Chemical non-equilibrium modelling of an argon-oxygen supersonic ICP
Energy Technology Data Exchange (ETDEWEB)
El Morsli, Mbark; Proulx, Pierre; Gravelle, Denis, E-mail: Mbark.El.Morsli@usherbrooke.ca [Departement de genie chimique, Universite de Sherbrooke (QC) J1K 2R1 (Canada)
2011-02-15
In this paper, a non-equilibrium mathematical model for an argon-oxygen inductively coupled plasma (ICP) torch with a supersonic nozzle is developed without making chemical equilibrium assumptions. Reaction rates of dissociation and recombination of diatomic gas and ionization are taken into account. Higher-order approximations of the Chapman-Enskog method are used to obtain better accuracy for transport properties, taking advantage of the most recent sets of collision integrals available in the literature. In order to validate the developed model, results are compared qualitatively and quantitatively with existing experimental data. The calculated results for the axial temperature profile for pure argon less than 10 mm above the substrate are in good agreement with spectroscopic measurements.
Microscopic Simulation and Macroscopic Modeling for Thermal and Chemical Non-Equilibrium
Liu, Yen; Panesi, Marco; Vinokur, Marcel; Clarke, Peter
2013-01-01
This paper deals with the accurate microscopic simulation and macroscopic modeling of extreme non-equilibrium phenomena, such as encountered during hypersonic entry into a planetary atmosphere. The state-to-state microscopic equations involving internal excitation, de-excitation, dissociation, and recombination of nitrogen molecules due to collisions with nitrogen atoms are solved time-accurately. Strategies to increase the numerical efficiency are discussed. The problem is then modeled using a few macroscopic variables. The model is based on reconstructions of the state distribution function using the maximum entropy principle. The internal energy space is subdivided into multiple groups in order to better describe the non-equilibrium gases. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients. The modeling is completely physics-based, and its accuracy depends only on the assumed expression of the state distribution function and the number of groups used. The model makes no assumption at the microscopic level, and all possible collisional and radiative processes are allowed. The model is applicable to both atoms and molecules and their ions. Several limiting cases are presented to show that the model recovers the classical twotemperature models if all states are in one group and the model reduces to the microscopic equations if each group contains only one state. Numerical examples and model validations are carried out for both the uniform and linear distributions. Results show that the original over nine thousand microscopic equations can be reduced to 2 macroscopic equations using 1 to 5 groups with excellent agreement. The computer time is decreased from 18 hours to less than 1 second.
Non-equilibrium dog-flea model
Ackerson, Bruce J.
2017-11-01
We develop the open dog-flea model to serve as a check of proposed non-equilibrium theories of statistical mechanics. The model is developed in detail. Then it is applied to four recent models for non-equilibrium statistical mechanics. Comparison of the dog-flea solution with these different models allows checking claims and giving a concrete example of the theoretical models.
Non-equilibrium modelling of distillation
Wesselingh, JA; Darton, R
1997-01-01
There are nasty conceptual problems in the classical way of describing distillation columns via equilibrium stages, and efficiencies or HETP's. We can nowadays avoid these problems by simulating the behaviour of a complete column in one go using a non-equilibrium model. Such a model has phase
Kusaba, Akira; Li, Guanchen; von Spakovsky, Michael R; Kangawa, Yoshihiro; Kakimoto, Koichi
2017-08-15
Clearly understanding elementary growth processes that depend on surface reconstruction is essential to controlling vapor-phase epitaxy more precisely. In this study, ammonia chemical adsorption on GaN(0001) reconstructed surfaces under metalorganic vapor phase epitaxy (MOVPE) conditions (3Ga-H and Nad-H + Ga-H on a 2 × 2 unit cell) is investigated using steepest-entropy-ascent quantum thermodynamics (SEAQT). SEAQT is a thermodynamic-ensemble based, first-principles framework that can predict the behavior of non-equilibrium processes, even those far from equilibrium where the state evolution is a combination of reversible and irreversible dynamics. SEAQT is an ideal choice to handle this problem on a first-principles basis since the chemical adsorption process starts from a highly non-equilibrium state. A result of the analysis shows that the probability of adsorption on 3Ga-H is significantly higher than that on Nad-H + Ga-H. Additionally, the growth temperature dependence of these adsorption probabilities and the temperature increase due to the heat of reaction is determined. The non-equilibrium thermodynamic modeling applied can lead to better control of the MOVPE process through the selection of preferable reconstructed surfaces. The modeling also demonstrates the efficacy of DFT-SEAQT coupling for determining detailed non-equilibrium process characteristics with a much smaller computational burden than would be entailed with mechanics-based, microscopic-mesoscopic approaches.
Chemical Reactions Using a Non-Equilibrium Wigner Function Approach
Directory of Open Access Journals (Sweden)
Ramón F. Álvarez-Estrada
2016-10-01
Full Text Available A three-dimensional model of binary chemical reactions is studied. We consider an ab initio quantum two-particle system subjected to an attractive interaction potential and to a heat bath at thermal equilibrium at absolute temperature T > 0 . Under the sole action of the attraction potential, the two particles can either be bound or unbound to each other. While at T = 0 , there is no transition between both states, such a transition is possible when T > 0 (due to the heat bath and plays a key role as k B T approaches the magnitude of the attractive potential. We focus on a quantum regime, typical of chemical reactions, such that: (a the thermal wavelength is shorter than the range of the attractive potential (lower limit on T and (b ( 3 / 2 k B T does not exceed the magnitude of the attractive potential (upper limit on T. In this regime, we extend several methods previously applied to analyze the time duration of DNA thermal denaturation. The two-particle system is then described by a non-equilibrium Wigner function. Under Assumptions (a and (b, and for sufficiently long times, defined by a characteristic time scale D that is subsequently estimated, the general dissipationless non-equilibrium equation for the Wigner function is approximated by a Smoluchowski-like equation displaying dissipation and quantum effects. A comparison with the standard chemical kinetic equations is made. The time τ required for the two particles to transition from the bound state to unbound configurations is studied by means of the mean first passage time formalism. An approximate formula for τ, in terms of D and exhibiting the Arrhenius exponential factor, is obtained. Recombination processes are also briefly studied within our framework and compared with previous well-known methods.
Non-equilibrium modelling of distillation
Wesselingh, J.A
This is a lecture on the way that we engineers model distillation. How we have done such modelling, how we would like to do it, and how far we have come at this moment. The ideas that I will be bringing forward are not my own. I owe them mostly to R. Krishna, R. Taylor, H. Kooijman and A. Gorak.
Data for non equilibrium modeling with AtomDB
Foster, Adam R.; Smith, Randall K.; Brickhouse, Nancy S.
2017-03-01
AtomDB version 3.0 is available as a beta release. The main additions to this release are additions for analyzing non-equilibrium collisional plasmas, in particular ionizing plasmas. This includes revisions to the emission code APEC, and new data generation and collection. Here we briefly outline the new model, and describe in detail the new data formats.
Göppel, Tobias; Palyulin, Vladimir V; Gerland, Ulrich
2016-07-27
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a drift-diffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
Modeling Non-Equilibrium Collisional Plasmas with AtomDB
Foster, Adam; Yamaguchi, H.; Smith, R. K.; Brickhouse, N. S.; Ji, L.; Kallman, T.; Wilms, J.
2013-04-01
Collisionally ionized plasmas that are in non-equilibrium ionization (NEI) show distinctly different emission from those in equilibrium. Recombining, or overionized, plasmas show significant recombination-driven continuum features, while ionizing plasmas show strong inner-shell emission lines, such as the Iron Kα line at 6.4-6.7keV. Existing models in analysis tools such as XSPEC treat only the equilibrium case and part of the ionizing plasma case due to a significant lack of atomic data. We present major updates to the AtomDB database, and new models for use XSPEC, which allow all types of these non-equilibrium plasmas to be modeled in a simple yet accurate fashion. This model has been created using a large amount of data obtained from published sources, supplemented by data we have calculated using the Flexible Atomic Code where required. We identify the spectral features that have been seen and can now be modeled using this data for existing missions as well as Astro-H. We also revisit archival data where recombining plasma emission has previously been identified.
Modeling Inflation Using a Non-Equilibrium Equation of Exchange
Chamberlain, Robert G.
2013-01-01
Inflation is a change in the prices of goods that takes place without changes in the actual values of those goods. The Equation of Exchange, formulated clearly in a seminal paper by Irving Fisher in 1911, establishes an equilibrium relationship between the price index P (also known as "inflation"), the economy's aggregate output Q (also known as "the real gross domestic product"), the amount of money available for spending M (also known as "the money supply"), and the rate at which money is reused V (also known as "the velocity of circulation of money"). This paper offers first a qualitative discussion of what can cause these factors to change and how those causes might be controlled, then develops a quantitative model of inflation based on a non-equilibrium version of the Equation of Exchange. Causal relationships are different from equations in that the effects of changes in the causal variables take time to play out-often significant amounts of time. In the model described here, wages track prices, but only after a distributed lag. Prices change whenever the money supply, aggregate output, or the velocity of circulation of money change, but only after a distributed lag. Similarly, the money supply depends on the supplies of domestic and foreign money, which depend on the monetary base and a variety of foreign transactions, respectively. The spreading of delays mitigates the shocks of sudden changes to important inputs, but the most important aspect of this model is that delays, which often have dramatic consequences in dynamic systems, are explicitly incorporated.macroeconomics, inflation, equation of exchange, non-equilibrium, Athena Project
Non-Equilibrium Turbulence and Two-Equation Modeling
Rubinstein, Robert
2011-01-01
Two-equation turbulence models are analyzed from the perspective of spectral closure theories. Kolmogorov theory provides useful information for models, but it is limited to equilibrium conditions in which the energy spectrum has relaxed to a steady state consistent with the forcing at large scales; it does not describe transient evolution between such states. Transient evolution is necessarily through nonequilibrium states, which can only be found from a theory of turbulence evolution, such as one provided by a spectral closure. When the departure from equilibrium is small, perturbation theory can be used to approximate the evolution by a two-equation model. The perturbation theory also gives explicit conditions under which this model can be valid, and when it will fail. Implications of the non-equilibrium corrections for the classic Tennekes-Lumley balance in the dissipation rate equation are drawn: it is possible to establish both the cancellation of the leading order Re1/2 divergent contributions to vortex stretching and enstrophy destruction, and the existence of a nonzero difference which is finite in the limit of infinite Reynolds number.
Non-equilibrium assembly of microtubules: from molecules to autonomous chemical robots.
Hess, H; Ross, Jennifer L
2017-09-18
Biological systems have evolved to harness non-equilibrium processes from the molecular to the macro scale. It is currently a grand challenge of chemistry, materials science, and engineering to understand and mimic biological systems that have the ability to autonomously sense stimuli, process these inputs, and respond by performing mechanical work. New chemical systems are responding to the challenge and form the basis for future responsive, adaptive, and active materials. In this article, we describe a particular biochemical-biomechanical network based on the microtubule cytoskeletal filament - itself a non-equilibrium chemical system. We trace the non-equilibrium aspects of the system from molecules to networks and describe how the cell uses this system to perform active work in essential processes. Finally, we discuss how microtubule-based engineered systems can serve as testbeds for autonomous chemical robots composed of biological and synthetic components.
Non-Equilibrium Modeling of Inductively Coupled RF Plasmas
2015-01-01
line with squares r = 0.04m, line with triangles r = 0.08m [wall]). On the other hand the free-electron temperature in- creases, reaches a maximum and...circles), in the mid- point of the torch (squares) and at the wall ( triangles ) at different pressures. The population distributions exhibit significant...De Pascale , P. Diomede, F. Esposito, C. Gorse, K. Hassouni, A. Laricchiuta, S. Longo, D. Pagano, D. Pietanza, and M. Rutigliano. Non-equilibrium
A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas
Energy Technology Data Exchange (ETDEWEB)
Munafò, A., E-mail: munafo@illinois.edu; Alfuhaid, S. A., E-mail: alfuhai2@illinois.edu; Panesi, M., E-mail: mpanesi@illinois.edu [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Talbot Laboratory, 104 S. Wright St., Urbana, Illinois 61801 (United States); Cambier, J.-L., E-mail: jean-luc.cambier@us.af.mil [Edwards Air Force Base Research Laboratory, 10 E. Saturn Blvd., Edwards AFB, California 93524 (United States)
2015-10-07
The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.
National Aeronautics and Space Administration — This SBIR project proposes to develop a gas-kinetic Navier-Stokes solver for simulation of hypersonic flows in thermal and chemical non-equilibrium. The...
A new particle-like method for high-speed flows with chemical non-equilibrium
Directory of Open Access Journals (Sweden)
Fábio Rodrigues Guzzo
2010-04-01
Full Text Available The present work is concerned with the numerical simulation of hypersonic blunt body flows with chemical non-equilibrium. New theoretical and numerical formulations for coupling the chemical reaction to the fluid dynamics are presented and validated. The fluid dynamics is defined for a stationary unstructured mesh and the chemical reaction process is defined for “finite quantities” moving through the stationary mesh. The fluid dynamics is modeled by the Euler equations and the chemical reaction rates by the Arrhenius law. Ideal gases are considered. The thermodynamical data are based on JANNAF tables and Burcat’s database. The algorithm proposed by Liou, known as AUSM+, is implemented in a cell-centered based finite volume method and in an unstructured mesh context. Multidimensional limited MUSCL interpolation method is used to perform property reconstructions and to achieve second-order accuracy in space. The minmod limiter is used. The second order accuracy, five stage, Runge-Kutta time-stepping scheme is employed to perform the time march for the fluid dynamics. The numerical code VODE, which is part of the CHEMKIN-II package, is adopted to perform the time integration for the chemical reaction equations. The freestream reacting fluid is composed of H2 and air at the stoichiometric ratio. The emphasis of the present paper is on the description of the new methodology for handling the coupling of chemical and fluid mechanic processes, and its validation by comparison with the standard time-splitting procedure. The configurations considered are the hypersonic flow over a wedge, in which the oblique detonation wave is induced by an oblique shock wave, and the hypersonic flow over a blunt body. Differences between the solutions obtained with each formulation are presented and discussed, including the effects of grid refinement in each case. The primary objective of such comparisons is the validation of the proposed methodology. Moreover, for
Thermal non-equilibrium heat transfer in a porous cavity in the presence of bio-chemical heat source
Directory of Open Access Journals (Sweden)
Nazari Mohsen
2015-01-01
Full Text Available This paper is concerned with thermal non-equilibrium natural convection in a square cavity filled with a porous medium in the presence of a biomass which is transported in the cavity. The biomass can consume a secondary moving substrate. The physics of the presented problem is related to the analysis of heat and mass transfer in a composting process that controlled by internal heat generation. The intensity of the bio-heat source generated in the cavity is equal to the rate of consumption of the substrate by the biomass. It is assumed that the porous medium is homogeneous and isotropic. A two-field model that represents the fluid and solid phase temperature fields separately is used for energy equation. A simplified Monod model is introduced along with the governing equations to describe the consumption of the substrate by the biomass. In other word, the transient biochemical heat source which is dependent on a solute concentration is considered in the energy equations. Investigation of the biomass activity and bio-chemical heat generation in the case of thermal non-equilibrium assumption has not been considered in the literature and they are open research topics. The effects of thermal non-equilibrium model on heat transfer, flow pattern and biomass transfer are investigated. The effective parameters which have a direct impact on the generated bio-chemical heat source are also presented. The influences of the non-dimensional parameters such as fluid-to-solid conductivity ratio on the temperature distribution are presented.
A continuous stochastic model for non-equilibrium dense gases
Sadr, M.; Gorji, M. H.
2017-12-01
While accurate simulations of dense gas flows far from the equilibrium can be achieved by direct simulation adapted to the Enskog equation, the significant computational demand required for collisions appears as a major constraint. In order to cope with that, an efficient yet accurate solution algorithm based on the Fokker-Planck approximation of the Enskog equation is devised in this paper; the approximation is very much associated with the Fokker-Planck model derived from the Boltzmann equation by Jenny et al. ["A solution algorithm for the fluid dynamic equations based on a stochastic model for molecular motion," J. Comput. Phys. 229, 1077-1098 (2010)] and Gorji et al. ["Fokker-Planck model for computational studies of monatomic rarefied gas flows," J. Fluid Mech. 680, 574-601 (2011)]. The idea behind these Fokker-Planck descriptions is to project the dynamics of discrete collisions implied by the molecular encounters into a set of continuous Markovian processes subject to the drift and diffusion. Thereby, the evolution of particles representing the governing stochastic process becomes independent from each other and thus very efficient numerical schemes can be constructed. By close inspection of the Enskog operator, it is observed that the dense gas effects contribute further to the advection of molecular quantities. That motivates a modelling approach where the dense gas corrections can be cast in the extra advection of particles. Therefore, the corresponding Fokker-Planck approximation is derived such that the evolution in the physical space accounts for the dense effects present in the pressure, stress tensor, and heat fluxes. Hence the consistency between the devised Fokker-Planck approximation and the Enskog operator is shown for the velocity moments up to the heat fluxes. For validation studies, a homogeneous gas inside a box besides Fourier, Couette, and lid-driven cavity flow setups is considered. The results based on the Fokker-Planck model are
Modelling Thomson scattering for systems with non-equilibrium electron distributions
Directory of Open Access Journals (Sweden)
Chapman D.A.
2013-11-01
Full Text Available We investigate the effect of non-equilibrium electron distributions in the analysis of Thomson scattering for a range of conditions of interest to inertial confinement fusion experiments. Firstly, a generalised one-component model based on quantum statistical theory is given in the random phase approximation (RPA. The Chihara expression for electron-ion plasmas is then adapted to include the new non-equilibrium electron physics. The theoretical scattering spectra for both diffuse and dense plasmas in which non-equilibrium electron distributions are expected to arise are considered. We find that such distributions strongly influence the spectra and are hence an important consideration for accurately determining the plasma conditions.
Non-equilibrium Monte Carlo dynamics of the Sherrington-Kirkpatrick mean field spin glass model
Baldassarri, Andrea
1996-01-01
We present a numerical study of the non-equilibrium dynamics of the Sherrington-Kirkpatrick model. We analize the overlap distribution between the configurations visited at the time t and in particular its scaling behaviour with the size of the system. We find two different non-equilibrium dynamical regimes. The first is a proper Out of Equilibrium Regime, that is the relevant regime for the dynamics of an infinite system. The second is an Intermediate Regime that separates the Out of Equilib...
Variational Principle for Non-Equilibrium Steady States of the XX Model
Matsui, T
2003-01-01
We show that non-equilibrium steady states of the one dimensional exactly solved XY model can be characterized by the variational principle of free energy of a long range interaction and that they cannot be a KMS state for any C$^*$-dynamical system.
Modelling non-equilibrium thermodynamic systems from the speed-gradient principle.
Khantuleva, Tatiana A; Shalymov, Dmitry S
2017-03-06
The application of the speed-gradient (SG) principle to the non-equilibrium distribution systems far away from thermodynamic equilibrium is investigated. The options for applying the SG principle to describe the non-equilibrium transport processes in real-world environments are discussed. Investigation of a non-equilibrium system's evolution at different scale levels via the SG principle allows for a fresh look at the thermodynamics problems associated with the behaviour of the system entropy. Generalized dynamic equations for finite and infinite number of constraints are proposed. It is shown that the stationary solution to the equations, resulting from the SG principle, entirely coincides with the locally equilibrium distribution function obtained by Zubarev. A new approach to describe time evolution of systems far from equilibrium is proposed based on application of the SG principle at the intermediate scale level of the system's internal structure. The problem of the high-rate shear flow of viscous fluid near the rigid plane plate is discussed. It is shown that the SG principle allows closed mathematical models of non-equilibrium processes to be constructed.This article is part of the themed issue 'Horizons of cybernetical physics'. © 2017 The Author(s).
A Tightly Coupled Non-Equilibrium Magneto-Hydrodynamic Model for Inductively Coupled RF Plasmas
2016-02-29
Journal Article 3. DATES COVERED (From - To) 12 May 2015 – 06 Oct 2015 4. TITLE AND SUBTITLE A Tightly Coupled Non-Equilibrium Magneto- Hydrodynamic ...development a tightly coupled magneto- hydrodynamic model for Inductively Coupled Radio- Frequency (RF) Plasmas. Non Local Thermodynamic Equilibrium (NLTE... hydrodynamic model for Inductively Coupled RF Plasmas A. Munafò,1, a) S. A. Alfuhaid,1, b) J.-L. Cambier,2, c) and M. Panesi1, d) 1)Department of
A mixture theory model for a particulate suspension flow in a thermal non-equilibrium context
Energy Technology Data Exchange (ETDEWEB)
Martins-Costa, M.L. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Lab. de Mecanica Teorica e Aplicada; Gama, R.M. Saldanha da [Laboratorio Nacional de Computacao Cientifica (LNCC), Rio de Janeiro, RJ (Brazil)
1998-07-01
The present work proposes a local model for a particulate suspension flow employing the continuum theory of mixture - specially developed to deal with multiphase phenomena. The flow of a Newtonian fluid with small solid particles in suspension - in which thermal non-equilibrium is allowed - is described as a mixture of solid and fluid constituents coexisting superposed. Thermo-dynamically consistent constitutive hypotheses are derived in order an adequate model for suspensions. (author)
Validation of vibration-dissociation coupling models in hypersonic non-equilibrium separated flows
Shoev, G.; Oblapenko, G.; Kunova, O.; Mekhonoshina, M.; Kustova, E.
2018-03-01
The validation of recently developed models of vibration-dissociation coupling is discussed in application to numerical solutions of the Navier-Stokes equations in a two-temperature approximation for a binary N2/N flow. Vibrational-translational relaxation rates are computed using the Landau-Teller formula generalized for strongly non-equilibrium flows obtained in the framework of the Chapman-Enskog method. Dissociation rates are calculated using the modified Treanor-Marrone model taking into account the dependence of the model parameter on the vibrational state. The solutions are compared to those obtained using traditional Landau-Teller and Treanor-Marrone models, and it is shown that for high-enthalpy flows, the traditional and recently developed models can give significantly different results. The computed heat flux and pressure on the surface of a double cone are in a good agreement with experimental data available in the literature on low-enthalpy flow with strong thermal non-equilibrium. The computed heat flux on a double wedge qualitatively agrees with available data for high-enthalpy non-equilibrium flows. Different contributions to the heat flux calculated using rigorous kinetic theory methods are evaluated. Quantitative discrepancy of numerical and experimental data is discussed.
Energy Technology Data Exchange (ETDEWEB)
Greskowiak, Janek; Hay, Michael B.; Prommer, Henning; Liu, Chongxuan; Post, Vincent; Ma, Rui; Davis, James A.; Zheng, Chunmiao; Zachara, John M.
2011-08-03
Coupled intra-grain diffusional mass-transfer and non-linear surface complexation processes play an important role for the transport behaviour of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes have been analysed and compared: (i) the physical non-equilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface complexation reactions in the intra-grain regions and approximates the diffusive mass exchange between the immobile intra-grain pore water and the advective pore water as multi-rate 1st-order mass transfer and (ii) the chemical non-equilibrium approach that approximates the diffusion-limited intra-grain surface complexation reactions by a set of multiple 1st-order surface complexation reaction kinetics, thereby eliminating the explicit treatment of aqueous speciation in the intra grain pore water. Model comparison has been carried out for column and field scale scenarios, representing the highly transient hydrological and geochemical conditions in the U(VI)-contaminated aquifer at the Hanford 300A site, Washington, USA. It was found that the response of apparent U(VI) adsorption/desorption kinetic behaviour to hydrogeochemically induced changes in U(VI) sorption strength is more pronounced in the physical than in the chemical non-equilibrium model. The magnitude of the differences in model behaviour depends particularly on the degree of disequilibrium between the advective and immobile phase U(VI) concentrations. While a clear difference in U(VI) transport behaviour between the two models was noticeable for the column-scale scenarios, only minor differences were found for the Hanford 300A field scale scenarios, where the model-generated disequilibrium conditions were less pronounced as a result of high frequent groundwater flow reversals.
Electron-Impact Excitation Cross Sections for Modeling Non-Equilibrium Gas
Huo, Winifred M.; Liu, Yen; Panesi, Marco; Munafo, Alessandro; Wray, Alan; Carbon, Duane F.
2015-01-01
In order to provide a database for modeling hypersonic entry in a partially ionized gas under non-equilibrium, the electron-impact excitation cross sections of atoms have been calculated using perturbation theory. The energy levels covered in the calculation are retrieved from the level list in the HyperRad code. The downstream flow-field is determined by solving a set of continuity equations for each component. The individual structure of each energy level is included. These equations are then complemented by the Euler system of equations. Finally, the radiation field is modeled by solving the radiative transfer equation.
The lagRST Model: A Turbulence Model for Non-Equilibrium Flows
Lillard, Randolph P.; Oliver, A. Brandon; Olsen, Michael E.; Blaisdell, Gregory A.; Lyrintzis, Anastasios S.
2011-01-01
This study presents a new class of turbulence model designed for wall bounded, high Reynolds number flows with separation. The model addresses deficiencies seen in the modeling of nonequilibrium turbulent flows. These flows generally have variable adverse pressure gradients which cause the turbulent quantities to react at a finite rate to changes in the mean flow quantities. This "lag" in the response of the turbulent quantities can t be modeled by most standard turbulence models, which are designed to model equilibrium turbulent boundary layers. The model presented uses a standard 2-equation model as the baseline for turbulent equilibrium calculations, but adds transport equations to account directly for non-equilibrium effects in the Reynolds Stress Tensor (RST) that are seen in large pressure gradients involving shock waves and separation. Comparisons are made to several standard turbulence modeling validation cases, including an incompressible boundary layer (both neutral and adverse pressure gradients), an incompressible mixing layer and a transonic bump flow. In addition, a hypersonic Shock Wave Turbulent Boundary Layer Interaction with separation is assessed along with a transonic capsule flow. Results show a substantial improvement over the baseline models for transonic separated flows. The results are mixed for the SWTBLI flows assessed. Separation predictions are not as good as the baseline models, but the over prediction of the peak heat flux downstream of the reattachment shock that plagues many models is reduced.
Two-Temperature Model of non-equilibrium electron relaxation: A Review
Singh, Navinder
2007-01-01
The present paper is a review of the phenomena related to non-equilibrium electron relaxation in bulk and nano-scale metallic samples. The workable Two-Temperature Model (TTM) based on Boltzmann-Bloch-Peierls (BBP) kinetic equation has been applied to study the ultra-fast(femto-second) electronic relaxation in various metallic systems. The advent of new ultra-fast (femto-second) laser technology and pump-probe spectroscopy has produced wealth of new results for micro and nano-scale electronic...
de Oliveira, Luciana Renata; Bazzani, Armando; Giampieri, Enrico; Castellani, Gastone C
2014-08-14
We propose a non-equilibrium thermodynamical description in terms of the Chemical Master Equation (CME) to characterize the dynamics of a chemical cycle chain reaction among m different species. These systems can be closed or open for energy and molecules exchange with the environment, which determines how they relax to the stationary state. Closed systems reach an equilibrium state (characterized by the detailed balance condition (D.B.)), while open systems will reach a non-equilibrium steady state (NESS). The principal difference between D.B. and NESS is due to the presence of chemical fluxes. In the D.B. condition the fluxes are absent while for the NESS case, the chemical fluxes are necessary for the state maintaining. All the biological systems are characterized by their "far from equilibrium behavior," hence the NESS is a good candidate for a realistic description of the dynamical and thermodynamical properties of living organisms. In this work we consider a CME written in terms of a discrete Kolmogorov forward equation, which lead us to write explicitly the non-equilibrium chemical fluxes. For systems in NESS, we show that there is a non-conservative "external vector field" whose is linearly proportional to the chemical fluxes. We also demonstrate that the modulation of these external fields does not change their stationary distributions, which ensure us to study the same system and outline the differences in the system's behavior when it switches from the D.B. regime to NESS. We were interested to see how the non-equilibrium fluxes influence the relaxation process during the reaching of the stationary distribution. By performing analytical and numerical analysis, our central result is that the presence of the non-equilibrium chemical fluxes reduces the characteristic relaxation time with respect to the D.B. condition. Within a biochemical and biological perspective, this result can be related to the "plasticity property" of biological systems and to their
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Luciana Renata de; Bazzani, Armando; Giampieri, Enrico; Castellani, Gastone C., E-mail: Gastone.Castellani@unibo.it [Physics and Astronomy Department, Bologna University and INFN Sezione di Bologna (Italy)
2014-08-14
We propose a non-equilibrium thermodynamical description in terms of the Chemical Master Equation (CME) to characterize the dynamics of a chemical cycle chain reaction among m different species. These systems can be closed or open for energy and molecules exchange with the environment, which determines how they relax to the stationary state. Closed systems reach an equilibrium state (characterized by the detailed balance condition (D.B.)), while open systems will reach a non-equilibrium steady state (NESS). The principal difference between D.B. and NESS is due to the presence of chemical fluxes. In the D.B. condition the fluxes are absent while for the NESS case, the chemical fluxes are necessary for the state maintaining. All the biological systems are characterized by their “far from equilibrium behavior,” hence the NESS is a good candidate for a realistic description of the dynamical and thermodynamical properties of living organisms. In this work we consider a CME written in terms of a discrete Kolmogorov forward equation, which lead us to write explicitly the non-equilibrium chemical fluxes. For systems in NESS, we show that there is a non-conservative “external vector field” whose is linearly proportional to the chemical fluxes. We also demonstrate that the modulation of these external fields does not change their stationary distributions, which ensure us to study the same system and outline the differences in the system's behavior when it switches from the D.B. regime to NESS. We were interested to see how the non-equilibrium fluxes influence the relaxation process during the reaching of the stationary distribution. By performing analytical and numerical analysis, our central result is that the presence of the non-equilibrium chemical fluxes reduces the characteristic relaxation time with respect to the D.B. condition. Within a biochemical and biological perspective, this result can be related to the “plasticity property” of biological
2017-01-01
This paper seeks to develop a more thermodynamically sound pedagogy for students of biological transport than is currently available from either of the competing schools of linear non-equilibrium thermodynamics (LNET) or Michaelis–Menten kinetics (MMK). To this end, a minimal model of facilitated diffusion was constructed comprising four reversible steps: cis-substrate binding, cis→trans bound enzyme shuttling, trans-substrate dissociation and trans→cis free enzyme shuttling. All model parameters were subject to the second law constraint of the probability isotherm, which determined the unidirectional and net rates for each step and for the overall reaction through the law of mass action. Rapid equilibration scenarios require sensitive ‘tuning’ of the thermodynamic binding parameters to the equilibrium substrate concentration. All non-equilibrium scenarios show sigmoidal force–flux relations, with only a minority of cases having their quasi-linear portions close to equilibrium. Few cases fulfil the expectations of MMK relating reaction rates to enzyme saturation. This new approach illuminates and extends the concept of rate-limiting steps by focusing on the free energy dissipation associated with each reaction step and thereby deducing its respective relative chemical impedance. The crucial importance of an enzyme's being thermodynamically ‘tuned’ to its particular task, dependent on the cis- and trans-substrate concentrations with which it deals, is consistent with the occurrence of numerous isoforms for enzymes that transport a given substrate in physiologically different circumstances. This approach to kinetic modelling, being aligned with neither MMK nor LNET, is best described as intuitive non-equilibrium thermodynamics, and is recommended as a useful adjunct to the design and interpretation of experiments in biotransport. PMID:28680687
Chapman, Brian
2017-06-01
This paper seeks to develop a more thermodynamically sound pedagogy for students of biological transport than is currently available from either of the competing schools of linear non-equilibrium thermodynamics (LNET) or Michaelis-Menten kinetics (MMK). To this end, a minimal model of facilitated diffusion was constructed comprising four reversible steps: cis-substrate binding, cis→trans bound enzyme shuttling, trans-substrate dissociation and trans→cis free enzyme shuttling. All model parameters were subject to the second law constraint of the probability isotherm, which determined the unidirectional and net rates for each step and for the overall reaction through the law of mass action. Rapid equilibration scenarios require sensitive 'tuning' of the thermodynamic binding parameters to the equilibrium substrate concentration. All non-equilibrium scenarios show sigmoidal force-flux relations, with only a minority of cases having their quasi-linear portions close to equilibrium. Few cases fulfil the expectations of MMK relating reaction rates to enzyme saturation. This new approach illuminates and extends the concept of rate-limiting steps by focusing on the free energy dissipation associated with each reaction step and thereby deducing its respective relative chemical impedance. The crucial importance of an enzyme's being thermodynamically 'tuned' to its particular task, dependent on the cis- and trans-substrate concentrations with which it deals, is consistent with the occurrence of numerous isoforms for enzymes that transport a given substrate in physiologically different circumstances. This approach to kinetic modelling, being aligned with neither MMK nor LNET, is best described as intuitive non-equilibrium thermodynamics, and is recommended as a useful adjunct to the design and interpretation of experiments in biotransport.
Non-Equilibrium Quantum Dissipation
Segal, Dvira; Reichman, David R.; Millis, Andrew J.
2007-01-01
Dissipative processes in non-equilibrium many-body systems are fundamentally different than their equilibrium counterparts. Such processes are of great importance for the understanding of relaxation in single molecule devices. As a detailed case study, we investigate here a generic spin-fermion model, where a two-level system couples to two metallic leads with different chemical potentials. We present results for the spin relaxation rate in the nonadiabatic limit for an arbitrary coupling to ...
Non-equilibrium radiation from viscous chemically reacting two-phase exhaust plumes
Penny, M. M.; Smith, S. D.; Mikatarian, R. R.; Ring, L. R.; Anderson, P. G.
1976-01-01
A knowledge of the structure of the rocket exhaust plumes is necessary to solve problems involving plume signatures, base heating, plume/surface interactions, etc. An algorithm is presented which treats the viscous flow of multiphase chemically reacting fluids in a two-dimensional or axisymmetric supersonic flow field. The gas-particle flow solution is fully coupled with the chemical kinetics calculated using an implicit scheme to calculate chemical production rates. Viscous effects include chemical species diffusion with the viscosity coefficient calculated using a two-equation turbulent kinetic energy model.
Evolution and non-equilibrium physics: A study of the Tangled Nature Model
Becker, Nikolaj; Sibani, Paolo
2014-01-01
We argue that the stochastic dynamics of interacting agents which replicate, mutate and die constitutes a non-equilibrium physical process akin to aging in complex materials. Specifically, our study uses extensive computer simulations of the Tangled Nature Model (TNM) of biological evolution to show that punctuated equilibria successively generated by the model's dynamics have increasing entropy and are separated by increasing entropic barriers. We further show that these states are organized in a hierarchy and that limiting the values of possible interactions to a finite interval leads to stationary fluctuations within a component of the latter. A coarse-grained description based on the temporal statistics of quakes, the events leading from one component of the hierarchy to the next, accounts for the logarithmic growth of the population and the decaying rate of change of macroscopic variables. Finally, we question the role of fitness in large-scale evolution models and speculate on the possible evolutionary role of rejuvenation and memory effects.
A non-equilibrium thermodynamic model for tumor extracellular matrix with enzymatic degradation
Xue, Shi-Lei; Li, Bo; Feng, Xi-Qiao; Gao, Huajian
2017-07-01
The extracellular matrix (ECM) of a solid tumor not only affords scaffolding to support tumor architecture and integrity but also plays an essential role in tumor growth, invasion, metastasis, and therapeutics. In this paper, a non-equilibrium thermodynamic theory is established to study the chemo-mechanical behaviors of tumor ECM, which is modeled as a poroelastic polyelectrolyte consisting of a collagen network and proteoglycans. By using the principle of maximum energy dissipation rate, we deduce a set of governing equations for drug transport and mechanosensitive enzymatic degradation in ECM. The results reveal that osmosis is primarily responsible for the compression resistance of ECM. It is suggested that a well-designed ECM degradation can effectively modify the tumor microenvironment for improved efficiency of cancer therapy. The theoretical predictions show a good agreement with relevant experimental observations. This study aimed to deepen our understanding of tumor ECM may be conducive to novel anticancer strategies.
Influence of turbulent fluctuations on non-equilibrium chemical reactions in the flow
Molchanov, A. M.; Yanyshev, D. S.; Bykov, L. V.
2017-11-01
In chemically nonequilibrium flows the problem of calculation of sources (formation rates) in equations for chemical species is of utter importance. Formation rate of each component is a non-linear function of mixture density, temperature and concentration of species. Thus the suggestion that the mean rate may be determined via mean values of the flow parameters could lead to significant errors. One of the most accurate approaches here is utilization of probability density function (PDF). In this paper the method for constructing such PDFs is developed. The developed model was verified by comparison with the experimental data. On the example of supersonic combustion it was shown that while the overall effect on the averaged flow field is often negligible, the point of ignition can be considerably shifted up the flow.
Efficient modeling of non-equilibrium quantum transport in 3D nanostructures
Energy Technology Data Exchange (ETDEWEB)
Greck, Peter; Schindler, Christoph; Vogl, Peter [Technische Universitaet Muenchen (Germany)
2010-07-01
We present non-equilibrium Green's function (NEGF) calculations based on an extension of the standard Buettiker Probe model. Buettiker Probes provide a phenomenological method to model incoherent scattering very efficiently. However, any effects of discrete energy coupling (e.g. by optical phonons) are not captured due to the simple structure of the model. Therefore, devices relying on resonant phonon effects such as THz quantum cascade lasers (QCLs) call for more sophisticated models for the scattering self energies. While the self-consistent Born approximation provides the required accuracy, it is extremely costly in terms of computational resources, especially for 3D nanostructures. We have extended the standard Buettiker Probe model in a way that accurately accounts for optical phonon scattering without losing the computational efficiency and simplicity of the Buettiker Probe model. The method allows one to control the scattering mechanisms individually. This renders realistic quantum transport calculations of 3D nanostructures feasible. We present detailed calculations of mid-infrared quantum cascade structures and compare the results with experimental data as well as with full NEGF results.
Aureli, Matteo; Doumanidis, Constantine C.; Gunduz, I. E.; Hussien, Aseel Gamal Suliman; Liao, Yiliang; Jaffar, Syed Murtaza; Rebholz, Claus; Doumanidis, Charalabos C.
2017-07-01
Nanostructured bimetallic reactive multilayers can be conveniently produced by ball milling of elemental powders. This research explores the non-equilibrium microscale conductive thermal transport in ball-milled particulate fractal structures during fabrication, arising from heat dissipation by bulk plastic deformation and surface friction. Upon impactor collisions, temperature increments are determined at interface joints and domain volumes using Green's functions, mirrored by source images with respect to warped ellipsoid domain boundaries. Heat source efficiency is calibrated via laboratory data to compensate for thermal expansion and impactor inelasticity, and the thermal analysis is coupled to a dynamic mechanics model of the particulate fracture. This thermomechanical model shows good agreement with the fractal dimensions of the observed microstructure from ball milling experiments. The model is intended to provide a comprehensive physical understanding of the fundamental process mechanism. In addition, the model could serve as a real-time thermal observer for closed-loop process control, as well as for interfacial diffusion and reaction analysis during ball milling.
State-to-state modeling of non equilibrium low-temperature atomic plasmas
Bultel, Arnaud; Morel, Vincent; Annaloro, Julien; Druguet, Marie-Claude
2017-03-01
The most relevant approach leading to a thorough understanding of the behavior of non equilibrium atomic plasmas is to elaborate state-to-state models in which the mass conservation equation is applied directly to atoms or ions on their excited states. The present communication reports the elaboration of such models and the results obtained. Two situations close to each other are considered. First, the plasmas produced behind shock fronts obtained in ground test facilities (shock tubes) or during planetary atmospheric entries of spacecrafts are discussed. We focused our attention on the nitrogen case for which a complete implementation of the CoRaM-N2 collisional-radiative model has been performed in a steady one-dimensional computation code based on the Rankine-Hugoniot assumptions. Second, the plasmas produced by the interaction between an ultra short laser pulse and a tungsten sample are discussed in the framework of the elaboration of the Laser-Induced Breakdown Spectroscopy (LIBS) technique. In the present case, tungsten has been chosen in the purpose of validating an in situ experimental method able to provide the elemental composition of the divertor wall of a tokamak like WEST or ITER undergoing high energetic deuterium and tritium nuclei fluxes.
Numerical modeling of an alloy droplet deposition with non-equilibrium solidification
Ramanuj, Vimal
Droplet deposition is a process of extensive relevance to the microfabrication industry. Various bonding and film deposition methods utilize single or multiple droplet impingements on a substrate with subsequent splat formation through simultaneous spreading and solidification. Splat morphology and solidification characteristics play vital roles in determining the final outcome. Experimental methods have limited reach in studying such phenomena owing to the extremely small time and length scales involved. Fundamental understanding of the governing principles of fluid flow, heat transfer and phase change provide effective means of studying such processes through computational techniques. The present study aims at numerically modeling and analyzing the phenomenon of splat formation and phase change in an alloy droplet deposition process. Phase change in alloys occurs non-isothermally and its formulation poses mathematical challenges. A highly non-linear flow field in conjunction with multiple interfaces and convection-diffusion governed phase transition are some of the highlighting features involved in the numerical formulation. Moreover, the non-equilibrium solidification behavior in eutectic systems is of prime concern. The peculiar phenomenon requires special treatments in terms of modeling solid phase species diffusion, liquid phase enrichment during solute partitioning and isothermal eutectic transformation. The flow field is solved using a two-step projection algorithm coupled with enhanced interface modeling schemes. The free surface tracking and reconstruction is achieved through two approaches: VOF-PLIC and CLSVOF to achieve optimum interface accuracy with minimal computational resources. The energy equation is written in terms of enthalpy with an additional source term to account for the phase change. The solidification phenomenon is modeled using a coupled temperature-solute scheme that reflects the microscopic effects arising due to dendritic growth
A. A. Dorofeev; D. M. Yagodnikov
2016-01-01
The paper studies the emerging hallmarks and the characteristics of a two-parameter chemical non-equilibrium structure of the combustion products of liquid propellants as applied to the low-thrust liquid propellant engines (LT LPE) operating in the aircraft control system. The study is based on hydrazine and nitrogen tetroxide products. The paper also analyses the catalytic and thermal decomposition of these substances in terms of inter-conditionality of the working process components in the ...
Non-Equilibrium Thermodynamics in Multiphase Flows
Mauri, Roberto
2013-01-01
Non-equilibrium thermodynamics is a general framework that allows the macroscopic description of irreversible processes. This book introduces non-equilibrium thermodynamics and its applications to the rheology of multiphase flows. The subject is relevant to graduate students in chemical and mechanical engineering, physics and material science. This book is divided into two parts. The first part presents the theory of non-equilibrium thermodynamics, reviewing its essential features and showing, when possible, some applications. The second part of this book deals with how the general theory can be applied to model multiphase flows and, in particular, how to determine their constitutive relations. Each chapter contains problems at the end, the solutions of which are given at the end of the book. No prior knowledge of statistical mechanics is required; the necessary prerequisites are elements of transport phenomena and on thermodynamics. “The style of the book is mathematical, but nonetheless it remains very re...
Directory of Open Access Journals (Sweden)
A. A. Dorofeev
2016-01-01
Full Text Available The paper studies the emerging hallmarks and the characteristics of a two-parameter chemical non-equilibrium structure of the combustion products of liquid propellants as applied to the low-thrust liquid propellant engines (LT LPE operating in the aircraft control system. The study is based on hydrazine and nitrogen tetroxide products. The paper also analyses the catalytic and thermal decomposition of these substances in terms of inter-conditionality of the working process components in the combustion chamber and liquid pre-burner. The paper offers a technique to simulate these types of non-equilibrium as applied both to the a priori estimate and to the parametric optimization of LT LPE performance. It presents the possible equations of chemical dissociation reactions of hydrazine under various conditions, which determine a chemical disequilibrium of the process, and gives the examples to specify the source files for the software systems "Astra 4.rs" or "Terra".The technique is implemented and tested on the basis of the software systems "Astra4.rs" and "Terra" in calculating the structure and properties of the liquid propellant combustion products, which include hydrazine, combustion products, ammonia, and products of their catalytic thermal decomposition. The paper provides numerical values of the upper and lower concentration limits of the non-equilibrium of a generated propellant, which correspond to the equilibrium ratio of concentrations between ammonia and products of its decomposition, as well as meet the absence of ammonia pyrolysis. For possible conditions of the non-equilibrium work process the values of void specific impulse are calculated.
A coupled implicit method for chemical non-equilibrium flows at all speeds
Energy Technology Data Exchange (ETDEWEB)
Shuen, J.S.; Choi, Y. (NASA Lewis Research Center, Cleveland, OH (United States)); Chen, K.H. (Univ. of Toledo, Cleveland, OH (United States))
1993-06-01
A time-accurate, coupled solution procedure is described for the chemical nonequilibrium Navier-Stokes equations over a wide range of Mach numbers. This method employs the strong conservation form of the governing equations, but uses primitive variables (p[sub g], u, v, h, Y[sub i]) as unknowns. Real gas properties and nonequilibrium chemistry are considered. Numerical tests include steady convergent-divergent nozzle flows with air dissociation/recombination chemistry, dump combustor flows with n-pentan air chemistry, and nonreacting unsteady driven cavity flows. Numerical results for both the steady and unsteady flows demonstrate the efficiency and robustness of the present algorithm for Mach numbers ranging from the incompressible limit to supersonic speeds. 26 refs., 10 figs.
A framework for modelling gene regulation which accommodates non-equilibrium mechanisms.
Ahsendorf, Tobias; Wong, Felix; Eils, Roland; Gunawardena, Jeremy
2014-12-05
Gene regulation has, for the most part, been quantitatively analysed by assuming that regulatory mechanisms operate at thermodynamic equilibrium. This formalism was originally developed to analyse the binding and unbinding of transcription factors from naked DNA in eubacteria. Although widely used, it has made it difficult to understand the role of energy-dissipating, epigenetic mechanisms, such as DNA methylation, nucleosome remodelling and post-translational modification of histones and co-regulators, which act together with transcription factors to regulate gene expression in eukaryotes. Here, we introduce a graph-based framework that can accommodate non-equilibrium mechanisms. A gene-regulatory system is described as a graph, which specifies the DNA microstates (vertices), the transitions between microstates (edges) and the transition rates (edge labels). The graph yields a stochastic master equation for how microstate probabilities change over time. We show that this framework has broad scope by providing new insights into three very different ad hoc models, of steroid-hormone responsive genes, of inherently bounded chromatin domains and of the yeast PHO5 gene. We find, moreover, surprising complexity in the regulation of PHO5, which has not yet been experimentally explored, and we show that this complexity is an inherent feature of being away from equilibrium. At equilibrium, microstate probabilities do not depend on how a microstate is reached but, away from equilibrium, each path to a microstate can contribute to its steady-state probability. Systems that are far from equilibrium thereby become dependent on history and the resulting complexity is a fundamental challenge. To begin addressing this, we introduce a graph-based concept of independence, which can be applied to sub-systems that are far from equilibrium, and prove that history-dependent complexity can be circumvented when sub-systems operate independently. As epigenomic data become increasingly
Directory of Open Access Journals (Sweden)
Katalin Martinás
2007-02-01
Full Text Available A microeconomic, agent based framework to dynamic economics is formulated in a materialist approach. An axiomatic foundation of a non-equilibrium microeconomics is outlined. Economic activity is modelled as transformation and transport of commodities (materials owned by the agents. Rate of transformations (production intensity, and the rate of transport (trade are defined by the agents. Economic decision rules are derived from the observed economic behaviour. The non-linear equations are solved numerically for a model economy. Numerical solutions for simple model economies suggest that the some of the results of general equilibrium economics are consequences only of the equilibrium hypothesis. We show that perfect competition of selfish agents does not guarantee the stability of economic equilibrium, but cooperativity is needed, too.
