrised by the two
Dang, Zhe
Bond Computing Systems: a Biologically Inspired and High-level Dynamics Model for Pervasive their com- putation power and verification problems. Among other results, we show that the computing power) techniques for pervasive computing systems. At a high-level, there are at least two views in modeling
Adaptive Model Predictive Control of the Hybrid Dynamics of a Fuel Cell System.
Paris-Sud XI, Université de
Adaptive Model Predictive Control of the Hybrid Dynamics of a Fuel Cell System. M. Fiacchini, T operation of a fuel cell system is presented. The aim of the control design is to guarantee that the oxygen control to a fuel cell plant is presented. The fuel cell, located in the laboratory of the Department
Butcher, Eric A.
2005-01-01
Nonlinear Dynamics (2005) 41: 237273 c Springer 2005 Order Reduction of Parametrically Excited Nonlinear Systems: Techniques and Applications S. C. SINHA1, , SANGRAM REDKAR1 , VENKATESH DESHMUKH2 , and ERIC A. BUTCHER2 1Nonlinear Systems Research Laboratory, Department of Mechanical Engineering, Auburn
DISCRETE AND CONTINUOUS doi:10.3934/dcds.2009.23.1169 DYNAMICAL SYSTEMS
Chen, Min
an hour or even shorter as in the cases of tsunami so proper warn- ing can be issued. Furthermore, in manyDISCRETE AND CONTINUOUS doi:10.3934/dcds.2009.23.1169 DYNAMICAL SYSTEMS Volume 23, Number 4, April 2009 pp. 11691190 NUMERICAL INVESTIGATION OF A TWO-DIMENSIONAL BOUSSINESQ SYSTEM Min Chen Department
Exploring the free-energy landscapes of biological systems with steered molecular dynamics
Chen, Liao Y.
1 Exploring the free-energy landscapes of biological systems with steered molecular dynamics fluctuation-dissipation-theorem (BD -FDT) to accurately compute the free-energy profiles for several compute the free-energy profiles for all the afore-listed systems that represent various important aspects
Reliability analysis of static and dynamic fault-tolerant systems subject to probabilistic
Sun, Yan Lindsay
Reliability analysis of static and dynamic fault-tolerant systems subject to probabilistic common Dartmouth, Massachusetts, USA 2 University of Rhode Island, Kingston, Rhode Island, USA 3 Applied Materials for publication on 8 October 2009. DOI: 10.1243/1748006XJRR260 Abstract: Fault-tolerant systems designed
Constructing Robust Dynamic Peer-to-Peer Systems Fabian Kuhn
churn. For distributed systems with high churn the orthodox group communication schemes seem futile systems, churn has not received the attention it deserves in the literature. With the exception of [12], P hash table (DHT) which is resilient to churn. We assume that joins and leaves occur in a worst
Dynamic Control of Serial-batch Processing Systems
Cerekci, Abdullah
2010-01-14
......................... 133 APPENDIX C: PAIRED-T TEST RESULTS FOR CHAPTER V .......................... 144 VITA ......................................................................................................................... 154 ix LIST OF FIGURES FIGURE... processor?s queue to improve the performance of the batch processor. 6 The assumptions relating to the serial-batch processor system are as follows: There are N incompatible product types being processed by the serial-batch processor system. Batch...
The growth rate of gas hydrate from refrigerant R12
Kendoush, Abdullah Abbas; Jassim, Najim Abid [Centre of Engineering Physics, Ministry of Sciences and Technology, P.O. Box 765, Baghdad (Iraq); Joudi, Khalid A. [Al-Nahrain University, Baghdad (Iraq)
2006-07-15
Experimental and theoretical investigations were presented dealing with three phase direct-contact heat transfer by evaporation of refrigerant drops in an immiscible liquid. Refrigerant R12 was used as the dispersed phase, while water and brine were the immiscible continuous phase. A numerical solution is presented to predict the formation rate of gas hydrates in test column. The solution provided an acceptable agreement when compared with experimental results. The gas hydrate growth rate increased with time. It increased with increasing dispersed phase flow rate. The presence of surface-active sodium chloride in water had a strong inhibiting effect on the gas hydrate formation rate. (author)
Examination of Hydrate Formation Methods: Trying to Create Representative Samples
Kneafsey, T.J.; Rees, E.V.L.; Nakagawa, S.; Kwon, T.-H.