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Anders, Frithjof B [Institut fuer Theoretische Physik, Universitaet Bremen, PO Box 330 440, D-28334 Bremen (Germany)], E-mail: anders@itp.uni-bremen.de
2008-05-14
We present a method for the calculation of dynamical correlation functions of quantum impurity systems out of equilibrium using Wilson's numerical renormalization group (NRG). Our formulation is based on a complete basis set of the Wilson chain and embeds the recently derived algorithm for equilibrium spectral functions. Our method fulfils the spectral weight conserving sum-rule exactly by construction. A local Coulomb repulsion U>0 is switched on at t = 0, and the asymptotic steady-state spectral functions are obtained for various values of U as well as magnetic field strength H and temperature T. These benchmark tests show excellent agreement between the time-evolved and the directly calculated equilibrium NRG spectra for finite U. This method could be used for calculating steady-state non-equilibrium spectral functions at finite bias through interacting nanodevices.
Directory of Open Access Journals (Sweden)
Zhixin Yang
Full Text Available The onset of double diffusive convection in a viscoelastic fluid-saturated porous layer is studied when the fluid and solid phase are not in local thermal equilibrium. The modified Darcy model is used for the momentum equation and a two-field model is used for energy equation each representing the fluid and solid phases separately. The effect of thermal non-equilibrium on the onset of double diffusive convection is discussed. The critical Rayleigh number and the corresponding wave number for the exchange of stability and over-stability are obtained, and the onset criterion for stationary and oscillatory convection is derived analytically and discussed numerically.
Yang, Zhixin; Wang, Shaowei; Zhao, Moli; Li, Shucai; Zhang, Qiangyong
2013-01-01
The onset of double diffusive convection in a viscoelastic fluid-saturated porous layer is studied when the fluid and solid phase are not in local thermal equilibrium. The modified Darcy model is used for the momentum equation and a two-field model is used for energy equation each representing the fluid and solid phases separately. The effect of thermal non-equilibrium on the onset of double diffusive convection is discussed. The critical Rayleigh number and the corresponding wave number for the exchange of stability and over-stability are obtained, and the onset criterion for stationary and oscillatory convection is derived analytically and discussed numerically.
Speck, Thomas; Chandler, David
2012-05-14
Recent progress has demonstrated that trajectory space for both kinetically constrained lattice models and atomistic models can be partitioned into a liquid-like and an inactive basin with a non-equilibrium phase transition separating these behaviors. Recent work has also established that excitations in atomistic models have statistics and dynamics like those in a specific class of kinetically constrained models. But it has not been known whether the non-equilibrium phase transitions occurring in the two classes of models have similar origins. Here, we show that the origin is indeed similar. In particular, we show that the number of excitations identified in an atomistic model serves as the order parameter for the inactive-active phase transition for that model. In this way, we show that the mechanism by which excitations are correlated in an atomistic model - by dynamical facilitation - is the mechanism from which the active-inactive phase transition emerges. We study properties of the inactive phase and show that it is amorphous lacking long-range order. We also discuss the choice of dynamical order parameters.
Lucarini, Valerio; Gallavotti, Giovanni
We construct different equivalent non-equilibrium ensembles in the Lorenz '96 model of atmospheric turbulence. The vector field can be decomposed into an energy-conserving, time-reversible part, plus a non-time reversible part, including forcing and dissipation. We construct a modified version of the model where viscosity varies with time, so that energy is conserved, and the dynamics is time-reversible. The statistical properties of the irreversible and reversible model are in excellent agreement, if in the latter the energy is kept constant at a value equal to the time-average realized with the irreversible model. The average contraction rate of the phase space of the time-reversible model agrees with that of the irreversible model, where it is constant by construction. We show that the phase space contraction rate obeys the fluctuation relation, and we interpret its finite time corrections. A local version of the fluctuation relation is explored and successfully checked. The equivalence between the two ensembles extends to the Lyapunov exponents.These results have relevance in motivating the importance of the chaotic hypothesis. in explaining that we have the freedom to model non-equilibrium systems using different but equivalent approaches.
A porous flow approach to model thermal non-equilibrium applicable to melt migration
Schmeling, Harro; Marquart, Gabriele; Grebe, Michael
2018-01-01
We develop an approach for heat exchange between a fluid and a solid phase of a porous medium where the temperatures of the fluid and matrix are not in thermal equilibrium. The formulation considers moving of the fluid within a resting or deforming porous matrix in an Eulerian coordinate system. The approach can be applied, for example, to partially molten systems or to brine transport in porous rocks. We start from an existing theory for heat exchange where the energy conservation equations for the fluid and the solid phases are separated and coupled by a heat exchange term. This term is extended to account for the full history of heat exchange. It depends on the microscopic geometry of the fluid phase. For the case of solid containing hot, fluid-filled channels, we derive an expression based on a time-dependent Fourier approach for periodic half-waves. On the macroscopic scale, the temporal evolution of the heat exchange leads to a convolution integral along the flow path of the solid, which simplifies considerably in case of a resting matrix. The evolution of the temperature in both phases with time is derived by inserting the heat exchange term into the energy equations. We explore the effects of thermal non-equilibrium between fluid and solid by considering simple cases with sudden temperature differences between fluid and solid as initial or boundary conditions, and by varying the fluid velocity with respect to the resting porous solid. Our results agree well with an analytical solution for non-moving fluid and solid. The temperature difference between solid and fluid depends on the Peclet number based on the Darcy velocity. For Peclet numbers larger than 1, the temperature difference after one diffusion time reaches 5 per cent of \\tilde{T} or more (\\tilde{T} is a scaling temperature, e.g. the initial temperature difference). Thus, our results imply that thermal non-equilibrium can play an important role for melt migration through partially molten systems
Non-equilibrium phase transitions
Henkel, Malte; Lübeck, Sven
2009-01-01
This book describes two main classes of non-equilibrium phase-transitions: (a) static and dynamics of transitions into an absorbing state, and (b) dynamical scaling in far-from-equilibrium relaxation behaviour and ageing. The first volume begins with an introductory chapter which recalls the main concepts of phase-transitions, set for the convenience of the reader in an equilibrium context. The extension to non-equilibrium systems is made by using directed percolation as the main paradigm of absorbing phase transitions and in view of the richness of the known results an entire chapter is devoted to it, including a discussion of recent experimental results. Scaling theories and a large set of both numerical and analytical methods for the study of non-equilibrium phase transitions are thoroughly discussed. The techniques used for directed percolation are then extended to other universality classes and many important results on model parameters are provided for easy reference.
Energy Technology Data Exchange (ETDEWEB)
Park, Ik Kyu; Cho, Heong Kyu; Kim, Jong Tae; Yoon, Han Young; Jeong, Jae Jun
2007-12-15
A computational model for transient, 3 dimensional 2 phase flows was developed by using 'unstructured-FVM-based, non-staggered, semi-implicit numerical scheme' considering the thermally non-equilibrium droplets. The assumption of the thermally equilibrium between liquid and droplets of previous studies was not used any more, and three energy conservation equations for vapor, liquid, liquid droplets were set up. Thus, 9 conservation equations for mass, momentum, and energy were established to simulate 2 phase flows. In this report, the governing equations and a semi-implicit numerical sheme for a transient 1 dimensional 2 phase flows was described considering the thermally non-equilibrium between liquid and liquid droplets. The comparison with the previous model considering the thermally non-equilibrium between liquid and liquid droplets was also reported.
Multiscale modeling and general theory of non-equilibrium plasma-assisted ignition and combustion
Yang, Suo; Nagaraja, Sharath; Sun, Wenting; Yang, Vigor
2017-11-01
A self-consistent framework for modeling and simulations of plasma-assisted ignition and combustion is established. In this framework, a ‘frozen electric field’ modeling approach is applied to take advantage of the quasi-periodic behaviors of the electrical characteristics to avoid the re-calculation of electric field for each pulse. The correlated dynamic adaptive chemistry (CO-DAC) method is employed to accelerate the calculation of large and stiff chemical mechanisms. The time-step is dynamically updated during the simulation through a three-stage multi-time scale modeling strategy, which utilizes the large separation of time scales in nanosecond pulsed plasma discharges. A general theory of plasma-assisted ignition and combustion is then proposed. Nanosecond pulsed plasma discharges for ignition and combustion can be divided into four stages. Stage I is the discharge pulse, with time scales of O (1-10 ns). In this stage, input energy is coupled into electron impact excitation and dissociation reactions to generate charged/excited species and radicals. Stage II is the afterglow during the gap between two adjacent pulses, with time scales of O (1 0 0 ns). In this stage, quenching of excited species dissociates O2 and fuel molecules, and provides fast gas heating. Stage III is the remaining gap between pulses, with time scales of O (1-100 µs). The radicals generated during Stages I and II significantly enhance exothermic reactions in this stage. The cumulative effects of multiple pulses is seen in Stage IV, with time scales of O (1-1000 ms), which include preheated gas temperatures and a large pool of radicals and fuel fragments to trigger ignition. For flames, plasma could significantly enhance the radical generation and gas heating in the pre-heat zone, thereby enhancing the flame establishment.
Energy Technology Data Exchange (ETDEWEB)
Lindskog, M., E-mail: martin.lindskog@teorfys.lu.se; Wacker, A. [Mathematical Physics, Lund University, Box 118, 22100 Lund (Sweden); Wolf, J. M.; Liverini, V.; Faist, J. [ETH Institute for Quantum Electronics, ETH-Zürich, 8093 Zürich (Switzerland); Trinite, V.; Maisons, G.; Carras, M. [III-V Lab, 1 Avenue Augustin Fresnel, 91767 Palaiseau (France); Aidam, R.; Ostendorf, R. [Fraunhofer-Institut für Angewandte Festkörperphysik, Tullastrasse 72, 79108 Freiburg (Germany)
2014-09-08
We study the operation of an 8.5 μm quantum cascade laser based on GaInAs/AlInAs lattice matched to InP using three different simulation models based on density matrix (DM) and non-equilibrium Green's function (NEGF) formulations. The latter advanced scheme serves as a validation for the simpler DM schemes and, at the same time, provides additional insight, such as the temperatures of the sub-band carrier distributions. We find that for the particular quantum cascade laser studied here, the behavior is well described by simple quantum mechanical estimates based on Fermi's golden rule. As a consequence, the DM model, which includes second order currents, agrees well with the NEGF results. Both these simulations are in accordance with previously reported data and a second regrown device.
Non-equilibrium supramolecular polymerization.
Sorrenti, Alessandro; Leira-Iglesias, Jorge; Markvoort, Albert J; de Greef, Tom F A; Hermans, Thomas M
2017-09-18
Supramolecular polymerization has been traditionally focused on the thermodynamic equilibrium state, where one-dimensional assemblies reside at the global minimum of the Gibbs free energy. The pathway and rate to reach the equilibrium state are irrelevant, and the resulting assemblies remain unchanged over time. In the past decade, the focus has shifted to kinetically trapped (non-dissipative non-equilibrium) structures that heavily depend on the method of preparation (i.e., pathway complexity), and where the assembly rates are of key importance. Kinetic models have greatly improved our understanding of competing pathways, and shown how to steer supramolecular polymerization in the desired direction (i.e., pathway selection). The most recent innovation in the field relies on energy or mass input that is dissipated to keep the system away from the thermodynamic equilibrium (or from other non-dissipative states). This tutorial review aims to provide the reader with a set of tools to identify different types of self-assembled states that have been explored so far. In particular, we aim to clarify the often unclear use of the term "non-equilibrium self-assembly" by subdividing systems into dissipative, and non-dissipative non-equilibrium states. Examples are given for each of the states, with a focus on non-dissipative non-equilibrium states found in one-dimensional supramolecular polymerization.
Energy Technology Data Exchange (ETDEWEB)
Duchemin, Ivan, E-mail: ivan.duchemin@cea.fr [INAC, SP2M/L-Sim, CEA/UJF Cedex 09, 38054 Grenoble (France); Jacquemin, Denis [Laboratoire CEISAM - UMR CNR 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3 (France); Institut Universitaire de France, 1 rue Descartes, 75005 Paris Cedex 5 (France); Blase, Xavier [CNRS, Inst. NÉEL, F-38000 Grenoble (France); Univ. Grenoble Alpes, Inst. NÉEL, F-38000 Grenoble (France)
2016-04-28
We have implemented the polarizable continuum model within the framework of the many-body Green’s function GW formalism for the calculation of electron addition and removal energies in solution. The present formalism includes both ground-state and non-equilibrium polarization effects. In addition, the polarization energies are state-specific, allowing to obtain the bath-induced renormalisation energy of all occupied and virtual energy levels. Our implementation is validated by comparisons with ΔSCF calculations performed at both the density functional theory and coupled-cluster single and double levels for solvated nucleobases. The present study opens the way to GW and Bethe-Salpeter calculations in disordered condensed phases of interest in organic optoelectronics, wet chemistry, and biology.
William Massman
2015-01-01
Increased use of prescribed fire by land managers and the increasing likelihood of wildfires due to climate change require an improved modeling capability of extreme heating of soils during fires. This issue is addressed here by developing and testing the soil (heat-moisture-vapor) HMVmodel, a 1-D (one-dimensional) non-equilibrium (liquid- vapor phase change)...
Theory and Modelling of Ultrafast X-ray Imaging of Dynamical Non-equilibrium Systems
DEFF Research Database (Denmark)
Lorenz, Ulf
Over the next few years, a new generation of x-ray sources is going online. These freeelectron lasers will provide extremely bright subpicosecond x-ray pulses. Traditionally, x-ray diraction has the advantage of directly determining the atomic positions within a sample. With these new machines......, it becomes feasible to exploit this concept for ultrafast processes; in eect, we can study chemical reactions as they occur. This thesis deals with theoretical aspect of ultrafast time-resolved x-ray diraction (TRXD).We derive general formulas for calculating the diraction signal that are closely related...
Systematic validation of non-equilibrium thermochemical models using Bayesian inference
Miki, Kenji
2015-10-01
© 2015 Elsevier Inc. The validation process proposed by Babuška et al. [1] is applied to thermochemical models describing post-shock flow conditions. In this validation approach, experimental data is involved only in the calibration of the models, and the decision process is based on quantities of interest (QoIs) predicted on scenarios that are not necessarily amenable experimentally. Moreover, uncertainties present in the experimental data, as well as those resulting from an incomplete physical model description, are propagated to the QoIs. We investigate four commonly used thermochemical models: a one-temperature model (which assumes thermal equilibrium among all inner modes), and two-temperature models developed by Macheret et al. [2], Marrone and Treanor [3], and Park [4]. Up to 16 uncertain parameters are estimated using Bayesian updating based on the latest absolute volumetric radiance data collected at the Electric Arc Shock Tube (EAST) installed inside the NASA Ames Research Center. Following the solution of the inverse problems, the forward problems are solved in order to predict the radiative heat flux, QoI, and examine the validity of these models. Our results show that all four models are invalid, but for different reasons: the one-temperature model simply fails to reproduce the data while the two-temperature models exhibit unacceptably large uncertainties in the QoI predictions.
Dynamic behaviour of reactive distillation tray columns described with a non-equilibrium cell model
Baur, R.; Taylor, R.; Krishna, R.
2001-01-01
In this paper we develop a generic, dynamic, nonequilibrium (NEQ) cell model for reactive distillation (RD) tray columns. The features of our model are (1) the use of Maxwell–Stefan equations for describing mass transfer between fluid phases, (2) the reaction is assumed to take place in the liquid
Kramer, K.; Werf, van der D.C.
2010-01-01
The environment is changing and so are forests, in their functioning, in species composition, and in the species’ genetic composition. Many empirical and process-based models exist to support forest management. However, most of these models do not consider the impact of environmental changes and
DEFF Research Database (Denmark)
Pugliese, Lorenzo; Bruun, Jacob; Kjaergaard, Charlotte
2017-01-01
Biogeochemical processes in subsurface flow constructed wetlands are influenced by flow direction, degree of saturation and influent loading position. This study presents a simulation tool, which aims to predict the performance of the unit and improve the design. The model was developed using...... the HYDRUS program, calibrated and verified on previously measured bromide (Br-) pulse tracer tests. Three different hydraulic designs (Horizontal (HF), Vertical upward (VF-up), Vertical downward (VF-down) and two different flow rates: Low (L), and High (H)) were investigated. The model simulated well the Br......- transport behaviour and the results underline the importance of the hydraulic design. Calibrated model parameters (longitudinal dispersivity, immobile liquid phase, mass transfer coefficient) showed a common trend for all the designs, for increasing flow rates within the investigated range. The VF...
Wang, Chi-Jen; Liu, Da-Jiang; Evans, James W
2015-04-28
Threshold versions of Schloegl's model on a lattice, which involve autocatalytic creation and spontaneous annihilation of particles, can provide a simple prototype for discontinuous non-equilibrium phase transitions. These models are equivalent to so-called threshold contact processes. A discontinuous transition between populated and vacuum states can occur selecting a threshold of N ≥ 2 for the minimum number, N, of neighboring particles enabling autocatalytic creation at an empty site. Fundamental open questions remain given the lack of a thermodynamic framework for analysis. For a square lattice with N = 2, we show that phase coexistence occurs not at a unique value but for a finite range of particle annihilation rate (the natural control parameter). This generic two-phase coexistence also persists when perturbing the model to allow spontaneous particle creation. Such behavior contrasts both the Gibbs phase rule for thermodynamic systems and also previous analysis for this model. We find metastability near the transition corresponding to a non-zero effective line tension, also contrasting previously suggested critical behavior. Mean-field type analysis, extended to treat spatially heterogeneous states, further elucidates model behavior.
Energy Technology Data Exchange (ETDEWEB)
Wang, Chi-Jen [Ames Laboratory–USDOE, Iowa State University, Ames, Iowa 50011 (United States); Department of Mathematics, Iowa State University, Ames, Iowa 50011 (United States); Liu, Da-Jiang [Ames Laboratory–USDOE, Iowa State University, Ames, Iowa 50011 (United States); Evans, James W. [Ames Laboratory–USDOE, Iowa State University, Ames, Iowa 50011 (United States); Department of Mathematics, Iowa State University, Ames, Iowa 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)
2015-04-28
Threshold versions of Schloegl’s model on a lattice, which involve autocatalytic creation and spontaneous annihilation of particles, can provide a simple prototype for discontinuous non-equilibrium phase transitions. These models are equivalent to so-called threshold contact processes. A discontinuous transition between populated and vacuum states can occur selecting a threshold of N ≥ 2 for the minimum number, N, of neighboring particles enabling autocatalytic creation at an empty site. Fundamental open questions remain given the lack of a thermodynamic framework for analysis. For a square lattice with N = 2, we show that phase coexistence occurs not at a unique value but for a finite range of particle annihilation rate (the natural control parameter). This generic two-phase coexistence also persists when perturbing the model to allow spontaneous particle creation. Such behavior contrasts both the Gibbs phase rule for thermodynamic systems and also previous analysis for this model. We find metastability near the transition corresponding to a non-zero effective line tension, also contrasting previously suggested critical behavior. Mean-field type analysis, extended to treat spatially heterogeneous states, further elucidates model behavior.
Exact solution of SU(4) non-equilibrium Kondo model at the Toulouse point.
Duki, Solomon; Mathur, Harsh
2007-03-01
SU(4) symmetry in quantum dots has become a growing interest in both semiconductor quantum dots and carbon nanotube quantum dots[1]. We investigate theoretically the properties of an SU(4) Kondo model out of equilibrium by solving the problem exactly at a special point in the parameter space. The solution reveals that, in contrast to the SU(2) model, there are two more excitations in the system other than the charge and spin excitations. We investigate the differential conductance for arbitrary voltage bias. [1] P. Jarillo-Herrero, J. Kong, H.S.J. van der Zant, C. Dekker, L.P. Kouwenhoven and S. De Franceschi, http://www.nature.com/openurl?urlver=Z39.88-2004&rftvalfmt=info:ofi/fmt:kev:mtx:journal&rft.genre=journal&rft. volume=434&rft.spage=484 &rft.date=2005 (Nature) 434, 484, (2005).
Model and Algorithm for Linkage Disequilibrium Analysis in a Non-equilibrium Population
Directory of Open Access Journals (Sweden)
Jingyuan eLiu
2012-07-01
Full Text Available The multilocus analysis of polymorphisms has emerged as a vital ingredient of population genetics and evolutionary biology. A fundamental assumption used for existing multilocus analysis approaches is Hardy-Weinberg equilibrium (HWE at which maternally- and paternally-derived gametes combine randomly during fertilization. Given the fact that natural populations are rarely panmictic, these approaches will have a significant limitation for practical use. We present a robust model for multilocus linkage disequilibrium analysis which does not rely on the assumption of random mating. This new disequilibrium model capitalizes on Weir’s definition of zygotic disequilibria and is based on an open-pollinated design in which multiple maternal individuals and their half-sib families are sampled from a natural population. This design captures two levels of associations: one is at the upper level that describes the pattern of co-segregation between different loci in the parental population and the other is at the lower level that specifies the extent of co-transmission of non-alleles at different loci from parents to their offspring. An MCMC method was implemented to estimate genetic parameters that define these associations. Simulation studies were used to validate the statistical behavior of the new model.
Non-equilibrium modeling of the PMSE Overshoot Effect revisited: A comprehensive study
Biebricher, Alexander; Havnes, Ove
2012-06-01
Numerical investigations of the Polar Mesosphere Summer Echoes (PMSE) Overshoot Effect have to date been undertaken under the premise of plasma neutrality and current equilibrium at any time. We find it necessary to revisit the calculations without these restrictions, since electrons and ions are attached to and absorbed by mesospheric dust particles at vastly different rates under PMSE conditions. We find that differences to earlier modeling might be so significant as to warrant further investigation. Furthermore, we conduct comprehensive studies of the PMSE Overshoot Effect and put the results in the context of experimental realities.
Modeling magnetohydrodynamics and non-equilibrium SoHO/UVCS line emission of CME shocks
Pagano, P.; Raymond, J. C.; Reale, F.
The Coronal Mass Ejections are plasma clouds expelled from the Sun into the interplanetary medium. We study the propagation of shock waves in the solar corona generated during Coronal Mass Ejections by means of a numerical multi-dimensional MHD model. The model describes the MHD evolution of a compressible plasma in an ambient magnetic field including tensor thermal conduction, radiative losses as main physical effects. We use the MHD version of the FLASH parallel hydrodynamic code with adaptive mesh refinement, originally developed at the University of Chicago USA). The code is highly modular and made efficiently parallel with the Message Passing Interface library. We analyze the diagnostic signatures of shock fronts generated by supersonic CME fragments detectable with the UltraViolet Coronagraphic Spectrometer on board the SoHO mission. To this aim we perform 3D MHD simulations of the shock propagation for the time it takes to cross the UVCS slit positioned at a distance of a few solar radii from the solar surface. In the presence of highly effective thermal conduction the simulation takes 200000 time steps to cover 1000 s of evolution. Considering a 3-D domain of 256x256x512 grid cells this kind of simulations requires thousands of hours of computer time and therefore high performance computing (HPC) systems. The simulations were run on the CINECA IBM/SP5 HPC cluster within the INAF/CINECA agreement. We show simulation results and some implications for UVCS observations.
Spectral-Lagrangian methods for collisional models of non-equilibrium statistical states
Gamba, Irene M.; Tharkabhushanam, Sri Harsha
2009-04-01
We propose a new spectral Lagrangian based deterministic solver for the non-linear Boltzmann transport equation (BTE) in d-dimensions for variable hard sphere (VHS) collision kernels with conservative or non-conservative binary interactions. The method is based on symmetries of the Fourier transform of the collision integral, where the complexity in its computation is reduced to a separate integral over the unit sphere S. The conservation of moments is enforced by Lagrangian constraints. The resulting scheme, implemented in free space, is very versatile and adjusts in a very simple manner to several cases that involve energy dissipation due to local micro-reversibility (inelastic interactions) or elastic models of slowing down process. Our simulations are benchmarked with available exact self-similar solutions, exact moment equations and analytical estimates for the homogeneous Boltzmann equation, both for elastic and inelastic VHS interactions. Benchmarking of the simulations involves the selection of a time self-similar rescaling of the numerical distribution function which is performed using the continuous spectrum of the equation for Maxwell molecules as studied first in Bobylev et al. [A.V. Bobylev, C. Cercignani, G. Toscani, Proof of an asymptotic property of self-similar solutions of the Boltzmann equation for granular materials, Journal of Statistical Physics 111 (2003) 403-417] and generalized to a wide range of related models in Bobylev et al. [A.V. Bobylev, C. Cercignani, I.M. Gamba, On the self-similar asymptotics for generalized non-linear kinetic Maxwell models, Communication in Mathematical Physics, in press. URL: ]. The method also produces accurate results in the case of inelastic diffusive Boltzmann equations for hard spheres (inelastic collisions under thermal bath), where overpopulated non-Gaussian exponential tails have been conjectured in computations by stochastic methods [T.V. Noije, M. Ernst, Velocity distributions in homogeneously cooling
Nebula Models of Non-Equilibrium Mineralogy: Wark-Lovering Rims
Cuzzi, J. N.; Petaev, M.; Krot, A. N.
2005-01-01
Introduction: The meteorite record contains several examples of minerals that would not persist if allowed to come to equilibrium with a cooling gas of solar composition. This includes all minerals in CAIs and AOAs. Their survival is generally ascribed to physical removal of the object from the gas (isolation into a large parent object, or ejection by a stellar wind), but could also result from outward radial diffusion into cooler regions, which we discuss here. Accretion of CAIs into planetesimals has also been relied on to preserve them against loss into the sun. However, this suggestion faces several objections. Simple outward diffusion in turbulence has recently been modeled in some detail, and can preserve CAIs against loss into the sun [2]. Naturally, outward radial diffusion in turbulence is slower than immediate ejection by a stellar wind, which occurs on an orbital timescale. Here we ask whether these different transport mechanisms can be distinguished by nonequilibrium mineralogy, which provides a sort of clock. Our application here is to one aspect of CAI mineralogy - the Wark-Lovering rims (WLR); even more specifically, to alteration of one layer in the WLR sequence from melilite (Mel) to anorthite (An).
Renklioglu, B.; Yalabik, M. C.
2012-12-01
Phase transitions of the two-finite temperature Ising model on a square lattice are investigated by using a position space renormalization group (PSRG) transformation. Different finite temperatures, T x and T y , and also different time-scale constants, α x and α y for spin exchanges in the x and y directions define the dynamics of the non-equilibrium system. The critical surface of the system is determined by RG flows as a function of these exchange parameters. The Onsager critical point (when the two temperatures are equal) and the critical temperature for the limit when the other temperature is infinite, previously studied by the Monte Carlo method, are obtained. In addition, two steady-state fixed points which correspond to the non-equilibrium phase transition are presented. These fixed points yield the different universality class properties of the non-equilibrium phase transitions.
Energy Technology Data Exchange (ETDEWEB)
Kashchenko, M.P. [Ural State Forest Engineering University, Sybirskiy trakt 37, 620100 Ekaterinburg (Russian Federation)], E-mail: mpk46@mail.ru; Skorikova, N.A.; Chashchina, V.G. [Ural State Forest Engineering University, Sybirskiy trakt 37, 620100 Ekaterinburg (Russian Federation)
2008-05-25
In the wave model of martensitic transformations, the influence of the tensile strain on the creation of non-equilibrium electrons is crucial for the principle of wave amplification by stimulated emission of phonons from an inverted electronic population. By consideration of the strain-effect on the electronic energy spectrum it is shown that - for certain interval of finite strain - the density of active electronic non-equilibrium states in a strained lattice can satisfy the conditions for a phonon-maser effect.
Duc, Linh Do; Horák, Vladimír; Kulish, Vladimir; Lukáč, Tomáš
2017-01-01
Carbon dioxide is widely used as the power gas in the gas guns community due to its ease of handling, storability at room temperature, and high vapor pressure depending only upon temperature, but not a tank size, as long as some liquid carbon dioxide remains in the tank. This high vapor pressure can be used as the pressurant, making it what is referred to as a self-pressurising propellant. However, as a two-phase substance, carbon dioxide does have its drawbacks: (1) vaporization of liquefied CO2 inside a tank when shooting rapidly or a lot causes the tank to get cool, resulting in pressure fluctuations that makes the gun's performance and accuracy worse, (2) solid carbon dioxide that is also known as dry ice can appear on the output valve of the tank while shooting and it can cause damage or slow the gun's performance down, if it works its way into some control components, including the barrel of the gun. Hence, it is crucial to obtain a scientific understanding of carbon dioxide behavior and further the discharge characteristics of a wide range of pressure-tank configurations. For the purpose of satisfying this goal, a comprehensive discharge mathematical model for carbon dioxide tank dynamics is required. In this paper, the possibility to develop an advanced non-equilibrium model of depressurization in two-phase fluids is discussed.
Directory of Open Access Journals (Sweden)
Ramon F. Alvarez-Estrada
2012-02-01
Full Text Available We consider non-equilibrium open statistical systems, subject to potentials and to external “heat baths” (hb at thermal equilibrium at temperature T (either with ab initio dissipation or without it. Boltzmann’s classical equilibrium distributions generate, as Gaussian weight functions in momenta, orthogonal polynomials in momenta (the position-independent Hermite polynomialsHn’s. The moments of non-equilibrium classical distributions, implied by the Hn’s, fulfill a hierarchy: for long times, the lowest moment dominates the evolution towards thermal equilibrium, either with dissipation or without it (but under certain approximation. We revisit that hierarchy, whose solution depends on operator continued fractions. We review our generalization of that moment method to classical closed many-particle interacting systems with neither a hb nor ab initio dissipation: with initial states describing thermal equilibrium at T at large distances but non-equilibrium at finite distances, the moment method yields, approximately, irreversible thermalization of the whole system at T, for long times. Generalizations to non-equilibrium quantum interacting systems meet additional difficulties. Three of them are: (i equilibrium distributions (represented through Wigner functions are neither Gaussian in momenta nor known in closed form; (ii they may depend on dissipation; and (iii the orthogonal polynomials in momenta generated by them depend also on positions. We generalize the moment method, dealing with (i, (ii and (iii, to some non-equilibrium one-particle quantum interacting systems. Open problems are discussed briefly.
Beretta, Gian Paolo
2015-01-01
Steepest-Entropy-Ascent Quantum Thermodynamics (SEAQT) provides a general framework for the description of non-equilibrium phenomena at any level, particularly the atomistic one. This theory and its dynamical postulate are used here to develop a general mathematical framework, which at an atomistic level, in particular, can be used to predict the non-equilibrium evolution in state of a closed, chemically reactive mixture such as the one examined here, i.e., a mixture of hydrogen (H2) and flourine (F) contained in an isolated tank of fixed volume. The general framework provided, however, is written for a reactive system subject to multiple reaction mechanisms. To predict this evolution in state, both the energy and particle number eigenvalue problems for a dilute gas are set up and solved analytically. Wall and non-ideal-gas behavior effects are neglected, although the extension to dense gases is straightforward but left for a future paper. The system-level energy and particle number eigenvalues and eigenstate...
Non-equilibrium thermodynamics
De Groot, Sybren Ruurds
1984-01-01
The study of thermodynamics is especially timely today, as its concepts are being applied to problems in biology, biochemistry, electrochemistry, and engineering. This book treats irreversible processes and phenomena - non-equilibrium thermodynamics.S. R. de Groot and P. Mazur, Professors of Theoretical Physics, present a comprehensive and insightful survey of the foundations of the field, providing the only complete discussion of the fluctuating linear theory of irreversible thermodynamics. The application covers a wide range of topics: the theory of diffusion and heat conduction, fluid dyn
Ramaswamy, Rajesh; Sbalzarini, Ivo F; González-Segredo, Nélido
2011-01-28
Stochastic effects from correlated noise non-trivially modulate the kinetics of non-linear chemical reaction networks. This is especially important in systems where reactions are confined to small volumes and reactants are delivered in bursts. We characterise how the two noise sources confinement and burst modulate the relaxation kinetics of a non-linear reaction network around a non-equilibrium steady state. We find that the lifetimes of species change with burst input and confinement. Confinement increases the lifetimes of all species that are involved in any non-linear reaction as a reactant. Burst monotonically increases or decreases lifetimes. Competition between burst-induced and confinement-induced modulation may hence lead to a non-monotonic modulation. We quantify lifetime as the integral of the time autocorrelation function (ACF) of concentration fluctuations around a non-equilibrium steady state of the reaction network. Furthermore, we look at the first and second derivatives of the ACF, each of which is affected in opposite ways by burst and confinement. This allows discriminating between these two noise sources. We analytically derive the ACF from the linear Fokker-Planck approximation of the chemical master equation in order to establish a baseline for the burst-induced modulation at low confinement. Effects of higher confinement are then studied using a partial-propensity stochastic simulation algorithm. The results presented here may help understand the mechanisms that deviate stochastic kinetics from its deterministic counterpart. In addition, they may be instrumental when using fluorescence-lifetime imaging microscopy (FLIM) or fluorescence-correlation spectroscopy (FCS) to measure confinement and burst in systems with known reaction rates, or, alternatively, to correct for the effects of confinement and burst when experimentally measuring reaction rates.
Directory of Open Access Journals (Sweden)
Rajesh Ramaswamy
2011-01-01
Full Text Available Stochastic effects from correlated noise non-trivially modulate the kinetics of non-linear chemical reaction networks. This is especially important in systems where reactions are confined to small volumes and reactants are delivered in bursts. We characterise how the two noise sources confinement and burst modulate the relaxation kinetics of a non-linear reaction network around a non-equilibrium steady state. We find that the lifetimes of species change with burst input and confinement. Confinement increases the lifetimes of all species that are involved in any non-linear reaction as a reactant. Burst monotonically increases or decreases lifetimes. Competition between burst-induced and confinement-induced modulation may hence lead to a non-monotonic modulation. We quantify lifetime as the integral of the time autocorrelation function (ACF of concentration fluctuations around a non-equilibrium steady state of the reaction network. Furthermore, we look at the first and second derivatives of the ACF, each of which is affected in opposite ways by burst and confinement. This allows discriminating between these two noise sources. We analytically derive the ACF from the linear Fokker-Planck approximation of the chemical master equation in order to establish a baseline for the burst-induced modulation at low confinement. Effects of higher confinement are then studied using a partial-propensity stochastic simulation algorithm. The results presented here may help understand the mechanisms that deviate stochastic kinetics from its deterministic counterpart. In addition, they may be instrumental when using fluorescence-lifetime imaging microscopy (FLIM or fluorescence-correlation spectroscopy (FCS to measure confinement and burst in systems with known reaction rates, or, alternatively, to correct for the effects of confinement and burst when experimentally measuring reaction rates.
Kudryavtsev, Alexey N.; Kashkovsky, Alexander V.; Borisov, Semyon P.; Shershnev, Anton A.
2017-10-01
In the present work a computer code RCFS for numerical simulation of chemically reacting compressible flows on hybrid CPU/GPU supercomputers is developed. It solves 3D unsteady Euler equations for multispecies chemically reacting flows in general curvilinear coordinates using shock-capturing TVD schemes. Time advancement is carried out using the explicit Runge-Kutta TVD schemes. Program implementation uses CUDA application programming interface to perform GPU computations. Data between GPUs is distributed via domain decomposition technique. The developed code is verified on the number of test cases including supersonic flow over a cylinder.
Directory of Open Access Journals (Sweden)
Francesco Farsaci
2017-11-01
Full Text Available After remarking on non-equilibrium thermodynamics with internal variables, this paper highlights the importance of these variables to the study of biological systems. Internal variables can provide a more detailed description of biological processes that occur inside cells, tissues and organs. In order to introduce a fractional model on a visco-inelastic medium based on Kluitenberg’s non-equilibrium thermodynamics, the origin of the complex dynamic modulus is shown by means of linear response theory. This research recalls our previous work to develop an ultrasound wave technique that allows us to investigate biological systems, and introduces the fractional visco-inelastic model and relative generalized relaxation time, to show that it is possible to obtain the Cole–Cole model in a particular case.
Directory of Open Access Journals (Sweden)
Gian Paolo Beretta
2008-08-01
Full Text Available A rate equation for a discrete probability distribution is discussed as a route to describe smooth relaxation towards the maximum entropy distribution compatible at all times with one or more linear constraints. The resulting dynamics follows the path of steepest entropy ascent compatible with the constraints. The rate equation is consistent with the Onsager theorem of reciprocity and the fluctuation-dissipation theorem. The mathematical formalism was originally developed to obtain a quantum theoretical unification of mechanics and thermodinamics. It is presented here in a general, non-quantal formulation as a part of an effort to develop tools for the phenomenological treatment of non-equilibrium problems with applications in engineering, biology, sociology, and economics. The rate equation is also extended to include the case of assigned time-dependences of the constraints and the entropy, such as for modeling non-equilibrium energy and entropy exchanges.
Energy Technology Data Exchange (ETDEWEB)
Bulashevich, K.A. [Ioffe Physico-Technical Institute, RAS, 26 Polytekhnicheskaya, St. Petersburg 194021 (Russian Federation); Soft-Impact Ltd., P.O. Box 83, 27 Engels av., St. Petersburg 194156 (Russian Federation); Karpov, S.Yu. [Soft-Impact Ltd., P.O. Box 83, 27 Engels av., St. Petersburg 194156 (Russian Federation); Suris, R.A. [Ioffe Physico-Technical Institute, RAS, 26 Polytekhnicheskaya, St. Petersburg 194021 (Russian Federation)
2006-06-15
We have derived an analytical approximation for the energy levels in a symmetric quantum well applicable in a wide range of the electric field variation. Suppression of the quantum-confined Stark effect due to the electric field screening by non-equilibrium carriers is considered self-consistently within the perturbation theory. Theoretical predictions are compared with available observations. Specific features of the quantum-confined Stark effect in light-emitting diode heterostructures are discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Raju, Ch Narasimha; Chatterjee, Ashok
2016-01-06
The Anderson-Holstein model with Caldeira-Leggett coupling with environment is considered to describe the damping effect in a single molecular transistor (SMT) which comprises a molecular quantum dot (with electron-phonon interaction) mounted on a substrate (environment) and coupled to metallic electrodes. The electron-phonon interaction is first eliminated using the Lang-Firsov transformation and the spectral density function, charge current and differential conductance are then calculated using the non-equilibrium Keldysh Green function technique. The effects of damping rate, and electron-electron and electron-phonon interactions on the transport properties of SMT are studied at zero temperature.
Raju, Ch. Narasimha; Chatterjee, Ashok
2016-01-01
The Anderson-Holstein model with Caldeira-Leggett coupling with environment is considered to describe the damping effect in a single molecular transistor (SMT) which comprises a molecular quantum dot (with electron-phonon interaction) mounted on a substrate (environment) and coupled to metallic electrodes. The electron-phonon interaction is first eliminated using the Lang-Firsov transformation and the spectral density function, charge current and differential conductance are then calculated using the non-equilibrium Keldysh Green function technique. The effects of damping rate, and electron-electron and electron-phonon interactions on the transport properties of SMT are studied at zero temperature.
Evolution and non-equilibrium physics
DEFF Research Database (Denmark)
Becker, Nikolaj; Sibani, Paolo
2014-01-01
We argue that the stochastic dynamics of interacting agents which replicate, mutate and die constitutes a non-equilibrium physical process akin to aging in complex materials. Specifically, our study uses extensive computer simulations of the Tangled Nature Model (TNM) of biological evolution...
Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry.
van den Bekerom, Dirk; den Harder, Niek; Minea, Teofil; Gatti, Nicola; Linares, Jose Palomares; Bongers, Waldo; van de Sanden, Richard; van Rooij, Gerard
2017-08-01
A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose of efficiently driving non-equilibrium chemistry is discussed. The advantage of a flowing plasma reactor is that continuous chemical processes can be driven with the flexibility of startup times in the seconds timescale. The plasma approach is generically suitable for conversion/activation of stable molecules such as CO2, N2 and CH4. Here the reduction of CO2 to CO is used as a model system: the complementary diagnostics illustrate how a baseline thermodynamic equilibrium conversion can be exceeded by the intrinsic non-equilibrium from high vibrational excitation. Laser (Rayleigh) scattering is used to measure the reactor temperature and Fourier Transform Infrared Spectroscopy (FTIR) to characterize in situ internal (vibrational) excitation as well as the effluent composition to monitor conversion and selectivity.
Prudnikov, Vladimir V.; Prudnikov, Pavel V.; Pospelov, Evgeny A.
2016-04-01
We have performed a numerical investigation of the influence of disorder on the dynamical non-equilibrium evolution of a 3D site-diluted Ising model from a low-temperature initial state with magnetization m 0 = 1. It is shown that two-time dependences of the autocorrelation and integrated response functions for systems with spin concentrations p = 1.0, 0.95, 0.8, 0.6 and 0.5 demonstrate ageing properties with anomalous slowing-down relaxation and violation of the fluctuation-dissipation ratio. It was revealed that during non-equilibrium critical dynamics in the long-time regime t-{{t}\\text{w}}\\gg {{t}\\text{w}}\\gg 1 the autocorrelation functions for diluted systems are extremely slow due to the pinning of domain walls on impurity sites. We have found that the fluctuation-dissipation ratio {{X}∞}=0 for diluted systems with spin concentration p memory effects for critical evolution in the ageing regime with realization of cyclic temperature change and quenching at T<{{T}\\text{c}} .
Blumenthal, Sarah D.; Mandell, Avi M.; Hébrard, Eric; Batalha, Natasha E.; Cubillos, Patricio E.; Rugheimer, Sarah; Wakeford, Hannah R.
2018-02-01
We aim to see if the difference between equilibrium and disequilibrium chemistry is observable in the atmospheres of transiting planets by the James Webb Space Telescope (JWST). We perform a case study comparing the dayside emission spectra of three planets like HD 189733b, WASP-80b, and GJ 436b, in and out of chemical equilibrium at two metallicities each. These three planets were chosen because they span a large range of planetary masses and equilibrium temperatures, from hot and Jupiter-sized to warm and Neptune-sized. We link the one-dimensional disequilibrium chemistry model from Venot et al. (2012), in which thermochemical kinetics, vertical transport, and photochemistry are taken into account, to the one-dimensional, pseudo line-by-line radiative transfer model, Pyrat bay, developed especially for hot Jupiters, and then simulate JWST spectra using PandExo for comparing the effects of temperature, metallicity, and radius. We find the most significant differences from 4 to 5 μm due to disequilibrium from CO and CO2 abundances, and also H2O for select cases. Our case study shows a certain “sweet spot” of planetary mass, temperature, and metallicity where the difference between equilibrium and disequilibrium is observable. For a planet similar to WASP-80b, JWST’s NIRSpec G395M can detect differences due to disequilibrium chemistry with one eclipse event. For a planet similar to GJ 436b, the observability of differences due to disequilibrium chemistry is possible at low metallicity given five eclipse events, but not possible at the higher metallicity.
Zhang, Yue; Barnes, George L; Yan, Tianying; Hase, William L
2010-05-07
Model non-equilibrium molecular dynamics (MD) simulations are presented of heat transfer from a hot Au {111} substrate to an alkylthiolate self-assembled monolayer (H-SAM) to assist in obtaining an atomic-level understanding of experiments by Wang et al. (Z. Wang, J. A. Carter, A. Lagutchev, Y. K. Koh, N.-H. Seong, D. G. Cahill, and D. D. Dlott, Science, 2007, 317, 787). Different models are considered to determine how they affect the heat transfer dynamics. They include temperature equilibrated (TE) and temperature gradient (TG) thermostat models for the Au(s) surface, and soft and stiff S/Au(s) models for bonding of the S-atoms to the Au(s) surface. A detailed analysis of the non-equilibrium heat transfer at the heterogeneous interface is presented. There is a short time temperature gradient within the top layers of the Au(s) surface. The S-atoms heat rapidly, much faster than do the C-atoms in the alkylthiolate chains. A high thermal conductivity in the H-SAM, perpendicular to the interface, results in nearly identical temperatures for the CH(2) and CH(3) groups versus time. Thermal-induced disorder is analyzed for the Au(s) substrate, the S/Au(s) interface and the H-SAM. Before heat transfer occurs from the hot Au(s) substrate to the H-SAM, there is disorder at the S/Au(s) interface and within the alkylthiolate chains arising from heat-induced disorder near the surface of hot Au(s). The short-time rapid heating of the S-atoms enhances this disorder. The increasing disorder of H-SAM chains with time results from both disorder at the Au/S interface and heat transfer to the H-SAM chains.
Kinetic modelling of NH3 production in N2-H2 non-equilibrium atmospheric-pressure plasma catalysis
Hong, Jungmi; Pancheshnyi, Sergey; Tam, Eugene; Lowke, John J.; Prawer, Steven; Murphy, Anthony B.
2017-04-01
Detailed plasma kinetics modelling is presented of a low electron energy N2-H2 atmospheric-pressure discharge for ammonia synthesis. The model considers both electron and vibrational kinetics, including excited N2(X, ν) and H2(X, ν) species, and surface reactions such as those occurring by the Eley-Rideal and Langmuir-Hinshelwood mechanisms and dissociative adsorption of molecules. The predictions of the model are compared to the measured NH3 concentration produced in a packed-bed dielectric barrier discharge reactor as a function of process parameters such as input gas composition and applied voltage. Unlike typical low-pressure plasma processes, under the plasma conditions considered here (reduced electric field E/N in the range 30-50 Td, electron density of the order 108 cm-3), the influence of ions is not significant. Instead, the reactions between radicals and vibrationally-excited molecules are more important. The active species in surface reactions, such as surface-adsorbed atomic nitrogen N(s) or hydrogen H(s), are found to be predominantly generated through the dissociative adsorption of molecules, in contrast to previously proposed mechanisms for plasma catalysis under low-pressure, high-E/N conditions. It is found that NH radicals play an important role at the early stages of the NH3-generation process, NH in turn is produced from N and H2(ν). Electron kinetics is shown to play a critical role in the molecular dissociation and vibrational excitation reactions that produce these precursors. It is further found that surface-adsorbed atomic hydrogen H(s) takes a leading role in the formation of NH3, which is another significant difference from the mechanisms in conventional thermo-chemical processes and low-pressure plasmas. The applied voltage, the gas temperature, the N2:H2 ratio in the input gas mixture and the reactivity of the surface material are all found to influence the ammonia production. The calculated results reproduce the observed trends in
Foundations of atmospheric pressure non-equilibrium plasmas
Bruggeman, Peter J.; Iza, Felipe; Brandenburg, Ronny
2017-12-01
Non-equilibrium plasmas have been intensively studied over the past century in the context of material processing, environmental remediation, ozone generation, excimer lamps and plasma display panels. Research on atmospheric pressure non-equilibrium plasmas intensified over the last two decades leading to a large variety of plasma sources that have been developed for an extended application range including chemical conversion, medicine, chemical analysis and disinfection. The fundamental understanding of these discharges is emerging but there remain a lot of unexplained phenomena in these intrinsically complex plasmas. The properties of non-equilibrium plasmas at atmospheric pressure span over a huge range of electron densities as well as heavy particle and electron temperatures. This paper provides an overview of the key underlying processes that are important for the generation and stabilization of atmospheric pressure non-equilibrium plasmas. The unique physical and chemical properties of theses discharges are also summarized.
Directory of Open Access Journals (Sweden)
William T Bean
Full Text Available Species distributions are known to be limited by biotic and abiotic factors at multiple temporal and spatial scales. Species distribution models, however, frequently assume a population at equilibrium in both time and space. Studies of habitat selection have repeatedly shown the difficulty of estimating resource selection if the scale or extent of analysis is incorrect. Here, we present a multi-step approach to estimate the realized and potential distribution of the endangered giant kangaroo rat. First, we estimate the potential distribution by modeling suitability at a range-wide scale using static bioclimatic variables. We then examine annual changes in extent at a population-level. We define "available" habitat based on the total suitable potential distribution at the range-wide scale. Then, within the available habitat, model changes in population extent driven by multiple measures of resource availability. By modeling distributions for a population with robust estimates of population extent through time, and ecologically relevant predictor variables, we improved the predictive ability of SDMs, as well as revealed an unanticipated relationship between population extent and precipitation at multiple scales. At a range-wide scale, the best model indicated the giant kangaroo rat was limited to areas that received little to no precipitation in the summer months. In contrast, the best model for shorter time scales showed a positive relation with resource abundance, driven by precipitation, in the current and previous year. These results suggest that the distribution of the giant kangaroo rat was limited to the wettest parts of the drier areas within the study region. This multi-step approach reinforces the differing relationship species may have with environmental variables at different scales, provides a novel method for defining "available" habitat in habitat selection studies, and suggests a way to create distribution models at spatial and
Pusateri, Elise Noel
An Electromagnetic Pulse (EMP) can severely disrupt the use of electronic devices in its path causing a significant amount of infrastructural damage. EMP can also cause breakdown of the surrounding atmosphere during lightning discharges. This makes modeling EMP phenomenon an important research effort in many military and atmospheric physics applications. EMP events include high-energy Compton electrons or photoelectrons that ionize air and produce low energy conduction electrons. A sufficient number of conduction electrons will damp or alter the EMP through conduction current. Therefore, it is important to understand how conduction electrons interact with air in order to accurately predict the EMP evolution and propagation in the air. It is common for EMP simulation codes to use an equilibrium ohmic model for computing the conduction current. Equilibrium ohmic models assume the conduction electrons are always in equilibrium with the local instantaneous electric field, i.e. for a specific EMP electric field, the conduction electrons instantaneously reach steady state without a transient process. An equilibrium model will work well if the electrons have time to reach their equilibrium distribution with respect to the rise time or duration of the EMP. If the time to reach equilibrium is comparable or longer than the rise time or duration of the EMP then the equilibrium model would not accurately predict the conduction current necessary for the EMP simulation. This is because transport coefficients used in the conduction current calculation will be found based on equilibrium reactions rates which may differ significantly from their non-equilibrium values. We see this deficiency in Los Alamos National Laboratory's EMP code, CHAP-LA (Compton High Altitude Pulse-Los Alamos), when modeling certain EMP scenarios at high altitudes, such as upward EMP, where the ionization rate by secondary electrons is over predicted by the equilibrium model, causing the EMP to short
Directory of Open Access Journals (Sweden)
Khadijeh Qorbani
2017-07-01
Full Text Available The ongoing search for new sources of energy has brought natural gas hydrate (NGH reservoirs to the forefront of attention in both academia and the industry. The amount of gas reserves trapped within these reservoirs surpasses all of the conventional fossil fuel sources explored so far, which makes it of utmost importance to predict their production potential and safety. One of the challenges facing those attempting to analyse their behaviour is that the large number of involved phases make NGHs unable to ever reach equilibrium in nature. Field-scale experiments are expensive and time consuming. However, computer simulations have now become capable of modelling different gas production scenarios, as well as production optimization analyses. In addition to temperature and pressure, independent thermodynamic parameters for hydrate stabilization include the hydrate composition and concentrations for all co-existing phases. It is therefore necessary to develop and implement realistic kinetic models accounting for all significant routes for dissociation and reformation. The reactive transport simulator makes it easy to deploy nonequilibrium thermodynamics for the study of CH4 production from hydrate-bearing sediments by considering each hydrate-related transition as a separate pseudo reaction. In this work, we have used the expanded version of the RetrasoCodeBright (RCB reactive transport simulator to model exploitation of the methane hydrate (MH reservoir located in the Nankai Trough, Japan. Our results showed that higher permeabilities in the horizontal direction dominated the pressure drop propagation throughout the hydrate layers and affected their hydrate dissociation rates. Additionally, the comparison of the vertical well versus the horizontal well pattern indicated that hydrate dissociation was slightly higher in the vertical well scenario compared to the horizontal.
Open problems in non-equilibrium physics
Energy Technology Data Exchange (ETDEWEB)
Kusnezov, D.
1997-09-22
The report contains viewgraphs on the following: approaches to non-equilibrium statistical mechanics; classical and quantum processes in chaotic environments; classical fields in non-equilibrium situations: real time dynamics at finite temperature; and phase transitions in non-equilibrium conditions.
Non-Equilibrium Thermodynamics of Self-Replicating Protocells
DEFF Research Database (Denmark)
Fellermann, Harold; Corominas-Murtra, Bernat; Hansen, Per Lyngs
2017-01-01
We provide a non-equilibrium thermodynamic description of the life-cycle of a droplet based, chemically feasible, system of protocells. By coupling the protocells metabolic kinetics with its thermodynamics, we demonstrate how the system can be driven out of equilibrium to ensure protocell growth...... and replication. This coupling allows us to derive the equations of evolution and to rigorously demonstrate how growth and replication life-cycle can be understood as a non-equilibrium thermodynamic cycle. The process does not appeal to genetic information or inheritance, and is based only on non......-equilibrium physics considerations. Our non-equilibrium thermodynamic description of simple, yet realistic, processes of protocell growth and replication, represents an advance in our physical understanding of a central biological phenomenon both in connection to the origin of life and for modern biology....
Zoschke, Kristin; Engel, Christina; Börnick, Hilmar; Worch, Eckhard
2011-10-01
The adsorption of the taste and odour (T&O) compounds geosmin and 2-methylisoborneol (2-MIB) onto powdered activated carbon (PAC) has been studied under conditions which are typical for a drinking water treatment plant that uses reservoir water for drinking water production. The reservoir water as well as the pre-treated water (after flocculation) contains NOM that competes with the trace compounds for the adsorption sites on the carbon surface. Although the DOC concentrations in the reservoir water and in the pre-treated water were different, no differences in the competitive adsorption could be seen. By using two special characterisation methods for NOM (adsorption analysis, LC/OCD) it could be proved that flocculation removes only NOM fractions which are irrelevant for competitive adsorption. Different model approaches were applied to describe the competitive adsorption of the T&O compounds and NOM, the tracer model, the equivalent background compound model, and the simplified equivalent background compound model. All these models are equilibrium models but in practice the contact time in flow-through reactors is typically shorter than the time needed to establish the adsorption equilibrium. In this paper it is demonstrated that the established model approaches can be used to describe competitive adsorption of T&O compounds and NOM also under non-equilibrium conditions. The results of the model applications showed that in particular the simplified equivalent background compound model is a useful tool to determine the PAC dosage required to reduce the T&O compounds below the threshold concentration. Copyright © 2011 Elsevier Ltd. All rights reserved.
DEFF Research Database (Denmark)
Zhu, W.; Tan, O.K.; Jiang, Jianzhong
1998-01-01
Nano-sized xSnO2-(1-x)alpha-Fe2O3 materials have been prepared using the high energy ball milling technique and their structural and gas sensing properties have been characterized. Based on experimental results, we propose a new structure model, xxx, forthese non-equilibrium, nano-sized xSnO2-(1-x...
Oka, Takashi; Aoki, Hideo
2010-01-01
Non-equilibrium phase transitions are studied theoretically for the two-dimensional Hubbard model subject to bias voltages from the electrodes coupled to the system. By combining the fluctuation exchange approximation with the Keldysh method for non-equilibrium, we have studied the properties of the non-equilibrium Fermi liquid phase and determined the phase diagram with transition to non-equilibrium magnetic and superconducting phases.
Non-equilibrium Dynamics of DNA Nanotubes
Hariadi, Rizal Fajar
Can the fundamental processes that underlie molecular biology be understood and simulated by DNA nanotechnology? The early development of DNA nanotechnology by Ned Seeman was driven by the desire to find a solution to the protein crystallization problem. Much of the later development of the field was also driven by envisioned applications in computing and nanofabrication. While the DNA nanotechnology community has assembled a versatile tool kit with which DNA nanostructures of considerable complexity can be assembled, the application of this tool kit to other areas of science and technology is still in its infancy. This dissertation reports on the construction of non-equilibrium DNA nanotube dynamic to probe molecular processes in the areas of hydrodynamics and cytoskeletal behavior. As the first example, we used DNA nanotubes as a molecular probe for elongational flow measurement in different micro-scale flow settings. The hydrodynamic flow in the vicinity of simple geometrical objects, such as a rigid DNA nanotube, is amenable to rigorous theoretical investigation. We measured the distribution of elongational flows produced in progressively more complex settings, ranging from the vicinity of an orifice in a microfluidic chamber to within a bursting bubble of Pacific ocean water. This information can be used to constrain theories on the origin of life in which replication involves a hydrodynamically driven fission process, such as the coacervate fission proposed by Oparin. A second theme of this dissertation is the bottom-up construction of a de novo artificial cytoskeleton with DNA nanotubes. The work reported here encompasses structural, locomotion, and control aspects of non-equilibrium cytoskeletal behavior. We first measured the kinetic parameters of DNA nanotube assembly and tested the accuracy of the existing polymerization models in the literature. Toward recapitulation of non-equilibrium cytoskeletal dynamics, we coupled the polymerization of DNA
Non-equilibrium thermodynamics analysis of transcriptional regulation kinetics
Hernández-Lemus, Enrique; Tovar, Hugo; Mejía, Carmen
2014-12-01
Gene expression in eukaryotic cells is an extremely complex and interesting phenomenon whose dynamics are controlled by a large number of subtle physicochemical processes commonly described by means of gene regulatory networks. Such networks consist in a series of coupled chemical reactions, conformational changes, and other biomolecular processes involving the interaction of the DNA molecule itself with a number of proteins usually called transcription factors as well as enzymes and other components. The kinetics behind the functioning of such gene regulatory networks are largely unknown, though its description in terms of non-equilibrium thermodynamics has been discussed recently. In this work we will derive general kinetic equations for a gene regulatory network from a non-equilibrium thermodynamical description and discuss its use in understanding the free energy constrains imposed in the network structure. We also will discuss explicit expressions for the kinetics of a simple model of gene regulation and show that the kinetic role of mRNA decay during the RNA synthesis stage (or transcription) is somehow limited due to the comparatively low values of decay rates. At the level discussed here, this implies a decoupling of the kinetics of mRNA synthesis and degradation a fact that may become quite useful when modeling gene regulatory networks from experimental data on whole genome gene expression.
Non-equilibrium dynamics from RPMD and CMD
Welsch, Ralph; Song, Kai; Shi, Qiang; Althorpe, Stuart C.; Miller, Thomas F.
2016-11-01
We investigate the calculation of approximate non-equilibrium quantum time correlation functions (TCFs) using two popular path-integral-based molecular dynamics methods, ring-polymer molecular dynamics (RPMD) and centroid molecular dynamics (CMD). It is shown that for the cases of a sudden vertical excitation and an initial momentum impulse, both RPMD and CMD yield non-equilibrium TCFs for linear operators that are exact for high temperatures, in the t = 0 limit, and for harmonic potentials; the subset of these conditions that are preserved for non-equilibrium TCFs of non-linear operators is also discussed. Furthermore, it is shown that for these non-equilibrium initial conditions, both methods retain the connection to Matsubara dynamics that has previously been established for equilibrium initial conditions. Comparison of non-equilibrium TCFs from RPMD and CMD to Matsubara dynamics at short times reveals the orders in time to which the methods agree. Specifically, for the position-autocorrelation function associated with sudden vertical excitation, RPMD and CMD agree with Matsubara dynamics up to O (t4) and O (t1) , respectively; for the position-autocorrelation function associated with an initial momentum impulse, RPMD and CMD agree with Matsubara dynamics up to O (t5) and O (t2) , respectively. Numerical tests using model potentials for a wide range of non-equilibrium initial conditions show that RPMD and CMD yield non-equilibrium TCFs with an accuracy that is comparable to that for equilibrium TCFs. RPMD is also used to investigate excited-state proton transfer in a system-bath model, and it is compared to numerically exact calculations performed using a recently developed version of the Liouville space hierarchical equation of motion approach; again, similar accuracy is observed for non-equilibrium and equilibrium initial conditions.
Non-equilibrium dynamics from RPMD and CMD.
Welsch, Ralph; Song, Kai; Shi, Qiang; Althorpe, Stuart C; Miller, Thomas F
2016-11-28
We investigate the calculation of approximate non-equilibrium quantum time correlation functions (TCFs) using two popular path-integral-based molecular dynamics methods, ring-polymer molecular dynamics (RPMD) and centroid molecular dynamics (CMD). It is shown that for the cases of a sudden vertical excitation and an initial momentum impulse, both RPMD and CMD yield non-equilibrium TCFs for linear operators that are exact for high temperatures, in the t = 0 limit, and for harmonic potentials; the subset of these conditions that are preserved for non-equilibrium TCFs of non-linear operators is also discussed. Furthermore, it is shown that for these non-equilibrium initial conditions, both methods retain the connection to Matsubara dynamics that has previously been established for equilibrium initial conditions. Comparison of non-equilibrium TCFs from RPMD and CMD to Matsubara dynamics at short times reveals the orders in time to which the methods agree. Specifically, for the position-autocorrelation function associated with sudden vertical excitation, RPMD and CMD agree with Matsubara dynamics up to O(t4) and O(t1), respectively; for the position-autocorrelation function associated with an initial momentum impulse, RPMD and CMD agree with Matsubara dynamics up to O(t5) and O(t2), respectively. Numerical tests using model potentials for a wide range of non-equilibrium initial conditions show that RPMD and CMD yield non-equilibrium TCFs with an accuracy that is comparable to that for equilibrium TCFs. RPMD is also used to investigate excited-state proton transfer in a system-bath model, and it is compared to numerically exact calculations performed using a recently developed version of the Liouville space hierarchical equation of motion approach; again, similar accuracy is observed for non-equilibrium and equilibrium initial conditions.
Non-equilibrium quantum heat machines
Alicki, Robert; Gelbwaser-Klimovsky, David
2015-11-01
Standard heat machines (engine, heat pump, refrigerator) are composed of a system (working fluid) coupled to at least two equilibrium baths at different temperatures and periodically driven by an external device (piston or rotor) sometimes called the work reservoir. The aim of this paper is to go beyond this scheme by considering environments which are stationary but cannot be decomposed into a few baths at thermal equilibrium. Such situations are important, for example in solar cells, chemical machines in biology, various realizations of laser cooling or nanoscopic machines driven by laser radiation. We classify non-equilibrium baths depending on their thermodynamic behavior and show that the efficiency of heat machines powered by them is limited by the generalized Carnot bound.
Spacecraft Sterilization Using Non-Equilibrium Atmospheric Pressure Plasma
Cooper, Moogega; Vaze, Nachiket; Anderson, Shawn; Fridman, Gregory; Vasilets, Victor N.; Gutsol, Alexander; Tsapin, Alexander; Fridman, Alexander
2007-01-01
As a solution to chemically and thermally destructive sterilization methods currently used for spacecraft, non-equilibrium atmospheric pressure plasmas are used to treat surfaces inoculated with Bacillus subtilis and Deinococcus radiodurans. Evidence of significant morphological changes and reduction in viability due to plasma exposure will be presented, including a 4-log reduction of B. subtilis after 2 minutes of dielectric barrier discharge treatment.
The effect of non-equilibrium metal cooling on the interstellar medium
Capelo, Pedro R.; Bovino, Stefano; Lupi, Alessandro; Schleicher, Dominik R. G.; Grassi, Tommaso
2018-01-01
By using a novel interface between the modern smoothed particle hydrodynamics code GASOLINE2 and the chemistry package KROME, we follow the hydrodynamical and chemical evolution of an isolated galaxy. In order to assess the relevance of different physical parameters and prescriptions, we constructed a suite of ten simulations, in which we vary the chemical network (primordial and metal species), how metal cooling is modelled (non-equilibrium versus equilibrium; optically thin versus thick approximation), the initial gas metallicity (from ten to hundred per cent solar), and how molecular hydrogen forms on dust. This is the first work in which metal injection from supernovae, turbulent metal diffusion, and a metal network with non-equilibrium metal cooling are self-consistently included in a galaxy simulation. We find that properly modelling the chemical evolution of several metal species and the corresponding non-equilibrium metal cooling has important effects on the thermodynamics of the gas, the chemical abundances, and the appearance of the galaxy: the gas is typically warmer, has a larger molecular gas mass fraction, and has a smoother disc. We also conclude that, at relatively high metallicity, the choice of molecular-hydrogen formation rates on dust is not crucial. Moreover, we confirm that a higher initial metallicity produces a colder gas and a larger fraction of molecular gas, with the low-metallicity simulation best matching the observed molecular Kennicutt-Schmidt relation. Finally, our simulations agree quite well with observations which link star formation rate to metal emission lines.
The effect of clusters and heterogeneous reactions on non-equilibrium plasma flue gas cleaning
Potapkin, B. V.; Deminsky, M. A.; Fridman, A. A.; Rusanov, V. D.
1995-06-01
Theoretical investigation of the effect of molecular clusters and aerosol particles on non-equilibrium plasma flue gas cleaning was made in this paper. Two types of heterogeneous reactions in aerosol and clusters are considered. It was shown that in both cases these reactions are essential in the evaluation of chemical composition. As a result of theoretical approach and modelling, the optimum regime of plasma generation for essential decreasing of purification energy cost was established.
Directory of Open Access Journals (Sweden)
Bauerfeldt Glauco F.
2000-01-01
Full Text Available In this work, a numerical modelling analysis of the gas-phase decomposition of pure SF6 and SF6/O2 mixtures, in the presence of silicon was performed. The relative rate of individual processes, the effect of the parameters uncertainties and the sensitivity coefficients were determined. The results were compared with literature experimental data for the plasma etching of silicon and with previous simulated results to adjust the model parameters. As in the CF4 system, the main etching agent is atomic fluorine and the concentration of the major species depends on the composition of the mixture. The shape of the sensitivity curves follows the general shape of the individual rate curves and the ratio between the calculated sensitivity coefficients is closely related to the contribution of each reaction.
Referesher Course on Contemporary Non-Equilibrium ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Referesher Course on Contemporary Non-Equilibrium Thermodynamics and Statistical Mechanics. Information and Announcements Volume 15 Issue 7 July 2010 pp 678-678 ...
Mathematical theory of non-equilibrium quantum statistical mechanics
Jaksic, V
2001-01-01
We review and further develop a mathematical framework for non-equilibrium quantum statistical mechanics recently proposed in [JP4, JP5, JP6, Ru3, Ru4, Ru5, Ru6]. In the algebraic formalism of quantum statistical mechanics we introduce notions of non-equilibrium steady states, entropy production and heat fluxes, and study their properties. Our basic paradigm is a model of a small (finite) quantum system coupled to several independent thermal reservoirs. We exhibit examples of such systems which have strictly positive entropy production.
Roldin, P.; Eriksson, A. C.; Nordin, E. Z.; Hermansson, E.; Mogensen, D.; Rusanen, A.; Boy, M.; Swietlicki, E.; Svenningsson, B.; Zelenyuk, A.; Pagels, J.
2014-08-01
We have developed the novel Aerosol Dynamics, gas- and particle-phase chemistry model for laboratory CHAMber studies (ADCHAM). The model combines the detailed gas-phase Master Chemical Mechanism version 3.2 (MCMv3.2), an aerosol dynamics and particle-phase chemistry module (which considers acid-catalysed oligomerization, heterogeneous oxidation reactions in the particle phase and non-ideal interactions between organic compounds, water and inorganic ions) and a kinetic multilayer module for diffusion-limited transport of compounds between the gas phase, particle surface and particle bulk phase. In this article we describe and use ADCHAM to study (1) the evaporation of liquid dioctyl phthalate (DOP) particles, (2) the slow and almost particle-size-independent evaporation of α-pinene ozonolysis secondary organic aerosol (SOA) particles, (3) the mass-transfer-limited uptake of ammonia (NH3) and formation of organic salts between ammonium (NH4+) and carboxylic acids (RCOOH), and (4) the influence of chamber wall effects on the observed SOA formation in smog chambers. ADCHAM is able to capture the observed α-pinene SOA mass increase in the presence of NH3(g). Organic salts of ammonium and carboxylic acids predominantly form during the early stage of SOA formation. In the smog chamber experiments, these salts contribute substantially to the initial growth of the homogeneously nucleated particles. The model simulations of evaporating α-pinene SOA particles support the recent experimental findings that these particles have a semi-solid tar-like amorphous-phase state. ADCHAM is able to reproduce the main features of the observed slow evaporation rates if the concentration of low-volatility and viscous oligomerized SOA material at the particle surface increases upon evaporation. The evaporation rate is mainly governed by the reversible decomposition of oligomers back to monomers. Finally, we demonstrate that the mass-transfer-limited uptake of condensable organic compounds
Aerospace Applications of Non-Equilibrium Plasma
Blankson, Isaiah M.
2016-01-01
Nonequilibrium plasma/non-thermal plasma/cold plasmas are being used in a wide range of new applications in aeronautics, active flow control, heat transfer reduction, plasma-assisted ignition and combustion, noise suppression, and power generation. Industrial applications may be found in pollution control, materials surface treatment, and water purification. In order for these plasma processes to become practical, efficient means of ionization are necessary. A primary challenge for these applications is to create a desired non-equilibrium plasma in air by preventing the discharge from transitioning into an arc. Of particular interest is the impact on simulations and experimental data with and without detailed consideration of non-equilibrium effects, and the consequences of neglecting non-equilibrium. This presentation will provide an assessment of the presence and influence of non-equilibrium phenomena for various aerospace needs and applications. Specific examples to be considered will include the forward energy deposition of laser-induced non-equilibrium plasmoids for sonic boom mitigation, weakly ionized flows obtained from pulsed nanosecond discharges for an annular Hall type MHD generator duct for turbojet energy bypass, and fundamental mechanisms affecting the design and operation of novel plasma-assisted reactive systems in dielectric liquids (water purification, in-pipe modification of fuels, etc.).
Non-equilibrium dynamic of a Universe formation
Lev, S. B.; Lev, B. I.
2017-09-01
A new stochastic model of dynamic of Universe formation is presented. This model takes into account the interaction of fundamental scalar field with possible multiplicative noise fluctuations of other nature. The noise-induced model of the Universe formation presented in this paper allows to describe its inflationary expansion till the present time. Such expansion can be explained in presented model if one takes into account the non-equilibrium dynamic of a transition into a new stable state.
Non-equilibrium thermodynamics and physical kinetics
Bikkin, Halid
2014-01-01
This graduate textbook covers contemporary directions of non-equilibrium statistical mechanics as well as classical methods of kinetics. With one of the main propositions being to avoid terms such as "obviously" and "it is easy to show", this treatise is an easy-to-read introduction into this traditional, yet vibrant field.
Pusateri, E. N.; Morris, H. E.; Nelson, E.; Ji, W.
2015-12-01
Electromagnetic pulse (EMP) events in the atmosphere are important physical phenomena that occur through both man-made and natural processes, such as lightning, and can be disruptive to surrounding electrical systems. Due to the disruptive nature of EMP, it is important to accurately predict EMP evolution and propagation with computational models. In EMP, low-energy conduction electrons are produced from Compton electron or photoelectron ionizations with air. These conduction electrons continue to interact with the surrounding air and alter the EMP waveform. Many EMP simulation codes use an equilibrium ohmic model for computing the conduction current. The equilibrium model works well when the equilibration time is short compared to the rise time or duration of the EMP. However, at high altitude, the conduction electron equilibration time can be comparable to or longer than the rise time or duration of the EMP. This matters, for example, when calculating the EMP propagating upward toward a satellite. In these scenarios, the equilibrium ionization rate becomes very large for even a modest electric field. The ohmic model produces an unphysically large number of conduction electrons that prematurely and abruptly short the EMP in the simulation code. An electron swarm model, which simulates the time evolution of conduction electrons, can be used to overcome the limitations exhibited by the equilibrium ohmic model. We have developed and validated an electron swarm model in an environment characterized by electric field and pressure previously in Pusateri et al. (2015). This swarm model has been integrated into CHAP-LA, a state-of-the-art EMP code developed by researchers at Los Alamos National Laboratory, which previously calculated conduction current using an ohmic model. We demonstrate the EMP damping behavior caused by the ohmic model at high altitudes and show improvements on high altitude EMP modeling obtained by employing the swarm model.
Non-equilibrium mechanics and dynamics of motor activated gels
MacKintosh, Fred C.; Levine, Alex J.
2007-01-01
The mechanics of cells is strongly affected by molecular motors that generate forces in the cellular cytoskeleton. We develop a model for cytoskeletal networks driven out of equilibrium by molecular motors exerting transient contractile stresses. Using this model we show how motor activity can dramatically increase the network's bulk elastic moduli. We also show how motor binding kinetics naturally leads to enhanced low-frequency stress fluctuations that result in non-equilibrium diffusive mo...
A non-equilibrium extension of quantum gravity
Mandrin, Pierre A
2016-01-01
A variety of quantum gravity models (including spin foams) can be described using a path integral formulation. A path integral has a well-known statistical mechanical interpretation in connection with a canonical ensemble. In this sense, a path integral describes the thermodynamic equilibrium of a local system in a thermal bath. This interpretation is in contrast to solutions of Einstein's Equations which depart from local thermodynamical equilibrium (one example is shown explicitly). For this reason, we examine an extension of the path integral model to a (locally) non-equilibrium description. As a non-equilibrium description, we propose to use a global microcanonical ensemble with constraints. The constraints reduce the set of admissible microscopic states to be consistent with the macroscopic geometry. We also analyse the relation between the microcanonical description and a statistical approach not based on dynamical assumptions which has been proposed recently. This analysis is of interest for the test o...
Fundamental Properties of Non-equilibrium Laser-Supported Detonation Wave
Shiraishi, Hiroyuki
2004-03-01
For developing laser propulsion, it is very important to analyze the mechanism of Laser-Supported Detonation (LSD), because it can generate high pressure and high temperature to be used by laser propulsion can be categorized as one type of hypersonic reacting flows, where exothermicity is supplied not by chemical reaction but by radiation absorption. I have numerically simulated the 1-D and Quasi-1-D LSD waves propagating through an inert gas, which absorbs CO2 gasdynamic laser, using a 2-temperature model. Calculated results show the fundamental properties of the non-equilibrium LSD Waves.
Investigation of Non-Equilibrium Radiation for Earth Entry
Brandis, A. M.; Johnston, C. O.; Cruden, B. A.
2016-01-01
For Earth re-entry at velocities between 8 and 11.5 km/s, the accuracy of NASA's computational uid dynamic and radiative simulations of non-equilibrium shock layer radiation is assessed through comparisons with measurements. These measurements were obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility. The experiments were aimed at measuring the spatially and spectrally resolved radiance at relevant entry conditions for both an approximate Earth atmosphere (79% N2 : 21% O2 by mole) as well as a more accurate composition featuring the trace species Ar and CO2 (78.08% N2 : 20.95% O2 : 0.04% CO2 : 0.93% Ar by mole). The experiments were configured to target a wide range of conditions, of which shots from 8 to 11.5 km/s at 0.2 Torr (26.7 Pa) are examined in this paper. The non-equilibrium component was chosen to be the focus of this study as it can account for a significant percentage of the emitted radiation for Earth re-entry, and more importantly, non-equilibrium has traditionally been assigned a large uncertainty for vehicle design. The main goals of this study are to present the shock tube data in the form of a non-equilibrium metric, evaluate the level of agreement between the experiment and simulations, identify key discrepancies and to examine critical aspects of modeling non-equilibrium radiating flows. Radiance pro les integrated over discreet wavelength regions, ranging from the Vacuum Ultra Violet (VUV) through to the Near Infra-Red (NIR), were compared in order to maximize both the spectral coverage and the number of experiments that could be used in the analysis. A previously defined non-equilibrium metric has been used to allow comparisons with several shots and reveal trends in the data. Overall, LAURA/HARA is shown to under-predict EAST by as much as 40% and over-predict by as much as 12% depending on the shock speed. DPLR/NEQAIR is shown to under-predict EAST by as much as 50% and over-predict by as much as 20% depending
Steady bipartite coherence induced by non-equilibrium environment
Huangfu, Yong; Jing, Jun
2018-01-01
We study the steady state of two coupled two-level atoms interacting with a non-equilibrium environment that consists of two heat baths at different temperatures. Specifically, we analyze four cases with respect to the configuration about the interactions between atoms and heat baths. Using secular approximation, the conventional master equation usually neglects steady-state coherence, even when the system is coupled with a non-equilibrium environment. When employing the master equation with no secular approximation, we find that the system coherence in our model, denoted by the off-diagonal terms in the reduced density matrix spanned by the eigenvectors of the system Hamiltonian, would survive after a long-time decoherence evolution. The absolute value of residual coherence in the system relies on different configurations of interaction channels between the system and the heat baths. We find that a large steady quantum coherence term can be achieved when the two atoms are resonant. The absolute value of quantum coherence decreases in the presence of additional atom-bath interaction channels. Our work sheds new light on the mechanism of steady-state coherence in microscopic quantum systems in non-equilibrium environments.
Ethanol reforming in non-equilibrium plasma of glow discharge
Levko, D
2012-01-01
The results of a detailed kinetic study of the main plasma chemical processes in non-equilibrium ethanol/argon plasma are presented. It is shown that at the beginning of the discharge the molecular hydrogen is mainly generated in the reaction of ethanol H-abstraction. Later hydrogen is formed from active H, CH2OH and CH3CHOH and formaldehyde. Comparison with experimental data has shown that the used kinetic mechanism predicts well the concentrations of main species at the reactor outlet.
Atomistic Simulation of Non-Equilibrium Phenomena in Hypersonic Flows
Norman, Paul Erik
The goal of this work is to model the heterogeneous recombination of atomic oxygen on silica surfaces, which is of interest for accurately predicting the heating on vehicles traveling at hypersonic speeds. This is accomplished by creating a finite rate catalytic model, which describes recombination with a set of elementary gas-surface reactions. Fundamental to a description of surface catalytic reactions are the in situ chemical structures on the surface where recombination can occur. Using molecular dynamics simulations with the Reax GSISiO potential, we find that the chemical sites active in direct gas-phase reactions on silica surfaces consist of a small number of specific structures (or defects). The existence of these defects on real silica surfaces is supported by experimental results and the structure and energetics of these defects have been verified with quantum chemical calculations. The reactions in the finite rate catalytic model are based on the interaction of molecular and atomic oxygen with these defects. Trajectory calculations are used to find the parameters in the forward rate equations, while a combination of detailed balance and transition state theory are used to find the parameters in the reverse rate equations. The rate model predicts that the oxygen recombination coefficient is relatively constant at T (300-1000 K), in agreement with experimental results. At T > 1000 K the rate model predicts a drop off in the oxygen recombination coefficient, in disagreement with experimental results, which predict that the oxygen recombination coefficient increases with temperature. A discussion of the possible reasons for this disagreement, including non-adiabatic collision dynamics, variable surface site concentrations, and additional recombination mechanisms is presented. This thesis also describes atomistic simulations with Classical Trajectory Calculation Direction Simulation Monte Carlo (CTC-DSMC), a particle based method for modeling non-equilibrium
Energy Technology Data Exchange (ETDEWEB)
Tsuboi, N.; Yamaguchi, H.; Matsumoto, Y. [The University of Tokyo, Tokyo (Japan)
2000-06-25
A DSMC (direct simulation Monte Carlo) simulation using Dynamic Molecular Collision (DMC) model based on Molecular Dynamics (MD) calculation is applied for solving a two-dimensional non-equilibrium hypersonic rarefied flow over a flat plate with and without angle of leading edge. Numerical results show that non-equilibrium characteristics between translational and rotational temperature are obtained behind leading edge over the plate. The results of the DSMC agree well with those of the experiments, however, the results of the Navier-Stokes are quite different from those of the experiments. The comparison between Larsen-Borgnakke (LB) model and DMC model reveals that the DMC model obtains excellent results without a parameter such as an inelastic parameter. (author)
Virkar, Anil V.
Transport through ionic conducting membranes is examined. An equation describing the chemical potential, μ s, of electrically neutral species, s, in the membrane is derived in terms of ionic and electronic currents, and ionic and electronic transport resistances. It is shown that the μ s in the membrane need not be mathematically bounded by the values at the two electrodes (reservoirs) if the ionic and the electronic currents through the membrane are in the same direction. Conditions could develop under which the μ s in the membrane may exceed the thermodynamic stability of the membrane even when exposed to stable conditions at the two electrodes. It is shown that during charging, chemical potential of lithium, μ Li, in the electrolyte of a lithium-ion battery may exceed that corresponding to pure lithium thus causing lithium precipitation and/or reaction with the electrolyte. It is also shown that in a lithium ion battery pack containing several cells, degradation may occur during discharge due to cell imbalance. In unbalanced cells, the SEI layer may form at both the anode/electrolyte and the cathode/electrolyte interfaces. A bi-layer separator comprising an electronic conductor and an electronic insulator is proposed for improved stability of lithium batteries.
The non-equilibrium nature of culinary evolution
Kinouchi, Osame; Diez-Garcia, Rosa W.; Holanda, Adriano J.; Zambianchi, Pedro; Roque, Antonio C.
2008-07-01
Food is an essential part of civilization, with a scope that ranges from the biological to the economic and cultural levels. Here, we study the statistics of ingredients and recipes taken from Brazilian, British, French and Medieval cookery books. We find universal distributions with scale invariant behaviour. We propose a copy-mutate process to model culinary evolution that fits our empirical data very well. We find a cultural 'founder effect' produced by the non-equilibrium dynamics of the model. Both the invariant and idiosyncratic aspects of culture are accounted for by our model, which may have applications in other kinds of evolutionary processes.
Non-equilibrium reactive flux: A unified framework for slow and fast reaction kinetics
Bose, Amartya; Makri, Nancy
2017-10-01
The flux formulation of reaction rate theory is recast in terms of the expectation value of the reactive flux with an initial condition that corresponds to a non-equilibrium, factorized reactant density. In the common case of slow reactive processes, the non-equilibrium expression reaches the plateau regime only slightly slower than the equilibrium flux form. When the reactants are described by a single quantum state, as in the case of electron transfer reactions, the factorized reactant density describes the true initial condition of the reactive process. In such cases, the time integral of the non-equilibrium flux expression yields the reactant population as a function of time, allowing characterization of the dynamics in cases where there is no clear separation of time scales and thus a plateau regime cannot be identified. The non-equilibrium flux offers a unified approach to the kinetics of slow and fast chemical reactions and is ideally suited to mixed quantum-classical methods.
Non-equilibrium reactive flux: A unified framework for slow and fast reaction kinetics.
Bose, Amartya; Makri, Nancy
2017-10-21
The flux formulation of reaction rate theory is recast in terms of the expectation value of the reactive flux with an initial condition that corresponds to a non-equilibrium, factorized reactant density. In the common case of slow reactive processes, the non-equilibrium expression reaches the plateau regime only slightly slower than the equilibrium flux form. When the reactants are described by a single quantum state, as in the case of electron transfer reactions, the factorized reactant density describes the true initial condition of the reactive process. In such cases, the time integral of the non-equilibrium flux expression yields the reactant population as a function of time, allowing characterization of the dynamics in cases where there is no clear separation of time scales and thus a plateau regime cannot be identified. The non-equilibrium flux offers a unified approach to the kinetics of slow and fast chemical reactions and is ideally suited to mixed quantum-classical methods.
Non-equilibrium many body dynamics
Energy Technology Data Exchange (ETDEWEB)
Creutz, M.; Gyulassy, M.
1997-09-22
This Riken BNL Research Center Symposium on Non-Equilibrium Many Body Physics was held on September 23-25, 1997 as part of the official opening ceremony of the Center at Brookhaven National Lab. A major objective of theoretical work at the center is to elaborate on the full spectrum of strong interaction physics based on QCD, including the physics of confinement and chiral symmetry breaking, the parton structure of hadrons and nuclei, and the phenomenology of ultra-relativistic nuclear collisions related to the up-coming experiments at RHIC. The opportunities and challenges of nuclear and particle physics in this area naturally involve aspects of the many body problem common to many other fields. The aim of this symposium was to find common theoretical threads in the area of non-equilibrium physics and modern transport theories. The program consisted of invited talks on a variety topics from the fields of atomic, condensed matter, plasma, astrophysics, cosmology, and chemistry, in addition to nuclear and particle physics. Separate abstracts have been indexed into the database for contributions to this workshop.
Crum, Dax M.; Valsaraj, Amithraj; David, John K.; Register, Leonard F.; Banerjee, Sanjay K.
2016-12-01
Particle-based ensemble semi-classical Monte Carlo (MC) methods employ quantum corrections (QCs) to address quantum confinement and degenerate carrier populations to model tomorrow's ultra-scaled metal-oxide-semiconductor-field-effect-transistors. Here, we present the most complete treatment of quantum confinement and carrier degeneracy effects in a three-dimensional (3D) MC device simulator to date, and illustrate their significance through simulation of n-channel Si and III-V FinFETs. Original contributions include our treatment of far-from-equilibrium degenerate statistics and QC-based modeling of surface-roughness scattering, as well as considering quantum-confined phonon and ionized-impurity scattering in 3D. Typical MC simulations approximate degenerate carrier populations as Fermi distributions to model the Pauli-blocking (PB) of scattering to occupied final states. To allow for increasingly far-from-equilibrium non-Fermi carrier distributions in ultra-scaled and III-V devices, we instead generate the final-state occupation probabilities used for PB by sampling the local carrier populations as function of energy and energy valley. This process is aided by the use of fractional carriers or sub-carriers, which minimizes classical carrier-carrier scattering intrinsically incompatible with degenerate statistics. Quantum-confinement effects are addressed through quantum-correction potentials (QCPs) generated from coupled Schrödinger-Poisson solvers, as commonly done. However, we use these valley- and orientation-dependent QCPs not just to redistribute carriers in real space, or even among energy valleys, but also to calculate confinement-dependent phonon, ionized-impurity, and surface-roughness scattering rates. FinFET simulations are used to illustrate the contributions of each of these QCs. Collectively, these quantum effects can substantially reduce and even eliminate otherwise expected benefits of considered In0.53Ga0.47 As FinFETs over otherwise identical
Universal Scaling Behavior of Non-Equilibrium Phase Transitions
Lübeck, Sven
Non-equilibrium critical phenomena have attracted a lot of research interest in the recent decades. Similar to equilibrium critical phenomena, the concept of universality remains the major tool to order the great variety of non-equilibrium phase transitions systematically. All systems belonging to a given universality class share the same set of critical exponents, and certain scaling functions become identical near the critical point. It is known that the scaling functions vary more widely between different universality classes than the exponents. Thus, universal scaling functions offer a sensitive and accurate test for a system's universality class. On the other hand, universal scaling functions demonstrate the robustness of a given universality class impressively. Unfortunately, most studies focus on the determination of the critical exponents, neglecting the universal scaling functions. In this work a particular class of non-equilibrium critical phenomena is considered, the so-called absorbing phase transitions. Absorbing phase transitions are expected to occur in physical, chemical as well as biological systems, and a detailed introduction is presented. The universal scaling behavior of two different universality classes is analyzed in detail, namely the directed percolation and the Manna universality class. Especially, directed percolation is the most common universality class of absorbing phase transitions. The presented picture gallery of universal scaling functions includes steady state, dynamical as well as finite size scaling functions. In particular, the effect of an external field conjugated to the order parameter is investigated. Incorporating the conjugated field, it is possible to determine the equation of state, the susceptibility, and to perform a modified finite-size scaling analysis appropriate for absorbing phase transitions. Focusing on these equations, the obtained results can be applied to other non-equilibrium continuous phase transitions
Quantum reciprocity conjecture for the non-equilibrium steady state
Energy Technology Data Exchange (ETDEWEB)
Coleman, P; Mao, W [Center for Materials Theory, Rutgers University, Piscataway, NJ 08854 (United States)
2004-05-26
A consideration of the lack of history dependence in the non-equilibrium steady state of a quantum system leads us to conjecture that in such a system there is a set of quantum mechanical observables whose retarded response functions are insensitive to the arrow of time, and which consequently satisfy a quantum analogue of the Onsager reciprocity relations. Systems which satisfy this conjecture can be described by an effective free energy functional. We demonstrate that the conjecture holds in a resonant level model of a multi-lead quantum dot. (letter to the editor)
Numerical Simulation of Non-Equilibrium Plasma Discharge for High Speed Flow Control
Balasubramanian, Ramakrishnan; Anandhanarayanan, Karupannasamy; Krishnamurthy, Rajah; Chakraborty, Debasis
2017-06-01
Numerical simulation of hypersonic flow control using plasma discharge technique is carried out using an in-house developed code CERANS-TCNEQ. The study is aimed at demonstrating a proof of concept futuristic aerodynamic flow control device. The Kashiwa Hypersonic and High Temperature wind tunnel study of plasma discharge over a flat plate had been considered for numerical investigation. The 7-species, 18-reaction thermo-chemical non-equilibrium, two-temperature air-chemistry model due Park is used to model the weakly ionized flow. Plasma discharge is modeled as Joule heating source terms in both the translation-rotational and vibrational energy equations. Comparison of results for plasma discharge at Mach 7 over a flat plate with the reference data reveals that the present study is able to mimic the exact physics of complex flow such as formation of oblique shock wave ahead of the plasma discharge region with a resultant rise in surface pressure and vibrational temperature up to 7000 K demonstrating the use of non-equilibrium plasma discharge for flow control at hypersonic speeds.
Non-equilibrium dynamics of Gaudin models
Barmettler, P.; Fioretto, D.; Gritsev, V.
2013-01-01
n classical mechanics the theory of non-linear dynamics provides a detailed framework for the distinction between near-integrable and chaotic systems. Quite in opposition, in quantum many-body theory no generic microscopic principle at the origin of complex dynamics is known. Here we show that the
Application of non-equilibrium plasmas in medicine
Directory of Open Access Journals (Sweden)
Mojsilović S.
2012-01-01
Full Text Available We review the potential of plasma medical applications, the connections to nanotechnologies and the results obtained by our group. A special issue in plasma medicine is the development of the plasma sources that would achieve non-equilibrium at atmospheric pressure in atmospheric gas mixture with no or only marginal heating of the gas, and with desired properties and mechanisms that may be controlled. Our studies have shown that control of radicals or chemically active products of the discharge such as ROS (reactive oxygen species and/or NO may be used to control the growth of the seeds. At the same time specially designed plasma needle and other sources were shown to be efficient to sterilize not only colonies of bacteria but also planctonic samples (microorganisms protected by water or bio films. Finally we have shown that plasma may induce differentiation of stem cells. Non-equilibrium plasmas may be used in detection of different specific markers in medicine. For example proton transfer mass spectroscopy may be employed in detection of volatile organic compounds without their dissociation and thus as a technique for instantaneous measurement of the presence of markers for numerous diseases. [Projekat Ministarstva nauke Republike Srbije, br. ON171037 i br. III41011
Non-Equilibrium Kinetics and Transport Properties in Reacting Flows in Nozzles
Alexandrova, T. Yu.; Chikhaoui, A.; Kustova, E. V.; Nagnibeda, E. A.
2003-05-01
Non-equilibrium vibration-dissociation kinetics, transport properties and dissociation rate coefficients in expanding flows are studied on the basis of different kinetic theory approaches: state-to-state, multi-temperature and one-temperature ones. The limits of validity of more simple models are discussed, the influence of non-equilibrium vibrational distributions, initial conditions, nozzle profile on the macroscopic parameters, heat transfer and reaction rates is investigated.
Investigation of Multiscale Non-equilibrium Flow Dynamics Under External Force Field
Xiao, Tianbai
2016-01-01
The multiple scale non-equilibrium gaseous flow behavior under external force field is investigated. Both theoretical analysis based on the kinetic model equation and numerical study are presented to demonstrate the dynamic effect of external force on the flow evolution, especially on the non-equilibrium heat flux. The current numerical experiment is based on the well-balanced unified gas-kinetic scheme (UGKS), which presents accurate solutions in the whole flow regime from the continuum Navier-Stokes solution to the transition and free molecular ones. The heat conduction in the non-equilibrium regime due to the external forcing term is quantitatively investigated. In the lid-driven cavity flow study, due to the external force field the density distribution inside cavity gets stratified and a multiscale non-equilibrium flow transport appears in a single gas dynamic system. With the increment of external forcing term, the flow topological structure changes dramatically, and the temperature gradient, shearing s...
Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification
Energy Technology Data Exchange (ETDEWEB)
Choi, Jeong [Iowa State Univ., Ames, IA (United States)
2011-01-01
The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these
NON-EQUILIBRIUM ELECTRONS IN THE OUTSKIRTS OF GALAXY CLUSTERS
Energy Technology Data Exchange (ETDEWEB)
Avestruz, Camille; Nagai, Daisuke; Lau, Erwin T. [Department of Physics, Yale University, New Haven, CT 06520 (United States); Nelson, Kaylea, E-mail: camille.avestruz@yale.edu, E-mail: camille.avestruz@yale.edu [Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06520 (United States)
2015-08-01
The analysis of X-ray and Sunyaev–Zel’dovich measurements of the intracluster medium (ICM) assumes that electrons are in thermal equilibrium with ions in the plasma. However, in the outskirts of galaxy clusters, the electron–ion equilibration timescale can become comparable to the Hubble time, leading to systematic biases in cluster mass estimates and mass-observable scaling relations. To quantify an upper limit of the impact of non-equilibrium electrons, we use a mass-limited sample of simulated galaxy clusters taken from a cosmological simulation with a two-temperature model that assumes the Spitzer equilibration time for the electrons and ions. We show that the temperature bias is more pronounced in more massive and rapidly accreting clusters. For the most extreme case, we find that the bias is of the order of 10% at half of the cluster virial radius and increases to 40% at the edge of the cluster. Gas in filaments is less susceptible to the non-equilibrium effect, leading to azimuthal variations in the temperature bias at large cluster-centric radii. Using mock Chandra observations of simulated clusters, we show that the bias manifests in ultra-deep X-ray observations of cluster outskirts and quantify the resulting biases in hydrostatic mass and cluster temperature derived from these observations. We provide a mass-dependent fitting function for the temperature bias profile, which can be useful for modeling the effect of electron-ion equilibration in galaxy clusters.
Non-equilibrium theory of arrested spinodal decomposition
Energy Technology Data Exchange (ETDEWEB)
Olais-Govea, José Manuel; López-Flores, Leticia; Medina-Noyola, Magdaleno [Instituto de Física “Manuel Sandoval Vallarta,” Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, SLP (Mexico)
2015-11-07
The non-equilibrium self-consistent generalized Langevin equation theory of irreversible relaxation [P. E. Ramŕez-González and M. Medina-Noyola, Phys. Rev. E 82, 061503 (2010); 82, 061504 (2010)] is applied to the description of the non-equilibrium processes involved in the spinodal decomposition of suddenly and deeply quenched simple liquids. For model liquids with hard-sphere plus attractive (Yukawa or square well) pair potential, the theory predicts that the spinodal curve, besides being the threshold of the thermodynamic stability of homogeneous states, is also the borderline between the regions of ergodic and non-ergodic homogeneous states. It also predicts that the high-density liquid-glass transition line, whose high-temperature limit corresponds to the well-known hard-sphere glass transition, at lower temperature intersects the spinodal curve and continues inside the spinodal region as a glass-glass transition line. Within the region bounded from below by this low-temperature glass-glass transition and from above by the spinodal dynamic arrest line, we can recognize two distinct domains with qualitatively different temperature dependence of various physical properties. We interpret these two domains as corresponding to full gas-liquid phase separation conditions and to the formation of physical gels by arrested spinodal decomposition. The resulting theoretical scenario is consistent with the corresponding experimental observations in a specific colloidal model system.
Non-equilibrium steady states of quantum systems on star graphs
Energy Technology Data Exchange (ETDEWEB)
Mintchev, Mihail, E-mail: mintchev@df.unipi.it [Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica, Universita di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy)
2011-10-14
Non-equilibrium steady states of quantum fields on star graphs are explicitly constructed. These states are parametrized by the temperature and the chemical potential, associated with each edge of the graph. Time reversal invariance is spontaneously broken. We study in this general framework the transport properties of the Schroedinger and the Dirac systems on a star graph, modeling a quantum wire junction. The interaction, which drives the system away from equilibrium, is localized in the vertex of the graph. All point-like vertex interactions, giving rise to self-adjoint Hamiltonians possibly involving the minimal coupling to a static electromagnetic field in the ambient space, are considered. In this context, we compute the exact electric steady current and the non-equilibrium charge density. We also investigate the heat transport and derive the Casimir energy density away from equilibrium. The appearance of Friedel-type oscillations of the charge and energy densities along the edges of the graph is established. We focus finally on the noise power and discuss the non-trivial impact of the point-like interactions on the noise. (paper)
Non-Equilibrium Thermodynamics of Transcriptional Bursts
Hernández-Lemus, Enrique
Gene transcription or Gene Expression (GE) is the process which transforms the information encoded in DNA into a functional RNA message. It is known that GE can occur in bursts or pulses. Transcription is irregular, with strong periods of activity, interspersed by long periods of inactivity. If we consider the average behavior over millions of cells, this process appears to be continuous. But at the individual cell level, there is considerable variability, and for most genes, very little activity at any one time. Some have claimed that GE bursting can account for the high variability in gene expression occurring between cells in isogenic populations. This variability has a big impact on cell behavior and thus on phenotypic conditions and disease. In view of these facts, the development of a thermodynamic framework to study gene expression and transcriptional regulation to integrate the vast amount of molecular biophysical GE data is appealing. Application of such thermodynamic formalism is useful to observe various dissipative phenomena in GE regulatory dynamics. In this chapter we will examine at some detail the complex phenomena of transcriptional bursts (specially of a certain class of anomalous bursts) in the context of a non-equilibrium thermodynamics formalism and will make some initial comments on the relevance of some irreversible processes that may be connected to anomalous transcriptional bursts.