2011-04-01
Forming representative gas hydrate-bearing laboratory samples is important so that the properties of these materials may be measured, while controlling the composition and other variables. Natural samples are rare, and have often experienced pressure and temperature changes that may affect the property to be measured [Waite et al., 2008]. Forming methane hydrate samples in the laboratory has been done a number of ways, each having advantages and disadvantages. The ice-to-hydrate method [Stern et al., 1996], contacts melting ice with methane at the appropriate pressure to form hydrate. The hydrate can then be crushed and mixed with mineral grains under controlled conditions, and then compacted to create laboratory samples of methane hydrate in a mineral medium. The hydrate in these samples will be part of the load-bearing frame of the medium. In the excess gas method [Handa and Stupin, 1992], water is distributed throughout a mineral medium (e.g. packed moist sand, drained sand, moistened silica gel, other porous media) and the mixture is brought to hydrate-stable conditions (chilled and pressurized with gas), allowing hydrate to form. This method typically produces grain-cementing hydrate from pendular water in sand [Waite et al., 2004]. In the dissolved gas method [Tohidi et al., 2002], water with sufficient dissolved guest molecules is brought to hydrate-stable conditions where hydrate forms. In the laboratory, this is can be done by pre-dissolving the gas of interest in water and then introducing it to the sample under the appropriate conditions. With this method, it is easier to form hydrate from more soluble gases such as carbon dioxide. It is thought that this method more closely simulates the way most natural gas hydrate has formed. Laboratory implementation, however, is difficult, and sample formation is prohibitively time consuming [Minagawa et al., 2005; Spangenberg and Kulenkampff, 2005]. In another version of this technique, a specified quantity of gas is placed in a sample, then the sample is flooded with water and cooled [Priest et al., 2009]. We have performed a number of tests in which hydrate was formed and the uniformity of the hydrate formation was examined. These tests have primarily used a variety of modifications of the excess gas method to make the hydrate, although we have also used a version of the excess water technique. Early on, we found difficulties in creating uniform samples with a particular sand/ initial water saturation combination (F-110 Sand, {approx} 35% initial water saturation). In many of our tests we selected this combination intentionally to determine whether we could use a method to make the samples uniform. The following methods were examined: Excess gas, Freeze/thaw/form, Freeze/pressurize/thaw, Excess gas followed by water saturation, Excess water, Sand and kaolinite, Use of a nucleation enhancer (SnoMax), and Use of salt in the water. Below, each method, the underlying hypothesis, and our results are briefly presented, followed by a brief conclusion. Many of the hypotheses investigated are not our own, but were presented to us. Much of the data presented is from x-ray CT scanning our samples. The x-ray CT scanner provides a three-dimensional density map of our samples. From this map and the physics that is occurring in our samples, we are able to gain an understanding of the spatial nature of the processes that occur, and attribute them to the locations where they occur.
Yitao Zhu; Daniel Dopico; Corina Sandu; Adrian Sandu
2014-10-30
Multibody dynamics simulations are currently widely accepted as valuable means for dynamic performance analysis of mechanical systems. The evolution of theoretical and computational aspects of the multibody dynamics discipline make it conducive these days for other types of applications, in addition to pure simulations. One very important such application is design optimization. A very important first step towards design optimization is sensitivity analysis of multibody system dynamics. Dynamic sensitivities are often calculated by means of finite differences. Depending of the number of parameters involved, this procedure can be computationally expensive. Moreover, in many cases, the results suffer from low accuracy when real perturbations are used. The main contribution to the state-of-the-art brought by this study is the development of the adjoint sensitivity approach of multibody systems in the context of the penalty formulation. The theory developed is demonstrated on one academic case study, a five-bar mechanism, and on one real-life system, a 14-DOF vehicle model. The five-bar mechanism is used to illustrate the sensitivity approach derived in this paper. The full vehicle model is used to demonstrate the capability of the new approach developed to perform sensitivity analysis and gradient-based optimization for large and complex multibody systems with respect to multiple design parameters.
Dynamic scheduling of manufacturing systems with setups and random disruptions
Tubilla Kuri, Fernando
2011-01-01
Manufacturing systems are often composed of machines that can produce a variety of items but that most undergo time-consuming (and possibly costly) setups when switching between product types. Scheduling these setups ...
Dynamical parameter determinations in Pluto’s system
Beauvalet, L.
Pluto is the multiple system that has been observed the longest. Yet, the masses of its smallest satellites, Nix and Hydra, which were discovered in 2005, are still imprecisely known, because of the short time span and ...
Dynamic Control for Batch Process Systems Using Stochastic Utility Evaluation
Park, Hongsuk
2012-10-19
Most research studies in the batch process control problem are focused on optimizing system performance. The methods address the problem by minimizing single criterion such as cycle time and tardiness, or bi-criteria such ...
: Differential Temporal Dynamic Logic with Nested Temporalities for Hybrid Systems
Platzer, André
A major task of computer science is to program objects of our physical world: cars, trains, airplanes look at a satellite with position x trying to leave the solar system, avoiding planets. To simplify
Fully coupled dynamic analysis of a floating wind turbine system
Withee, Jon E
2004-01-01
The use of wind power is in a period of rapid growth worldwide and wind energy systems have emerged as a promising technology for utilizing offshore wind resources for the large scale generation of electricity. Drawing ...