Non-equilibrium dissipative supramolecular materials with a tunable lifetime
Tena-Solsona, Marta; Rieß, Benedikt; Grötsch, Raphael K.; Löhrer, Franziska C.; Wanzke, Caren; Käsdorf, Benjamin; Bausch, Andreas R.; Müller-Buschbaum, Peter; Lieleg, Oliver; Boekhoven, Job
2017-07-01
Many biological materials exist in non-equilibrium states driven by the irreversible consumption of high-energy molecules like ATP or GTP. These energy-dissipating structures are governed by kinetics and are thus endowed with unique properties including spatiotemporal control over their presence. Here we show man-made equivalents of materials driven by the consumption of high-energy molecules and explore their unique properties. A chemical reaction network converts dicarboxylates into metastable anhydrides driven by the irreversible consumption of carbodiimide fuels. The anhydrides hydrolyse rapidly to the original dicarboxylates and are designed to assemble into hydrophobic colloids, hydrogels or inks. The spatiotemporal control over the formation and degradation of materials allows for the development of colloids that release hydrophobic contents in a predictable fashion, temporary self-erasing inks and transient hydrogels. Moreover, we show that each material can be re-used for several cycles.
Experimental studies in non-equilibrium physics
Cressman, John Robert, Jr.
This work is a collection of three experiments aimed at studying different facets of non-equilibrium dynamics. Chapter I concerns strongly compressible turbulence, which turns out to be very different from incompressible turbulence. The focus is on the dispersion of contaminants in such a flow. This type of turbulence can be studied, at very low mach number, by measuring the velocity fields of particles that float on a turbulently stirred body of water. It turns out that in the absence of incompressibility, the turbulence causes particles to cluster rather than to disperse. The implications of the observations are far reaching and include the transport of pollutants on the oceans surface, phytoplankton growth, as well as industrial applications. Chapter II deals with the effects of polymer additives on drag reduction and turbulent suppression, a well-known phenomenon that is not yet understood. In an attempt to simplify the problem, the effects of a polymer additive were investigated in a vortex street formed in a flowing soap film. Measurements suggest that an increase in elongational viscosity is responsible for a substantial reduction in periodic velocity fluctuations. This study also helps to illuminate the mechanism responsible for vortex separation in the wake of a bluff body. Chapter III describes an experiment designed to test a theoretical approach aimed at generalizing the classical fluctuation dissipation theorem (FDT). This theorem applies to systems driven only slightly away from thermal equilibrium, whereas ours, a liquid crystal under-going electroconvection, is so strongly driven, that the FDT does not apply. Both theory and experiment focus on the flux in global power fluctuations. Physical limitations did not permit a direct test of the theory, however it was possible to establish several interesting characteristics of the system: the source of the fluctuations is the transient defect structures that are generated when the system is driven hard
Non-equilibrium phase transitions in complex plasma
Sutterlin, K. R.; Wysocki, A.; Rath, C.; Ivlev, A. V.; Thomas, H. M.; Khrapak, S.; Zhdanov, S.; Rubin-Zuzic, M.; W. J. Goedheer,; Fortov, V. E.; Lipaev, A. M.; Molotkov, V. I.; Petrov, O. F.; Morfill, G. E.; Lowen, H.
2010-01-01
Complex plasma being the 'plasma state of soft matter' is especially suitable for investigations of non-equilibrium phase transitions. Non-equilibrium phase transitions can manifest in dissipative structures or self-organization. Two specific examples are lane formation and phase
Extension of CE/SE method to non-equilibrium dissociating flows
Wen, C.Y.
2017-12-08
In this study, the hypersonic non-equilibrium flows over rounded nose geometries are numerically investigated by a robust conservation element and solution element (CE/SE) code, which is based on hybrid meshes consisting of triangular and quadrilateral elements. The dissociating and recombination chemical reactions as well as the vibrational energy relaxation are taken into account. The stiff source terms are solved by an implicit trapezoidal method of integration. Comparison with laboratory and numerical cases are provided to demonstrate the accuracy and reliability of the present CE/SE code in simulating hypersonic non-equilibrium flows.
Non-Equilibrium Thermodynamic Chemistry and the Composition of the Atmosphere of Mars
Levine, J. S.; Summers, M. E.
2003-01-01
A high priority objective of the Mars Exploration Program is to Determine if life exists today (MEPAG Goal I, Objective A). The measurement of gases of biogenic origin may be an approach to detect the presence of microbial life on the surface or subsurface of Mars. Chemical thermodynamic calculations indicate that on both Earth and Mars, certain gases should exist in extremely low concentrations, if at all. Microbial metabolic activity is an important non-equilibrium chemistry process on Earth, and if microbial life exists on Mars, may be an important nonequilibrium chemistry process on Mars. The non-equilibrium chemistry of the atmosphere of Mars is discussed in this paper.
Topologically protected modes in non-equilibrium stochastic systems
Murugan, Arvind; Vaikuntanathan, Suriyanarayanan
2017-01-01
Non-equilibrium driving of biophysical processes is believed to enable their robust functioning despite the presence of thermal fluctuations and other sources of disorder. Such robust functions include sensory adaptation, enhanced enzymatic specificity and maintenance of coherent oscillations. Elucidating the relation between energy consumption and organization remains an important and open question in non-equilibrium statistical mechanics. Here we report that steady states of systems with non-equilibrium fluxes can support topologically protected boundary modes that resemble similar modes in electronic and mechanical systems. Akin to their electronic and mechanical counterparts, topological-protected boundary steady states in non-equilibrium systems are robust and are largely insensitive to local perturbations. We argue that our work provides a framework for how biophysical systems can use non-equilibrium driving to achieve robust function.
DEFF Research Database (Denmark)
Papior, Nick Rübner; Lorente, Nicolás; Frederiksen, Thomas
2017-01-01
We present novel methods implemented within the non-equilibrium Green function code (NEGF) TRANSIESTA based on density functional theory (DFT). Our flexible, next-generation DFT–NEGF code handles devices with one or multiple electrodes (Ne≥1) with individual chemical potentials and electronic tem...
Problems of perturbation series in non-equilibrium quantum field theories
Altherr, Tanguy
1994-01-01
In the standard framework of non-equilibrium quantum field theories, the pinch singularities associated to multiple products of \\delta-functions do not cancel in a perturbative expansion unless the particle distributions are those for a system in thermal and chemical equilibrium.
Thermal Non-equilibrium Consistent with Widespread Cooling
Winebarger, A.; Lionello, R.; Mikic, Z.; Linker, J.; Mok, Y.
2014-01-01
Time correlation analysis has been used to show widespread cooling in the solar corona; this cooling has been interpreted as a result of impulsive (nanoflare) heating. In this work, we investigate wide-spread cooling using a 3D model for a solar active region which has been heated with highly stratified heating. This type of heating drives thermal non-equilibrium solutions, meaning that though the heating is effectively steady, the density and temperature in the solution are not. We simulate the expected observations in narrowband EUV images and apply the time correlation analysis. We find that the results of this analysis are qualitatively similar to the observed data. We discuss additional diagnostics that may be applied to differentiate between these two heating scenarios.
Non-Equilibrium Steady States of the XY Chain
Aschbacher, W H
2002-01-01
We study the non-equilibrium statistical mechanics of the two-sided XY chain. We start from an initial state in which the left and right part of the lattice {x|xM}, are at inverse temperatures beta_L and beta_R. Using a simple scattering theoretic analysis, we construct the unique non-equilibrium steady state (NESS). This state depends on beta_L and beta_R, but not on the choice of the decoupling parameter M. We prove that in the non-equilibrium case, beta_L \
Astumian, R D
2018-01-11
In the absence of input energy, a chemical reaction in a closed system ineluctably relaxes toward an equilibrium state governed by a Boltzmann distribution. The addition of a catalyst to the system provides a way for more rapid equilibration toward this distribution, but the catalyst can never, in and of itself, drive the system away from equilibrium. In the presence of external fluctuations, however, a macromolecular catalyst (e.g., an enzyme) can absorb energy and drive the formation of a steady state between reactant and product that is not determined solely by their relative energies. Due to the ubiquity of non-equilibrium steady states in living systems, the development of a theory for the effects of external fluctuations on chemical systems has been a longstanding focus of non-equilibrium thermodynamics. The theory of stochastic pumping has provided insight into how a non-equilibrium steady-state can be formed and maintained in the presence of dissipation and kinetic asymmetry. This effort has been greatly enhanced by a confluence of experimental and theoretical work on synthetic molecular machines designed explicitly to harness external energy to drive non-equilibrium transport and self-assembly.
A non-equilibrium equation-of-motion approach to quantum transport utilizing projection operators.
Ochoa, Maicol A; Galperin, Michael; Ratner, Mark A
2014-11-12
We consider a projection operator approach to the non-equilibrium Green function equation-of-motion (PO-NEGF EOM) method. The technique resolves problems of arbitrariness in truncation of an infinite chain of EOMs and prevents violation of symmetry relations resulting from the truncation (equivalence of left- and right-sided EOMs is shown and symmetry with respect to interchange of Fermi or Bose operators before truncation is preserved). The approach, originally developed by Tserkovnikov (1999 Theor. Math. Phys. 118 85) for equilibrium systems, is reformulated to be applicable to time-dependent non-equilibrium situations. We derive a canonical form of EOMs, thus explicitly demonstrating a proper result for the non-equilibrium atomic limit in junction problems. A simple practical scheme applicable to quantum transport simulations is formulated. We perform numerical simulations within simple models and compare results of the approach to other techniques and (where available) also to exact results.
Mesoscopic non-equilibrium thermodynamics of non-isothermal reaction-diffusion.
Bedeaux, D; Pagonabarraga, I; Ortiz de Zárate, J M; Sengers, J V; Kjelstrup, S
2010-10-21
We show how the law of mass action can be derived from a thermodynamic basis, in the presence of temperature gradients, chemical potential gradients and hydrodynamic flow. The solution gives the law of mass action for the forward and the reverse contributions to the net chemical reaction. In addition we derive the fluctuation-dissipation theorem for the fluctuating contributions to the reaction rate, heat flux and mass fluxes. All these results arise without any other assumptions than those which are common in mesoscopic non-equilibrium thermodynamics; namely quasi-stationary transport across a high activation energy barrier, and local equilibrium along the reaction coordinate. Arrhenius-type behaviour of the kinetic coefficients is recovered. The thermal conductivity, Soret coefficient and diffusivity are significantly influenced by the presence of a chemical reaction. We thus demonstrate how chemical reactions can be fully reconciled with non-equilibrium thermodynamics.
Power conversion efficiency of non-equilibrium light absorption
Directory of Open Access Journals (Sweden)
I. Santamaría-Holek
2017-04-01
Full Text Available We deduce a novel expression for the non-equilibrium photochemical potential and the power conversion efficiency of non-equilibrium light absorption by a thermostated material. Application of our results for the case of electron migration from valence to conduction bands in photovoltaic cells allows us to accurately interpolate experimental results for the maximal efficiencies of Ge-, Si-, GaAs-based cells and the like.
Achieving Radiation Tolerance through Non-Equilibrium Grain Boundary Structures.
Vetterick, Gregory A; Gruber, Jacob; Suri, Pranav K; Baldwin, Jon K; Kirk, Marquis A; Baldo, Pete; Wang, Yong Q; Misra, Amit; Tucker, Garritt J; Taheri, Mitra L
2017-09-25
Many methods used to produce nanocrystalline (NC) materials leave behind non-equilibrium grain boundaries (GBs) containing excess free volume and higher energy than their equilibrium counterparts with identical 5 degrees of freedom. Since non-equilibrium GBs have increased amounts of both strain and free volume, these boundaries may act as more efficient sinks for the excess interstitials and vacancies produced in a material under irradiation as compared to equilibrium GBs. The relative sink strengths of equilibrium and non-equilibrium GBs were explored by comparing the behavior of annealed (equilibrium) and as-deposited (non-equilibrium) NC iron films on irradiation. These results were coupled with atomistic simulations to better reveal the underlying processes occurring on timescales too short to capture using in situ TEM. After irradiation, NC iron with non-equilibrium GBs contains both a smaller number density of defect clusters and a smaller average defect cluster size. Simulations showed that excess free volume contribute to a decreased survival rate of point defects in cascades occurring adjacent to the GB and that these boundaries undergo less dramatic changes in structure upon irradiation. These results suggest that non-equilibrium GBs act as more efficient sinks for defects and could be utilized to create more radiation tolerant materials in future.
Dotov, D G; Kim, S; Frank, T D
2015-02-01
We derive explicit expressions for the non-equilibrium thermodynamical variables of a canonical-dissipative limit cycle oscillator describing rhythmic motion patterns of active systems. These variables are statistical entropy, non-equilibrium internal energy, and non-equilibrium free energy. In particular, the expression for the non-equilibrium free energy is derived as a function of a suitable control parameter. The control parameter determines the Hopf bifurcation point of the deterministic active system and describes the effective pumping of the oscillator. In analogy to the equilibrium free energy of the Landau theory, it is shown that the non-equilibrium free energy decays as a function of the control parameter. In doing so, a similarity between certain equilibrium and non-equilibrium phase transitions is pointed out. Data from an experiment on human rhythmic movements is presented. Estimates for pumping intensity as well as the thermodynamical variables are reported. It is shown that in the experiment the non-equilibrium free energy decayed when pumping intensity was increased, which is consistent with the theory. Moreover, pumping intensities close to zero could be observed at relatively slow intended rhythmic movements. In view of the Hopf bifurcation underlying the limit cycle oscillator model, this observation suggests that the intended limit cycle movements were actually more similar to trajectories of a randomly perturbed stable focus. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Non-equilibrium plasma prevention of Schistosoma japonicum transmission
Wang, Xing-Quan; Wang, Feng-Peng; Chen, Wei; Huang, Jun; Bazaka, Kateryna; Ostrikov, Kostya (Ken)
2016-10-01
Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment. We investigated the use of physical non-equilibrium plasma generated at atmospheric pressure using custom-made dielectric barrier discharge reactor to kill S. japonicum cercariae. Survival rate decreased with treatment time and applied power. Plasmas generated in O2 and air gas discharges were more effective in killing S. japonicum cercariae than that generated in He, which is directly related to the mechanism by which cercariae are inactivated. Reactive oxygen species, such as O atoms, abundant in O2 plasma and NO in air plasma play a major role in killing of S. japonicum cercariae via oxidation mechanisms. Similar level of efficacy is also shown for a gliding arc discharge plasma jet generated in ambient air, a system that may be more appropriate for scale-up and integration into existing water treatment processes.
Non-equilibrium quantum heat machines
Alicki, Robert; Gelbwaser, David
2015-01-01
Standard heat machines (engine, heat pump, refrigerator) are composed of a system ("working fluid") coupled to at least two equilibrium baths at different temperatures and periodically driven by an external device (piston or rotor) called sometimes work reservoir. The aim of this paper is to go beyond this scheme by considering environments which are stationary but cannot be decomposed into few baths at thermal equilibrium. Such situations are important, for example in solar cells, chemical m...
Non-equilibrium reacting gas flows kinetic theory of transport and relaxation processes
Nagnibeda, Ekaterina; Nagnibeda, Ekaterina
2009-01-01
This volume develops the kinetic theory of transport phenomena and relaxation processes in the flows of reacting gas mixtures. The theory is applied to the modeling of non-equilibrium flows behind strong shock waves, in the boundary layer, and in nozzles.
Lyapunov Functions, Stationary Distributions, and Non-equilibrium Potential for Reaction Networks
DEFF Research Database (Denmark)
Anderson, David F; Craciun, Gheorghe; Gopalkrishnan, Manoj
2015-01-01
We consider the relationship between stationary distributions for stochastic models of reaction systems and Lyapunov functions for their deterministic counterparts. Specifically, we derive the well-known Lyapunov function of reaction network theory as a scaling limit of the non-equilibrium potent...
New phenomena in non-equilibrium quantum physics
Kitagawa, Takuya
From its beginning in the early 20th century, quantum theory has become progressively more important especially due to its contributions to the development of technologies. Quantum mechanics is crucial for current technology such as semiconductors, and also holds promise for future technologies such as superconductors and quantum computing. Despite of the success of quantum theory, its applications have been mostly limited to equilibrium or static systems due to 1. lack of experimental controllability of non-equilibrium quantum systems 2. lack of theoretical frameworks to understand non-equilibrium dynamics. Consequently, physicists have not yet discovered too many interesting phenomena in non-equilibrium quantum systems from both theoretical and experimental point of view and thus, non-equilibrium quantum physics did not attract too much attentions. The situation has recently changed due to the rapid development of experimental techniques in condensed matter as well as cold atom systems, which now enables a better control of non-equilibrium quantum systems. Motivated by this experimental progress, we constructed theoretical frameworks to study three different non-equilibrium regimes of transient dynamics, steady states and periodically drives. These frameworks provide new perspectives for dynamical quantum process, and help to discover new phenomena in these systems. In this thesis, we describe these frameworks through explicit examples and demonstrate their versatility. Some of these theoretical proposals have been realized in experiments, confirming the applicability of the theories to realistic experimental situations. These studies have led to not only the improved fundamental understanding of non-equilibrium processes in quantum systems, but also suggested entirely different venues for developing quantum technologies.
Wu, Wei; Wang, Jin
2013-09-28
found to be a Lyapunov functional of the deterministic spatially dependent system. Therefore, the intrinsic potential landscape can characterize the global stability of the deterministic system. The relative entropy functional of the stochastic spatially dependent non-equilibrium system is found to be the Lyapunov functional of the stochastic dynamics of the system. Therefore, the relative entropy functional quantifies the global stability of the stochastic system with finite fluctuations. Our theory offers an alternative general approach to other field-theoretic techniques, to study the global stability and dynamics of spatially dependent non-equilibrium field systems. It can be applied to many physical, chemical, and biological spatially dependent non-equilibrium systems.
Non-equilibrium plasma experiments at The Pennsylvania State University
Knecht, Sean; Bilen, Sven; Micci, Michael
2013-10-01
The authors have recently established the capability at The Pennsylvania State University to generate non-equilibrium plasma in atmospheric-pressure air and liquids such as water and saline. The plasma is generated using a high-voltage pulser (Pacific-Electronics PT-55), which is capable of voltage pulses of 75-ns width, peak voltage >50 kV, with rise-times on the order of nanoseconds. The electrodes are tungsten wires of various diameters (50 μm, 175 μm, 254 μm) insulated with nylon tubing. The spacing of the electrodes is controlled with translating mounts with resolution of tens of microns. Spectroscopy (Ocean Optics Model HR2000) is presently used for line identification only. Current and voltage vs. time will be measured with a 500-MHz bandwidth oscilloscope, a high-voltage probe and a shunt resistor connected to the ground side of the circuit. Research directions presently being pursued include the effects of solution electrical conductivity on plasma production and propellant ignition studies. Data from several types of experiments will be presented.
Non-Equilibrium Properties from Equilibrium Free Energy Calculations
Pohorille, Andrew; Wilson, Michael A.
2012-01-01
Calculating free energy in computer simulations is of central importance in statistical mechanics of condensed media and its applications to chemistry and biology not only because it is the most comprehensive and informative quantity that characterizes the eqUilibrium state, but also because it often provides an efficient route to access dynamic and kinetic properties of a system. Most of applications of equilibrium free energy calculations to non-equilibrium processes rely on a description in which a molecule or an ion diffuses in the potential of mean force. In general case this description is a simplification, but it might be satisfactorily accurate in many instances of practical interest. This hypothesis has been tested in the example of the electrodiffusion equation . Conductance of model ion channels has been calculated directly through counting the number of ion crossing events observed during long molecular dynamics simulations and has been compared with the conductance obtained from solving the generalized Nernst-Plank equation. It has been shown that under relatively modest conditions the agreement between these two approaches is excellent, thus demonstrating the assumptions underlying the diffusion equation are fulfilled. Under these conditions the electrodiffusion equation provides an efficient approach to calculating the full voltage-current dependence routinely measured in electrophysiological experiments.
Thermal non-equilibrium in heterogeneous media
de Lemos, Marcelo J S
2016-01-01
This book presents, in a self-contained fashion, a series of studies on flow and heat transfer in porous media, in which distinct energy balances are considered for the porous matrix and for the permeating fluid. Detailed mathematical modeling is presented considering both volume and time averaging operators simultaneously applied to the governing equations. System involving combustion in the gaseous phase, moving bed and double-diffusion mechanism are analyzed. Numerical results are presented for each case. In the end, this book contains the description of a tool that might benefit engineers in developing and designing more efficient thermal equipment.
Free energy for non-equilibrium quasi-stationary states
Allahverdyan, A. E.; Martirosyan, N. H.
2017-03-01
We study a class of non-equilibrium quasi-stationary states for a Markov system interacting with two different thermal baths. We show that the work done under a slow, external change of parameters admits a potential, i.e., the free energy. Three conditions are needed for the existence of free energy in this non-equilibrium system: time-scale separation between variables of the system, partial controllability (external fields couple only with the slow variable), and an effective detailed balance. These conditions are facilitated in the continuous limit for the slow variable. In contrast to its equilibrium counterpart, the non-equilibrium free energy can increase with temperature. One example of this is that entropy reduction by means of external fields (cooling) can be easier (in the sense of the work cost) if it starts from a higher temperature.
Electrolytes supramolecular interactions and non-equilibrium phenomena in concentrated solutions
Aseyev, Georgii Georgievich
2014-01-01
Electrolyte solutions play a key role in traditional chemical industry processes as well as other sciences such as hydrometallurgy, geochemistry, and crystal chemistry. Knowledge of electrolyte solutions is also key in oil and gas exploration and production, as well as many other environmental engineering endeavors. Until recently, a gap existed between the electrolyte solution theory dedicated to diluted solutions, and the theory, practice, and technology involving concentrated solutions.Electrolytes: Supramolecular Interactions and Non-Equilibrium Phenomena in Concentrated Solutions addresse
Landscape and flux theory of non-equilibrium open economy
Zhang, Kun; Wang, Jin
2017-09-01
The economy is open and never in true equilibrium due to the exchanges with outside. However, most of the quantitative studies have been focused on the equilibrium economy. Despite of the recent efforts, it is still challenging to formulate a quantitative theory for uncovering the principles of non-equilibrium open economy. In this study, we developed a landscape and flux theory for non-equilibrium economy. We quantified the states of economy and identify the multi-stable states as the basins of attractions on the underlying landscape. We found the global driving force of the non-equilibrium economy is determined by both the underlying landscape gradient and the curl probability flux measuring the degree of non-equilibriumness through the detailed balance breaking. The non-equilibrium thermodynamics, the global stability, the optimal path and speed of the non-equilibrium economy can be formulated and quantified. In the conventional economy, the supply and demand usually has only one equilibrium. By considering nonlinear supply-demand dynamics, we found that both bi-stable states and limit cycle oscillations can emerge. By shifting the slope of demand curve, we can see how the bi-stability transforms to the limit cycle dynamics and vice versa. By parallel shifting the demand curve, we can also see how the monopoly, the competition, and the bistable monopoly and competition states emerge and transform to one other. We can also see how the mono-stable monopoly, the limit cycle and the mono-stable competition states emerge and transform to one another.
Rheology modulated non-equilibrium fluctuations in time-dependent diffusion processes
Maity, Debonil; Bandopadhyay, Aditya; Chakraborty, Suman
2016-11-01
The effect of non-Newtonian rheology, manifested through a viscoelastic linearized Maxwell model, on the time-dependent non-equilibrium concentration fluctuations due to free diffusion as well as thermal diffusion of a species is analyzed theoretically. Contrary to the belief that non-equilibrium Rayleigh line is not influenced by viscoelastic effects, through rigorous calculations, we put forward the fact that viscoelastic effects do influence the non-equilibrium Rayleigh line, while the effects are absent for the equilibrium scenario. The non-equilibrium process is quantified through the concentration fluctuation auto-correlation function, also known as the structure factor. The analysis reveals that the effect of rheology is prominent for both the cases of free diffusion and thermal diffusion at long times, where the influence of rheology dictates not only the location of the peaks in concentration dynamic structure factors, but also the magnitudes; such peaks in dynamic structure factors are absent in the case of Newtonian fluid. At smaller times, for the case of free diffusion, presence of time-dependent peak(s) are observed, which are weakly dependent on the influence of rheology, a phenomenon which is absent in the case of thermal diffusion. Different regimes of the frequency dependent overall dynamic structure factor, depending on the interplay of the fluid relaxation time and momentum diffusivity, are evaluated. The static structure factor is not affected to a great extent for the case of free-diffusion and is unaffected for the case of thermal diffusion.
Convection with local thermal non-equilibrium and microfluidic effects
Straughan, Brian
2015-01-01
This book is one of the first devoted to an account of theories of thermal convection which involve local thermal non-equilibrium effects, including a concentration on microfluidic effects. The text introduces convection with local thermal non-equilibrium effects in extraordinary detail, making it easy for readers newer to the subject area to understand. This book is unique in the fact that it addresses a large number of convection theories and provides many new results which are not available elsewhere. This book will be useful to researchers from engineering, fluid mechanics, and applied mathematics, particularly those interested in microfluidics and porous media.
Introduction to non-equilibrium quantum statistical mechanics
Aschbacher, W; Pautrat, Y; Pillet, C A
2005-01-01
These notes are an expanded version of the lectures given by the second and fourth autor in the summer school "Open Quantum System" held in Grenoble, June 16-July 4, 2003. They provide an introduction to recent developments in non-equilibrium statistical mechanics of open quantum systems, including a completely worked out (simple) example. We discuss non-equilibrium steady states (NESS) and their structural properties, entropy production, linear response theory and weak coupling limit. The emphasis is on Ruelle's scattering approach to the construction of NESS.
Topics in non-equilibrium quantum statistical mechanics
Aschbacher, W; Pautrat, Y; Pillet, C
2005-01-01
These notes are an expanded and revised version of the lectures given by the second and fourth autor in the summer school "Open Quantum System" held in Grenoble, June 16-July 4, 2003. They provide an introduction to recent developments in non-equilibrium statistical mechanics of open quantum systems, including a completely worked out (simple) example. We discuss non-equilibrium steady states (NESS) and their structural properties, entropy production, linear response theory and weak coupling limit. The emphasis is on Ruelle's scattering approach to the construction of NESS.
Bright solitons in non-equilibrium coherent quantum matter.
Pinsker, F; Flayac, H
2016-01-01
We theoretically demonstrate a mechanism for bright soliton generation in spinor non-equilibrium Bose-Einstein condensates made of atoms or quasi-particles such as polaritons in semiconductor microcavities. We give analytical expressions for bright (half) solitons as minimizing functions of a generalized non-conservative Lagrangian elucidating the unique features of inter and intra-competition in non-equilibrium systems. The analytical results are supported by a detailed numerical analysis that further shows the rich soliton dynamics inferred by their instability and mutual cross-interactions.
A Characterization of Conserved Quantities in Non-Equilibrium Thermodynamics
Directory of Open Access Journals (Sweden)
Ignacio Romero
2013-12-01
Full Text Available The well-known Noether theorem in Lagrangian and Hamiltonian mechanics associates symmetries in the evolution equations of a mechanical system with conserved quantities. In this work, we extend this classical idea to problems of non-equilibrium thermodynamics formulated within the GENERIC (General Equations for Non-Equilibrium Reversible-Irreversible Coupling framework. The geometric meaning of symmetry is reviewed in this formal setting and then utilized to identify possible conserved quantities and the conditions that guarantee their strict conservation. Examples are provided that demonstrate the validity of the proposed definition in the context of finite and infinite dimensional thermoelastic problems.
Non-equilibrium critical behavior of thin Ising films
Medvedeva, Maria A.; Prudnikov, Pavel V.; Elin, Alexey S.
2017-10-01
In this paper we study the non-equilibrium properties of Ising ferromagnetic films using Monte Carlo simulations by short-time dynamic method. We have found thickness dependency of critical exponents z, θ ‧ and β / ν . Ageing effects were observed in non-equilibrium critical behavior. Former was carried out both from high-temperature and low-temperature initial states. A characteristic time of relaxation, which diverges at a transition temperature in the thermodynamic limit, is obtained as a function of the system size and waiting time.
Fluctuations and large deviations in non-equilibrium systems
Indian Academy of Sciences (India)
For systems in contact with two reservoirs at different densities or with two thermostats at different temperatures, the large deviation function of the density gives a possible way of extending the notion of free energy to non-equilibrium systems. This large deviation function of the density can be calculated explicitly for ...
Fluctuations and large deviations in non-equilibrium systems
Indian Academy of Sciences (India)
systems. Keywords. Non-equilibrium systems; large deviations; current fluctuations. PACS Nos 02.50.-r; 05.40.-a; 05.70.Ln; 82.20.-w. 1. Introduction. The goal of this talk is to give a short review on results [1–8] obtained recently on the steady .... binary variable indicating whether site i is occupied or empty, the time evolution.
Ge, Hao; Qian, Hong
2011-01-06
A theory for an non-equilibrium phase transition in a driven biochemical network is presented. The theory is based on the chemical master equation (CME) formulation of mesoscopic biochemical reactions and the mathematical method of large deviations. The large deviations theory provides an analytical tool connecting the macroscopic multi-stability of an open chemical system with the multi-scale dynamics of its mesoscopic counterpart. It shows a corresponding non-equilibrium phase transition among multiple stochastic attractors. As an example, in the canonical phosphorylation-dephosphorylation system with feedback that exhibits bistability, we show that the non-equilibrium steady-state (NESS) phase transition has all the characteristics of classic equilibrium phase transition: Maxwell construction, a discontinuous first-derivative of the 'free energy function', Lee-Yang's zero for a generating function and a critical point that matches the cusp in nonlinear bifurcation theory. To the biochemical system, the mathematical analysis suggests three distinct timescales and needed levels of description. They are (i) molecular signalling, (ii) biochemical network nonlinear dynamics, and (iii) cellular evolution. For finite mesoscopic systems such as a cell, motions associated with (i) and (iii) are stochastic while that with (ii) is deterministic. Both (ii) and (iii) are emergent properties of a dynamic biochemical network.
Numerical Simulation of Non-Equilibrium Two-Phase Wet Steam Flow through an Asymmetric Nozzle
Directory of Open Access Journals (Sweden)
Miah Md Ashraful Alam
2017-11-01
Full Text Available The present study reported of the numerical investigation of a high-speed wet steam flow through an asymmetric nozzle. The spontaneous non-equilibrium homogeneous condensation of wet steam was numerically modeled based on the classical nucleation theory and droplet growth rate equation combined with the field conservations within the computational fluid dynamics (CFD code of ANSYS Fluent 13.0. The equations describing droplet formations and interphase change were solved sequentially after solving the main flow conservation equations. The calculations were carried out assuming the flow two-dimensional, compressible, turbulent, and viscous. The SST k-ω model was used for modeling the turbulence within an unstructured mesh solver. The validation of numerical model was accomplished, and the results showed a good agreement between the numerical simulation and experimental data. The effect of spontaneous non-equilibrium condensation on the jet and shock structures was revealed, and the condensation shown a great influence on the jet structure.
Dyke, J. G.; Gans, F.; Kleidon, A.
2011-06-01
Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life's ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes.
Directory of Open Access Journals (Sweden)
J. G. Dyke
2011-06-01
Full Text Available Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life's ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes.
Global dynamics of non-equilibrium gliding in animals.
Yeaton, Isaac J; Socha, John J; Ross, Shane D
2017-03-17
Gliding flight-moving horizontally downward through the air without power-has evolved in a broad diversity of taxa and serves numerous ecologically relevant functions such as predator escape, expanding foraging locations, and finding mates, and has been suggested as an evolutionary pathway to powered flight. Historically, gliding has been conceptualized using the idealized conditions of equilibrium, in which the net aerodynamic force on the glider balances its weight. While this assumption is appealing for its simplicity, recent studies of glide trajectories have shown that equilibrium gliding is not the norm for most species. Furthermore, equilibrium theory neglects the aerodynamic differences between species, as well as how a glider can modify its glide path using control. To investigate non-equilibrium glide behavior, we developed a reduced-order model of gliding that accounts for self-similarity in the equations of motion, such that the lift and drag characteristics alone determine the glide trajectory. From analysis of velocity polar diagrams of horizontal and vertical velocity from several gliding species, we find that pitch angle, the angle between the horizontal and chord line, is a control parameter that can be exploited to modulate glide angle and glide speed. Varying pitch results in changing locations of equilibrium glide configurations in the velocity polar diagram that govern passive glide dynamics. Such analyses provide a new mechanism of interspecies comparison and tools to understand experimentally-measured kinematics data and theory. In addition, this analysis suggests that the lift and drag characteristics of aerial and aquatic autonomous gliders can be engineered to passively alter glide trajectories with minimal control effort.
Stochastic relaxational dynamics applied to finance: towards non-equilibrium option pricing theory
Otto, Matthias
1999-01-01
Non-equilibrium phenomena occur not only in physical world, but also in finance. In this work, stochastic relaxational dynamics (together with path integrals) is applied to option pricing theory. A recently proposed model (by Ilinski et al.) considers fluctuations around this equilibrium state by introducing a relaxational dynamics with random noise for intermediate deviations called ``virtual'' arbitrage returns. In this work, the model is incorporated within a martingale pricing method for ...
Measurement of Radiative Non-Equilibrium for Air Shocks Between 7-9 Km/s
Cruden, Brett A.; Brandis, Aaron M.
2016-01-01
This paper describes a recent characterization of non-equilibrium radiation for shock speeds between 7 and 9 km/s in the NASA Ames Electric Arc Shock Tube (EAST) Facility. Data is spectrally resolved from 190- 1450 nm and spatially resolved behind the shock front. Comparisons are made to DPLR/NEQAIR simulations using different modeling options and recommendations for future study are made based on these comparisons.
Non-equilibrium statistical physics with application to disordered systems
Cáceres, Manuel Osvaldo
2017-01-01
This textbook is the result of the enhancement of several courses on non-equilibrium statistics, stochastic processes, stochastic differential equations, anomalous diffusion and disorder. The target audience includes students of physics, mathematics, biology, chemistry, and engineering at undergraduate and graduate level with a grasp of the basic elements of mathematics and physics of the fourth year of a typical undergraduate course. The little-known physical and mathematical concepts are described in sections and specific exercises throughout the text, as well as in appendices. Physical-mathematical motivation is the main driving force for the development of this text. It presents the academic topics of probability theory and stochastic processes as well as new educational aspects in the presentation of non-equilibrium statistical theory and stochastic differential equations.. In particular it discusses the problem of irreversibility in that context and the dynamics of Fokker-Planck. An introduction on fluc...
Energy Technology Data Exchange (ETDEWEB)
Coppola, C. M.; Longo, S. [Dipartimento di Chimica, Universita degli Studi di Bari, Via Orabona 4, I-70126 Bari (Italy); D' Introno, R. [Dipartimento di Fisica, Universita degli Studi di Bari, Via Amendola 173, I-70126 Bari (Italy); Galli, D. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Tennyson, J., E-mail: carla.coppola@chimica.uniba.it [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
2012-03-01
Energy exchange processes play a crucial role in the early universe, affecting the thermal balance and the dynamical evolution of the primordial gas. In the present work we focus on the consequences of a non-thermal distribution of the level populations of H{sub 2}: first, we determine the excitation temperatures of vibrational transitions and the non-equilibrium heat transfer; second, we compare the modifications to chemical reaction rate coefficients with respect to the values obtained assuming local thermodynamic equilibrium; and third, we compute the spectral distortions to the cosmic background radiation generated by the formation of H{sub 2} in vibrationally excited levels. We conclude that non-equilibrium processes cannot be ignored in cosmological simulations of the evolution of baryons, although their observational signatures remain below current limits of detection. New fits to the equilibrium and non-equilibrium heat transfer functions are provided.
Non-equilibrium thermal entanglement for a three spin chain
Pumulo, N.; Sinayskiy, I.; Petruccione, F.
2011-08-01
The dynamics of a chain of three spins coupled at both ends to separate bosonic baths at different temperatures is studied. An exact analytical solution of the master equation in the Born-Markov approximation for the reduced density matrix of the chain is constructed. It is shown that for long times the reduced density matrix converges to the non-equilibrium steady state. Dynamical and steady state properties of the concurrence between the first and the last spin are studied.
Kawakatsu, T.; Matsuyama, A.; Ohta, T.; Tanaka, H.; Tanaka, S.
2011-07-01
, Culture, Sports, Science and Technology (MEXT) of Japan. We thank those who contributed to this symposium as well as members of the 'Soft Matter Physics' project for their valuable discussions and collaborations. Non-equilibrium soft matter contents Insights on raft behavior from minimal phenomenological models G Garbès Putzel and M Schick Dynamical membrane curvature instability controlled by intermonolayer friction Anne-Florence Bitbol, Jean-Baptiste Fournier, Miglena I Angelova and Nicolas Puff Numerical investigations of the dynamics of two-component vesicles Takashi Taniguchi, Miho Yanagisawa and Masayuki Imai Asymmetric distribution of cone-shaped lipids in a highly curved bilayer revealed by a small angle neutron scattering technique Y Sakuma, N Urakami, T Taniguchi and M Imai Hydration, phase separation and nonlinear rheology of temperature-sensitive water-soluble polymers Fumihiko Tanaka, Tsuyoshi Koga, Isamu Kaneda and Françoise M Winnik Morphology and rheology of an immiscible polymer blend subjected to a step electric field under shear flow H Orihara, Y Nishimoto, K Aida, Y H Na, T Nagaya and S Ujiie Surfactant-induced friction reduction for hydrogels in the boundary lubrication regime Kosuke Kamada, Hidemitsu Furukawa, Takayuki Kurokawa, Tomohiro Tada, Taiki Tominaga, Yukihiro Nakano and Jian Ping Gong Fabrication and structural analysis of polyrotaxane fibers and films Yasuhiro Sakai, Kentaro Ueda, Naoya Katsuyama, Koji Shimizu, Shunya Sato, Jun Kuroiwa, Jun Araki, Akira Teramoto, Koji Abe, Hideaki Yokoyama and Kohzo Ito Micellization kinetics of diblock copolymers in a homopolymer matrix: a self-consistent field study Raghuram Thiagarajan and David C Morse Hierarchical self-assembly of two-length-scale multiblock copolymers Gerrit ten Brinke, Katja Loos, Ivana Vukovic and Gerrit Gobius du Sart Kaleidoscopic morphologies from ABC star-shaped terpolymers Yushu Matsushita, Kenichi Hayashida, Tomonari Dotera and Atsushi Takano Direct and inverted nematic
Theoretical investigation of shock stand-off distance for non-equilibrium flows over spheres
Shen, Hua
2018-02-20
We derived a theoretical solution of the shock stand-off distance for a non-equilibrium flow over spheres based on Wen and Hornung’s solution and Olivier’s solution. Compared with previous approaches, the main advantage of the present approach is allowing an analytic solution without involving any semi-empirical parameter for the whole non-equilibrium flow regimes. The effects of some important physical quantities therefore can be fully revealed via the analytic solution. By combining the current solution with Ideal Dissociating Gas (IDG) model, we investigate the effects of free stream kinetic energy and free stream dissociation level (which can be very different between different facilities) on the shock stand-off distance.
Comparative study of theoretical methods for non-equilibrium quantum transport
Energy Technology Data Exchange (ETDEWEB)
Eckel, J; Thorwart, M [Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs-Universitaet Freiburg, 79104 Freiburg (Germany); Heidrich-Meisner, F [Department of Physics, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitaet Muenchen, D-80333 Muenchen (Germany); Jakobs, S G; Pletyukhov, M [Institut fuer Theoretische Physik A, RWTH Aachen, 52056 Aachen (Germany); Egger, R, E-mail: eckelj@thphy.uni-duesseldorf.d [Institut fuer Theoretische Physik, Heinrich-Heine-Universitaet Duesseldorf, 40225 Duesseldorf (Germany)
2010-04-15
We present a detailed comparison of three different methods designed to tackle non-equilibrium quantum transport, namely the functional renormalization group (fRG), the time-dependent density matrix renormalization group (tDMRG) and the iterative summation of real-time path integrals (ISPI). For the non-equilibrium single-impurity Anderson model (including a Zeeman term at the impurity site), we demonstrate that the three methods are in quantitative agreement over a wide range of parameters at the particle-hole symmetric point as well as in the mixed-valence regime. We further compare these techniques with two quantum Monte Carlo approaches and the time-dependent numerical renormalization group method.
Optimal response to non-equilibrium disturbances under truncated Burgers-Hopf dynamics
Thalabard, Simon; Turkington, Bruce
2017-04-01
We model and compute the average response of truncated Burgers-Hopf dynamics to finite perturbations away from the Gibbs equipartition energy spectrum using a dynamical optimization framework recently conceptualized in a series of papers. Non-equilibrium averages are there approximated in terms of geodesic paths in probability space that ‘best-fit’ the Liouvillean dynamics over a family of quasi-equilibrium trial densities. By recasting the geodesic principle as an optimal control problem, we solve numerically for the non-equilibrium responses using an augmented Lagrangian, non-linear conjugate gradient descent method. For moderate perturbations, we find an excellent agreement between the optimal predictions and the direct numerical simulations of the truncated Burgers-Hopf dynamics. In this near-equilibrium regime, we argue that the optimal response theory provides an approximate yet predictive counterpart to fluctuation-dissipation identities.
Role of non-equilibrium conformations on driven polymer translocation.
Katkar, H H; Muthukumar, M
2018-01-14
constant effective velocity of translocation, it is found that for flexible (ssDNA and synthetic) polymers with NK Kuhn segments, the condition ⟨τ⟩/NK equilibrium to non-equilibrium behavior would occur at NK ∼ O(1000).
Dynamical Detailed Balance and Local Kms Condition for Non-Equilibrium States
Accardi, Luigi; Imafuku, Kentaro
The principle of detailed balance is at the basis of equilibrium physics and is equivalent to the Kubo-Martin-Schwinger (KMS) condition (under quite general assumptions). In the present paper we prove that a large class of non-equilibrium quantum systems satisfies a dynamical generalization of the detailed balance condition (dynamical detailed balance) expressing the fact that all the micro-currents, associated to the Bohr frequencies are constant. The usual (equilibrium) detailed balance condition is characterized by the property that this constant is identically zero. From this we deduce a simple and experimentally measurable relation expressing the microcurrent associated to a transition between two levels ɛm→ɛn as a linear combination of the occupation probabilities of the two levels, with coefficients given by the generalized susceptivities (transport coefficients). We then give a second characterization of the dynamical detailed balance condition using a master equation rather than the microcurrents. Finally we show that these two conditions are equivalent to a "local" generalization of the usual KMS condition. Summing up: rather than postulating some ansatz on the basis of phenomenological models or of numerical simulations, we deduce, directly in the quantum domain and from fundamental principles, some natural and simple non equilibrium generalizations of the three main characterizations of equilibrium states. Then we prove that these three, apparently very far, conditions are equivalent. These facts support our convinction that these three equivalent conditions capture a universal aspect of non equilibrium phenomena.
Non-equilibrium condensation of supercritical carbon dioxide in a converging-diverging nozzle
Ameli, Alireza; Afzalifar, Ali; Turunen-Saaresti, Teemu
2017-03-01
Carbon dioxide (CO2) is a promising alternative as a working fluid for future energy conversion and refrigeration cycles. CO2 has low global warming potential compared to refrigerants and supercritical CO2 Brayton cycle ought to have better efficiency than today’s counter parts. However, there are several issues concerning behaviour of supercritical CO2 in aforementioned applications. One of these issues arises due to non-equilibrium condensation of CO2 for some operating conditions in supercritical compressors. This paper investigates the non-equilibrium condensation of carbon dioxide in the course of an expansion from supercritical stagnation conditions in a converging-diverging nozzle. An external look-up table was implemented, using an in-house FORTRAN code, to calculate the fluid properties in supercritical, metastable and saturated regions. This look-up table is coupled with the flow solver and the non-equilibrium condensation model is introduced to the solver using user defined expressions. Numerical results are compared with the experimental measurements. In agreement with the experiment, the distribution of Mach number in the nozzle shows that the flow becomes supersonic in upstream region near the throat where speed of sound is minimum also the equilibrium reestablishment occurs at the outlet boundary condition.
Physical mechanism for biopolymers to aggregate and maintain in non-equilibrium states.
Ma, Wen-Jong; Hu, Chin-Kun
2017-06-08
Many human or animal diseases are related to aggregation of proteins. A viable biological organism should maintain in non-equilibrium states. How protein aggregate and why biological organisms can maintain in non-equilibrium states are not well understood. As a first step to understand such complex systems problems, we consider simple model systems containing polymer chains and solvent particles. The strength of the spring to connect two neighboring monomers in a polymer chain is controlled by a parameter s with s → ∞ for rigid-bond. The strengths of bending and torsion angle dependent interactions are controlled by a parameter s A with s A → -∞ corresponding to no bending and torsion angle dependent interactions. We find that for very small s A , polymer chains tend to aggregate spontaneously and the trend is independent of the strength of spring. For strong springs, the speed distribution of monomers in the parallel (along the direction of the spring to connect two neighboring monomers) and perpendicular directions have different effective temperatures and such systems are in non-equilibrium states.
Nayak, B.; Menon, S. V. G.
2017-04-01
A generalized enthalpy-based equation of state, which includes thermal electron excitations and non-equilibrium thermal energies, is formulated for binary solid and porous mixtures. Our approach gives rise to an extra contribution to mixture volume, in addition to those corresponding to average mixture parameters. This excess term involves the difference of thermal enthalpies of the two components, which depend on their individual temperatures. We propose to use the Hugoniot of the components to compute non-equilibrium temperatures in the mixture. These are then compared with the average temperature obtained from the mixture Hugoniot, thereby giving an estimate of non-equilibrium effects. The Birch-Murnaghan model for the zero-temperature isotherm and a linear thermal model are then used for applying the method to several mixtures, including one porous case. Comparison with experimental data on the pressure-volume Hugoniot and shock speed versus particle speed shows good agreement.
Non-equilibrium steady state in the hydro regime
Energy Technology Data Exchange (ETDEWEB)
Pourhasan, Razieh [Science Institute, University of Iceland,Dunhaga 5, 107 Reykjavik (Iceland)
2016-02-01
We study the existence and properties of the non-equilibrium steady state which arises by putting two copies of systems at different temperatures into a thermal contact. We solve the problem for the relativistic systems that are described by the energy-momentum of a perfect hydro with general equation of state (EOS). In particular, we examine several simple examples: a hydro with a linear EOS, a holographic CFT perturbed by a relevant operator and a barotropic fluid, i.e., P=P(E). Our studies suggest that the formation of steady state is a universal result of the hydro regime regardless of the kind of fluid.
Exploiting non-equilibrium phase separation for self-assembly.
Grünwald, Michael; Tricard, Simon; Whitesides, George M; Geissler, Phillip L
2016-02-07
Demixing can occur in systems of two or more particle species that experience different driving forces, e.g., mixtures of self-propelled active particles or of oppositely charged colloids subject to an electric field. Here we show with macroscopic experiments and computer simulations that the forces underlying such non-equilibrium segregation can be used to control the self-assembly of particles that lack attractive interactions. We demonstrate that, depending on the direction, amplitude and frequency of a periodic external force acting on one particle species, the structures formed by a second, undriven species can range from compact clusters to elongated, string-like patterns.
Non-equilibrium Kondo effect in double quantum dot
Energy Technology Data Exchange (ETDEWEB)
Kiselev, M.N. E-mail: kiselev@physik.uni-wuerzburg.de; Kikoin, K.A.; Molenkamp, L.W
2004-05-01
We investigate theoretically a non-equilibrium transport through a double quantum dot (DQD) in a parallel geometry. It is shown that the resonance Kondo tunneling through a parallel DQD with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the renormalization group technique we derive scaling equations and calculate the differential conductance as a function of an auxiliary DC-bias for parallel DQD being in a regime described by SO(4) symmetry.
Non-equilibrium temperature of well-developed quantum turbulence
Energy Technology Data Exchange (ETDEWEB)
Jou, D. [Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Mongiovi, M.S., E-mail: mongiovi@unipa.i [Dipartimento di Metodi e Modelli Matematici, Universita di Palermo, Facolta di Ingegneria, Viale delle Scienze, 90128 Palermo (Italy)
2009-06-22
A non-equilibrium effective temperature of quantum vortex tangles is defined as the average energy of closed vortex loops. The resulting thermodynamic expressions for the entropy and the energy in terms of the temperature of the tangle are confirmed by a microscopic analysis based on a potential distribution function for the length of vortex loops. Furthermore, these expressions for the entropy and energy in terms of temperature are analogous to those of black holes: this may be of interest for establishing further connections between topological defects in superfluids and cosmology.
Non-equilibrium dynamics of isolated quantum systems
Directory of Open Access Journals (Sweden)
Calabrese Pasquale
2015-01-01
Full Text Available The non-equilibrium dynamics of isolated quantum systems represent a theoretical and experimental challenge raising many fundamental questions with applications to different fields of modern physics. In these proceedings, we briefly review some of the recent findings on the subject, with particular emphasis to the existence of stationary expectation values of local observables and to their statistical mechanics description. It turns out that the appropriate statistical ensemble describing these asymptotic values depends on whether the Hamiltonian governing the time evolution is integrable or not.
Shape characteristics of equilibrium and non-equilibrium fractal clusters.
Mansfield, Marc L; Douglas, Jack F
2013-07-28
It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other
Nagarajan, Ramanathan
2015-07-01
Micelles generated in water from most amphiphilic block copolymers are widely recognized to be non-equilibrium structures. Typically, the micelles are prepared by a kinetic process, first allowing molecular scale dissolution of the block copolymer in a common solvent that likes both the blocks and then gradually replacing the common solvent by water to promote the hydrophobic blocks to aggregate and create the micelles. The non-equilibrium nature of the micelle originates from the fact that dynamic exchange between the block copolymer molecules in the micelle and the singly dispersed block copolymer molecules in water is suppressed, because of the glassy nature of the core forming polymer block and/or its very large hydrophobicity. Although most amphiphilic block copolymers generate such non-equilibrium micelles, no theoretical approach to a priori predict the micelle characteristics currently exists. In this work, we propose a predictive approach for non-equilibrium micelles with glassy cores by applying the equilibrium theory of micelles in two steps. In the first, we calculate the properties of micelles formed in the mixed solvent while true equilibrium prevails, until the micelle core becomes glassy. In the second step, we freeze the micelle aggregation number at this glassy state and calculate the corona dimension from the equilibrium theory of micelles. The condition when the micelle core becomes glassy is independently determined from a statistical thermodynamic treatment of diluent effect on polymer glass transition temperature. The predictions based on this "non-equilibrium" model compare reasonably well with experimental data for polystyrene-polyethylene oxide diblock copolymer, which is the most extensively studied system in the literature. In contrast, the application of the equilibrium model to describe such a system significantly overpredicts the micelle core and corona dimensions and the aggregation number. The non-equilibrium model suggests ways to
Kreula, J. M.; Clark, S. R.; Jaksch, D.
2016-09-01
We propose a non-linear, hybrid quantum-classical scheme for simulating non-equilibrium dynamics of strongly correlated fermions described by the Hubbard model in a Bethe lattice in the thermodynamic limit. Our scheme implements non-equilibrium dynamical mean field theory (DMFT) and uses a digital quantum simulator to solve a quantum impurity problem whose parameters are iterated to self-consistency via a classically computed feedback loop where quantum gate errors can be partly accounted for. We analyse the performance of the scheme in an example case.
Understanding Non-equilibrium Thermodynamics Foundations, Applications, Frontiers
Jou, David; Lebon, Georgy
2007-01-01
This book offers a homogeneous presentation of the many faces of non-equilibrium thermodynamics. The first part is devoted to a description of the nowadays thermodynamic formalism recognized as the classical theory of non-equilibrium processes. This part of the book may serve as a basis to an introductory course dedicated to first-year graduate students in sciences and engineering. The classical description can however not be complete, as it rests on the hypothesis of local equilibrium. This has fostered the development of many theories going beyond local equilibrium and which cannot be put aside. The second part of the book is concerned with these different approaches, and will be of special interest for PhD students and researchers. For the sake of homogeneity, the authors have used the general structure and methods presented in the first part. Indeed, besides their differences, all these formalisms are not closed boxes but present some overlappings and parallelisms which are emphasized in this book. For pe...
Non-Equilibrium Solidification of Undercooled Metallic Melts
Directory of Open Access Journals (Sweden)
Dieter M. Herlach
2014-06-01
Full Text Available If a liquid is undercooled below its equilibrium melting temperature an excess Gibbs free energy is created. This gives access to solidification of metastable solids under non-equilibrium conditions. In the present work, techniques of containerless processing are applied. Electromagnetic and electrostatic levitation enable to freely suspend a liquid drop of a few millimeters in diameter. Heterogeneous nucleation on container walls is completely avoided leading to large undercoolings. The freely suspended drop is accessible for direct observation of rapid solidification under conditions far away from equilibrium by applying proper diagnostic means. Nucleation of metastable crystalline phases is monitored by X-ray diffraction using synchrotron radiation during non-equilibrium solidification. While nucleation preselects the crystallographic phase, subsequent crystal growth controls the microstructure evolution. Metastable microstructures are obtained from deeply undercooled melts as supersaturated solid solutions, disordered superlattice structures of intermetallics. Nucleation and crystal growth take place by heat and mass transport. Comparative experiments in reduced gravity allow for investigations on how forced convection can be used to alter the transport processes and design materials by using undercooling and convection as process parameters.
Non-equilibrium thermodynamics of harmonically trapped bosons
Ángel García-March, Miguel; Fogarty, Thomás; Campbell, Steve; Busch, Thomas; Paternostro, Mauro
2016-10-01
We apply the framework of non-equilibrium quantum thermodynamics to the physics of quenched small-sized bosonic quantum gases in a one-dimensional harmonic trap. We show that dynamical orthogonality can occur in these few-body systems with strong interactions after a quench and we find its occurrence analytically for an infinitely repulsive pair of atoms. We further show this phenomena is related to the fundamental excitations that dictate the dynamics from the spectral function. We establish a clear qualitative link between the amount of (irreversible) work performed on the system and the establishment of entanglement. We extend our analysis to multipartite systems by examining the case of three trapped atoms. We show the initial (pre-quench) interactions play a vital role in determining the dynamical features, while the qualitative features of the two particle case appear to remain valid. Finally, we propose the use of the atomic density profile as a readily accessible indicator of the non-equilibrium properties of the systems in question.
Turbulence as a Problem in Non-equilibrium Statistical Mechanics
Goldenfeld, Nigel; Shih, Hong-Yan
2017-05-01
The transitional and well-developed regimes of turbulent shear flows exhibit a variety of remarkable scaling laws that are only now beginning to be systematically studied and understood. In the first part of this article, we summarize recent progress in understanding the friction factor of turbulent flows in rough pipes and quasi-two-dimensional soap films, showing how the data obey a two-parameter scaling law known as roughness-induced criticality, and exhibit power-law scaling of friction factor with Reynolds number that depends on the precise form of the nature of the turbulent cascade. These results hint at a non-equilibrium fluctuation-dissipation relation that applies to turbulent flows. The second part of this article concerns the lifetime statistics in smooth pipes around the transition, showing how the remarkable super-exponential scaling with Reynolds number reflects deep connections between large deviation theory, extreme value statistics, directed percolation and the onset of coexistence in predator-prey ecosystems. Both these phenomena reflect the way in which turbulence can be fruitfully approached as a problem in non-equilibrium statistical mechanics.
Liu, Hui; Chen, Fu; Sun, Huiyong; Li, Dan; Hou, Tingjun
2017-04-11
By means of estimators based on non-equilibrium work, equilibrium free energy differences or potentials of mean force (PMFs) of a system of interest can be computed from biased molecular dynamics (MD) simulations. The approach, however, is often plagued by slow conformational sampling and poor convergence, especially when the solvent effects are taken into account. Here, as a possible way to alleviate the problem, several widely used implicit-solvent models, which are derived from the analytic generalized Born (GB) equation and implemented in the AMBER suite of programs, were employed in free energy calculations based on non-equilibrium work and evaluated for their abilities to emulate explicit water. As a test case, pulling MD simulations were carried out on an alanine polypeptide with different solvent models and protocols, followed by comparisons of the reconstructed PMF profiles along the unfolding coordinate. The results show that when employing the non-equilibrium work method, sampling with an implicit-solvent model is several times faster and, more importantly, converges more rapidly than that with explicit water due to reduction of dissipation. Among the assessed GB models, the Neck variants outperform the OBC and HCT variants in terms of accuracy, whereas their computational costs are comparable. In addition, for the best-performing models, the impact of the solvent-accessible surface area (SASA) dependent nonpolar solvation term was also examined. The present study highlights the advantages of implicit-solvent models for non-equilibrium sampling.
Heat transfer in porous medium embedded with vertical plate: Non-equilibrium approach - Part A
Energy Technology Data Exchange (ETDEWEB)
Badruddin, Irfan Anjum [Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Quadir, G. A. [School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis (Malaysia)
2016-06-08
Heat transfer in a porous medium embedded with vertical flat plate is investigated by using thermal non-equilibrium model. Darcy model is employed to simulate the flow inside porous medium. It is assumed that the heat transfer takes place by natural convection and radiation. The vertical plate is maintained at isothermal temperature. The governing partial differential equations are converted into non-dimensional form and solved numerically using finite element method. Results are presented in terms of isotherms and streamlines for various parameters such as heat transfer coefficient parameter, thermal conductivity ratio, and radiation parameter.
Non-equilibrium analysis of the two-color operation in semiconductor quantum-well lasers
Energy Technology Data Exchange (ETDEWEB)
Baeumner, Ada; Koch, Stephan W. [Department of Physics and Material Science Center, Philipps University, Renthof 5, 35032 Marburg (Germany); Moloney, Jerome V. [Arizona Center of Mathematical Science and College of Optical Science, University of Arizona, Tucson 85721, Arizona (United States)
2011-04-15
The relevance of hole burning for stable two-color operation in semiconductor quantum-well lasers is studied using a non-equilibrium laser model on the basis of the semiconductor Maxwell-Bloch equations. The field propagation is described via a traveling-wave method. The polarization dynamics is computed using the semiconductor Bloch equations for the microscopic transition and occupation probabilities. Numerical examples for single- and dual-mode operation are presented for a microresonator model system. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Non-equilibrium phase transitions in a liquid crystal.
Dan, K; Roy, M; Datta, A
2015-09-07
The present manuscript describes kinetic behaviour of the glass transition and non-equilibrium features of the "Nematic-Isotropic" (N-I) phase transition of a well known liquid crystalline material N-(4-methoxybenzylidene)-4-butylaniline from the effects of heating rate and initial temperature on the transitions, through differential scanning calorimetry (DSC), Fourier transform infrared and fluorescence spectroscopy. Around the vicinity of the glass transition temperature (Tg), while only a change in the baseline of the ΔCp vs T curve is observed for heating rate (β) > 5 K min(-1), consistent with a glass transition, a clear peak for β ≤ 5 K min(-1) and the rapid reduction in the ΔCp value from the former to the latter rate correspond to an order-disorder transition and a transition from ergodic to non-ergodic behaviour. The ln β vs 1000/T curve for the glass transition shows convex Arrhenius behaviour that can be explained very well by a purely entropic activation barrier [Dan et al., Eur. Phys. Lett. 108, 36007 (2014)]. Fourier transform infrared spectroscopy indicates sudden freezing of the out-of-plane distortion vibrations of the benzene rings around the glass transition temperature and a considerable red shift indicating enhanced coplanarity of the benzene rings and, consequently, enhancement in the molecular ordering compared to room temperature. We further provide a direct experimental evidence of the non-equilibrium nature of the N-I transition through the dependence of this transition temperature (TNI) and associated enthalpy change (ΔH) on the initial temperature (at fixed β-values) for the DSC scans. A plausible qualitative explanation based on Mesquita's extension of Landau-deGennes theory [O. N. de Mesquita, Braz. J. Phys. 28, 257 (1998)] has been put forward. The change in the molecular ordering from nematic to isotropic phase has been investigated through fluorescence anisotropy measurements where the order parameter, quantified by the
Non-equilibrium steady states in supramolecular polymerization
Sorrenti, Alessandro; Leira-Iglesias, Jorge; Sato, Akihiro; Hermans, Thomas M.
2017-06-01
Living systems use fuel-driven supramolecular polymers such as actin to control important cell functions. Fuel molecules like ATP are used to control when and where such polymers should assemble and disassemble. The cell supplies fresh ATP to the cytosol and removes waste products to sustain steady states. Artificial fuel-driven polymers have been developed recently, but keeping them in sustained non-equilibrium steady states (NESS) has proven challenging. Here we show a supramolecular polymer that can be kept in NESS, inside a membrane reactor where ATP is added and waste removed continuously. Assembly and disassembly of our polymer is regulated by phosphorylation and dephosphorylation, respectively. Waste products lead to inhibition, causing the reaction cycle to stop. Inside the membrane reactor, however, waste can be removed leading to long-lived NESS conditions. We anticipate that our approach to obtain NESS can be applied to other stimuli-responsive materials to achieve more life-like behaviour.
Quantum gases finite temperature and non-equilibrium dynamics
Szymanska, Marzena; Davis, Matthew; Gardiner, Simon
2013-01-01
The 1995 observation of Bose-Einstein condensation in dilute atomic vapours spawned the field of ultracold, degenerate quantum gases. Unprecedented developments in experimental design and precision control have led to quantum gases becoming the preferred playground for designer quantum many-body systems. This self-contained volume provides a broad overview of the principal theoretical techniques applied to non-equilibrium and finite temperature quantum gases. Covering Bose-Einstein condensates, degenerate Fermi gases, and the more recently realised exciton-polariton condensates, it fills a gap by linking between different methods with origins in condensed matter physics, quantum field theory, quantum optics, atomic physics, and statistical mechanics. Thematically organised chapters on different methodologies, contributed by key researchers using a unified notation, provide the first integrated view of the relative merits of individual approaches, aided by pertinent introductory chapters and the guidance of ed...
Non-equilibrium Josephson current through interacting quantum dots
Energy Technology Data Exchange (ETDEWEB)
Pala, M.G. [IMEP-MINATEC (UMR CNRS/INPG/UJF), Grenoble (France); Governale, M.; Koenig, J. [Inst. fuer Theoretische Physik III, Ruhr-Univ. Bochum (Germany)
2007-07-01
We study transport through a quantum dot weakly coupled to both normal and superconducting leads. To this aim, we generalize a diagrammatic real-time transport theory to account for superconductivity in the leads. In particular, we consider a system consisting of a quantum dot tunnel coupled to one normal and two superconducting leads. A finite voltage can be applied between the normal and the superconducting leads to drive the dot out of equilibrium. The dot is described by a single, spin-degenerate level, with arbitrary Coulomb repulsion U. The tunnel coupling to the superconducting leads induces a coherent superposition of the empty and doubly occupied dot states (proximity effect). In turn, this may mediate a Josephson current between the two superconductors. We find a situation in which the Josephson current is switched on due to the interplay of Coulomb interaction and non-equilibrium in the dot. (orig.)
Non-equilibrium dynamics near a quantum multicritical point
Energy Technology Data Exchange (ETDEWEB)
Patra, Ayoti; Mukherjee, Victor; Dutta, Amit, E-mail: ayoti@iitk.ac.in, E-mail: victor@iitk.ac.in, E-mail: dutta@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur - 208016 (India)
2011-05-01
We study the non-equilibrium dynamics of a quantum system close to a quantum multi-critical point (MCP) using the example of a one-dimensional spin-1/2 transverse XY spin chain. We summarize earlier results of defect generenation and fidelity susceptibility for quenching through MCP and close to the MCP, respectively. For a quenching scheme which enables the system to hit the MCP along different paths, we emphasize the role of path on exponents associated with quasicritical points which appear in the scaling relations. Finally, we explicitly derive the scaling of concurrence and negativity for two spin entanglement generated following a slow quenching across the MCP and enlist the results for different quenching schemes. We explicity show the dependence of the scaling on the quenching path and dicuss the limiting situations.
Non-equilibrium transport in a series of quantum dots
Energy Technology Data Exchange (ETDEWEB)
Xu Qingqiang; Xiong Shijie [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)
2006-11-15
We investigate non-equilibrium transport properties in a series of quantum dots in which the Kondo resonance is influenced by the coupling between dots. Based on the Anderson Hamiltonian in the strongly interacting limit, we show the splitting of the Kondo resonance at the Fermi surface and the appearance of negative differential conductance when the magnitude of the interdot coupling is in the order of the coupling between the dots and the leads. We illustrate the relationship between the negative differential conductance and the local densities of states at the dots under different biases. We also show the profile of energies of dots in the series when a finite bias is applied. Furthermore, the differences in transport properties between even and odd numbers of quantum dots in the series are investigated.
Correlations within the non-equilibrium Green's function method
Mahzoon, M. H.; Danielewicz, P.; Rios, A.
2017-12-01
Non-equilibrium Green's Function (NGF) method is a powerful tool for studying the evolution of quantum many-body systems. Different types of correlations can be systematically incorporated within the formalism. The time evolution of the single-particle Green's functions is described in terms of the Kadanoff-Baym equations. The current work initially focuses on introducing the correlations within infinite nuclear matter in one dimension and then in a finite system in the NGF approach. Starting from the harmonic oscillator Hamiltonian, by switching on adiabatically the mean-field and correlations simultaneously, a correlated state with ground-state characteristics is arrived at within the NGF method. Furthermore the use of cooling to for improving the adiabatic switching is explored.
Dynamical Symmetries and Causality in Non-Equilibrium Phase Transitions
Directory of Open Access Journals (Sweden)
Malte Henkel
2015-11-01
Full Text Available Dynamical symmetries are of considerable importance in elucidating the complex behaviour of strongly interacting systems with many degrees of freedom. Paradigmatic examples are cooperative phenomena as they arise in phase transitions, where conformal invariance has led to enormous progress in equilibrium phase transitions, especially in two dimensions. Non-equilibrium phase transitions can arise in much larger portions of the parameter space than equilibrium phase transitions. The state of the art of recent attempts to generalise conformal invariance to a new generic symmetry, taking into account the different scaling behaviour of space and time, will be reviewed. Particular attention will be given to the causality properties as they follow for co-variant n-point functions. These are important for the physical identification of n-point functions as responses or correlators.
Non-equilibrium stochastic dynamics in continuum: The free case
Directory of Open Access Journals (Sweden)
Y.Kondratiev
2008-12-01
Full Text Available We study the problem of identification of a proper state-space for the stochastic dynamics of free particles in continuum, with their possible birth and death. In this dynamics, the motion of each separate particle is described by a fixed Markov process M on a Riemannian manifold X. The main problem arising here is a possible collapse of the system, in the sense that, though the initial configuration of particles is locally finite, there could exist a compact set in X such that, with probability one, infinitely many particles will arrive at this set at some time t>0. We assume that X has infinite volume and, for each α���1, we consider the set Θα of all infinite configurations in X for which the number of particles in a compact set is bounded by a constant times the α-th power of the volume of the set. We find quite general conditions on the process M which guarantee that the corresponding infinite particle process can start at each configuration from Θα, will never leave Θα, and has cadlag (or, even, continuous sample paths in the vague topology. We consider the following examples of applications of our results: Brownian motion on the configuration space, free Glauber dynamics on the configuration space (or a birth-and-death process in X, and free Kawasaki dynamics on the configuration space. We also show that if X=Rd, then for a wide class of starting distributions, the (non-equilibrium free Glauber dynamics is a scaling limit of (non-equilibrium free Kawasaki dynamics.
AtomDB 3.0: Atomic Data for Non-equilibrium Ionization Studies
Foster, Adam; Smith, R. K.; Yamaguchi, H.; Ji, L.; Wilms, J.
2014-01-01
Collisional plasmas outside of equilibrium exist in a range of astrophysical phenomena, most notably in solar flares and supernova remnants (SNRs). Discovery of strong recombination edges in several mixed-morphology SNRs (e.g. IC 443, W49B) have demonstrated the need for a model of not only ionizing, but also recombining non-equilibium ionization (NEI) plasma. We have developed new capabilities in AtomDB (www.atomdb.org), allowing modeling of NEI plasma in both equilibrium and non-equilibrium, including emission from all inner shell processes such as Kα and Kβ emission. In order to accurately model the NEI spectrum, we have compiled and benchmarked new rate coefficients for inner shell processes. We have also created XSPEC models for these, ready for use now. We show examples of these models for the SNR case, and discuss the implications of the new model. We also describe the new code libraries available for non-equilibrium ionization studies. This work is funded by NASA grant NNH11ZDA001N-ADAP and Smithsonian Institute grant 40040106IH0034.
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Energy Technology Data Exchange (ETDEWEB)
Doyon, Benjamin, E-mail: benjamin.doyon@kcl.ac.uk
2015-03-15
Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Non-equilibrium phase transitions in a driven-dissipative system of interacting bosons
Young, Jeremy T.; Foss-Feig, Michael; Gorshkov, Alexey V.; Maghrebi, Mohammad F.
2017-04-01
Atomic, molecular, and optical systems provide unique opportunities to study simple models of driven-dissipative many-body quantum systems. Typically, one is interested in the resultant steady state, but the non-equilibrium nature of the physics involved presents several problems in understanding its behavior theoretically. Recently, it has been shown that in many of these models, it is possible to map the steady-state phase transitions onto classical equilibrium phase transitions. In the language of Keldysh field theory, this relation typically only becomes apparent after integrating out massive fields near the critical point, leaving behind a single massless field undergoing near-equilibrium dynamics. In this talk, we study a driven-dissipative XXZ bosonic model and discover critical points at which two fields become gapless. Each critical point separates three different possible phases: a uniform phase, an anti-ferromagnetic phase, and a limit cycle phase. Furthermore, a description in terms of an equilibrium phase transition does not seem possible, so the associated phase transitions appear to be inherently non-equilibrium.
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Directory of Open Access Journals (Sweden)
Benjamin Doyon
2015-03-01
Full Text Available Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Michelini, Fabienne; Crépieux, Adeline; Beltako, Katawoura
2017-05-04
We discuss some thermodynamic aspects of energy conversion in electronic nanosystems able to convert light energy into electrical or/and thermal energy using the non-equilibrium Green's function formalism. In a first part, we derive the photon energy and particle currents inside a nanosystem interacting with light and in contact with two electron reservoirs at different temperatures. Energy conservation is verified, and radiation laws are discussed from electron non-equilibrium Green's functions. We further use the photon currents to formulate the rate of entropy production for steady-state nanosystems, and we recast this rate in terms of efficiency for specific photovoltaic-thermoelectric nanodevices. In a second part, a quantum dot based nanojunction is closely examined using a two-level model. We show analytically that the rate of entropy production is always positive, but we find numerically that it can reach negative values when the derived particule and energy currents are empirically modified as it is usually done for modeling realistic photovoltaic systems.
Path-space variational inference for non-equilibrium coarse-grained systems
Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plecháč, Petr
2016-06-01
In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.
Dynamic Wetting in a Non-Equilibrium Gas: The Effect of Gas Pressure on Air Entrainment
Sprittles, James
2014-11-01
Experimentally, it is now well established that lowering the pressure of an ambient gas can suppress wetting failures, or ``air entrainment,'' at a liquid-solid-gas moving contact-line in both coating processes and drop impact dynamics. In this work, we consider the possibility that non-equilibrium effects in the gas are responsible for such phenomena. These can be included into a continuum framework by allowing for slip at both the solid-gas and liquid-gas interfaces, caused by Knudsen layers attached to these boundaries, which is related to the mean free path in the gas, and hence the ambient pressure. This model has been incorporated into a computational framework developed for dynamic wetting phenomena, which resolves all scales in the problem, so that these new effects can be investigated. It is shown that reductions in gas pressure, and hence increases in slip, can dramatically modify the flow field in the gas-film in front of a moving contact-line so that air entrainment is prevented. Specifically, in a dip-coating setup it is shown that the new model (a) describes experimental results for the critical wetting speed at a given gas pressure and (b) allows us to identify new parameters associated with the non-equilibrium gas dynamics which govern the contact-line's motion.
Sarangapani, Prasad; Hudson, Steven; Pathak, Jai; Migler, Kalman
2013-03-01
Equilibrium and non-equilibrium clustering are ubiquitous phenomena in soft matter physics and are typically observed in systems ranging from colloidal suspensions to monoclonal antibodies (mAbs). Such phenomena are central to understanding and preventing irreversible aggregation in addition to controlling viscosity challenges related to formulation and drug delivery of protein therapeutics. Curiously, little work has been done in exploring the cluster size dependence of low-shear viscosity and intrinsic viscosity in protein solutions in a controlled manner. In this work, we carefully control cluster size of reversible and irreversible clusters formed by globular proteins or monoclonal antibodies over a concentration range of 2 mg/mL-500 mg/mL and pH from 3-9. We find a marked dependence of low-shear viscosity on cluster size using custom-designed silicon-based microfluidic viscometers. Measurements of cluster sizes using static light scattering reveal a correlation of low shear viscosity as well as intrinsic viscosity with the average cluster size. We model the composition dependence of viscosity for the case of equilibrium and non-equilibrium clusters using an adaptation of a model recently presented by Minton for protein mixtures.
Numerical analysis of a non equilibrium two-component two-compressible flow in porous media
Saad, Bilal Mohammed
2013-09-01
We propose and analyze a finite volume scheme to simulate a non equilibrium two components (water and hydrogen) two phase flow (liquid and gas) model. In this model, the assumption of local mass non equilibrium is ensured and thus the velocity of the mass exchange between dissolved hydrogen and hydrogen in the gas phase is supposed finite. The proposed finite volume scheme is fully implicit in time together with a phase-by-phase upwind approach in space and it is discretize the equations in their general form with gravity and capillary terms We show that the proposed scheme satisfies the maximum principle for the saturation and the concentration of the dissolved hydrogen. We establish stability results on the velocity of each phase and on the discrete gradient of the concentration. We show the convergence of a subsequence to a weak solution of the continuous equations as the size of the discretization tends to zero. At our knowledge, this is the first convergence result of finite volume scheme in the case of two component two phase compressible flow in several space dimensions.
Geometry and symmetry in non-equilibrium thermodynamic systems
Sonnino, Giorgio
2017-06-01
The ultimate aim of this series of works is to establish the closure equations, valid for thermodynamic systems out from the Onsager region, and to describe the geometry and symmetry in thermodynamic systems far from equilibrium. Geometry of a non-equilibrium thermodynamic system is constructed by taking into account the second law of thermodynamics and by imposing the validity of the Glansdorff-Prigogine Universal Criterion of Evolution. These two constraints allow introducing the metrics and the affine connection of the Space of the Thermodynamic Forces, respectively. The Lie group associated to the nonlinear Thermodynamic Coordinate Transformations (TCT) leaving invariant both the entropy production σ and the Glansdorff-Prigogine dissipative quantity P, is also described. The invariance under TCT leads to the formulation of the Thermodynamic Covariance Principle (TCP): The nonlinear closure equations, i.e. the flux-force relations, must be covariant under TCT. In other terms, the fundamental laws of thermodynamics should be manifestly covariant under transformations between the admissible thermodynamic forces (i.e. under TCT). The symmetry properties of a physical system are intimately related to the conservation laws characterizing the thermodynamic system. Noether's theorem gives a precise description of this relation. The macroscopic theory for closure relations, based on this geometrical description and subject to the TCP, is referred to as the Thermodynamic Field Theory (TFT). This theory ensures the validity of the fundamental theorems for systems far from equilibrium.
Non-equilibrium phenomena near vapor-liquid interfaces
Kryukov, Alexei; Puzina, Yulia
2013-01-01
This book presents information on the development of a non-equilibrium approach to the study of heat and mass transfer problems using vapor-liquid interfaces, and demonstrates its application to a broad range of problems. In the process, the following peculiarities become apparent: 1. At vapor condensation on the interface from gas-vapor mixture, non-condensable components can lock up the interface surface and condensation stops completely. 2. At the evolution of vapor film on the heater in superfluid helium (He-II), the boiling mass flux density from the vapor-liquid interface is effectively zero at the macroscopic scale. 3. In problems concerning the motion of He-II bridges inside capillaries filled by vapor, in the presence of axial heat flux the He-II bridge cannot move from the heater as would a traditional liquid, but in the opposite direction instead. Thus the heater attracts the superfluid helium bridge. 4. The shape of liquid-vapor interface at film boiling on the axis-symmetric heaters immersed in l...
Equilibrium and Non-Equilibrium Condensation Phenomena in Tuneable 3D and 2D Bose Gases
2016-04-01
AFRL-AFOSR-UK-TR-2016-0009 Equilibrium and non- equilibrium condensation phenomena in tuneable 3D and 2D Bose gases Zoran Hadzibabic THE CHANCELLOR...31-Aug-2015 4. TITLE AND SUBTITLE Equilibrium and non- equilibrium condensation phenomena in tuneable 3D and 2D Bose gases 5a. CONTRACT NUMBER... equilibrium and non- equilibrium many-body phenomena, trapping ultracold atomic gases in different geometries including both 3 and 2 spatial dimensions
Asymptotic analysis of discrete schemes for non-equilibrium radiation diffusion
Cui, Xia; Yuan, Guang-wei; Shen, Zhi-jun
2016-05-01
Motivated by providing well-behaved fully discrete schemes in practice, this paper extends the asymptotic analysis on time integration methods for non-equilibrium radiation diffusion in [2] to space discretizations. Therein studies were carried out on a two-temperature model with Larsen's flux-limited diffusion operator, both the implicitly balanced (IB) and linearly implicit (LI) methods were shown asymptotic-preserving. In this paper, we focus on asymptotic analysis for space discrete schemes in dimensions one and two. First, in construction of the schemes, in contrast to traditional first-order approximations, asymmetric second-order accurate spatial approximations are devised for flux-limiters on boundary, and discrete schemes with second-order accuracy on global spatial domain are acquired consequently. Then by employing formal asymptotic analysis, the first-order asymptotic-preserving property for these schemes and furthermore for the fully discrete schemes is shown. Finally, with the help of manufactured solutions, numerical tests are performed, which demonstrate quantitatively the fully discrete schemes with IB time evolution indeed have the accuracy and asymptotic convergence as theory predicts, hence are well qualified for both non-equilibrium and equilibrium radiation diffusion.
Topics in Statistical Physics: Protein Stability, Non-Equilibrium Thermodynamics and Bibliometrics
Hazoglou, Michael
This dissertation will cover three distinct topics of protein stability, non-equilibrium thermodynamics and scientometrics. In senescent organisms aging is correlated with oxidative damage of proteins. The damage done to proteins destabilizes them inhibiting their function. The implications of a simplified model based on side-chain modification of charged residues using Debye-Hückel theory will be presented. Short length and highly charged proteins are susceptible to destabilization from oxidative damage. Among these proteins already studied in aging several proteins fit this description of being short and highly charged. There is a noticeable enrichment of short-highly-charged proteins in categories of proteins known to be important in aging. Maximum Caliber (MaxCal) is a potential theory of non-equilibrium statistical mechanics. It will be shown how MaxCal is used to derive the Onsager reciprocal relations, Green-Kubo relations and Prigogine's Principle and extend these relations beyond the near-equilibrium regime. The last topic is the citation and publication trends of papers and authors, respectively. A discussion of how pure-birth processes can be applied to understanding citation trends and how birth-processes can be used in classifying papers into different categories of performance.
Non-Equilibrium Relations for Bounded Rational Decision-Making in Changing Environments
Directory of Open Access Journals (Sweden)
Jordi Grau-Moya
2017-12-01
Full Text Available Living organisms from single cells to humans need to adapt continuously to respond to changes in their environment. The process of behavioural adaptation can be thought of as improving decision-making performance according to some utility function. Here, we consider an abstract model of organisms as decision-makers with limited information-processing resources that trade off between maximization of utility and computational costs measured by a relative entropy, in a similar fashion to thermodynamic systems undergoing isothermal transformations. Such systems minimize the free energy to reach equilibrium states that balance internal energy and entropic cost. When there is a fast change in the environment, these systems evolve in a non-equilibrium fashion because they are unable to follow the path of equilibrium distributions. Here, we apply concepts from non-equilibrium thermodynamics to characterize decision-makers that adapt to changing environments under the assumption that the temporal evolution of the utility function is externally driven and does not depend on the decision-maker’s action. This allows one to quantify performance loss due to imperfect adaptation in a general manner and, additionally, to find relations for decision-making similar to Crooks’ fluctuation theorem and Jarzynski’s equality. We provide simulations of several exemplary decision and inference problems in the discrete and continuous domains to illustrate the new relations.
Directory of Open Access Journals (Sweden)
Hynek Lavička
2013-12-01
Full Text Available In this work, we investigate the Model of Employment, Production and Consumption, as introduced in a series of papers by I. Wright [1–3] from the perspective of statistical physics, and we focus on the presence of equilibrium. The model itself belongs to the class of multi-agent computational models, which aim to explain macro-economic behavior using explicit micro-economic interactions.Based on the mean-field approximation, we form the Fokker-Plank equation(s and then formulate conditions forming the stationary solution, which results in a system of non-linear integral-differential equations. This approximation then allows the presence of non-equilibrium stationary states, where the model is a mixed additive-multiplicative model.
Real-time powder diffraction studies of energy materials under non-equilibrium conditions
Directory of Open Access Journals (Sweden)
Vanessa K. Peterson
2017-09-01
Full Text Available Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage of energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function.
Real-time powder diffraction studies of energy materials under non-equilibrium conditions
Energy Technology Data Exchange (ETDEWEB)
Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong
2017-09-01
Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage of energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function.
Non-equilibrium transitions in multiscale systems with a bifurcating slow manifold
Grafke, Tobias; Vanden-Eijnden, Eric
2017-09-01
Noise-induced transitions between metastable fixed points in systems evolving on multiple time scales are analyzed in situations where the time scale separation gives rise to a slow manifold with bifurcation. This analysis is performed within the realm of large deviation theory. It is shown that these non-equilibrium transitions make use of a reaction channel created by the bifurcation structure of the slow manifold, leading to vastly increased transition rates. Several examples are used to illustrate these findings, including an insect outbreak model, a system modeling phase separation in the presence of evaporation, and a system modeling transitions in active matter self-assembly. The last example involves a spatially extended system modeled by a stochastic partial differential equation.
Microwave assisted combustion synthesis of non-equilibrium intermetallic compounds.
Veronesi, Paolo; Rosa, Roberto; Colombini, Elena; Leonelli, Cristina; Poli, Giorgio; Casagrande, Angelo
2010-01-01
A simplified model of the microwave-assisted combustion synthesis of Ni and Al metal powders to form the NiAl intermetallic on titanium and steel substrates is presented. The simulation couples an electro-thermal model with a chemical model, accounting for local heat generation due to the highly exothermic nature of the reactions between the powders. Numerical results, validated by experimental values, show that the capability of microwaves to convey energy, and not heat, can be used to alter the temperature profiles during and after the combustion synthesis, leading to unique intermetallic microstructures. This phenomenon is ascribed to the extended existence of high temperature liquid intermetallic phases, which react with the metallic substrates at the interface. Moreover, microwave heating selectivity allows to maintain the bulk of the substrate metallic materials to a much lower temperature, compared to combustion synthesis in conventionally heated furnaces, thus reducing possible unwanted transformations like phase change or oxidation.
Role of non-equilibrium conformations on driven polymer translocation
Katkar, H. H.; Muthukumar, M.
2018-01-01
One of the major theoretical methods in understanding polymer translocation through a nanopore is the Fokker-Planck formalism based on the assumption of quasi-equilibrium of polymer conformations. The criterion for applicability of the quasi-equilibrium approximation for polymer translocation is that the average translocation time per Kuhn segment, ⟨τ⟩/NK, is longer than the relaxation time τ0 of the polymer. Toward an understanding of conditions that would satisfy this criterion, we have performed coarse-grained three dimensional Langevin dynamics and multi-particle collision dynamics simulations. We have studied the role of initial conformations of a polyelectrolyte chain (which were artificially generated with a flow field) on the kinetics of its translocation across a nanopore under the action of an externally applied transmembrane voltage V (in the absence of the initial flow field). Stretched (out-of-equilibrium) polyelectrolyte chain conformations are deliberately and systematically generated and used as initial conformations in translocation simulations. Independent simulations are performed to study the relaxation behavior of these stretched chains, and a comparison is made between the relaxation time scale and the mean translocation time (⟨τ⟩). For such artificially stretched initial states, ⟨τ⟩/NK theory of polyelectrolyte dynamics reveals that the Zimm relaxation time (τZimm) is shorter than the mean translocation time for several polymers including single stranded DNA (ssDNA), double stranded DNA (dsDNA), and synthetic polymers. Even when these data are rescaled assuming a constant effective velocity of translocation, it is found that for flexible (ssDNA and synthetic) polymers with NK Kuhn segments, the condition ⟨τ⟩/NK < τZimm is satisfied. We predict that for flexible polymers such as ssDNA, a crossover from quasi-equilibrium to non-equilibrium behavior would occur at NK ˜ O(1000).
Measurement and Prediction of Radiative Non-Equilibrium for Air Shocks Between 7-9 km/s
Cruden, Brett A.; Brandis, Aaron M.
2017-01-01
The present paper describes a recent characterization of thermochemical non-equilibrium for shock speeds between 7 and 9 km/s in the NASA Ames Electric Arc Shock Tube (EAST) Facility. Data are spectrally resolved from 190-1450 nm and spatially resolved behind the shock front. The data are analyzed in terms of a spectral non-equilibrium metric, defined as the average radiance within +/- 2 cm of the peak. Simulations with DPLR/NEQAIR using different rate chemistries show these conditions to be poorly replicated. The sources of discrepancy are examined, leading to an update to the NEQAIR non-Boltzmann model and DPLR rate chemistry. New parameters for the rate chemistry and non-Boltzmann modeling are reported.
Coherent application of a contact structure to formulate Classical Non-Equilibrium Thermodynamics
Knobbe, E; Roekaerts, D.J.E.M.
2017-01-01
This contribution presents an outline of a new mathematical formulation for
Classical Non-Equilibrium Thermodynamics (CNET) based on a contact
structure in differential geometry. First a non-equilibrium state space is introduced as the third key element besides the first and second law of
Non-equilibrium Transport and Relaxation in Diffusive Nanowires with Kondo Impurities
DEFF Research Database (Denmark)
Kroha, Johann; Rosch, Achim; Paaske, Jens
2003-01-01
Combining non-equilibrium transport with spectroscopic measurements provides a unique tool for the investigation of the microscopic processes in mesoscopic conductors. Experiments on resistive quantum wires show that the non-equilibrium quasiparticle distribution function f(E,V) as a function of ...
On the definition of equilibrium and non-equilibrium states in dynamical systems
Akimoto, Takuma
2008-01-01
We propose a definition of equilibrium and non-equilibrium states in dynamical systems on the basis of the time average. We show numerically that there exists a non-equilibrium non-stationary state in the coupled modified Bernoulli map lattice.
The non-equilibrium basis of Turing Instability and localised biological work.
Schiffmann, Yoram
2017-08-01
Turing's theory for biological pattern formation is based on the instability of the homogeneous state, which occurs if certain key criteria are met. The problem of how chemical energy is converted to localised biological work requires one to understand not only the basis of localised power generation, but also the age-old puzzle of how organisms decrease their entropy; these problems can only be solved by the identification of the Turing Instability. At the heart of this is how natural selection, not chemistry, has fashioned the large non-equilibrium overall affinity (ΔG is a large negative quantity) for the oxidation of the fuel molecules. Natural selection has also resulted in the homeostasis at non-equilibrium values of the hydrolysis of molecules like ATP, GTP, which are the energy links between the overall oxidation of the fuel and biological work. The conditions for such homeostasis are central requirements for the Turing Instability and are the essence of being alive. The Turing-Child (TC) patterns are the spontaneous primary spatial cause not only of localised biological work in multicellular systems (especially those in patterning and development) but also of intracellular patterns including the mitotic spindle and the contractile ring. The Turing picture comprises the nonuniform distribution of the concentrations of the Turing morphogens, cAMP and ATP, and the Child picture is the resulting nonuniform distribution of the metabolic rate and of power. The TC pattern is shaped as the dominant eigenfunction in the combination of eigenfunctions which provides the spatial pattern of the Turing morphogens. The TC patterns and the bifurcation parameter manifest quantisation and symmetry as in music and in applications of quantum mechanics. The notion of correlation diagrams is also introduced. Copyright © 2017 Elsevier Ltd. All rights reserved.
Non-equilibrium physics and evolution--adaptation, extinction, and ecology: a key issues review.
Kussell, E; Vucelja, M
2014-10-01
Evolutionary dynamics in nature constitute an immensely complex non-equilibrium process. We review the application of physical models of evolution, by focusing on adaptation, extinction, and ecology. In each case, we examine key concepts by working through examples. Adaptation is discussed in the context of bacterial evolution, with a view toward the relationship between growth rates, mutation rates, selection strength, and environmental changes. Extinction dynamics for an isolated population are reviewed, with emphasis on the relation between timescales of extinction, population size, and temporally correlated noise. Ecological models are discussed by focusing on the effect of spatial interspecies interactions on diversity. Connections between physical processes--such as diffusion, turbulence, and localization--and evolutionary phenomena are highlighted.
Energy Technology Data Exchange (ETDEWEB)
Koerting, V., E-mail: koerting@nbi.d [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Niels Bohr Institute, Universitetsparken, DK-2100 Copenhagen (Denmark); The Niels Bohr International Academy, The Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Fritsch, P. [Physics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Kehrein, S., E-mail: stefan.kehrein@physik.lmu.d [Physics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany)
2011-05-15
Since the experimental realization of Kondo physics in quantum dots, its far-from-equilibrium properties have generated considerable theoretical interest. This is due to the interesting interplay of non-equilibrium physics and correlation effects in this model, which has now been analyzed using several new theoretical methods that generalize renormalization techniques to non-equilibrium situations. While very good agreement between these methods has been found for the spin-1/2 Kondo model, it is desirable to have a better understanding of their applicability for more complicated impurity models. In this paper the differences and commons between two such approaches, namely the flow equation method out of equilibrium and the frequency-dependent poor man's scaling approach are presented for the non-equilibrium double quantum dot system. This will turn out to be a particularly suitable testing ground while being experimentally interesting in its own right. An outlook is given on the quantum critical behavior of the double quantum dot system and its accessibility with the two methods.
Protein accumulation in the endoplasmic reticulum as a non-equilibrium phase transition.
Budrikis, Zoe; Costantini, Giulio; La Porta, Caterina A M; Zapperi, Stefano
2014-04-11
Several neurological disorders are associated with the aggregation of aberrant proteins, often localized in intracellular organelles such as the endoplasmic reticulum. Here we study protein aggregation kinetics by mean-field reactions and three dimensional Monte carlo simulations of diffusion-limited aggregation of linear polymers in a confined space, representing the endoplasmic reticulum. By tuning the rates of protein production and degradation, we show that the system undergoes a non-equilibrium phase transition from a physiological phase with little or no polymer accumulation to a pathological phase characterized by persistent polymerization. A combination of external factors accumulating during the lifetime of a patient can thus slightly modify the phase transition control parameters, tipping the balance from a long symptomless lag phase to an accelerated pathological development. The model can be successfully used to interpret experimental data on amyloid-β clearance from the central nervous system.
Energy Technology Data Exchange (ETDEWEB)
Lu, X., E-mail: luxinpei@hotmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Naidis, G.V. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Laroussi, M. [Plasma Engineering & Medicine Institute, Old Dominion University, Norfolk, VA 23529 (United States); Reuter, S. [Leibniz Institute for Plasma Science and Technology, Felix-Hausdorff-Strasse 2, 17489 Greifswald (Germany); Graves, D.B. [Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720 (United States); Ostrikov, K. [Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000 (Australia); School of Physics, Chemistry, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000 (Australia); Commonwealth Scientific and Industrial Research Organization, P.O.Box 218, Lindfield, NSW 2070 (Australia); School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)
2016-05-04
Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molecular, and radical species that are produced in these plasmas and then transported from the point of generation to the point of interaction with the material, medium, living cells or tissues being processed. The most important mechanisms of generation and transport of the key species in the plasmas of atmospheric-pressure plasma jets and other non-equilibrium atmospheric-pressure plasmas are introduced and examined from the viewpoint of their applications in plasma hygiene and medicine and other relevant fields. Sophisticated high-precision, time-resolved plasma diagnostics approaches and techniques are presented and their applications to monitor the reactive species and plasma dynamics in the plasma jets and other discharges, both in the gas phase and during the plasma interaction with liquid media, are critically reviewed. The large amount of experimental data is supported by the theoretical models of reactive species generation and transport in the plasmas, surrounding gaseous environments, and plasma interaction with liquid media. These models are presented and their limitations are discussed. Special attention is paid to biological effects of the plasma-generated reactive oxygen and nitrogen (and some other) species in basic biological processes such as cell metabolism, proliferation, survival, etc. as well as plasma applications in bacterial inactivation, wound healing, cancer treatment and some others. Challenges and opportunities for theoretical and experimental research are discussed and the authors’ vision for the emerging convergence trends across several disciplines and application domains is presented to
Maćkowiak, Sz; Heyes, D M; Dini, D; Brańka, A C
2016-10-28
The phase behavior of a confined liquid at high pressure and shear rate, such as is found in elastohydrodynamic lubrication, can influence the traction characteristics in machine operation. Generic aspects of this behavior are investigated here using Non-equilibrium Molecular Dynamics (NEMD) simulations of confined Lennard-Jones (LJ) films under load with a recently proposed wall-driven shearing method without wall atom tethering [C. Gattinoni et al., Phys. Rev. E 90, 043302 (2014)]. The focus is on thick films in which the nonequilibrium phases formed in the confined region impact on the traction properties. The nonequilibrium phase and tribological diagrams are mapped out in detail as a function of load, wall sliding speed, and atomic scale surface roughness, which is shown can have a significant effect. The transition between these phases is typically not sharp as the external conditions are varied. The magnitude of the friction coefficient depends strongly on the nonequilibrium phase adopted by the confined region of molecules, and in general does not follow the classical friction relations between macroscopic bodies, e.g., the frictional force can decrease with increasing load in the Plug-Slip (PS) region of the phase diagram owing to structural changes induced in the confined film. The friction coefficient can be extremely low (∼0.01) in the PS region as a result of incommensurate alignment between a (100) face-centered cubic wall plane and reconstructed (111) layers of the confined region near the wall. It is possible to exploit hysteresis to retain low friction PS states well into the central localization high wall speed region of the phase diagram. Stick-slip behavior due to periodic in-plane melting of layers in the confined region and subsequent annealing is observed at low wall speeds and moderate external loads. At intermediate wall speeds and pressure values (at least) the friction coefficient decreases with increasing well depth of the LJ potential
Energy Technology Data Exchange (ETDEWEB)
Okumura, M; Onishi, H; Yamada, S; Machida, M, E-mail: okumura@riken.j
2010-11-01
We study non-equilibrium properties of one-dimensional Hubbard model by the density-matrix renormalization-group method. First, we demonstrate stability of 'doublon', which characterized by double occupation on a site due to the integrability of the model. Next, we present a kind of anomalous transport caused by the doublons created under strong non-equilibrium conditions in an optical lattice system regarded as an ideal testbed to investigate fundamental properties of the Hubbard model. Finally, we give a result on development of the pair correlation function in a strong non-equilibrium condition. This can be understood as a development of coherence among many excited doublons.
Ji, Shengxiang; Nagpal, Umang; Liu, Guoliang; Delcambre, Sean P; Müller, Marcus; de Pablo, Juan J; Nealey, Paul F
2012-06-26
The majority of past work on directed assembly of block copolymers on chemically nanopatterned surfaces (or chemical patterns) has focused on AB diblock copolymers, and the resulting morphologies have generally corresponded to equilibrium states. Here we report a study on directed assembly of ABA triblock copolymers. Directed assembly of thin films of symmetric poly(methyl methacrylate-b-styrene-b-methyl methacrylate) (PMMA-b-PS-b-PMMA) triblock copolymers is shown to be capable of achieving a high degree of perfection, registration, and accuracy on striped patterns having periods, L(s), commensurate with the bulk period of the copolymer, L(o). When L(s) is incommensurate with L(o), the triblock copolymer domains can reach dimensions up to 55% larger or 13% smaller than L(o). The range over which triblock copolymers tolerate departures from a commensurate L(s) is significantly larger than that accessible with the corresponding diblock copolymer material on analogous directed assembly systems. The assembly kinetics of the triblock copolymer is approximately 3 orders of magnitude slower than observed in the diblock system. Theoretically informed simulations are used to interpret our experimental observations; a thermodynamic analysis reveals that triblocks can form highly ordered, non-equilibrium metastable structures that do not arise in the diblock.
Modeling chemical kinetics graphically
Heck, A.
2012-01-01
In literature on chemistry education it has often been suggested that students, at high school level and beyond, can benefit in their studies of chemical kinetics from computer supported activities. Use of system dynamics modeling software is one of the suggested quantitative approaches that could
Lubeck, S.; Heger, P. C.
2003-01-01
In this work we analyze the universal scaling functions and the critical exponents at the upper critical dimension of a continuous phase transition. The consideration of the universal scaling behavior yields a decisive check of the value of the upper critical dimension. We apply our method to a non-equilibrium continuous phase transition. But focusing on the equation of state of the phase transition it is easy to extend our analysis to all equilibrium and non-equilibrium phase transitions obs...
Equilibrium and non-equilibrium electron tunneling via discrete quantum states
Deshmukh, Mandar M.; Bonet, Edgar; Pasupathy, A. N.; Ralph, D. C.
2001-01-01
Tunneling is measured via the quantum levels of a metal nanoparticle. We analyze quantitatively the resonance energies, widths, and amplitudes, both in the regime where only one state is accessible for tunneling and in the non-equilibrium regime when additional states are made accessible one-by-one. For tunneling through one state, our results agree with expectations for sequential tunneling, but in the non-equilibrium regime the resonances are broadened and shifted in ways that require takin...
Non-equilibrium processes in p + Ag collisions at GeV energies
Fidelus, M.; Filges, D.; Goldenbaum, F.; Jarczyk, L.; Kamys, B.; Kistryn, M.; Kistryn, St.; Kozik, E.; Kulessa, P.; Machner, H.; Magiera, A.; Piskor-Ignatowicz, B.; Pysz, K.; Rudy, Z.; Sharma, Sushil K.; Siudak, R.; Wojciechowski, M.; PISA Collaboration
2017-12-01
The double differential spectra d2σ /d Ω d E of p , d , t , 3,4,6He, 6,7,8,9Li, 7,9,10Be, and 10,11,12B were measured at seven scattering angles, 15.6∘, 20∘, 35∘, 50∘, 65∘, 80∘, and 100∘, in the laboratory system for proton induced reactions on a silver target. Measurements were done for three proton energies: 1.2, 1.9, and 2.5 GeV. The experimental data were compared to calculations performed by means of two-step theoretical microscopic models. The first step of the reaction was described by the intranuclear cascade model incl4.6 and the second one by four different models (ABLA07, GEM2, gemini++, and SMM) using their standard parameter settings. Systematic deviations of the data from predictions of the models were observed. The deviations were especially large for the forward scattering angles and for the kinetic energy of emitted particles in the range from about 50 to 150 MeV. This suggests that some important non-equilibrium mechanism is lacking in the present day microscopic models of proton-nucleus collisions in the studied beam energy range.
Papior, Nick; Lorente, Nicolás; Frederiksen, Thomas; García, Alberto; Brandbyge, Mads
2017-03-01
We present novel methods implemented within the non-equilibrium Green function code (NEGF) TRANSIESTA based on density functional theory (DFT). Our flexible, next-generation DFT-NEGF code handles devices with one or multiple electrodes (Ne ≥ 1) with individual chemical potentials and electronic temperatures. We describe its novel methods for electrostatic gating, contour optimizations, and assertion of charge conservation, as well as the newly implemented algorithms for optimized and scalable matrix inversion, performance-critical pivoting, and hybrid parallelization. Additionally, a generic NEGF ;post-processing; code (TBTRANS/PHTRANS) for electron and phonon transport is presented with several novelties such as Hamiltonian interpolations, Ne ≥ 1 electrode capability, bond-currents, generalized interface for user-defined tight-binding transport, transmission projection using eigenstates of a projected Hamiltonian, and fast inversion algorithms for large-scale simulations easily exceeding 106 atoms on workstation computers. The new features of both codes are demonstrated and bench-marked for relevant test systems.
Pore-scale Analysis of Equilibrium and Non-equilibrium DNAPL Mass Transfer
Roberts, K. L.; Willson, C. S.; Thompson, K. E.; Moe, W. M.
2008-12-01
A large number of groundwater aquifers are contaminated by dense nonaqueous phase liquids (DNAPL) comprised of chlorinated hydrocarbons. While there have been a large number of experimental and modeling studies investigating NAPL dissolution at various length scales, rate-limiting processes involved in DNAPL dissolution remain poorly understood. Appropriate mathematical models for describing localized phenomena in a manner conducive to continuum scale modeling are not yet fully developed or have not been robustly tested in comparison to experimental data. Here, high-resolution (i.e., ~10 micron) synchrotron X-ray tomography was used to non-destructively obtain three-dimensional images of the internal structure of a series of unconsolidated porous media (40/50 Accusand) systems at various stages of tetrachloroethene (PCE) dissolution during equilibrium and non-equilibrium mass transfer conditions. Algorithms developed by our group were used to: (1) quantify the granular packing characteristics (e.g., grain sizes, shapes, coordination number); (2) pore network structure (e.g., individual pore body geometry and connectivity); and (3) DNAPL blob characteristics (e.g., blobs sizes, interfacial areas); and (4) correlations between the blob characteristics and pore network structure. Generation of the detailed pore network structure allowed pore network modeling to be performed on the actual void space geometry and topology. A unique aspect of this approach is that it directly incorporated pore-scale preferential flow paths that formed due to pore-level heterogeneities and NAPL blob location and geometry. Analysis of the granular packing and pore network structure properties indicate that the column preparation technique resulted in uniform packing among the different systems. This allowed us to assess the impact of flowrates and local pore-level properties on mass transfer and dissolution of individual DNAPL blobs. Experimental results from columns subjected to low flow
Non-equilibrium plasma prevention of Schistosoma japonicum transmission
Xing-Quan Wang; Feng-Peng Wang; Wei Chen; Jun Huang; Kateryna Bazaka; Kostya (Ken) Ostrikov
2016-01-01
Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatmen...
Transonic flow of steam with non-equilibrium and homogenous condensation
Virk, Akashdeep Singh; Rusak, Zvi
2017-11-01
A small-disturbance model for studying the physical behavior of a steady transonic flow of steam with non-equilibrium and homogeneous condensation around a thin airfoil is derived. The steam thermodynamic behavior is described by van der Waals equation of state. The water condensation rate is calculated according to classical nucleation and droplet growth models. The current study is based on an asymptotic analysis of the fluid flow and condensation equations and boundary conditions in terms of the small thickness of the airfoil, small angle of attack, closeness of upstream flow Mach number to unity and small amount of condensate. The asymptotic analysis gives the similarity parameters that govern the problem. The flow field may be described by a non-homogeneous transonic small-disturbance equation coupled with a set of four ordinary differential equations for the calculation of the condensate mass fraction. An iterative numerical scheme which combines Murman & Cole's (1971) method with Simpson's integration rule is applied to solve the coupled system of equations. The model is used to study the effects of energy release from condensation on the aerodynamic performance of airfoils operating at high pressures and temperatures and near the vapor-liquid saturation conditions.
Ultrafast non-equilibrium carrier dynamics in semiconductor laser mode-locking
Hader, J.; Scheller, M.; Laurain, A.; Kilen, I.; Baker, C.; Moloney, J. V.; Koch, S. W.
2017-01-01
Experimental and theoretical results on the mode-locking dynamics in vertical-external-cavity surface-emitting lasers with semiconductor and graphene saturable absorber mirrors are reviewed with an emphasis on the role of nonequilibrium carrier effects. The systems are studied theoretically using a fully microscopic many-body model for the carrier distributions and polarizations, coupled to Maxwell’s equations for the field propagation. Pump-probe measurements are performed with (sub-) 100 fs resolution. The analysis shows that the non-equilibrium carrier dynamics in the gain quantum-wells and saturable absorber medium significantly influences the system’s response and the resulting mode-locked pulses. The microscopic model is used to study the pulse build up from spontaneous emission noise and to determine the dependence of achievable pulse lengths and fluences on the amounts of saturable and non-saturable losses and the optical gain. The change of the group delay dispersion (GDD) on the pump level is examined and the dependence of the pulse lengths on the total amount of GDD is demonstrated experimentally. Theory-experiment comparisons are used to demonstrate the highly quantitative accuracy of the fully microscopic modeling.
Non-equilibrium solidification of undercooled droplets during ...
Indian Academy of Sciences (India)
equilibrium solidification of ... A mathematical model, based on classical theory of heterogeneous nucleation and volume separation of nucleants among droplets size distribution, is described to predict undercooling of droplets. Newtonian heat flow ...
Energy Technology Data Exchange (ETDEWEB)
Hotta, Ryuuichi; Morozumi, Takuya; Takata, Hiroyuki [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Tomsk state Pedagogical University Tomsk 634041 (Russian Federation)
2012-07-27
We develop the method analyzing particle number non-conserving phenomena with non-equilibrium quantum field-theory. In this study, we consider a CP violating model with interaction Hamiltonian that breaks particle number conservation. To derive the quantum Boltzmann equation for the particle number, we solve Schwinger-Dyson equation, which are obtained from two particle irreducible closed-time-path (2PI CTP) effective action. In this calculation, we show the contribution from interaction Hamiltonian to the time evolution of expectation value of particle number.
Aquilanti, Vincenzo; Coutinho, Nayara Dantas; Carvalho-Silva, Valter Henrique
2017-03-01
the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.
Carbon Dioxide reduction by non-equilibrium electrocatalysis plasma reactor
Amouroux, J.; Cavadias, S.; Doubla, A.
2011-03-01
A possible strategy to increase the added value from CCS, is to consider it as a raw material for the production of liquid fuels, or chemical products. The most studied ways related to CO2 reduction, with formation of molecules such as CH3OH or syngas, is the reaction with H2 (exothermic reaction needing catalytic activation), or CH4 (endothermic reaction taking place at high temperature) with the use of a catalyst. The synthesis of CH3OH is performed on Lewis acid type sites (default of electrons) Cu/Zn/Al2O3. However the products of the reaction i.e. the water and methanol molecules, are very polar, resulting in a very low desorption rate. So in this reaction the key step is water desorption (Lewis basis). The increase of temperature in order to increase this desorption rate, leads to a cracking and the deposition of carbon in the catalyst, limiting its lifetime. Plasma driven catalysis allows firstly, a vibrational activation of CO2, H2 or CH4 through electron-molecule collisions, making easier their dissociation at low temperature and secondly expels water from the catalyst sites by supplying electrons (electropolarisation). The results show an increase of the yield in CH3OH with plasma and catalyst, confirming the action of the plasma. However energy consumption remains relatively high.
Dynamical TAP equations for non-equilibrium Ising spin glasses
DEFF Research Database (Denmark)
Roudi, Yasser; Hertz, John
2011-01-01
We derive and study dynamical TAP equations for Ising spin glasses obeying both synchronous and asynchronous dynamics using a generating functional approach. The system can have an asymmetric coupling matrix, and the external fields can be time-dependent. In the synchronously updated model, the TAP...... equations take the form of self consistent equations for magnetizations at time t+1, given the magnetizations at time t. In the asynchronously updated model, the TAP equations determine the time derivatives of the magnetizations at each time, again via self consistent equations, given the current values...... of the magnetizations. Numerical simulations suggest that the TAP equations become exact for large systems....
Energy Technology Data Exchange (ETDEWEB)
Westbrook, C.K.; Pitz, W.J. [Lawrence Livermore National Laboratory, CA (United States)
1993-12-01
This project emphasizes numerical modeling of chemical kinetics of combustion, including applications in both practical combustion systems and in controlled laboratory experiments. Elementary reaction rate parameters are combined into mechanisms which then describe the overall reaction of the fuels being studied. Detailed sensitivity analyses are used to identify those reaction rates and product species distributions to which the results are most sensitive and therefore warrant the greatest attention from other experimental and theoretical research programs. Experimental data from a variety of environments are combined together to validate the reaction mechanisms, including results from laminar flames, shock tubes, flow systems, detonations, and even internal combustion engines.
Non-equilibrium solidification of undercooled droplets during ...
Indian Academy of Sciences (India)
Unknown
Abstract. Thermal history of droplets associated with gas atomization of melt has been investigated. A mathematical model, based on classical theory of heterogeneous nucleation and volume separation of nucleants among droplets size distribution, is described to predict undercooling of droplets. Newtonian heat flow.
Some recent developments in non-equilibrium statistical physics
Indian Academy of Sciences (India)
will be illustrated by applying them to simple systems such as the Brownian ratchet model for molecular motors and ... this concept to the asymmetric exclusion process (ASEP), a simple driven lattice gas that plays the role of ... for example, the motion of a pendulum clock allows us to measure time by slicing it into periods of ...
Non-Equilibrium Ionization Effects Induced During Coronal Flares
Orlando, S.; Peres, G.; Reale, F.; Rosner, R.; Siegel, A.
We present preliminary results of hydrodynamic modeling of flares occurring in plasma confined in coronal loops. Our analysis focuses on the deviations from ionization equilibrium on the population fractions of the most abundant elements in astrophysical plasmas, and on the possible implications for plasma diagnostics.
Non-equilibrium thermochemical heat storage in porous media
DEFF Research Database (Denmark)
Nagel, T.; Shao, H.; Singh, Ashok
2013-01-01
compressible gas flow through a porous solid is presented along with its finite element implementation where solid-gas reactions occur and both phases have individual temperature fields. The model is embedded in the Theory of Porous Media and the derivation is based on the evaluation of the Clausius...... determine reaction kinetics. To advance this technology beyond the laboratory stage requires a thorough theoretical understanding of the multiphysics phenomena and their quantification on a scale relevant to engineering analyses. Here, the theoretical derivation of a macroscopic model for multicomponent......Thermochemical energy storage can play an important role in the establishment of a reliable renewable energy supply and can increase the efficiency of industrial processes. The application of directly permeated reactive beds leads to strongly coupled mass and heat transport processes that also...
The non-equilibrium phase diagrams of flow-induced crystallization and melting of polyethylene.
Wang, Zhen; Ju, Jianzhu; Yang, Junsheng; Ma, Zhe; Liu, Dong; Cui, Kunpeng; Yang, Haoran; Chang, Jiarui; Huang, Ningdong; Li, Liangbin
2016-09-09
Combining extensional rheology with in-situ synchrotron ultrafast x-ray scattering, we studied flow-induced phase behaviors of polyethylene (PE) in a wide temperature range up to 240 °C. Non-equilibrium phase diagrams of crystallization and melting under flow conditions are constructed in stress-temperature space, composing of melt, non-crystalline δ, hexagonal and orthorhombic phases. The non-crystalline δ phase is demonstrated to be either a metastable transient pre-order for crystallization or a thermodynamically stable phase. Based on the non-equilibrium phase diagrams, nearly all observations in flow-induced crystallization (FIC) of PE can be well understood. The interplay of thermodynamic stabilities and kinetic competitions of the four phases creates rich kinetic pathways for FIC and diverse final structures. The non-equilibrium flow phase diagrams provide a detailed roadmap for precisely processing of PE with designed structures and properties.
Beyond the second law entropy production and non-equilibrium systems
Lineweaver, Charles; Niven, Robert; Regenauer-Lieb, Klaus
2014-01-01
The Second Law, a cornerstone of thermodynamics, governs the average direction of dissipative, non-equilibrium processes. But it says nothing about their actual rates or the probability of fluctuations about the average. This interdisciplinary book, written and peer-reviewed by international experts, presents recent advances in the search for new non-equilibrium principles beyond the Second Law, and their applications to a wide range of systems across physics, chemistry and biology. Beyond The Second Law brings together traditionally isolated areas of non-equilibrium research and highlights potentially fruitful connections between them, with entropy production playing the unifying role. Key theoretical concepts include the Maximum Entropy Production principle, the Fluctuation Theorem, and the Maximum Entropy method of statistical inference. Applications of these principles are illustrated in such diverse fields as climatology, cosmology, crystal growth morphology, Earth system science, environmental physics, ...
A non-equilibrium formulation of food security resilience
Smerlak, Matteo
2016-01-01
Resilience, the ability to recover from adverse events ("shocks"), is of fundamental importance to food security. This is especially true in poor countries, where basic needs are frequently threatened by economic, environmental, and health shocks. An empirically sound formalization of the concept of food security resilience, however, is lacking. Here we introduce a general framework for quantifying resilience based on a simple definition: a unit is resilient if $(a)$ its long-term food security trend is not deteriorating and $(b)$ the effects of shocks on this trend do not persist over time. Our approach can be applied to any food security variable for which high-frequency time-series data is available, can accommodate any unit of analysis (e.g., individuals, households, countries), and is especially useful in rapidly changing contexts wherein standard equilibrium-based economic models are ineffective. We illustrate our method with an analysis of per capita kilocalorie availability for 161 countries between 1...
Superconductors in non-equilibrium. Higgs oscillations and induced superconductivity
Energy Technology Data Exchange (ETDEWEB)
Bittner, Nikolaj; Schnyder, Andreas; Manske, Dirk [Max-Planck-Institut fuer Festkoerperforschung, D-70569 Stuttgart (Germany); Krull, Holger [Max-Planck-Institut fuer Festkoerperforschung, D-70569 Stuttgart (Germany); Lehrstuhl fuer Theoretische Physik, Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Tohyama, Takami [Department of Applied Physics, Tokyo University of Science, Tokyo 125-8585 (Japan)
2016-07-01
Nonequilibrium pump-probe time-domain spectroscopy opens new perspectives in studying the dynamical properties of the strongly correlated electron systems. In particular, new effects, such as transient superconductivity or Higgs oscillations of the superconducting condensate, can be obtained. Using various methods we present a theoretical study of the nonequilibrium dynamics in superconductors. Firstly, within the framework of the density matrix formalism we study Higgs oscillations in superconductors, which allow to detect the properties of the superconducting condensate as a function of time. For two-band superconductors the interplay between the phase (Leggett) and amplitude (Higgs) modes is analyzed in detail and new predictions are made. Secondly, employing the time-dependent Lanczos algorithm to the one-dimensional extended Hubbard model we observe appearance of a transient Meissner effect, which is a fingerprint of the induced superconductivity.
Non-equilibrium tuning of attractive colloidal gels
Boromand, Arman; Maia, Joao
2015-11-01
In colloidal gel systems, the presence of multiple interactions in multiple length scales such as Van der Waals, depletion attractions, and electrostatic repulsions makes these systems challenging from both experimental and simulation aspects. Recently, there has been growing interest to tune and manipulate the structural and dynamics properties of those systems without adjusting interparticle interactions, just by taking them out of equilibrium. In this work, we used Core-Modified Dissipative Particle Dynamics (CM-DPD) with a modified depletion potential, as a coarse-grain model to address the gel formation process in short ranged-attractive colloidal suspensions for a range of volume fractions and attraction strengths. It is suggested that at high volume fractions and near the glass transition, there is a transformation from non-bonded glass to bonded-glass for which that the effect of topological frustration (caging) will be alleviated by the presence of attractive potentials (bonding) i.e. melting during cooling. In the first part of the presentation, we discuss our similar findings for semi-dilute volume fraction of attractive bimodal colloidal gels at equilibrium, which can be explained through local densification of attractive colloidal gels. In the second part, structural and dynamics properties of arrested gels will be studied under shear and after cessation of shear to study how the different flow profiles and history will alter final morphology of the gel systems.
Non-equilibrium water flow in multimodal soil porous system
Kodesova, R.; Nikodem, A.; Jirku, V.
2009-04-01
Soil hydraulic properties of various horizons of Haplic Luvisol were studied under the laboratory and field conditions. Multistep outflow experiments were performed in the laboratory, and tension disk and Guelph permeameter tests were carried out in the field. The dual-permeability flow model in HYDRUS-1D and HYDRUS-2D were used to estimate the soil hydraulic parameters of matrix and macropore domains from the laboratory and field transient flow data via numerical inversion. First, the laboratory experimental data were analyzed to obtain soil hydraulic properties of the one-dimensional (small column) dual-permeability system. Parameters obtained for the matrix domains were then used to analyze field transient flow data of both permeameters tests to estimate parameters of macropore domains in the radially symmetric dual-permeability system. Results showed impact of various pore fractions (gravitational and large capillary pores) and multimodality of soil porous system, which were previously documented by Kodesova et al. (2008) in the micromorphological images, on preferential flow occurrence in structured soils. Acknowledgement: Authors acknowledge the financial support of the Grant Agency of the Czech Republic grant No. 526/08/0434, and the Ministry of Education, Youth and Sports grant No. MSM 6046070901.
Studying effects of non-equilibrium radiative transfer via HPC
Energy Technology Data Exchange (ETDEWEB)
Holladay, Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2018-01-24
This report presents slides on Ph.D. Research Goals; Local Thermodynamic Equilibrium (LTE) Implications; Calculating an Opacity; Opacity: Pictographic Representation; Opacity: Pictographic Representation; Opacity: Pictographic Representation; Collisional Radiative Modeling; Radiative and Collisional Excitation; Photo and Electron Impact Ionization; Autoionization; The Rate Matrix; Example: Total Photoionization rate; The Rate Coefficients; inlinlte version 1.1; inlinlte: Verification; New capabilities: Rate Matrix – Flexibility; Memory Option Comparison; Improvements over previous DCA solver; Inter- and intra-node load balancing; Load Balance – Full Picture; Load Balance – Full Picture; Load Balance – Internode; Load Balance – Scaling; Description; Performance; xRAGE Simulation; Post-process @ 2hr; Post-process @ 4hr; Post-process @ 8hr; Takeaways; Performance for 1 realization; Motivation for QOI; Multigroup Er; Transport and NLTE large effects (1mm, 1keV); Transport large effect, NLTE lesser (1mm, 750eV); Blastwave Diagnostici – Description & Performance; Temperature Comparison; NLTE has effect on dynamics at wall; NLTE has lesser effect in the foam; Global Takeaways; The end.
Quantum Emulation of Extreme Non-Equilibrium Phenomena with Trapped Atoms
Rajagopal, Shankari V.; Fujiwara, Kurt M.; Senaratne, Ruwan; Singh, Kevin; Geiger, Zachary A.; Weld, David M.
2017-08-01
Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium. We describe three related emerging directions of research into extreme non-equilibrium phenomena in atom traps: quantum emulation of ultrafast atom-light interactions, coherent phasonic spectroscopy in tunable quasicrystals, and realization of Floquet matter in strongly-driven lattice systems. We show that all three should enable quantum emulation in parameter regimes inaccessible in solid-state experiments, facilitating a complementary approach to open problems in non-equilibrium condensed matter.
Non-Equilibrium Liouville and Wigner Equations: Moment Methods and Long-Time Approximations
Directory of Open Access Journals (Sweden)
Ramon F. Álvarez-Estrada
2014-03-01
Full Text Available We treat the non-equilibrium evolution of an open one-particle statistical system, subject to a potential and to an external “heat bath” (hb with negligible dissipation. For the classical equilibrium Boltzmann distribution, Wc,eq, a non-equilibrium three-term hierarchy for moments fulfills Hermiticity, which allows one to justify an approximate long-time thermalization. That gives partial dynamical support to Boltzmann’s Wc,eq, out of the set of classical stationary distributions, Wc;st, also investigated here, for which neither Hermiticity nor that thermalization hold, in general. For closed classical many-particle systems without hb (by using Wc,eq, the long-time approximate thermalization for three-term hierarchies is justified and yields an approximate Lyapunov function and an arrow of time. The largest part of the work treats an open quantum one-particle system through the non-equilibrium Wigner function, W. Weq for a repulsive finite square well is reported. W’s (< 0 in various cases are assumed to be quasi-definite functionals regarding their dependences on momentum (q. That yields orthogonal polynomials, HQ,n(q, for Weq (and for stationary Wst, non-equilibrium moments, Wn, of W and hierarchies. For the first excited state of the harmonic oscillator, its stationary Wst is a quasi-definite functional, and the orthogonal polynomials and three-term hierarchy are studied. In general, the non-equilibrium quantum hierarchies (associated with Weq for the Wn’s are not three-term ones. As an illustration, we outline a non-equilibrium four-term hierarchy and its solution in terms of generalized operator continued fractions. Such structures also allow one to formulate long-time approximations, but make it more difficult to justify thermalization. For large thermal and de Broglie wavelengths, the dominant Weq and a non-equilibrium equation for W are reported: the non-equilibrium hierarchy could plausibly be a three-term one and possibly not
Trapped ion system for sympathetic cooling and non-equilibrium dynamics
Doret, Charlie; Jubin, Sierra; Stevenson, Sarah
2017-04-01
Atomic systems are superbly suited to the study of non-equilibrium dynamics. These systems' exquisite isolation from environmental perturbations leads to long relaxation times that enable exploration of far-from-equilibrium phenomena. We present progress towards trapping chains of multiple co-trapped calcium isotopes geared towards measuring thermal equilibration and sympathetic cooling rates. We also discuss plans for future experiments in non-equilibrium statistical mechanics, including exploration of the quantum-to-classical crossover between ballistic transport and diffusive, Fourier's Law conduction. This work is supported by Cottrell College Science Award from the Research Corporation for Science Advancement and by Williams College.
Leaching from MSWI bottom ash: Evaluation of non-equilibrium in column percolation experiments
DEFF Research Database (Denmark)
Hyks, Jiri; Astrup, Thomas; Christensen, Thomas Højlund
2009-01-01
Impacts of non-equilibrium on results of percolation experiments on municipal solid waste incineration (MSWI) bottom ash were investigated. Three parallel column experiments were performed: two columns with undisturbed percolation and one column with two sets of 1-month-long flow interruptions...... that the leaching of DOC-related metals in laboratory column experiments may be considerably underestimated compared with full-scale scenarios in which the impacts from non-equilibrium may be significantly lower. The leaching of Mo (or MoO42-) may be controlled solely by its availability in the mobile zone, which...
Many-body quantum electrodynamics networks: Non-equilibrium condensed matter physics with light
Le Hur, Karyn; Henriet, Loïc; Petrescu, Alexandru; Plekhanov, Kirill; Roux, Guillaume; Schiró, Marco
2016-10-01
We review recent developments regarding the quantum dynamics and many-body physics with light, in superconducting circuits and Josephson analogues, by analogy with atomic physics. We start with quantum impurity models addressing dissipative and driven systems. Both theorists and experimentalists are making efforts towards the characterization of these non-equilibrium quantum systems. We show how Josephson junction systems can implement the equivalent of the Kondo effect with microwave photons. The Kondo effect can be characterized by a renormalized light frequency and a peak in the Rayleigh elastic transmission of a photon. We also address the physics of hybrid systems comprising mesoscopic quantum dot devices coupled with an electromagnetic resonator. Then, we discuss extensions to Quantum Electrodynamics (QED) Networks allowing one to engineer the Jaynes-Cummings lattice and Rabi lattice models through the presence of superconducting qubits in the cavities. This opens the door to novel many-body physics with light out of equilibrium, in relation with the Mott-superfluid transition observed with ultra-cold atoms in optical lattices. Then, we summarize recent theoretical predictions for realizing topological phases with light. Synthetic gauge fields and spin-orbit couplings have been successfully implemented in quantum materials and with ultra-cold atoms in optical lattices - using time-dependent Floquet perturbations periodic in time, for example - as well as in photonic lattice systems. Finally, we discuss the Josephson effect related to Bose-Hubbard models in ladder and two-dimensional geometries, producing phase coherence and Meissner currents. The Bose-Hubbard model is related to the Jaynes-Cummings lattice model in the large detuning limit between light and matter (the superconducting qubits). In the presence of synthetic gauge fields, we show that Meissner currents subsist in an insulating Mott phase. xml:lang="fr"
Developments in Power efficient dissociation of CO2 using non-equilibrium plasma activation
van de Sanden, Richard
2013-09-01
Sustainable energy generation by means of, either photovoltaic conversion, concentrated solar power or wind, will certainly form a significant part of the energy mix in 2025. The intermittency as well as the temporal variation and the regional spread of this energy source, however, requires a means to store and transport energy on a large scale. In this presentation the means of storage will be addressed of sustainable energy transformed into fuels and the prominent role plasma science and technology can play in this great challenge. The storage of sustainable energy in these so called solar fuels, e.g. hydrocarbons and alcohols, by means of artificial photosynthesis from the feedstock CO2 and H2O, will enable a CO2 neutral power generation infrastructure, which is close to the present infrastructure based on fossil fuels. The challenge will be to achieve power efficient dissociation of CO2 or H2O or both, after which traditional chemical conversion (Fisher-Tropsch, Sabatier, etc.) towards fuels can take place. A promising route is the dissociation or activation of CO2 by means of plasma, possible combined with catalysis. Taking advantage of non-equilibrium plasma conditions to reach optimal energy efficiency we have started a solar fuels program at the beginning of 2012 focusing on CO2 plasma dissociation into CO and O2. The plasma is generated in a low loss microwave cavity with microwave powers up to 10 kW using a supersonic expansion to quench the plasma and prevent vibrational-translational relaxation losses. New ideas on the design of the facility and results on power efficient conversion (more then 50%) of large CO2 flows (up to 75 standard liter per minute with 11% conversion) at low gas temperatures will be presented.
Michelini, Fabienne; Crépieux, Adeline; Beltako, Katawoura
2017-05-01
We discuss some thermodynamic aspects of energy conversion in electronic nanosystems able to convert light energy into electrical or/and thermal energy using the non-equilibrium Green’s function formalism. In a first part, we derive the photon energy and particle currents inside a nanosystem interacting with light and in contact with two electron reservoirs at different temperatures. Energy conservation is verified, and radiation laws are discussed from electron non-equilibrium Green’s functions. We further use the photon currents to formulate the rate of entropy production for steady-state nanosystems, and we recast this rate in terms of efficiency for specific photovoltaic-thermoelectric nanodevices. In a second part, a quantum dot based nanojunction is closely examined using a two-level model. We show analytically that the rate of entropy production is always positive, but we find numerically that it can reach negative values when the derived particule and energy currents are empirically modified as it is usually done for modeling realistic photovoltaic systems.
Javoy, Marc
1999-10-01
This article presents a critical review of method, concepts and prejudices used bv modelists of the Earth's chemical composition over approximate the last fifty years and of the resulting compositions. Brief descriptions are given of admitted accretion mechanisms, of the starting materials most often considered and of the major parameters and recurrent concepts: 'reduced" state, mantle homogeneity vs heterogeneity, 'low pressure' core formation, 'great impact', refractory, lithophile, siderophile, compatible, incompatible character of elements, depleted and degassed mantle, Urey ratio, as well as the description of a commonly-used instrument, possibly harmful to Iogic, the famous Ockham's razor. Differences between models are now restricted to the lower mantle composition:the 'primary' (before crust differentiation) upper mentle varies little from model to model and the idea of a 10-15% combined Si-O-S concentration as representing the necessary light elements in the core is gaining more and more ground. The dominant type of model derives more or less directly from the CI cabonaceous composition by complete devolatilization and reduction. Its mantle is homogeneous and convecting mainly in a one-level mode, in accordence with dominant geophysicists' views but in rather strong disagreement with geochemical data and models which insist on the strong decoupling between lower and upper mantle. Its low Si excess is generally supposed to have been absorbed by the core, whereas its high refractory lithophile element (RLE) content creates mass balance problems relative to presently observed mantle and crust concentrations. The alternative type is a two-lavel mantle with a Si and Fe-rich, RLE-poor, lower mantle, previously based mainly on seismic and mineral physics data, and now also on geochemical and cosmochemical arguments.
Dan, K; Roy, M; Datta, A
2016-02-14
The present manuscript describes the role of entropic and enthalpic forces mediated by organic non-polar (hexane) and polar (methanol) solvents on the bulk and microscopic phase transition of a well known nematic liquid crystalline material MBBA (N-(4-methoxybenzylidene)-4-butylaniline) through Differential Scanning calorimetry (DSC), UV-Visible (UV-Vis), and Fourier Transform Infrared (FTIR) spectroscopy. DSC study indicates continuous linear decreases in both nematic-isotropic (N-I) phase transition temperature and enthalpy of MBBA in presence of hexane while both these parameters show a saturation after an initial decay in methanol. These distinct transitional behaviours were explained in terms of the "depletion force" model for entropic screening in hexane and "screening-self-screening" model for methanol. Heating rate dependent DSC studies find that non-Arrhenius behaviour, characteristic of pristine MBBA and a manifestation of non-equilibrium nature [Dan et al., J. Chem. Phys. 143, 094501 (2015)], is preserved in presence of entropic screening in the hexane solution, while it changes to Arrhenius behaviour (signifying equilibrium behaviour) in presence of enthalpic screening in methanol solution. FTIR spectra show similar dependence on the solvent induced screening in the intensities of the imine (-C = N) stretch and the out-of-plane distortion vibrations of the benzene rings of MBBA with hexane and methanol as in DSC, further establishing our entropic and enthalpic screening models. UV-Vis spectra of the electronic transitions in MBBA as a function of temperature also exhibit different dependences of intensities on the solvent induced screening, and an exponential decrease is observed in presence of hexane while methanol completely changes the nature of interaction to follow a linear dependence.
Directory of Open Access Journals (Sweden)
Zhengfeng Fan
2017-01-01
Full Text Available The non-equilibrium between ions and electrons in the hot spot can relax the ignition conditions in inertial confinement fusion [Fan et al., Phys. Plasmas 23, 010703 (2016], and obvious ion-electron non-equilibrium could be observed by our simulations of high-foot implosions when the ion-electron relaxation is enlarged by a factor of 2. On the other hand, in many shots of high-foot implosions on the National Ignition Facility, the observed X-ray enhancement factors due to ablator mixing into the hot spot are less than unity assuming electrons and ions have the same temperature [Meezan et al., Phys. Plasmas 22, 062703 (2015], which is not self-consistent because it can lead to negative ablator mixing into the hot spot. Actually, this non-consistency implies ion-electron non-equilibrium within the hot spot. From our study, we can infer that ion-electron non-equilibrium exists in high-foot implosions and the ion temperature could be ∼9% larger than the equilibrium temperature in some NIF shots.
Valeriani, C.; Allen, R.J.; Morelli, M.J.; Frenkel, D.; ten Wolde, P.R.
2009-01-01
We present a method for computing stationary distributions for activated processes in equilibrium and non-equilibrium systems using Forward Flux Sampling (FFS). In this method, the stationary distributions are obtained directly from the rate constant calculations for the forward and backward
Kinetic and mesoscopic non-equilibrium description of the Ca2+ pump : A comparison
Lervik, A.; Bedeaux, D.; Kjelstrup, S.H.
2012-01-01
We analyse the operation of the Ca2?-ATPase ion pump using a kinetic cycle diagram. Using the methodology of Hill, we obtain the cycle fluxes, entropy production and efficiency of the pump. We compare these results with a mesoscopic non-equilibrium description of the pump and show that the kinetic
Non-equilibrium dynamics of single polymer adsorption to solid surfaces
Panja, D.|info:eu-repo/dai/nl/370992105; Barkema, G.T.|info:eu-repo/dai/nl/101275080; Kolomeisky, A.B.
2009-01-01
The adsorption of polymers to surfaces is crucial for understanding many fundamental processes in nature. Recent experimental studies indicate that the adsorption dynamics is dominated by non-equilibrium effects. We investigate the adsorption of a single polymer of length N to a planar solid surface
The distribution coefficient (KD) for the human drug carbamazepine was measured using a non-equilibrium technique. Repacked soil columns were prepared using an Airport silt loam (Typic Natrustalf) with an average organic matter content of 2.45%. Carbamazepine solutions were then leached through th...
Westerhoff, Hans V.; Lolkema, Juke S.; Otto, Roel; Hellingwerf, K
1982-01-01
Microbial growth is analyzed in terms of mosaic and phenomenological non-equilibrium thermodynamics. It turns out that already existing parameters devised to measure bacterial growth, such as YATP, µ, and Qsubstrate, have as thermodynamic equivalents flow ratio, output flow and input flow. With this
A novel four-wing non-equilibrium chaotic system and its circuit ...
Indian Academy of Sciences (India)
A novel four-wing non-equilibrium chaotic system and its circuit implementation. YUAN LIN1,2,∗, CHUNHUA WANG1, HAIZHEN HE1 and LI LI ZHOU1. 1College of Information Science and Engineering, Hunan University, Changsha 410082, China. 2College of Electrical and Information Engineering, Hunan Institute of ...
Non-equilibrium condensation process in holographic superconductor with nonlinear electrodynamics
Energy Technology Data Exchange (ETDEWEB)
Liu, Yunqi; Gong, Yungui [School of Physics, Huazhong University of Science and Technology,Wuhan, Hubei 430074 (China); Wang, Bin [IFSA Collaborative Innovation Center, Department of Physics and Astronomy, Shanghai Jiao Tong University,Shanghai 200240 (China)
2016-02-17
We study the non-equilibrium condensation process in a holographic superconductor with nonlinear corrections to the U(1) gauge field. We start with an asymptotic Anti-de-Sitter(AdS) black hole against a complex scalar perturbation at the initial time, and solve the dynamics of the gravitational systems in the bulk. When the black hole temperature T is smaller than a critical value T{sub c}, the scalar perturbation grows exponentially till saturation, the final state of spacetime approaches to a hairy black hole. In the bulk theory, we find the clue of the influence of nonlinear corrections in the gauge filed on the process of the scalar field condensation. We show that the bulk dynamics in the non-equilibrium process is completely consistent with the observations on the boundary order parameter. Furthermore we examine the time evolution of horizons in the bulk non-equilibrium transformation process from the bald AdS black hole to the AdS hairy hole. Both the evolution of apparent and event horizons show that the original AdS black hole configuration requires more time to finish the transformation to become a hairy black hole if there is nonlinear correction to the electromagnetic field. We generalize our non-equilibrium discussions to the holographic entanglement entropy and find that the holographic entanglement entropy can give us further understanding of the influence of the nonlinearity in the gauge field on the scalar condensation.
Directory of Open Access Journals (Sweden)
Restuccia Liliana
2016-06-01
Full Text Available The paper deals with the meaning of non-equilibrium temperatures in nanosystems with an internal variable, describing defects inside them, and implications on heat transport. In equilibrium all definitions of temperature lead to the same value, but in nonequilibrium steady states they lead to different values, giving information on different degrees of freedom. We discuss the caloric and entropic non-equilibrium temperatures and the relations among them, in defective nanosystems (crystals with dislocations or porous channels, carbon nanotubes in a solid matrix and so on, crossed by an external energy flux. Here, we present a model for nanocrystals with dislocation defects submitted to an external energy flux. The dislocations may have a strong influence on the effective thermal conductivity, and their own dynamics may be coupled in relevant way to the heat flux dynamics. In the linear case the constitutive relations, the rate equations for the internal variable and the heat flux are worked out and a generalized telegraphic heat equation is derived in the anisotropic and isotropic case, describing the thermal disturbances with finite velocity.
Khajehpour Tadavani, Somayeh; Yethiraj, Anand
2017-10-18
We present experiments on a model system consisting of dielectric (silicone oil) drops in a "leaky dielectric" (castor oil) carrier fluid that exhibits dynamic non-equilibrium phases as a function of the amplitude and frequency of an external AC electric field. At high frequencies, the dielectric drops are pinned to a periodic lattice by dielectrophoretic forces induced by a patterned bottom electrode. Beginning with this state of imposed order, we examine the processes that take this system from order to disorder, with decreasing frequency corresponding to an increase in the range of the hydrodynamic forces. We find two kinds of disorder, shape- and translational disorder, that occur in frequency-amplitude space. We also find regimes where drop breakup is dominant, and where order/disorder of large drops can be probed without significant drop breakup. With decreasing frequency (i.e., increasing hydrodynamic coupling between drops) and on timescales from seconds to minutes, the drops exhibit motion that resembles Brownian motion of particles in a crystal, with an effective temperature that increases with the strength of the electrohydrodynamic driving force. In this limit, the system behaves like a thermal system and the lattice is seen to melt at an effective Lindemann parameter of Leff ∼ 0.08. This non-equilibrium thermodynamics, probed on timescales from seconds to minutes, likely arises from the pseudo-random velocity fields in the carrier fluid, as evidenced by the fractional, t(3/2), super-diffusive tracer dynamics at shorter timescales.
Directory of Open Access Journals (Sweden)
Baoguo Wang
2012-12-01
Full Text Available Hypersonic flows about space vehicles produce flowfields in thermodynamic non-equilibrium with the local Knudsen numbers Kn which may lie in all the three regimes: continuum, transition and rarefied. Continuum flows can be modeled accurately by solving the Navier–Stokes (NS equations; however, the flows in transition and rarefied regimes require a kinetic approach such as the direct simulation Monte Carlo (DSMC method or the solution of the Boltzmann equation. The Boltzmann equation and the general solution approach, using the splitting method, will be introduced in this paper. Details of the method used for solving both the classical Boltzmann equation (CBE and the generalized Boltzmann equation (GBE are also provided. The gas mixture discussed in this paper may consist of both monoatomic and diatomic gases. In particular, the method is applied to simulate two of the three primary constituents of air (N2, O2, and Ar in a binary mixture at 1:1 density ratio at Mach 2 and 5, with gases in translational, rotational and vibrational non-equilibrium.
Effect of Non-Equilibrium Surface Thermochemistry in Simulation of Carbon Based Ablators
Chen, Yih-Kanq; Gokcen, Tahir
2012-01-01
This study demonstrates that coupling of a material thermal response code and a flow solver using non-equilibrium gas/surface interaction model provides time-accurate solutions for the multidimensional ablation of carbon based charring ablators. The material thermal response code used in this study is the Two-dimensional Implicit Thermal-response and AblatioN Program (TITAN), which predicts charring material thermal response and shape change on hypersonic space vehicles. Its governing equations include total energy balance, pyrolysis gas mass conservation, and a three-component decomposition model. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation (DPLR) method. Loose coupling between the material response and flow codes is performed by solving the surface mass balance in DPLR and the surface energy balance in TITAN. Thus, the material surface recession is predicted by finite-rate gas/surface interaction boundary conditions implemented in DPLR, and the surface temperature and pyrolysis gas injection rate are computed in TITAN. Two sets of nonequilibrium gas/surface interaction chemistry between air and the carbon surface developed by Park and Zhluktov, respectively, are studied. Coupled fluid-material response analyses of stagnation tests conducted in NASA Ames Research Center arc-jet facilities are considered. The ablating material used in these arc-jet tests was Phenolic Impregnated Carbon Ablator (PICA). Computational predictions of in-depth material thermal response and surface recession are compared with the experimental measurements for stagnation cold wall heat flux ranging from 107 to 1100 Watts per square centimeter.
Pattern formation and non-equilibrium processes on crystalline surfaces induced by energetic ions
Chan, Wai Lun
Low energy ion bombardment can create self-assembly patterns on a surface through the competition of various ion-induced and surface relaxation processes. Different morphologies (e.g. ripples, mounds, and smoothing) can be formed on the surface depending on the sputtering conditions. In this work, we study how the observation of different kind of morphologies can be explained by the interplay between different microscopic processes on the surface. Copper surfaces are mainly used to investigate these questions. A kinetic phase diagram is proposed to delineate different pattern formation regimes. In addition, by measuring the temperature and flux dependence of the pattern wavelength, we investigate non-equilibrium processes such as ion-induced defect creation, which are otherwise difficult to observe directly. We find that during sputtering, the surface relaxation is primarily enhanced by the defects created by the bombardment process. Another part of the work is devoted to understand the relaxation kinetics of these nano-scale patterns on crystalline surfaces. Relaxations under thermal annealing and with a deposition flux are considered. Our results show that the relaxation under a deposition flux is fundamentally different from the thermal relaxation. Finally, we measure the surface stress created during the ion bombardment process. Stress as high as a few GPa can be induced in the ion-implanted layer and the creation of this stress is explained by the kinetics of ion-induced point defects. The works presented in this dissertation include a combination of experiments, simulations and continuum models. Each of the questions investigated is at least supported by two of these methods.
Collective phenomena in the non-equilibrium quark-gluon plasma
Energy Technology Data Exchange (ETDEWEB)
Schenke, Bjoern Peter
2008-07-03
In this work we study the non-equilibrium dynamics of a quark-gluon plasma, as created in heavy-ion collisions. We investigate how big of a role plasma instabilities can play in the isotropization and equilibration of a quark-gluon plasma. In particular, we determine, among other things, how much collisions between the particles can reduce the growth rate of unstable modes. This is done both in a model calculation using the hard-loop approximation, as well as in a real-time lattice simulation combining both classical Yang-Mills-fields as well as inter-particle collisions. The new extended version of the simulation is also used to investigate jet transport in isotropic media, leading to a cutoff-independent result for the transport coefficient q. The precise determination of such transport coefficients is essential, since they can provide important information about the medium created in heavy ion collisions. In anisotropic media, the effect of instabilities on jet transport is studied, leading to a possible explanation for the experimental observation that high-energy jets traversing the plasma perpendicular to the beam axis experience much stronger broadening in rapidity than in azimuth. The investigation of collective modes in the hard-loop limit is extended to fermionic modes, which are shown to be all stable. Finally, we study the possibility of using high energy photon production as a tool to experimentally determine the anisotropy of the created system. Knowledge of the degree of local momentum-space anisotropy reached in a heavy-ion collision is essential for the study of instabilities and their role for isotropization and thermalization, because their growth rate depends strongly on the anisotropy. (orig.)
Yeh, Leehwa
1993-01-01
The phase-space-picture approach to quantum non-equilibrium statistical mechanics via the characteristic function of infinite-mode squeezed coherent states is introduced. We use quantum Brownian motion as an example to show how this approach provides an interesting geometrical interpretation of quantum non-equilibrium phenomena.
Linear response theory and optimal control for a molecular system under non-equilibrium conditions
Wang, Han; Hartmann, Carsten; Schütte, Christof
2013-12-01
In this paper, we propose a straightforward generalisation of the linear response theory on a finite time-horizon to systems in non-equilibrium that are subject to external forcing. We briefly revisit the standard linear response result for equilibrium systems, where we consider Langevin dynamics as a special case, and then give an alternative derivation using a change-of-measure argument that does not rely on any stationarity or reversibility assumption. This procedure easily enables us to calculate the second-order correction to the linear response formula (which may or may not be useful in practice). Furthermore, we outline how the novel non-equilibrium linear response formula can be used to compute optimal controls of molecular systems for cases in which one wants to steer the system to maximise a certain target expectation value. We illustrate our approach with simple numerical examples.
What Can Reinforcement Learning Teach Us About Non-Equilibrium Quantum Dynamics
Bukov, Marin; Day, Alexandre; Sels, Dries; Weinberg, Phillip; Polkovnikov, Anatoli; Mehta, Pankaj
Equilibrium thermodynamics and statistical physics are the building blocks of modern science and technology. Yet, our understanding of thermodynamic processes away from equilibrium is largely missing. In this talk, I will reveal the potential of what artificial intelligence can teach us about the complex behaviour of non-equilibrium systems. Specifically, I will discuss the problem of finding optimal drive protocols to prepare a desired target state in quantum mechanical systems by applying ideas from Reinforcement Learning [one can think of Reinforcement Learning as the study of how an agent (e.g. a robot) can learn and perfect a given policy through interactions with an environment.]. The driving protocols learnt by our agent suggest that the non-equilibrium world features possibilities easily defying intuition based on equilibrium physics.
The molecular photo-cell: quantum transport and energy conversion at strong non-equilibrium.
Ajisaka, Shigeru; Žunkovič, Bojan; Dubi, Yonatan
2015-02-09
The molecular photo-cell is a single molecular donor-acceptor complex attached to electrodes and subject to external illumination. Besides the obvious relevance to molecular photo-voltaics, the molecular photo-cell is of interest being a paradigmatic example for a system that inherently operates in out-of-equilibrium conditions and typically far from the linear response regime. Moreover, this system includes electrons, phonons and photons, and environments which induce coherent and incoherent processes, making it a challenging system to address theoretically. Here, using an open quantum systems approach, we analyze the non-equilibrium transport properties and energy conversion performance of a molecular photo-cell, including both coherent and incoherent processes and treating electrons, photons, and phonons on an equal footing. We find that both the non-equilibrium conditions and decoherence play a crucial role in determining the performance of the photovoltaic conversion and the optimal energy configuration of the molecular system.
Scaling approach to quantum non-equilibrium dynamics of many-body systems
Energy Technology Data Exchange (ETDEWEB)
Gritsev, Vladimir; Barmettler, Peter [Physics Department, University of Fribourg, Chemin du Musee 3, 1700 Fribourg (Switzerland); Demler, Eugene, E-mail: vladimir.gritsev@unifr.c [Lyman Laboratory of Physics, Physics Department, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States)
2010-11-15
Understanding the non-equilibrium quantum dynamics of many-body systems is one of the most challenging problems in modern theoretical physics. While numerous approximate and exact solutions exist for systems in equilibrium, examples of non-equilibrium dynamics of many-body systems that allow reliable theoretical analysis are few and far between. In this paper, we discuss a broad class of time-dependent interacting systems subject to external linear and parabolic potentials, for which the many-body Schroedinger equation can be solved using a scaling transformation. We demonstrate that scaling solutions exist for both local and non-local interactions, and derive appropriate self-consistency equations. We apply this approach to several specific experimentally relevant examples of interacting bosons in one and two dimensions. As an intriguing result, we find that weakly and strongly interacting Bose gases expanding from a parabolic trap can exhibit very similar dynamics.
On Non-Equilibrium Thermodynamics of Space-Time and Quantum Gravity
Munkhammar, Joakim
2015-01-01
Based on recent results from general relativistic statistical mechanics and black hole information transfer limits a space-time entropy-action equivalence is proposed as a generalization of the holographic principle. With this conjecture, the action principle can be replaced by the second law of thermodynamics, and for the Einstein-Hilbert action the Einstein field equations are conceptually the result of thermodynamic equilibrium. For non-equilibrium situations Jaynes' information-theoretic approach to maximum entropy production is adopted instead of the second law of thermodynamics. As it turns out, for appropriate choices of constants quantum gravity is obtained. For the special case of a free particle the Bekenstein-Verlinde entropy-to-displacement relation of holographic gravity, and thus the traditional holographic principle, emerges. Although Jacobson's original thermodynamic equilibrium approach proposed that gravity might not necessarily be quantized, this particular non-equilibrium treatment might r...
Energy Technology Data Exchange (ETDEWEB)
Pruschke, Th., E-mail: pruschke@theorie.physik.uni-goettingen.d [Insitute for Theoretical Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goetingen (Germany); Dirks, A.; Gezzi, R. [Insitute for Theoretical Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goetingen (Germany)
2009-10-15
We present an extension of the concepts of the functional renormalization group approach to quantum many-body problems in non-equilibrium situations. The approach is completely general and allows calculations for both stationary and time-dependent situations. As a specific example we study the stationary state transport through a quantum dot with local Coulomb correlations. We discuss the influence of finite bias voltage and temperature on the current and conductance.
Non-equilibrium Thermodynamics and the Production of Entropy Life, Earth, and Beyond
Kleidon, Axel
2005-01-01
The present volume studies the application of concepts from non-equilibrium thermodynamics to a variety of research topics. Emphasis is on the Maximum Entropy Production (MEP) principle and applications to Geosphere-Biosphere couplings. Written by leading researchers form a wide range of background, the book proposed to give a first coherent account of an emerging field at the interface of thermodynamics, geophysics and life sciences.
Non-equilibrium thermodynamics theory of econometric source discovery for large data analysis
van Bergem, Rutger; Jenkins, Jeffrey; Benachenhou, Dalila; Szu, Harold
2014-05-01
Almost all consumer and firm transactions are achieved using computers and as a result gives rise to increasingly large amounts of data available for analysts. The gold standard in Economic data manipulation techniques matured during a period of limited data access, and the new Large Data Analysis (LDA) paradigm we all face may quickly obfuscate most tools used by Economists. When coupled with an increased availability of numerous unstructured, multi-modal data sets, the impending 'data tsunami' could have serious detrimental effects for Economic forecasting, analysis, and research in general. Given this reality we propose a decision-aid framework for Augmented-LDA (A-LDA) - a synergistic approach to LDA which combines traditional supervised, rule-based Machine Learning (ML) strategies to iteratively uncover hidden sources in large data, the artificial neural network (ANN) Unsupervised Learning (USL) at the minimum Helmholtz free energy for isothermal dynamic equilibrium strategies, and the Economic intuitions required to handle problems encountered when interpreting large amounts of Financial or Economic data. To make the ANN USL framework applicable to economics we define the temperature, entropy, and energy concepts in Economics from non-equilibrium molecular thermodynamics of Boltzmann viewpoint, as well as defining an information geometry, on which the ANN can operate using USL to reduce information saturation. An exemplar of such a system representation is given for firm industry equilibrium. We demonstrate the traditional ML methodology in the economics context and leverage firm financial data to explore a frontier concept known as behavioral heterogeneity. Behavioral heterogeneity on the firm level can be imagined as a firm's interactions with different types of Economic entities over time. These interactions could impose varying degrees of institutional constraints on a firm's business behavior. We specifically look at behavioral heterogeneity for firms
Electrical pulse measurement, inelastic relaxation, and non-equilibrium transport in a quantum dot
Energy Technology Data Exchange (ETDEWEB)
Fujisawa, T [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198 (Japan); Austing, D G [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198 (Japan); Institute of Microstructural Science M23A, National Research Council of Canada, Ottawa, ON K1A 0R6 (Canada); Tokura, Y [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198 (Japan); Hirayama, Y [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198 (Japan); CREST, 4-1-8 Honmachi, Kawaguchi 331-0012 (Japan); Tarucha, S [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198 (Japan); University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); ERATO Mesoscopic Correlation Project, 3-1 Morinosato-Wakamiya, Atsugi 243-0198 (Japan)
2003-08-27
We review electrical pulse experiments carried out to probe inelastic energy relaxation processes and related non-equilibrium transport characteristics of quantum dots (QDs) in the Coulomb blockade (CB) regime. In contrast to the relatively short momentum relaxation time ({approx}10 ns) that can be understood on the basis of acoustic phonon emission, the spin-flip relaxation time is found to be extremely long ({approx}200 {mu}s). The spin relaxation process in our QDs is actually dominated by a cotunnelling process, and thus the intrinsic spin relaxation should have a longer relaxation time. The long relaxation time is discussed in terms of potential applications to spin-based quantum information storage. On the other hand, the extremely long spin relaxation process can induce considerable fluctuation of the spin, charge, and total energy of the QD. The absence of efficient spin relaxation processes can cause highly non-equilibrium transport, which actually 'breaks down' the single-electron tunnelling scheme. The non-equilibrium effects must be considered when electrons and spins are manipulated in the CB regime. (topical review)
Non-equilibrium spatial distribution of Rashba spin torque in ferromagnetic metal layer
Directory of Open Access Journals (Sweden)
N. L. Chung
2012-06-01
Full Text Available We study the spatial distribution of spin torque induced by a strong Rashba spin-orbit coupling (RSOC in a ferromagnetic (FM metal layer, using the Keldysh non-equilibrium Green's function method. In the presence of the s-d interaction between the non-equilibrium conduction electrons and the local magnetic moments, the RSOC effect induces a torque on the moments, which we term the Rashba spin torque. A correlation between the Rashba spin torque and the spatial spin current is presented in this work, clearly mapping the spatial distribution of Rashba spin torque in a nano-sized ferromagnetic device. When local magnetism is turned on, the out-of-plane (Sz Spin Hall effect (SHE is disrupted, but rather unexpectedly an in-plane (Sy SHE is detected. We also study the effect of Rashba strength (αR and splitting exchange (Δ on the non-equilibrium Rashba spin torque averaged over the device. Rashba spin torque allows an efficient transfer of spin momentum such that a typical switching field of 20 mT can be attained with a low current density of less than 107A/cm2.
The effect of non-equilibrium condensation on the drag coefficient in a transonic airfoil flow
Kim, I. W.; Alam, M. M. A.; Lee, S. J.; Kwon, Y. D.; Kwon, S. B.
2012-12-01
In this study, a transonic flow past NACA0012 profile at angle of attack α=00 whose aspect ratio AR is 1.0 with non-equilibrium condensation is analyzed by numerical analysis using a TVD scheme and is investigated using an intermittent indraft type supersonic wind tunnel. Transonic flows of 0.78-0.90 in free stream Mach number with the variations of the stagnation relative humidity(Φ0) are tested. For the same free stream Mach number, the increase in Φ0 causes decrease in the drag coefficient of profile which is composed of the drag components of form, viscous and wave. In the case of the same M∞ and T0, for more than Φ0=30%, despite the irreversibility of process in non-equilibrium condensation, the drag by shock wave decreases considerably with the increase of Φ0. On the other hand, it shows that the effect of condensation on the drag coefficients of form and viscous is negligible. As an example, the decreasing rate in the drag coefficient of profile caused by the influence of non-equilibrium condensation for the case of M∞=0.9 and Φ0 =50% amounts to 34%. Also, it were turned out that the size of supersonic bubble (that is, the maximum height of supersonic zone) and the deviation of pressure coefficient from the value for M=1 decrease with the increase of Φ0 for the same M∞.
Multi-Modality Pulsed AC Source for Medical Applications of Non-Equilibrium Plasmas
Friedrichs, Daniel; Gilbert, James
2014-10-01
A burgeoning field has developed around the use of non-equilibrium (``cold'') plasmas for various medical applications, including wound treatment, surface sterilization, non-thermal hemostasis, and selective cell destruction. Proposed devices typically utilize pulsed DC power sources, which have no other therapeutic utility, and may encounter significant regulatory restrictions regarding their safety for use in patient care. Additionally, dedicated capital equipment is difficult for healthcare facilities to justify. In this work, we have demonstrated for the first time the generation of non-equilibrium plasma using pulsed AC output from a specially-designed electrosurgical generator. The ability to power novel non-equilibrium plasma devices from a piece of equipment already ubiquitous in operating theatres should significantly reduce the barriers to adoption of plasma devices. We demonstrate the ability of a prototype device, coupled to this source, to reduce bacterial growth in vitro. Such a system could allow a single surgical instrument to provide both non-thermal sterilization and thermal tissue dissection.
Futera, Zdenek; English, Niall J.
2017-07-01
The response of water to externally applied electric fields is of central relevance in the modern world, where many extraneous electric fields are ubiquitous. Historically, the application of external fields in non-equilibrium molecular dynamics has been restricted, by and large, to relatively inexpensive, more or less sophisticated, empirical models. Here, we report long-time non-equilibrium ab initio molecular dynamics in both static and oscillating (time-dependent) external electric fields, therefore opening up a new vista in rigorous studies of electric-field effects on dynamical systems with the full arsenal of electronic-structure methods. In so doing, we apply this to liquid water with state-of-the-art non-local treatment of dispersion, and we compute a range of field effects on structural and dynamical properties, such as diffusivities and hydrogen-bond kinetics.
Energy Technology Data Exchange (ETDEWEB)
Murakami, Izumi; Kato, Takako [National Inst. for Fusion Science, Toki, Gifu (Japan); Safronova, U.
1999-01-01
We have calculated the dielectronic recombination rate coefficients from Li-like Ne (Ne{sup 7+}) ions to Be-like Ne (Ne{sup 6+}) ions for selected excited states of Ne{sup 6+} ions. A collisional-radiative model (CRM) for Ne{sup 6+} ions is constructed to calculate the population density of each excited state in non-equilibrium ionization plasmas, including recombining processes. NeVII spectral line intensities and the radiative power loss are calculated with the CRM. A density effect caused by collisional excitation from the metastable state 2s2p {sup 3}P is found at an electron density of 10{sup 5} - 10{sup 17} cm{sup -3}. The collisional excitations between excited states become important at high electron temperature T{sub e} > or approx. 100 eV. (author)
Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas
Petrović, Zoran; Mason, Nigel; Hamaguchi, Satoshi; Radmilović-Radjenović, Marija
2007-06-01
Serbian Academy of Sciences and Arts and Institute of Physics, Belgrade. Each Symposium has sought to highlight a key topic of plasma research and the 5th EU - Japan symposium explored the role of Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas since these are key elements of plasma processing. Other aspects of technologies for manufacturing integrated circuits were also considered. Unlike bio-medicine and perhaps politics, in plasma processing free radicals are `good radicals' but their kinetics are difficult to understand since there remains little data on their collisions with electrons and ions. One of the goals of the symposium was to facilitate communication between experimentalists and theorists in binary collision physics with plasma modellers and practitioners of plasma processing in order to optimize efforts to provide much needed data for both molecules and radicals of practical importance. The non-equilibrium nature of plasmas is critical in the efficient manufacturing of high resolution structures by anisotropic plasma etching on Si wafers since they allow separate control of the directionality and energy of ions and provide a high level of separation between the mean energies of electrons and ions. As nanotechnologies become practical, plasma processing may play a key role, not only in manufacturing of integrated circuits, but also for self-organization of massively parallel manufacturing of nanostructures. In this Symposium the key issues that are hindering the development of such new, higher resolution technologies were discussed and some possible solutions were proposed. In particular, damage control, fast neutral etching, processes at surface and modeling of profiles were addressed in several of the lectures. A wide range of topics are covered in this book including atomic and molecular collision physics - primarily focused towards formation and analysis of radicals, basic swarm data and breakdown kinetics, basic kinetics of RF and DC
Energy Technology Data Exchange (ETDEWEB)
Weisgerber, H.
2002-03-01
The exhaust gas flow in the model thrust nozzle under investigation is characterized by chemical and thermal (vibrational) non-equilibrium which is experimentally detected by differing rotational and vibrational temperatures in the supersonic region of the nozzle. An analytical method to determine the vibrational relaxation time from expansion experiments is presented and validated using literature data. The nitrogen vibrational temperature at the nozzle exit strongly depends on the relaxation time of collisions with water molecules; for this process a correlation from the literature is selected. The measurements are completed by an experimental and numerical analysis of velocimetry tracer particle motion in flows with strong velocity gradients and an experimental investigation of the causes and effects of laser beam distortions occurring in high enthalpy flows. So a reliable database is presented for a reacting flow in a model nozzle of rectangular cross-section which was already used to validate a CFD code including the model of thermal non-equilibrium effects. (orig.) [German] Die Stroemung eines Abgases in der untersuchten Modellschubduese ist charakterisiert durch chemisches und thermisches (vibratorisches) Nichtgleichgewicht, das durch die Abweichung der Vibrations- von der Rotationstemperatur des Stickstoffmolekuels im Ueberschallteil der Duese experimentell belegt wird. Eine Methode zur analytischen Ermittlung der Vibrationsrelaxationszeit aus Expansionsexperimenten wird vorgestellt und anhand von Literaturdaten validiert. Die entscheidende Groesse fuer die Vibrationstemperatur des Stickstoffs am Duesenaustritt ist die Relaxationszeit beim Stoss mit einem Wassermolekuel; aus den fuer diesen Vorgang vorliegenden Literaturangaben wird eine Korrelation ausgewaehlt. Zur Absicherung der Messungen wird zum einen das Folgeverhalten von zur Geschwindigkeitsmessung zugefuegten Partikeln in Stroemungen mit starken Geschwindigkeitsgradienten experimentell und
Hubeny, Ivan
2015-01-01
This book provides an in-depth and self-contained treatment of the latest advances achieved in quantitative spectroscopic analyses of the observable outer layers of stars and similar objects. Written by two leading researchers in the field, it presents a comprehensive account of both the physical foundations and numerical methods of such analyses. The book is ideal for astronomers who want to acquire deeper insight into the physical foundations of the theory of stellar atmospheres, or who want to learn about modern computational techniques for treating radiative transfer in non-equilibrium situations. It can also serve as a rigorous yet accessible introduction to the discipline for graduate students.
Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films
Energy Technology Data Exchange (ETDEWEB)
Chase, T. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Trigo, M.; Reid, A. H.; Dürr, H. A. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Li, R.; Vecchione, T.; Shen, X.; Weathersby, S.; Coffee, R.; Hartmann, N.; Wang, X. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Reis, D. A. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)
2016-01-25
We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.
The effect of time-dependent coupling on non-equilibrium steady states
DEFF Research Database (Denmark)
Cornean, Horia; Neidhardt, Hagen; Zagrebnov, Valentin
Consider (for simplicity) two one-dimensional semi-infinite leads coupled to a quantum well via time dependent point interactions. In the remote past the system is decoupled, and each of its components is at thermal equilibrium. In the remote future the system is fully coupled. We define...... and compute the non equilibrium steady state (NESS) generated by this evolution. We show that when restricted to the subspace of absolute continuity of the fully coupled system, the state does not depend at all on the switching. Moreover, we show that the stationary charge current has the same invariant...
Depletion of superfluidity in a disordered non-equilibrium quantum condensate
Energy Technology Data Exchange (ETDEWEB)
Janot, Alexander; Rosenow, Bernd [Institut fuer Theoretische Physik, Universitaet Leipzig, 04009 Leipzig (Germany); Hyart, Timo [Institute of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Eastham, Paul [School of Physics, Trinity College, Dublin 2 (Ireland)
2013-07-01
Observations of quantum coherence in driven systems, e.g. polariton condensates, have strongly stimulated experimental as well as theoretical efforts during the last decade. We analyze the superfluid stiffness of a non-equilibrium quantum-condensate in a disordered environment taking gain and loss of particles into account. To this end a modified effective Gross-Pitaevskii equation is employed. We find that the disorder-driven depletion of superfluidity is strongly enhanced due to the gain-loss mechanism. It turns out that the condensate remains stiff at finite length scales only.
The effect of time-dependent coupling on non-equilibrium steady states
DEFF Research Database (Denmark)
Cornean, Horia; Neidhardt, Hagen; Zagrebnov, Valentin A.
2009-01-01
Consider (for simplicity) two one-dimensional semi-infinite leads coupled to a quantum well via time dependent point interactions. In the remote past the system is decoupled, and each of its components is at thermal equilibrium. In the remote future the system is fully coupled. We define...... and compute the non equilibrium steady state (NESS) generated by this evolution. We show that when restricted to the subspace of absolute continuity of the fully coupled system, the state does not depend at all on the switching. Moreover, we show that the stationary charge current has the same invariant...
Microcavity quantum-dot systems for non-equilibrium Bose-Einstein condensation
Energy Technology Data Exchange (ETDEWEB)
Piper, I M; Ediger, M; Wilson, A M; Wu, Y; Phillips, R T [Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Eastham, P R [School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Hugues, M; Hopkinson, M, E-mail: imp24@cam.ac.u [Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)
2010-09-01
We review the practical conditions required to achieve a non-equilibrium BEC driven by quantum dynamics in a system comprising a microcavity field mode and a distribution of localised two-level systems driven to a step-like population inversion profile. A candidate system based on eight 3.8nm layers of In{sub 0.23}Ga{sub 0.77}As in GaAs shows promising characteristics with regard to the total dipole strength which can be coupled to the field mode.
Marshall Mccall, Patrick
Living cells are hierarchically self-organized forms of active soft matter: molecules on the nanometer scale form functional structures and organelles on the micron scale, which then compose cells on the scale of 10s of microns. While the biological functions of intracellular organelles are defined by the composition and properties of the structures themselves, how those bulk properties emerge from the properties and interactions of individual molecules remains poorly understood. Actin, a globular protein which self-assembles into dynamic semi-flexible polymers, is the basic structural material of cells and the major component of many functional organelles. In this thesis, I have used purified actin as a model system to explore the interplay between molecular-scale dynamics and organelle-scale functionality, with particular focus on the role of molecular-scale non-equilibrium activity. One of the most canonical forms of molecular-scale non-equilibrium activity is that of mechanoenzymes, also called motor proteins. These proteins utilized the free energy liberated by hydrolysis of ATP to perform mechanical work, thereby introducing non-equilibrium "active" stresses on the molecular scale. Combining experiments with mathematical modeling, we demonstrate in this thesis that non-equilibrium motor activity is sufficient to drive self-organization and pattern formation of the multimeric actin-binding motor protein Myosin II on 1D reconstituted actomyosin bundles. Like myosin, actin is itself an ATPase. However, nono-equilibrium ATP hydrolysis on actin is known to regulate the stability and assembly kinetics of actin filaments rather than generate active stresses per se. At the level of single actin filaments, the inhomogeneous nucleotide composition generated along the filament length by hydrolysis directs binding of regulatory proteins like cofilin, which mediate filament disassembly and thereby accelerate actin filament turnover. The concequences of this non-equilibrium
Energy Technology Data Exchange (ETDEWEB)
Cooper, F. [Los Alamos National Labs., NM (United States)
1997-09-22
This paper contains viewgraphs on unusual dileptons at Brookhaven RHIC. A field theory approach is used based on a non-equilibrium chiral phase transformation utilizing the schroedinger and Heisenberg picture.
Yoshimura, Shinji; Kasahara, Hiroshi; Akiyama, Tsuyoshi
2017-10-01
Medical applications of non-equilibrium atmospheric plasmas have recently been attracting a great deal of attention, where many types of plasma sources have been developed to meet the purposes. For example, plasma-activated medium (PAM), which is now being studied for cancer treatment, has been produced by irradiating non-equilibrium atmospheric pressure plasma with ultrahigh electron density to a culture medium. Meanwhile, in order to measure electron density in magnetic confinement plasmas, a CO2 laser dispersion interferometer has been developed and installed on the Large Helical Device (LHD) at the National Institute for Fusion Science, Japan. The dispersion interferometer has advantages that the measurement is insensitive to mechanical vibrations and changes in neutral gas density. Taking advantage of these properties, we applied the dispersion interferometer to electron density diagnostics of atmospheric pressure plasmas produced by the NU-Global HUMAP-WSAP-50 device, which is used for producing PAM. This study was supported by the Grant of Joint Research by the National Institutes of Natural Sciences (NINS).
Giant THz photoconductivity and possible non-equilibrium superconductivity in metallic K3C60
Mitrano, M.; Cantaluppi, A.; Nicoletti, D.; Kaiser, S.; Perucchi, A.; Lupi, S.; Di Pietro, P.; Pontiroli, D.; Riccò, M.; Clark, S. R.; Jaksch, D.; Cavalleri, A.
2015-01-01
The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects like the optical enhancement of superconductivity 1 . Recently, nonlinear excitation 2 , 3 of certain phonons in bilayer cuprates was shown to induce superconducting-like optical properties at temperatures far above Tc 4,5,6. This effect was accompanied by the disruption of competing charge-density-wave correlations7,8, which explained some but not all of the experimental results. Here, we report a similar phenomenon in a very different compound. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. Strikingly, these same signatures are observed at equilibrium when cooling metallic K3C60 below the superconducting transition temperature (Tc = 20 K). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this scenario as a possible explanation of our results. PMID:26855424
Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity.
O'Meara, Brian C; Smith, Stacey D; Armbruster, W Scott; Harder, Lawrence D; Hardy, Christopher R; Hileman, Lena C; Hufford, Larry; Litt, Amy; Magallón, Susana; Smith, Stephen A; Stevens, Peter F; Fenster, Charles B; Diggle, Pamela K
2016-05-11
Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction) and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years. © 2016 The Author(s).
Non-equilibrium forces drive the anomalous diffusion of telomeres in the nucleus of mammalian cells
Stadler, Lorenz; Weiss, Matthias
2017-11-01
Telomeres are vital nucleotide sequences at both ends of each chromosome, and their motion reports on the local dynamics of decondensed chromatin in the nucleus of interphase cells. Here, we show that the previously reported subdiffusive motion of telomeres is driven by non-equilibrium cytoskeletal forces. In particular, breaking down microtubules leads to a significantly reduced generalized diffusion coefficient of telomeres. This translates into a markedly reduced effective temperature in the stochastic forces that govern the telomeres’ random walk. Moreover, telomere motion in cells that lack microtubules is well described by the monomer dynamics of a Rouse polymer that is embeddded in a viscoelastic medium. In contrast, active cytoskeletal forces in untreated cells override the environment’s elastic contributions, resulting in the well-known scaling for conventional Rouse dynamics in viscous media. Our data highlight that even subdiffusive motion in cells in most cases may not be a simple thermal transport process but rather is driven by non-equilibrium events.
Ion acceleration in non-equilibrium plasmas driven by fast drifting electron
Energy Technology Data Exchange (ETDEWEB)
Castro, G. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S.Sofia 64, 95123 Catania (Italy); Di Bartolo, F., E-mail: fdibartolo@unime.it [Università di Messina, V.le F. Stagno D’Alcontres 31, 98166, Messina (Italy); Gambino, N. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Metodologie Fisiche e Chimiche per L’ingegneria, Viale A.Doria 6, 95125 Catania (Italy); Mascali, D. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Romano, F.P. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); CNR-IBAM Via Biblioteca 4, 95124 Catania (Italy); Anzalone, A.; Celona, L.; Gammino, S. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Di Giugno, R. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S.Sofia 64, 95123 Catania (Italy); Lanaia, D. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Miracoli, R. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S.Sofia 64, 95123 Catania (Italy); Serafino, T. [CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Tudisco, S. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy)
2013-05-01
We hereby present results on ion acceleration mechanisms in non equilibrium plasmas generated by microwaves or high intensity laser pulses. Experiments point out that in magnetized plasmas X–B conversion takes place for under resonance values of the magnetic field, i.e. an electromagnetic mode is converted into an electrostatic wave. The strong self-generated electric field, of the order of 10{sup 7} V/m, causes a E × B drift which accelerates both ions and electrons, as it is evident by localized sputtering in the plasma chamber. These fields are similar (in magnitude) to the ones obtainable in laser generated plasmas at intensity of 10{sup 12} W/cm{sup 2}. In this latter case, we observe that the acceleration mechanism is driven by electrons drifting much faster than plasma bulk, thus generating an extremely strong electric field ∼10{sup 7} V/m. The two experiments confirm that ions acceleration at low energy is possible with table-top devices and following complementary techniques: i.e. by using microwave-driven (producing CW beams) plasmas, or non-equilibrium laser-driven plasmas (producing pulsed beams). Possible applications involve ion implantation, materials surface modifications, ion beam assisted lithography, etc.
Non-Equilibrium Dynamics of C-QED Arrays in Strong Correlation Regime
Zhang, Xin-Ding; Li, Zhi-Hang; Zhang, Xiao-Ming
2016-11-01
Recently increasing interests are attracted in the physics of controlled arrays of nonlinear cavity resonators because of the rapid experimental progress achieved in cavity and circuit quantum electrodynamics (QED). For a driven-dissipative two-dimentional planar C-QED array, standard Markov master equation is generally used to study the dynamics of this system. However, when in the case that the on-site photon-photon interaction enters strong correlation regime, standard Markov master equation may lead to incorrect results. In this paper we study the non-equilibrium dynamics of a two-dimentional C-QED array, which is homogeneously pumped by an external pulse, at the same time dissipation exits. We study the evolution of the average photon number of a single cavity by deriving a modified master equation to. In comparison with the standard master equation, the numerical result obtained by our newly derived master equation shows significant difference for the non-equilibrium dynamics of the system.
Effect of Non-Equilibrium Condensation on Force Coefficients in Transonic Airfoil Flow
Energy Technology Data Exchange (ETDEWEB)
Choi, Seung Min; Kang, Hui Bo; Kwon, Young Doo; Kwon, Soon Bum [Kyungpook National Univeristy, Daegu (Korea, Republic of); Jeon, Heung Kyun [Daegu Health College, Daegu (Korea, Republic of)
2014-12-15
The present study investigated the effects of non-equilibrium condensation with the angle of attack on the coefficients of pressure, lift, and drag in the transonic 2-D flow of NACA0012 by numerical analysis of the total variation diminishing (TVD) scheme. At T{sub 0}=298 K and α=3°, the lift coefficients for M{sub ∞}=0.78 and 0.81 decreased monotonically with increasing Φ{sub 0}. In contrast, for M{sub ∞} corresponding to the Mach number of the force break, CL increased with Φ{sub 0}. For α=3° and Φ{sub 0}=0%, CD increased markedly as M{sub ∞} increased. However, at Φ{sub 0}=60% and α=3°, which corresponded to the case of the condensation having a large influence, CD increased slightly as M{sub ∞} increased. The decrease in profile drag by non-equilibrium condensation grew as the angle of attack and stagnation relative humidity increased for the same free stream transonic Mach number. At Φ{sub 0}=0%, the coefficient of the wave drag increased with the attack angle and free stream Mach number. When Φ{sub 0}>50%, the coefficient of the wave drag decreased as α and M{sub ∞} increased. Lowering Φ{sub 0} and increasing M{sub ∞} increased the maximum Mach number.
Su, Xianli; Wei, Ping; Li, Han; Liu, Wei; Yan, Yonggao; Li, Peng; Su, Chuqi; Xie, Changjun; Zhao, Wenyu; Zhai, Pengcheng; Zhang, Qingjie; Tang, Xinfeng; Uher, Ctirad
2017-05-01
Considering only about one third of the world's energy consumption is effectively utilized for functional uses, and the remaining is dissipated as waste heat, thermoelectric (TE) materials, which offer a direct and clean thermal-to-electric conversion pathway, have generated a tremendous worldwide interest. The last two decades have witnessed a remarkable development in TE materials. This Review summarizes the efforts devoted to the study of non-equilibrium synthesis of TE materials with multi-scale structures, their transport behavior, and areas of applications. Studies that work towards the ultimate goal of developing highly efficient TE materials possessing multi-scale architectures are highlighted, encompassing the optimization of TE performance via engineering the structures with different dimensional aspects spanning from the atomic and molecular scales, to nanometer sizes, and to the mesoscale. In consideration of the practical applications of high-performance TE materials, the non-equilibrium approaches offer a fast and controllable fabrication of multi-scale microstructures, and their scale up to industrial-size manufacturing is emphasized here. Finally, the design of two integrated power generating TE systems are described-a solar thermoelectric-photovoltaic hybrid system and a vehicle waste heat harvesting system-that represent perhaps the most important applications of thermoelectricity in the energy conversion area. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Chemical model reduction under uncertainty
Najm, Habib
2016-01-05
We outline a strategy for chemical kinetic model reduction under uncertainty. We present highlights of our existing deterministic model reduction strategy, and describe the extension of the formulation to include parametric uncertainty in the detailed mechanism. We discuss the utility of this construction, as applied to hydrocarbon fuel-air kinetics, and the associated use of uncertainty-aware measures of error between predictions from detailed and simplified models.
Directory of Open Access Journals (Sweden)
Lilian Govone
2017-12-01
Full Text Available This paper presents a theoretical investigation of the second law performance of double diffusive forced convection in microreactors with the inclusion of nanofluid and radiation effects. The investigated microreactors consist of a single microchannel, fully filled by a porous medium. The transport of heat and mass are analysed by including the thick walls and a first order, catalytic chemical reaction on the internal surfaces of the microchannel. Two sets of thermal boundary conditions are considered on the external surfaces of the microchannel; (1 constant temperature and (2 constant heat flux boundary condition on the lower wall and convective boundary condition on the upper wall. The local thermal non-equilibrium approach is taken to thermally analyse the porous section of the system. The mass dispersion equation is coupled with the transport of heat in the nanofluid flow through consideration of Soret effect. The problem is analytically solved and illustrations of the temperature fields, Nusselt number, total entropy generation rate and performance evaluation criterion (PEC are provided. It is shown that the radiation effect tends to modify the thermal behaviour within the porous section of the system. The radiation parameter also reduces the overall temperature of the system. It is further demonstrated that, expectedly, the nanoparticles reduce the temperature of the system and increase the Nusselt number. The total entropy generation rate and consequently PEC shows a strong relation with radiation parameter and volumetric concentration of nanoparticles.
Chemical Oscillations-Mathematical Modelling
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 7. Chemical Oscillations - Mathematical Modelling ... Protein Science and Engineering Unit Institute of Microbial Technology Sector 39A Chandigarh 160 036; Department of Chemistry and Centre for Advanced Studies in Chemistry Punjab ...
Directory of Open Access Journals (Sweden)
Enrico Sciubba
2017-11-01
Full Text Available The paper discusses how the two thermodynamic properties, energy (U and exergy (E, can be used to solve the problem of quantifying the entropy of non-equilibrium systems. Both energy and exergy are a priori concepts, and their formal dependence on thermodynamic state variables at equilibrium is known. Exploiting the results of a previous study, we first calculate the non-equilibrium exergy En-eq can be calculated for an arbitrary temperature distributions across a macroscopic body with an accuracy that depends only on the available information about the initial distribution: the analytical results confirm that En-eq exponentially relaxes to its equilibrium value. Using the Gyftopoulos-Beretta formalism, a non-equilibrium entropy Sn-eq(x,t is then derived from En-eq(x,t and U(x,t. It is finally shown that the non-equilibrium entropy generation between two states is always larger than its equilibrium (herein referred to as “classical” counterpart. We conclude that every iso-energetic non-equilibrium state corresponds to an infinite set of non-equivalent states that can be ranked in terms of increasing entropy. Therefore, each point of the Gibbs plane corresponds therefore to a set of possible initial distributions: the non-equilibrium entropy is a multi-valued function that depends on the initial mass and energy distribution within the body. Though the concept cannot be directly extended to microscopic systems, it is argued that the present formulation is compatible with a possible reinterpretation of the existing non-equilibrium formulations, namely those of Tsallis and Grmela, and answers at least in part one of the objections set forth by Lieb and Yngvason. A systematic application of this paradigm is very convenient from a theoretical point of view and may be beneficial for meaningful future applications in the fields of nano-engineering and biological sciences.
Mattioli, Marco
2016-12-01
In this mini-review, we report results from M. Mattioli, et al. [Phys. Rev. Lett. 111, 165302 (2013)], M. Dalmonte, et al. [Phys. Rev. B 92, 045106 (2015)] and M. Mattioli, et al. [New J. Phys. 17, 113039 (2015)], where it is shown that Rydberg atoms trapped in one-dimensional optical lattices are a useful tool to investigate the equilibrium phase diagram and the non-equilibrium dynamics of extended Hubbard models and Kinetically Constrained Models, respectively. Atoms weakly-dressed to an high-lying Rydberg state, which interact with a constant potential extended over several lattice sites, can be in an exotic quantum liquid state, the cluster Luttinger liquid phase [42, 43]. Furthermore, we show how a many-body model of interacting three-level atoms in the V-shaped configuration, where one of the level is a Rydberg state, might relax to equilibrium according to the same rules, so-called kinetic constraints, which are known to reproduce the characteristic dynamical arrest and separation of timescales of real glass-forming materials [62].
Approximate solutions for half-dark solitons in spinor non-equilibrium Polariton condensates
Energy Technology Data Exchange (ETDEWEB)
Pinsker, Florian, E-mail: florian.pinsker@gmail.com
2015-11-15
In this work I generalize and apply an analytical approximation to analyze 1D states of non-equilibrium spinor polariton Bose–Einstein condensates (BEC). Solutions for the condensate wave functions carrying black solitons and half-dark solitons are presented. The derivation is based on the non-conservative Lagrangian formalism for complex Ginzburg–Landau type equations (cGLE), which provides ordinary differential equations for the parameters of the dark soliton solutions in their dynamic environment. Explicit expressions for the stationary dark soliton solution are stated. Subsequently the method is extended to spin sensitive polariton condensates, which yields ordinary differential equations for the parameters of half-dark solitons. Finally a stationary case with explicit expressions for half-dark solitons is presented.
Zhao, Yong; Abreu, Eladio; Kim, Jinyong; Stadler, Guido; Eskiocak, Ugur; Terns, Michael P.; Terns, Rebecca M.; Shay, Jerry W.; Wright, Woodring E.
2011-01-01
SUMMARY Specific information about how telomerase acts in vivo is necessary for understanding telomere dynamics in human tumor cells. Our results imply that under homeostatic telomere length-maintenance conditions only one molecule of telomerase acts at each telomere during every cell division and processively adds ~60 nt to each end. In contrast, multiple molecules of telomerase act at each telomere when telomeres are elongating (non-equilibrium conditions). Telomerase extension is less processive during the first few weeks following the reversal of long-term treatment with the telomerase inhibitor GRN163L, a time when Cajal bodies fail to deliver telomerase RNA to telomeres. This result implies that processing of telomerase by Cajal bodies may affect its processivity. Overexpressed telomerase is also less processive than the endogenously expressed telomerase. These findings reveal two major distinct extension modes adopted by telomerase in vivo. PMID:21549308
A modular particle continuum numerical method for hypersonic non-equilibrium gas flows
Schwartzentruber, T. E.; Scalabrin, L. C.; Boyd, I. D.
2007-07-01
A modular particle-continuum (MPC) numerical method for steady-state flows is presented which solves the Navier-Stokes equations in regions of near-equilibrium and uses the direct simulation Monte Carlo (DSMC) method to simulate regions of non-equilibrium gas flow. Existing, state-of-the-art, DSMC and Navier-Stokes solvers are coupled together using a novel modular implementation which requires only a limited number of additional hybrid functions. Hybrid functions are used to adaptively position particle-continuum interfaces and update boundary conditions in each module at appropriate times. The MPC method is validated for 2D flow over a cylinder at various hypersonic Mach numbers where the global Knudsen number is 0.01. For the cases considered, the MPC method is verified to accurately reproduce DSMC flow field results as well as local particle velocity distributions up to 2.2 times faster than full DSMC simulations.
Morphological instability of a non-equilibrium ice-colloid interface
Peppin, S. S. L.
2009-10-02
We assess the morphological stability of a non-equilibrium ice-colloidal suspension interface, and apply the theory to bentonite clay. An experimentally convenient scaling is employed that takes advantage of the vanishing segregation coefficient at low freezing velocities, and when anisotropic kinetic effects are included, the interface is shown to be unstable to travelling waves. The potential for travelling-wave modes reveals a possible mechanism for the polygonal and spiral ice lenses observed in frozen clays. A weakly nonlinear analysis yields a long-wave evolution equation for the interface shape containing a new parameter related to the highly nonlinear liquidus curve in colloidal systems. We discuss the implications of these results for the frost susceptibility of soils and the fabrication of microtailored porous materials. © 2009 The Royal Society.
Non-equilibrium properties of interatomic potentials in cascade simulations in tungsten
Energy Technology Data Exchange (ETDEWEB)
Sand, A.E., E-mail: andrea.meinander@helsinki.fi [Department of Physics, P.O. Box 43, FI-00014, University of Helsinki (Finland); Dequeker, J.; Becquart, C.S. [Unité Matériaux et Transformations, UMET, UMR 8207, Université de Lille 1, F-59655, Villeneuve d’Ascq (France); Domain, C. [EDF-R& D, Département MMC, Les renardières, F-77818, Moret sur Loing (France); Nordlund, K. [Department of Physics, P.O. Box 43, FI-00014, University of Helsinki (Finland)
2016-03-15
The reliability of atomistic simulations of primary radiation damage hinges on the quality of the interatomic potential. However, irradiation induced collision cascades involve strongly non-equilibrium processes, and thus depend on properties of potentials not usually included in the potential fitting. Here, we compare the predictions of five interatomic potentials for tungsten in cascade simulations with primary knock-on energies ranging from threshold energies for defect production, up to 200 keV. The highest energies represent the energetic recoils induced by the 14 MeV fusion neutron irradiation. We further compare properties related to dynamic collisions predicted by the different potentials to DFT calculations, to assess the accuracy of these predictions. We also present two hardened versions of a recent EAM-type potential, and demonstrate explicitly the importance of carefully adjusting the range of the potential at interaction distances smaller than those included in the fitting of potentials to equilibrium properties.
On the non-equilibrium dynamics of cavitation around the underwater projectile in variable motion
Chen, Y.; Lu, C. J.; Li, J.; Chen, X.; Gong, Z. X.
2015-12-01
In this work, the dynamic behavior of the non-equilibrium cavitation occurring around the underwater projectiles navigating with variable speed was numerically and theoretically investigated. The cavity collapse induced by the decelerating motion of the projectiles can be classified into two types: periodic oscillation and damped oscillation. In each type the evolution of the total mass of vapor in cavity are found to have strict correlation with the pressure oscillation in far field. By defining the equivalent radius of cavity, we introduce the specific kinetic energy of collapse and demonstrate that its change-rate is in good agreement with the pressure disturbance. We numerically investigated the influence of angle of attack on the collapse effect. The result shows that when the projectile decelerates, an asymmetric-focusing effect of the pressure induced by collapse occurs on its pressure side. We analytically explained such asymmetric-focusing effect.
Entropy-based artificial viscosity stabilization for non-equilibrium Grey Radiation-Hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Delchini, Marc O., E-mail: delchinm@email.tamu.edu; Ragusa, Jean C., E-mail: jean.ragusa@tamu.edu; Morel, Jim, E-mail: jim.morel@tamu.edu
2015-09-01
The entropy viscosity method is extended to the non-equilibrium Grey Radiation-Hydrodynamic equations. The method employs a viscous regularization to stabilize the numerical solution. The artificial viscosity coefficient is modulated by the entropy production and peaks at shock locations. The added dissipative terms are consistent with the entropy minimum principle. A new functional form of the entropy residual, suitable for the Radiation-Hydrodynamic equations, is derived. We demonstrate that the viscous regularization preserves the equilibrium diffusion limit. The equations are discretized with a standard Continuous Galerkin Finite Element Method and a fully implicit temporal integrator within the MOOSE multiphysics framework. The method of manufactured solutions is employed to demonstrate second-order accuracy in both the equilibrium diffusion and streaming limits. Several typical 1-D radiation-hydrodynamic test cases with shocks (from Mach 1.05 to Mach 50) are presented to establish the ability of the technique to capture and resolve shocks.
Non-equilibrium quantum theory for nanodevices based on the Feynman-Vernon influence functional
Energy Technology Data Exchange (ETDEWEB)
Jin Jinshuang; Tu, Matisse Wei-Yuan; Zhang Weimin [Department of Physics and Center for Quantum Information Science, National Cheng Kung University, Tainan 70101, Taiwan (China); Yan Yijing, E-mail: wzhang@mail.ncku.edu.t [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong)
2010-08-15
In this paper, we present a non-equilibrium quantum theory for transient electron dynamics in nanodevices based on the Feynman-Vernon influence functional. Applying the exact master equation for nanodevices we recently developed to the more general case in which all the constituents of a device vary in time in response to time-dependent external voltages, we obtained non-perturbatively the transient quantum transport theory in terms of the reduced density matrix. The theory enables us to study transient quantum transport in nanostructures with back-reaction effects from the contacts, with non-Markovian dissipation and decoherence being fully taken into account. For a simple illustration, we apply the theory to a single-electron transistor subjected to ac bias voltages. The non-Markovian memory structure and the nonlinear response functions describing transient electron transport are obtained.
Energy Technology Data Exchange (ETDEWEB)
Cramer, M [Institut fuer Theoretische Physik, Albert-Einstein Allee 11, Universitaet Ulm, D-89069 Ulm (Germany); Eisert, J, E-mail: marcus.cramer@macnews.d, E-mail: jense@qipc.or [Institute for Mathematical Sciences, Imperial College London, Prince' s Gardens, London SW7 2PE (United Kingdom)
2010-05-15
We prove that quantum many-body systems on a one-dimensional lattice locally relax to Gaussian states under non-equilibrium dynamics generated by a bosonic quadratic Hamiltonian. This is true for a large class of initial states-pure or mixed-which have to satisfy merely weak conditions concerning the decay of correlations. The considered setting is a proven instance of a situation where dynamically evolving closed quantum systems locally appear as if they had truly relaxed, to maximum entropy states for fixed second moments. This furthers the understanding of relaxation in suddenly quenched quantum many-body systems. The proof features a non-commutative central limit theorem for non-i.i.d. random variables, showing convergence to Gaussian characteristic functions, giving rise to trace-norm closeness. We briefly link our findings to the ideas of typicality and concentration of measure.
Qualitative Aspects Of Non-Equilibrium Statistical Distributions For Turbulent Flows
Directory of Open Access Journals (Sweden)
Devashish Vikas Gupta
2015-08-01
Full Text Available This paper puts forward the key features of plausible time-evolving statistical distributions of the Scale and Spin of eddies describing the phenomenon of turbulence. Statistical distributions generally describe the state of the system in equilibrium states but describing turbulent flows demands non-equilibrium statistics as there is energy dissipation due to viscosity of the fluid and variations in macroscopic properties of the system with time. The approach put forward proves to be highly advantageous to explain the variation of eddy scale using the Scale Displacement Equation. It ascertains a huge gain in understanding characteristics of the fluids subject to high Reynolds numbers. The phenomenon of Spin Interference which is responsible for the variation of eddy spin in the system is also described intensively. The put forth Scale and Spin statistics parametrized by time demonstrate some interesting features that are fundamentally linked to the behaviour of fluids.
Effects of non-equilibrium particle distributions in deuterium-tritium burning
Energy Technology Data Exchange (ETDEWEB)
Michta, D; Graziani, F; Pruet, J; Luu, T
2009-08-18
We investigate the effects of non-equilibrium particle distributions resulting from rapid deuterium-tritium burning in plasmas using a Fokker-Planck code that incorporates small-angle Coulomb scattering, Brehmsstrahlung, Compton scattering, and thermal-nuclear burning. We find that in inertial confinement fusion environments, deviations away from Maxwellian distributions for either deuterium or tritium ions are small and result in 1% changes in the energy production rates. The deuterium and tritium effective temperatures are not equal, but differ by only about 2.5% near the time of peak burn rate. Simulations with high Z (Xe) dopants show that the dopant temperature closely tracks that of the fuel. On the other hand, fusion product ion distributions are highly non-Maxwellian, and careful treatments of energy-exchange between these ions and other particles is important for determining burn rates.
Non-equilibrium phase-transitions in multi-component Rydberg gases
Ding, D S; Shi, B S; Guo, G C
2016-01-01
Highly-excited Rydberg atoms have strong long-range interactions resulting in exotic optical prop erties such as large single photon non-linearities and intrinsic bistability. In this paper we study optical-driven non-equilibrium phase transitions in a thermal Rydberg gas with a sensitivity two order of magnitude higher than in previous work. In this regime we can elucidate the effect of inter actions on the bistable optical response, and exploit different branches in the potential in order to study multi-component Rydberg gases with a rich of phase diagram including overlapping bistable regions. In addition, we study the effect of polarization on the width of the hysteresis loop. Finally, we observe that the medium exhibits a dynamical instability resulting from the competing dynamics of excitation and decay.
A general theory of non-equilibrium dynamics of lipid-protein fluid membranes
DEFF Research Database (Denmark)
Lomholt, Michael Andersen; Hansen, Per Lyngs; Miao, L.
2005-01-01
We present a general and systematic theory of non-equilibrium dynamics of multi-component fluid membranes, in general, and membranes containing transmembrane proteins, in particular. Developed based on a minimal number of principles of statistical physics and designed to be a meso....../macroscopic-scale effective description, the theory is formulated in terms of a set of equations of hydrodynamics and linear constitutive relations. As a particular emphasis of the theory, the equations and the constitutive relations address both the thermodynamic and the hydrodynamic consequences of the unconventional...... material characteristics of lipid-protein membranes and contain proposals as well as predictions which have not yet been made in already existing work on membrane hydrodynamics and which may have experimental relevance. The framework structure of the theory makes possible its applications to a range of non...
Critical dynamics a field theory approach to equilibrium and non-equilibrium scaling behavior
Täuber, Uwe C
2014-01-01
Introducing a unified framework for describing and understanding complex interacting systems common in physics, chemistry, biology, ecology, and the social sciences, this comprehensive overview of dynamic critical phenomena covers the description of systems at thermal equilibrium, quantum systems, and non-equilibrium systems. Powerful mathematical techniques for dealing with complex dynamic systems are carefully introduced, including field-theoretic tools and the perturbative dynamical renormalization group approach, rapidly building up a mathematical toolbox of relevant skills. Heuristic and qualitative arguments outlining the essential theory behind each type of system are introduced at the start of each chapter, alongside real-world numerical and experimental data, firmly linking new mathematical techniques to their practical applications. Each chapter is supported by carefully tailored problems for solution, and comprehensive suggestions for further reading, making this an excellent introduction to critic...
NON-EQUILIBRIUM MOLECULAR DYNAMICS USED TO OBTAIN SORET COEFFICIENTS OF BINARY HYDROCARBON MIXTURES
Directory of Open Access Journals (Sweden)
F. A. Furtado
2015-09-01
Full Text Available AbstractThe Boundary Driven Non-Equilibrium Molecular Dynamics (BD-NEMD method is employed to evaluate Soret coefficients of binary mixtures. Using a n-decane/n-pentane mixture at 298 K, we study several parameters and conditions of the simulation procedure such as system size, time step size, frequency of perturbation, and the undesired warming up of the system during the simulation. The Soret coefficients obtained here deviated around 20% when comparing with experimental data and with simulated results from the literature. We showed that fluctuations in composition gradients and the consequent deviations of the Soret coefficient may be due to characteristic fluctuations of the composition gradient. Best results were obtained with the smallest time steps and without using a thermostat, which shows that there is room for improvement and/or development of new BD-NEMD algorithms.
Cheraghchi, Hosein
2011-07-01
The electronic nonlinear transport through ultra-narrow graphene nanoribbons (sub-10 nm) was studied. A stable region of negative differential resistance (NDR) appears in the I-V characteristic curve of odd zigzag graphene nanoribbons (ZGNRs) at both positive and negative polarity. This NDR originates from a transport gap induced by a selection rule that blocks the electron transition between disconnected energy bands of ZGNR. Based on this transition rule, the on/off ratio of the current increases exponentially with ribbon length up to 105. In addition, charging effects and the spatial distribution of bond currents were studied by using the non-equilibrium Green's function formalism in the presence of electron-electron interaction at a mean-field level. We also performed an ab initio density functional theory calculation of the transmission through a passivated graphene nanoribbon to demonstrate the robustness of the transport gap against hydrogen termination of the zigzag edges.
Information Geometry of Non-Equilibrium Processes in a Bistable System with a Cubic Damping
Directory of Open Access Journals (Sweden)
Rainer Hollerbach
2017-06-01
Full Text Available A probabilistic description is essential for understanding the dynamics of stochastic systems far from equilibrium, given uncertainty inherent in the systems. To compare different Probability Density Functions (PDFs, it is extremely useful to quantify the difference among different PDFs by assigning an appropriate metric to probability such that the distance increases with the difference between the two PDFs. This metric structure then provides a key link between stochastic systems and information geometry. For a non-equilibrium process, we define an infinitesimal distance at any time by comparing two PDFs at times infinitesimally apart and sum these distances in time. The total distance along the trajectory of the system quantifies the total number of different states that the system undergoes in time and is called the information length. By using this concept, we investigate the information geometry of non-equilibrium processes involved in disorder-order transitions between the critical and subcritical states in a bistable system. Specifically, we compute time-dependent PDFs, information length, the rate of change in information length, entropy change and Fisher information in disorder-to-order and order-to-disorder transitions and discuss similarities and disparities between the two transitions. In particular, we show that the total information length in order-to-disorder transition is much larger than that in disorder-to-order transition and elucidate the link to the drastically different evolution of entropy in both transitions. We also provide the comparison of the results with those in the case of the transition between the subcritical and supercritical states and discuss implications for fitness.
Energy Technology Data Exchange (ETDEWEB)
Sengupta, Tapan K., E-mail: tksen@iitk.ac.in; Bhole, Ashish; Shruti, K. S. [HPCL, Department of Aerospace Engineering, IIT Kanpur, Kanpur, UP (India); Sengupta, Aditi [Department of Engineering, University of Cambridge, Cambridge (United Kingdom); Sharma, Nidhi [Graduate Student, HPCL, Department of Aerospace Engineering, IIT Kanpur, Kanpur, UP (India); Sengupta, Soumyo [Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States)
2016-09-15
Direct numerical simulations of Rayleigh-Taylor instability (RTI) between two air masses with a temperature difference of 70 K is presented using compressible Navier-Stokes formulation in a non-equilibrium thermodynamic framework. The two-dimensional flow is studied in an isolated box with non-periodic walls in both vertical and horizontal directions. The non-conducting interface separating the two air masses is impulsively removed at t = 0 (depicting a heaviside function). No external perturbation has been used at the interface to instigate the instability at the onset. Computations have been carried out for rectangular and square cross sections. The formulation is free of Boussinesq approximation commonly used in many Navier-Stokes formulations for RTI. Effect of Stokes’ hypothesis is quantified, by using models from acoustic attenuation measurement for the second coefficient of viscosity from two experiments. Effects of Stokes’ hypothesis on growth of mixing layer and evolution of total entropy for the Rayleigh-Taylor system are reported. The initial rate of growth is observed to be independent of Stokes’ hypothesis and the geometry of the box. Following this stage, growth rate is dependent on the geometry of the box and is sensitive to the model used. As a consequence of compressible formulation, we capture pressure wave-packets with associated reflection and rarefaction from the non-periodic walls. The pattern and frequency of reflections of pressure waves noted specifically at the initial stages are reflected in entropy variation of the system.
Energy Technology Data Exchange (ETDEWEB)
Coe, D.L.; Kamens, R.M. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Environmental Sciences and Engineering
1994-12-31
To study non-equilibrium gas-particle partitioning of various PAHs, three specially designed smog chamber experiments were conducted (October 1993, January 1994, and February 1994). Automobile diesel exhaust was injected for five minutes into a 190 m{sup 3} Teflon film chamber and allowed to age during the night at temperatures below 15 C. A large denuder system was utilized during the injection period in order to remove PAH vapors from the injection stream. Thus, PAH-laden particles were observed to off-gas in the near absence of vapor phase PAHs during the initial stages of the 8-hour experiments. The large denuder was designed as a parallel plate system, made of activated charcoal impregnated filters. It was characterized to remove greater than 90% of PAH vapors from the diesel injection system. During the experiments, air samples were collected in the chamber at 20-minute intervals for the first 2 hours, and hourly thereafter. The sampling system consisted of an XAD-4 coated annular denuder, followed by a quartz-fiber filter, which is then followed by a second annular denuder. Sample extracts were analyzed on Hewlett-Packard GC/MS. Results from these experiments are compared to output from a radial diffusion computer model, detailed in another paper (``Modeling the Mass Transfer of Semi-Volatile Organics in Combustion Aerosols`` by Jay R. Odum and Richard M. Kamens).
Frentrup, Hendrik; Hart, Kyle E; Colina, Coray M; Müller, Erich A
2015-03-10
We study the permeation dynamics of helium and carbon dioxide through an atomistically detailed model of a polymer of intrinsic microporosity, PIM-1, via non-equilibrium molecular dynamics (NEMD) simulations. This work presents the first explicit molecular modeling of gas permeation through a high free-volume polymer sample, and it demonstrates how permeability and solubility can be obtained coherently from a single simulation. Solubilities in particular can be obtained to a very high degree of confidence and within experimental inaccuracies. Furthermore, the simulations make it possible to obtain very specific information on the diffusion dynamics of penetrant molecules and yield detailed maps of gas occupancy, which are akin to a digital tomographic scan of the polymer network. In addition to determining permeability and solubility directly from NEMD simulations, the results shed light on the permeation mechanism of the penetrant gases, suggesting that the relative openness of the microporous topology promotes the anomalous diffusion of penetrant gases, which entails a deviation from the pore hopping mechanism usually observed in gas diffusion in polymers.
Directory of Open Access Journals (Sweden)
Hendrik Frentrup
2015-03-01
Full Text Available We study the permeation dynamics of helium and carbon dioxide through an atomistically detailed model of a polymer of intrinsic microporosity, PIM-1, via non-equilibrium molecular dynamics (NEMD simulations. This work presents the first explicit molecular modeling of gas permeation through a high free-volume polymer sample, and it demonstrates how permeability and solubility can be obtained coherently from a single simulation. Solubilities in particular can be obtained to a very high degree of confidence and within experimental inaccuracies. Furthermore, the simulations make it possible to obtain very specific information on the diffusion dynamics of penetrant molecules and yield detailed maps of gas occupancy, which are akin to a digital tomographic scan of the polymer network. In addition to determining permeability and solubility directly from NEMD simulations, the results shed light on the permeation mechanism of the penetrant gases, suggesting that the relative openness of the microporous topology promotes the anomalous diffusion of penetrant gases, which entails a deviation from the pore hopping mechanism usually observed in gas diffusion in polymers.
Spezia, Riccardo; Martínez-Nuñez, Emilio; Vazquez, Saulo; Hase, William L
2017-04-28
In this Introduction, we show the basic problems of non-statistical and non-equilibrium phenomena related to the papers collected in this themed issue. Over the past few years, significant advances in both computing power and development of theories have allowed the study of larger systems, increasing the time length of simulations and improving the quality of potential energy surfaces. In particular, the possibility of using quantum chemistry to calculate energies and forces 'on the fly' has paved the way to directly study chemical reactions. This has provided a valuable tool to explore molecular mechanisms at given temperatures and energies and to see whether these reactive trajectories follow statistical laws and/or minimum energy pathways. This themed issue collects different aspects of the problem and gives an overview of recent works and developments in different contexts, from the gas phase to the condensed phase to excited states.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'. © 2017 The Author(s).
Baushke, Samuel W; Stedtfeld, Robert D; Tourlousse, Dieter M; Ahmad, Farhan; Wick, Lukas M; Gulari, Erdogan; Tiedje, James M; Hashsham, Syed A
2012-07-01
Non-equilibrium dissociation curves (NEDCs) have the potential to identify non-specific hybridizations on high throughput, diagnostic microarrays. We report a simple method for the identification of non-specific signals by using a new parameter that does not rely on comparison of perfect match and mismatch dissociations. The parameter is the ratio of specific dissociation temperature (T(d-w)) to theoretical melting temperature (T(m)) and can be obtained by automated fitting of a four-parameter, sigmoid, empirical equation to the thousands of curves generated in a typical experiment. The curves fit perfect match NEDCs from an initial experiment with an R(2) of 0.998±0.006 and root mean square of 108±91 fluorescent units. Receiver operating characteristic curve analysis showed low temperature hybridization signals (20-48°C) to be as effective as area under the curve as primary data filters. Evaluation of three datasets that target 16S rRNA and functional genes with varying degrees of target sequence similarity showed that filtering out hybridizations with T(d-w)/T(m)<0.78 greatly reduced false positive results. In conclusion, T(d-w)/T(m) successfully screened many non-specific hybridizations that could not be identified using single temperature signal intensities alone, while the empirical modeling allowed a simplified approach to the high throughput analysis of thousands of NEDCs. Copyright © 2012 Elsevier B.V. All rights reserved.
Long, Min; Sun, Wei; Niu, Shu; Zhou, Xin; Ji, Li
2017-08-01
We investigate the physical properties of stellar winds launched in super stellar clusters (SSCs). Chandra observations have detected the presence of diffuse X-ray emission caused by hot gas from such winds in SSCs, and provide the best probe for understanding interactions between the stellar winds and the complex nursery regions. However, the details of the origin of cluster winds, the mass and energy ejection, the formation of diffuse X-ray emission, the fraction of winds contribution to the distribution of diffuse X-ray emission still remain unclear. We developed a multiphysics hydrodynamic model including self-gravity, head conduction and performed 3D simulations with an unprecedented grid resolution due to adaptive mesh refinement (AMR) capability in a case study of NGC 3603, as a supplement to the analysis of the archived 500 ks Chandra observations. The synthetic emission will be computed by assuming the gas in a non-equilibrium ionization (NEI) state indicated by Chandra observation, not coronal ionization equilibrium (CIE) that most works assumed, by using a customized NEI calculation module based on AtomDB. The results will be compared to the Chandra observations.
Chemical management policies and a distribution model for chemical accidents
National Research Council Canada - National Science Library
Yeo, Min-Kyeong; Han, Taek-Hyeon; Kim, Soon Seok; Lee, Jin Ah; Park, Hyung-Geun
2017-01-01
.... A comparison of chemical substance dispersion models finds that ALOHA, from the United States, fails to include environmental factors such as topographical changes and atmospheric conditions and does...
Chemical kinetics and combustion modeling
Energy Technology Data Exchange (ETDEWEB)
Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)
1993-12-01
The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.
Directory of Open Access Journals (Sweden)
Seung Jun Lee
2016-06-01
Full Text Available We report on our investigation of a low Reynolds number non-equilibrium electrokinetic flow in a micro/nanochannel platform. Non-equilibrium electrokinetic phenomena include so-called concentration polarization in a moderate electric field and vortex formation in a high electric field. We conducted a spectral analysis of non-equilibrium electrokinetic vortices at a micro/nanochannel interface. We found that periodic vortices are formed while the frequency varies with the applied voltages and solution concentrations. At a frequency as high as 60 Hz, vortex generation was obtained with the strongest electric field and the lowest concentration. The power spectra show increasing frequency with increasing voltage or decreasing concentration. We expect that our spectral analysis results will be useful for micromixer developers in the micromachine research field.
Andreozzi, Laura; Giordano, Marco; Leporini, Dino; Tosi, Mario
2007-04-01
This special issue of Journal of Physics: Condensed Matter presents the Proceedings of the Fourh Workshop on Non-Equilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials, held in Pisa from 17-22 September 2006. This was the fourth of a series of workshops on this theme started in 1995 as a joint initiative of the Università di Pisa and the Scuola Normale Superiore. The 2006 edition was attended by about 200 participants from Europe, Asia and the Americas. As for the earlier workshops, the main objective was to bring together scientists from different areas of science, technology and engineering, to comparatively discuss experimental facts and theoretical predictions on the dynamical processes that occur in supercooled fluids and other disordered materials in non-equilibrium states. The underlying conceptual unity of the field provides a common background for the scientific community working in its various areas. In this edition the number of sessions was increased to cover a wider range of topics of general and current interest, in a larger number of stimulating lectures. The core of the workshop was a set of general lectures followed by more specific presentations on current issues in the main areas of the field. The sessions were in sequence devoted to: non-equilibrium dynamics, aging and secondary relaxations, biomaterials, polyamorphism and water, polymer dynamics I, complex systems, pressure-temperature scaling, thin films, nanometre length-scale studies, folded states of proteins and polymer crystals, theoretical aspects and energy landscape approaches, relaxation and heterogeneous dynamics, rheology in fluids and entangled polymers, biopolymers, and polymer dynamics II. We thank the session chairmen and all speakers for the high quality of their contributions. The structure of this issue of the proceedings follows the sequence of the oral presentations in the workshop, complemented by some papers selected from the poster sessions. Two
Relaxation of non-equilibrium entanglement networks in thin polymer films.
McGraw, Joshua D; Fowler, Paul D; Ferrari, Melissa L; Dalnoki-Veress, Kari
2013-01-01
It is known that polymer films, prepared by spin coating, inherit non-equilibrium configurations which can affect macroscopic film properties. Here we present the results of crazing experiments that support this claim; our measurements indicate that the as-cast chain configurations are strongly stretched as compared to equilibrium Gaussian configurations. The results of our experiments also demonstrate that the entanglement network equilibrates on a time scale comparable to one reptation time. Having established that films can be prepared with an equilibrium entanglement network, we proceed by confining polymers to films in which the thickness is comparable to the molecular size. By stacking two such films, a bilayer is created with a buried entropic interface. Such an interface has no enthalpic cost, only an entropic penalty associated with the restricted configurations of molecules that cannot cross the mid-plane of the bilayer. In the melt, the entropic interface heals as chains from the two layers mix and entangle with one another; crazing measurements allow us to probe the dynamics of two films becoming one. Healing of the entropic interface is found to take less than one bulk reptation time.
Effects of non-equilibrium angle fluctuation on F1-ATPase kinetics induced by temperature increase.
Tamiya, Yuji; Watanabe, Rikiya; Noji, Hiroyuki; Li, Chun-Biu; Komatsuzaki, Tamiki
2018-01-17
F 1 -ATPase (F 1 ) is an efficient rotary protein motor, whose reactivity is modulated by the rotary angle to utilize thermal fluctuation. In order to elucidate how its kinetics are affected by the change in the fluctuation, we have extended the reaction-diffusion formalism [R. Watanabe et al., Biophys. J., 2013, 105, 2385] applicable to a wider range of temperatures based on experimental data analysis of F 1 derived from thermophilic Bacillus under high ATP concentration conditions. Our simulation shows that the rotary angle distribution manifests a stronger non-equilibrium feature as the temperature increases, because ATP hydrolysis and P i release are more accelerated compared with the timescale of rotary angle relaxation. This effect causes the rate coefficient obtained from dwell time fitting to deviate from the Arrhenius relation in P i release, which has been assumed in the previous activation thermodynamic quantities estimation using linear Arrhenius fitting. Larger negative correlation is also found between hydrolysis and P i release waiting time in a catalytic dwell with the increase in temperature. This loss of independence between the two successive reactions at the catalytic dwell sheds doubt on the conventional dwell time fitting to obtain rate coefficients with a double exponential function at temperatures higher than 65 °C, which is close to the physiological temperature of the thermophilic Bacillus.
Long-lived non-equilibrium interstitial solid solutions in binary mixtures
Ríos de Anda, Ioatzin; Turci, Francesco; Sear, Richard P.; Royall, C. Patrick
2017-09-01
We perform particle resolved experimental studies on the heterogeneous crystallisation process of two component mixtures of hard spheres. The components have a size ratio of 0.39. We compared these with molecular dynamics simulations of homogenous nucleation. We find for both experiments and simulations that the final assemblies are interstitial solid solutions, where the large particles form crystalline close-packed lattices, whereas the small particles occupy random interstitial sites. This interstitial solution resembles that found at equilibrium when the size ratios are 0.3 [L. Filion et al., Phys. Rev. Lett. 107, 168302 (2011)] and 0.4 [L. Filion, Ph.D. thesis, Utrecht University, 2011]. However, unlike these previous studies, for our system simulations showed that the small particles are trapped in the octahedral holes of the ordered structure formed by the large particles, leading to long-lived non-equilibrium structures in the time scales studied and not the equilibrium interstitial solutions found earlier. Interestingly, the percentage of small particles in the crystal formed by the large ones rapidly reaches a maximum of ˜14% for most of the packing fractions tested, unlike previous predictions where the occupancy of the interstitial sites increases with the system concentration. Finally, no further hopping of the small particles was observed.
Directory of Open Access Journals (Sweden)
Pil Seung Chung
2017-05-01
Full Text Available During the operation of hard disk drive (HDD, the perfluoropolyether (PFPE lubricant experiences elastic or viscous shear/elongation deformations, which affect the performance and reliability of the HDD. Therefore, the viscoelastic responses of PFPE could provide a finger print analysis in designing optimal molecular architecture of lubricants to control the tribological phenomena. In this paper, we examine the rheological responses of PFPEs including storage (elastic and loss (viscous moduli (G′ and G″ by monitoring the time-dependent-stress-strain relationship via non-equilibrium molecular dynamics simulations. We analyzed the rheological responses by using Cox-Merz rule, and investigated the molecular structural and thermal effects on the solid-like and liquid-like behaviors of PFPEs. The temperature dependence of the endgroup agglomeration phenomena was examined, where the functional endgroups are decoupled as the temperature increases. By analyzing the relaxation processes, the molecular rheological studies will provide the optimal lubricant selection criteria to enhance the HDD performance and reliability for the heat-assisted magnetic recording applications.
Effects of non-equilibrium plasma in the treatment of ligature-induced peri-implantitis.
Shi, Qi; Song, Ke; Zhou, Xincai; Xiong, Zilan; Du, Tianfeng; Lu, Xinpei; Cao, Yingguang
2015-05-01
To evaluate the effects of non-equilibrium plasma in the treatment of ligature-induced peri-implantitis in beagle dogs. Six beagles received 12 implants installed in the position of the fourth mandibular premolars. Ligature-induced peri-implantitis was initiated at 3 months post-implantation. When approximately 40% of the supporting bone was lost, the ligatures were removed. The implants were subjected to the muco-periosteal scaling and chlorhexidine irrigation with or without plasma irrigation. Three months later, clinical, radiographic and microbiological analyses were performed. Block biopsies were prepared for micro-CT and histomorphometric analysis. The primary outcome was the difference in bone healing of peri-implant sites, and the secondary outcomes included changes in clinical parameters (SBI, PD) and bacterial detection. At baseline, no significant differences were observed between the two groups. At 3 months post-treatment, the plasma group showed a significantly higher bone level than the control group (p implantitis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Thermodynamics of Tropical Cyclones: A Thermodynamic Approach to Nonlinear Non-equilibrium Phenomena
Ozawa, H.; Shimokawa, S.
2016-12-01
A formation process of circulatory motion of tropical cyclones is investigated from a thermodynamic viewpoint. The generation rate of mechanical energy by a fluid motion under diabatic heating and cooling, and the dissipation rate of this energy due to irreversible processes are formulated from the 1st and 2nd laws of thermodynamics. This formulation is applied to a tropical cyclone, and the formation process of the circulatory motion is examined from a balance between the generation and dissipation rates of mechanical energy in the fluid system. We find from this formulation and data analysis that the thermodynamic efficiency of tropical cyclones is about 40% lower than the Carnot maximum efficiency because of the presence of thermal dissipation due to irreversible transport of sensible and latent heat in the system. We show that a tropical cyclone tends to develop within a few days through a feedback supply of mechanical energy when the sea surface temperature is higher than 300 K, and when the horizontal scale of circulation becomes larger than the vertical height of the troposphere, being consistent with statistical properties of typhoons observed in the western North Pacific. Applications of this method to other nonlinear non-equilibrium phenomena are also discussed. Ref.) H. Ozawa and S. Shimokawa, Tellus A 67, 24216 (2015).
Applications of non-equilibrium thermodynamics to signaling and metabolic pathways
Hu, Dawei; Liu, Ensheng; Yuan, Jian-Min
2006-03-01
Signaling transduction pathways play important roles in regulating cell functions, such as growth, differentiation, and apoptosis. Metabolic pathways, on the other hand, generate many metabolites utilized by human body. Abnormal regulations of the enzymes and metabolites associated with these pathways may be related to diseases. In view of their importance, we are interested in applying non-equilibrium thermodynamics to investigate the properties and dynamic behaviors of these two types of pathways. The systems of concentration are the MAPK, coupled MAPK-PI3K, and insulin metabolic pathways. In the case of signaling pathways we study the properties of thermodynamic variables, such as the affinities and fluxes of individual reaction steps, as affected by the perturbations of rate constants, protein-protein interactions, and cross talks. In the case of metabolic pathways, we study the system dynamics, the stability of steady states, and the flux-affinity relations as functions of constant inputs and outputs as well as the parameters of feedback loops. Our goals are to shed light on the design principles of the biological pathways and to rank the most vulnerable nodes of these pathways.
Long-lived non-equilibrium interstitial solid solutions in binary mixtures.
Ríos de Anda, Ioatzin; Turci, Francesco; Sear, Richard P; Royall, C Patrick
2017-09-28
We perform particle resolved experimental studies on the heterogeneous crystallisation process of two component mixtures of hard spheres. The components have a size ratio of 0.39. We compared these with molecular dynamics simulations of homogenous nucleation. We find for both experiments and simulations that the final assemblies are interstitial solid solutions, where the large particles form crystalline close-packed lattices, whereas the small particles occupy random interstitial sites. This interstitial solution resembles that found at equilibrium when the size ratios are 0.3 [L. Filion et al., Phys. Rev. Lett. 107, 168302 (2011)] and 0.4 [L. Filion, Ph.D. thesis, Utrecht University, 2011]. However, unlike these previous studies, for our system simulations showed that the small particles are trapped in the octahedral holes of the ordered structure formed by the large particles, leading to long-lived non-equilibrium structures in the time scales studied and not the equilibrium interstitial solutions found earlier. Interestingly, the percentage of small particles in the crystal formed by the large ones rapidly reaches a maximum of ∼14% for most of the packing fractions tested, unlike previous predictions where the occupancy of the interstitial sites increases with the system concentration. Finally, no further hopping of the small particles was observed.
Non-equilibrium plasma kinetics of reacting CO: an improved state to state approach
Pietanza, L. D.; Colonna, G.; Capitelli, M.
2017-12-01
Non-equilibrium plasma kinetics of reacting CO for conditions typically met in microwave discharges have been developed based on the coupling of excited state kinetics and the Boltzmann equation for the electron energy distribution function (EEDF). Particular attention is given to the insertion in the vibrational kinetics of a complete set of electron molecule resonant processes linking the whole vibrational ladder of the CO molecule, as well as to the role of Boudouard reaction, i.e. the process of forming CO2 by two vibrationally excited CO molecules, in shaping the vibrational distribution of CO and promoting reaction channels assisted by vibrational excitation (pure vibrational mechanisms, PVM). PVM mechanisms can become competitive with electron impact dissociation processes (DEM) in the activation of CO. A case study reproducing the conditions of a microwave discharge has been considered following the coupled kinetics also in the post discharge conditions. Results include the evolution of EEDF in discharge and post discharge conditions highlighting the role of superelastic vibrational and electronic collisions in shaping the EEDF. Moreover, PVM rate coefficients and DEM ones are studied as a function of gas temperature, showing a non-Arrhenius behavior, i.e. the rate coefficients increase with decreasing gas temperature as a result of a vibrational–vibrational (V–V) pumping up mechanism able to form plateaux in the vibrational distribution function. The accuracy of the results is discussed in particular in connection to the present knowledge of the activation energy of the Boudouard process.
Non-Equilibrium Plasma Processing for the Preparation of Antibacterial Surfaces
Directory of Open Access Journals (Sweden)
Eloisa Sardella
2016-06-01
Full Text Available Non-equilibrium plasmas offer several strategies for developing antibacterial surfaces that are able to repel and/or to kill bacteria. Due to the variety of devices, implants, and materials in general, as well as of bacteria and applications, plasma assisted antibacterial strategies need to be tailored to each specific surface. Nano-composite coatings containing inorganic (metals and metal oxides or organic (drugs and biomolecules compounds can be deposited in one step, and used as drug delivery systems. On the other hand, functional coatings can be plasma-deposited and used to bind antibacterial molecules, for synthesizing surfaces with long lasting antibacterial activity. In addition, non-fouling coatings can be produced to inhibit the adhesion of bacteria and reduce the formation of biofilm. This paper reviews plasma-based strategies aimed to reduce bacterial attachment and proliferation on biomedical materials and devices, but also onto materials used in other fields. Most of the activities described have been developed in the lab of the authors.
On the relevance of the maximum entropy principle in non-equilibrium statistical mechanics
Auletta, Gennaro; Rondoni, Lamberto; Vulpiani, Angelo
2017-07-01
At first glance, the maximum entropy principle (MEP) apparently allows us to derive, or justify in a simple way, fundamental results of equilibrium statistical mechanics. Because of this, a school of thought considers the MEP as a powerful and elegant way to make predictions in physics and other disciplines, rather than a useful technical tool like others in statistical physics. From this point of view the MEP appears as an alternative and more general predictive method than the traditional ones of statistical physics. Actually, careful inspection shows that such a success is due to a series of fortunate facts that characterize the physics of equilibrium systems, but which are absent in situations not described by Hamiltonian dynamics, or generically in nonequilibrium phenomena. Here we discuss several important examples in non equilibrium statistical mechanics, in which the MEP leads to incorrect predictions, proving that it does not have a predictive nature. We conclude that, in these paradigmatic examples, an approach that uses a detailed analysis of the relevant aspects of the dynamics cannot be avoided.
Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands.
Valente, Luis M; Phillimore, Albert B; Etienne, Rampal S
2015-08-01
Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Galápagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Galápagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin's finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms. © 2015 The Authors Ecology Letters published by John Wiley & Sons Ltd and CNRS.
Zhang, Hong; Zegeling, Paul Andries
2017-01-01
An adaptive moving mesh finite difference method is presented to solve two types of equations with dynamic capillary pressure effect in porous media. One is the non-equilibrium Richards Equation and the other is the modified Buckley-Leverett equation. The governing equations are discretized with an
2015-01-01
This book presents cutting-edge experimental and computational results and provides comprehensive coverage on the impact of non-equilibrium structure and dynamics on the properties of soft matter confined to the nanoscale. The book is organized into three main sections: · Equilibration and physical aging: by treating non-equilibrium phenomena with the formal methodology of statistical physics in bulk, the analysis of the kinetics of equilibration sheds new light on the physical origin of the non-equilibrium character of thin polymer films. Both the impact of sample preparation and that of interfacial interactions are analyzed using a large set of experiments. A historical overview of the investigation of the non-equilibrium character of thin polymer films is also presented. Furthermore, the discussion focuses on how interfaces and geometrical confinement perturb the pathways and kinetics of equilibrations of soft glasses (a process of tremendous technological interest). · Irr...
Energy Technology Data Exchange (ETDEWEB)
Tanaka, Kouichi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan); Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Kitsunezuka, Masashi; Shinma, Atsushi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan)
2013-11-21
Developing a composite material of polymers and micrometer-sized fillers with higher heat conductance is crucial to realize modular packaging of electronic components at higher densities. Enhancement mechanisms of the heat conductance of the polymer-filler interfaces by adding the surface-coupling agent in such a polymer composite material are investigated through the non-equilibrium molecular dynamics (MD) simulation. A simulation system is composed of α-alumina as the filler, bisphenol-A epoxy molecules as the polymers, and model molecules for the surface-coupling agent. The inter-atomic potential between the α-alumina and surface-coupling molecule, which is essential in the present MD simulation, is constructed to reproduce the calculated energies with the electronic density-functional theory. Through the non-equilibrium MD simulation runs, we find that the thermal resistance at the interface decreases significantly by increasing either number or lengths of the surface-coupling molecules and that the effective thermal conductivity of the system approaches to the theoretical value corresponding to zero thermal-resistance at the interface. Detailed analyses about the atomic configurations and local temperatures around the interface are performed to identify heat-transfer routes through the interface.
Chemical model reduction under uncertainty
Malpica Galassi, Riccardo
2017-03-06
A general strategy for analysis and reduction of uncertain chemical kinetic models is presented, and its utility is illustrated in the context of ignition of hydrocarbon fuel–air mixtures. The strategy is based on a deterministic analysis and reduction method which employs computational singular perturbation analysis to generate simplified kinetic mechanisms, starting from a detailed reference mechanism. We model uncertain quantities in the reference mechanism, namely the Arrhenius rate parameters, as random variables with prescribed uncertainty factors. We propagate this uncertainty to obtain the probability of inclusion of each reaction in the simplified mechanism. We propose probabilistic error measures to compare predictions from the uncertain reference and simplified models, based on the comparison of the uncertain dynamics of the state variables, where the mixture entropy is chosen as progress variable. We employ the construction for the simplification of an uncertain mechanism in an n-butane–air mixture homogeneous ignition case, where a 176-species, 1111-reactions detailed kinetic model for the oxidation of n-butane is used with uncertainty factors assigned to each Arrhenius rate pre-exponential coefficient. This illustration is employed to highlight the utility of the construction, and the performance of a family of simplified models produced depending on chosen thresholds on importance and marginal probabilities of the reactions.
Energy Technology Data Exchange (ETDEWEB)
Smith, C E; Spakovsky, M R von [Center for Energy Systems Research, M.E. Department Virginia Polytechnic Institute and State University, Blacksburg, VA (United States); Sciacovelli, A; Verda, V, E-mail: vonspako@vt.ed [Department of Energy Engineering, Politecnico di Torino, c.so Duca degli Abruzzi 24, 10129 Torino (Italy)
2010-06-01
Quantum thermodynamics (QT) provides a general framework for the description of non-equilibrium phenomena at any level, particularly the atomistic one. This theory and its dynamical postulate are used here to model the storage of hydrogen on and in a carbon nanotube. The tube is placed at the center of a tank with a volume of 250 nm{sup 3}. The thermodynamic system of interest is the hydrogen, which is assumed isolated and having boundaries that coincide with the walls of the tank and the carbon nanotube. The hydrogen is initially prepared in a state far from stable equilibrium (i.e., with the hydrogen molecules probabilistically near one of the outer tank walls) after which the system is allowed to relax (evolve) to a state of stable equilibrium. To predict this evolution in state, the so-called energy eigenvalue problem, which entails a many-body problem that for dilute and moderately dense gases can be modeled using virial expansion theory, is first solved for the geometry involved. The energy eigenvalues and eigenstates of the system found are then used by the nonlinear Beretta equation of motion of QT to determine the evolution of the thermodynamic state of the system as well as the 3D spatial distributions of the hydrogen molecules in time. The simulation results provide a quantification of the entropy generated due to irreversibilities at an atomistic level and show in detail the trajectory of the thermodynamic state of the system as the hydrogen molecules, which are initially arranged to be far from the carbon nanotube, spread out in the system and eventually become probabilistically more concentrated near the carbon atoms, which make up the nanotube.
Suleimenov, I.; Aushev, V.; Adamov, T.; Vasiliev, I.
Modern investigations show that the effect of acoustic and acoustic-gravity waves amplification strongly influence on the temperature balance in atmosphere. These waves may be amplified due to the transformation of energy of chemically active (or ionized) components into the energy of wave motion, i.e. the nature of the effect is the same as the amplification of sound in other non-equilibrium gas media (for example, in gas discharge plasma). Recently Jiyao Xu (1999) reported that the theory of such waves might be developed in the same way as the theory of acoustic-gravity waves. It is shown that the influence of inhomogeneous altitude distribution of temperature should be taken into account for the correct interpretation of temperature balance in the atmosphere. In other words, the self-agreed problem have to be solved: transformation of chemical energy into energy of wave motion change the vertical profile of the atmosphere temperature, but the profile of the temperature itself determine the amplification coefficient of the wave. The results of analytical solution of the problem are reported. We show that the sign of temperature gradient strongly influence on the behavior of amplified acoustic and acoustic-gravity waves. The regime of amplification is stable when the second derivative of the temperature is negative (temperature has minimum at some point). In other words the stable channel of amplification of the waves may exist, for example, in the tube when the temperature of the walls is higher than the temperature of the gas at the axe. The different instabilities appear in the opposite case when the temperature in the reference point has a maximum. In particular, it means that the amplification of acoustic waves in gas discharge tubes cannot be stable. Moreover, our results show that self-generation of acoustic-gravity in middle atmosphere due to photochemical reactions cannot be stable process too. This conclusion is in accordance with known experimental
Tarquini, Simone
2017-08-01
A simple formula relates lava discharge rate to the heat radiated per unit time from the surface of active lava flows (the "thermal proxy"). Although widely used, the physical basis of this proxy is still debated. In the present contribution, lava flows are approached as open, dissipative systems that, under favorable conditions, can attain a non-equilibrium stationary state. In this system framework, the onset, growth, and demise of lava flow units can be explained as a self-organization phenomenon characterized by a given temporal frequency defined by the average life span of active lava flow units. Here, I review empirical, physical, and experimental models designed to understand and link the flow of mass and energy through a lava flow system, as well as measurements and observations that support a "real-world" view. I set up two systems: active lava flow system (or ALFS) for flowing, fluid lava and a lava deposit system for solidified, cooling lava. The review highlights surprising similarities between lava flows and electric currents, which typically work under stationary conditions. An electric current propagates almost instantaneously through an existing circuit, following the Kirchhoff law (a least dissipation principle). Flowing lavas, in contrast, build up a slow-motion "lava circuit" over days, weeks, or months by following a gravity-driven path down the steepest slopes. Attainment of a steady-state condition is hampered (and the classic thermal proxy does not hold) if the supply stops before completion of the "lava circuit." Although gravity determines initial flow path and extension, the least dissipation principle means that subsequent evolution of mature portions of the active lava flow system is controlled by increasingly insulated conditions.
Suh, Donghyuk; Radak, Brian K; Chipot, Christophe; Roux, Benoît
2018-01-07
Molecular dynamics (MD) trajectories based on classical equations of motion can be used to sample the configurational space of complex molecular systems. However, brute-force MD often converges slowly due to the ruggedness of the underlying potential energy surface. Several schemes have been proposed to address this problem by effectively smoothing the potential energy surface. However, in order to recover the proper Boltzmann equilibrium probability distribution, these approaches must then rely on statistical reweighting techniques or generate the simulations within a Hamiltonian tempering replica-exchange scheme. The present work puts forth a novel hybrid sampling propagator combining Metropolis-Hastings Monte Carlo (MC) with proposed moves generated by non-equilibrium MD (neMD). This hybrid neMD-MC propagator comprises three elementary elements: (i) an atomic system is dynamically propagated for some period of time using standard equilibrium MD on the correct potential energy surface; (ii) the system is then propagated for a brief period of time during what is referred to as a "boosting phase," via a time-dependent Hamiltonian that is evolved toward the perturbed potential energy surface and then back to the correct potential energy surface; (iii) the resulting configuration at the end of the neMD trajectory is then accepted or rejected according to a Metropolis criterion before returning to step 1. A symmetric two-end momentum reversal prescription is used at the end of the neMD trajectories to guarantee that the hybrid neMD-MC sampling propagator obeys microscopic detailed balance and rigorously yields the equilibrium Boltzmann distribution. The hybrid neMD-MC sampling propagator is designed and implemented to enhance the sampling by relying on the accelerated MD and solute tempering schemes. It is also combined with the adaptive biased force sampling algorithm to examine. Illustrative tests with specific biomolecular systems indicate that the method can yield
Suh, Donghyuk; Radak, Brian K.; Chipot, Christophe; Roux, Benoît
2018-01-01
Molecular dynamics (MD) trajectories based on classical equations of motion can be used to sample the configurational space of complex molecular systems. However, brute-force MD often converges slowly due to the ruggedness of the underlying potential energy surface. Several schemes have been proposed to address this problem by effectively smoothing the potential energy surface. However, in order to recover the proper Boltzmann equilibrium probability distribution, these approaches must then rely on statistical reweighting techniques or generate the simulations within a Hamiltonian tempering replica-exchange scheme. The present work puts forth a novel hybrid sampling propagator combining Metropolis-Hastings Monte Carlo (MC) with proposed moves generated by non-equilibrium MD (neMD). This hybrid neMD-MC propagator comprises three elementary elements: (i) an atomic system is dynamically propagated for some period of time using standard equilibrium MD on the correct potential energy surface; (ii) the system is then propagated for a brief period of time during what is referred to as a "boosting phase," via a time-dependent Hamiltonian that is evolved toward the perturbed potential energy surface and then back to the correct potential energy surface; (iii) the resulting configuration at the end of the neMD trajectory is then accepted or rejected according to a Metropolis criterion before returning to step 1. A symmetric two-end momentum reversal prescription is used at the end of the neMD trajectories to guarantee that the hybrid neMD-MC sampling propagator obeys microscopic detailed balance and rigorously yields the equilibrium Boltzmann distribution. The hybrid neMD-MC sampling propagator is designed and implemented to enhance the sampling by relying on the accelerated MD and solute tempering schemes. It is also combined with the adaptive biased force sampling algorithm to examine. Illustrative tests with specific biomolecular systems indicate that the method can yield
Equilibrium and non-equilibrium concentration fluctuations in a critical binary mixture.
Giavazzi, Fabio; Fornasieri, Alessandro; Vailati, Alberto; Cerbino, Roberto
2016-10-01
When a macroscopic concentration gradient is present across a binary mixture, long-ranged non-equilibrium concentration fluctuations (NCF) appear as a consequence of the coupling between the gradient and spontaneous equilibrium velocity fluctuations. Long-ranged equilibrium concentration fluctuations (ECF) may be also observed when the mixture is close to a critical point. Here we study the interplay between NCF and critical ECF in a near-critical mixture aniline/cyclohexane in the presence of a vertical concentration gradient. To this aim, we exploit a commercial optical microscope and a simple, custom-made, temperature-controlled cell to obtain simultaneous static and dynamic scattering information on the fluctuations. We first characterise the critical ECF at fixed temperature T above the upper critical solution temperature Tc, in the wide temperature range [Formula: see text] °C. In this range, we observe the expected critical scaling behaviour for both the scattering intensity and the mass diffusion coefficient and we determine the critical exponents [Formula: see text], [Formula: see text] and [Formula: see text], which are found in agreement with the 3D Ising values. We then study the system in the two-phase region (T T i. During the transient, a vertical diffusive mass flux is present that causes the onset of NCF, whose amplitude vanishes with time, as the flux goes to zero. We also study the time dependence of the equilibrium scattering intensity I eq, of the crossover wave vector q co and of the diffusion coefficient D during diffusion and find that all these quantities exhibit an exponential relaxation enslaved to the diffusive kinetics.
Construction of Low Dissipative High Order Well-Balanced Filter Schemes for Non-Equilibrium Flows
Wang, Wei; Yee, H. C.; Sjogreen, Bjorn; Magin, Thierry; Shu, Chi-Wang
2009-01-01
The goal of this paper is to generalize the well-balanced approach for non-equilibrium flow studied by Wang et al. [26] to a class of low dissipative high order shock-capturing filter schemes and to explore more advantages of well-balanced schemes in reacting flows. The class of filter schemes developed by Yee et al. [30], Sjoegreen & Yee [24] and Yee & Sjoegreen [35] consist of two steps, a full time step of spatially high order non-dissipative base scheme and an adaptive nonlinear filter containing shock-capturing dissipation. A good property of the filter scheme is that the base scheme and the filter are stand alone modules in designing. Therefore, the idea of designing a well-balanced filter scheme is straightforward, i.e., choosing a well-balanced base scheme with a well-balanced filter (both with high order). A typical class of these schemes shown in this paper is the high order central difference schemes/predictor-corrector (PC) schemes with a high order well-balanced WENO filter. The new filter scheme with the well-balanced property will gather the features of both filter methods and well-balanced properties: it can preserve certain steady state solutions exactly; it is able to capture small perturbations, e.g., turbulence fluctuations; it adaptively controls numerical dissipation. Thus it shows high accuracy, efficiency and stability in shock/turbulence interactions. Numerical examples containing 1D and 2D smooth problems, 1D stationary contact discontinuity problem and 1D turbulence/shock interactions are included to verify the improved accuracy, in addition to the well-balanced behavior.
Studies and comparison of currently utilized models for ablation in Electrothermal-chemical guns
Jia, Shenli; Li, Rui; Li, Xingwen
2009-10-01
Wall ablation is a key process taking place in the capillary plasma generator in Electrothermal-Chemical (ETC) guns, whose characteristic directly decides the generator's performance. In the present article, this ablation process is theoretically studied. Currently widely used mathematical models designed to describe such process are analyzed and compared, including a recently developed kinetic model which takes into account the unsteady state in plasma-wall transition region by dividing it into two sub-layers, a Knudsen layer and a collision dominated non-equilibrium Hydrodynamic layer, a model based on Langmuir Law, as well as a simplified model widely used in arc-wall interaction process in circuit breakers, which assumes a proportional factor and an ablation enthalpy obtained empirically. Bulk plasma state and parameters are assumed to be consistent while analyzing and comparing each model, in order to take into consideration only the difference caused by model itself. Finally ablation rate is calculated in each method respectively and differences are discussed.
Equilibrium and non-equilibrium effects in nucleus-nucleus collisions
Bravina, L V; Zabrodin, E E; Bass, S A; Belkacem, M; Bleicher, M; Brandstetter, M; Hofmann, M; Soff, S; Spieles, C; Weber, H; Stockerand, H; Greiner, W
1999-01-01
Local thermal and chemical equilibration is studied for central A+A collisions at 10.7-160 AGeV in the ultrarelativistic quantum molecular dynamics model (UrQMD). The UrQMD model exhibits strong deviations from local equilibrium at the high density hadron-string phase formed during the early stage of the collision. Equilibration of the hadron-resonance matter is established in the central cell of volume V=125 fm/sup 3/ at later stages, t>or=10 fm/c, of the resulting quasi-isentropic expansion. The thermodynamical functions in the cell and their time evolution are presented. Deviations of the UrQMD quasi-equilibrium state from the statistical mechanics equilibrium are found. They increase with energy per baryon and lead to a strong enhancement of the pion number density as compared to statistical mechanics estimates at SPS energies. (38 refs).
Comparison of Vibrational Relaxation Modeling for Strongly Non-Equilibrium Flows
2014-01-01
3 where SVT is a steric factor, ! is the oscillator frequency, m̃ is the collision reduced mass, µ is the oscillator reduced mass, is the oscillator...f !"i+fCOL exp ("COL) nX r=0 (1)r r! (i r)! (f r)! 1 "rCOL 2 (2) "COL = SVT 4⇡3! m̃ 2/µ ↵2h sinh2 ⇣⇡! ↵v̄ ⌘ (3) For diatom...factors, SVT and SVV, and the parameter ↵ determine the rate of vibrational relaxation, while the inherent form of the transition probability
Computational Tool for Kinetic Modeling of Non-Equilibrium Multiphase Flows in Ablation Project
National Aeronautics and Space Administration — Development of highly accurate tools to predict aerothermal environments and associated effects on vehicles is needed to enable advanced spacecraft for future NASA...
First-principles modelling of scanning tunneling microscopy using non-equilibrium Green's functions
DEFF Research Database (Denmark)
Lin, H.P.; Rauba, J.M.C.; Thygesen, Kristian Sommer
2010-01-01
The investigation of electron transport processes in nano-scale architectures plays a crucial role in the development of surface chemistry and nano-technology. Experimentally, an important driving force within this research area has been the concurrent refinements of scanning tunneling microscopy...... into account. As an illustrating example we apply the NEGF-STM method to the Si(001)(2x1):H surface with sub-surface P doping and discuss the results in comparison to the Bardeen and Tersoff-Hamann methods....
Non-equilibrium Simulation of CO2-hydrate Phase Transitions from Mixtures of CO2 and N2 Gases
Qorbani Nashaqi, K.
2015-12-01
Storage of CO2 in aquifers is one of several options for reducing the emissions of CO2 to the atmosphere. Generally this option requires sealing integrity through layers of clay or shale. Many reservoirs have regions of temperature and pressure inside hydrate formation conditions. Whether hydrate formation can provide long term extra sealing still remains unverified in view of all co-existing phases that affect hydrate stability. Yet another storage option for CO2 is in the form of hydrate through exchange of in situ CH4 hydrate. Injection of CO2 into hydrate filled sediments is challenging due to the partial filling of pores with hydrate which results in low porosity and low permeability. Formation of new hydrate from injected CO2 will enhance these problems, Mixing N2 gas with the CO2 will increase permeability and will reduce driving forces for formation of new hydrate from pore water and injection gas. Hydrate can generally not reach thermodynamic equilibrium due to Gibbs' phase rule and the combined first and second laws of thermodynamics. These thermodynamic constraints on distribution of masses over co-existing phases are dynamically coupled to local mass- and heat-transport. Reservoir simulations are one possible method for investigation of possible scenarios related to injection of CO2 with N2 into aquifers containing CH4 hydrate. In this work we have developed prevoiusly modified RetrasoCodeBrite (RCB) simulator to handle injection of CO2/N2 gas mixtures. Hydrate formation and dissociation were determined by investigating Gibbs free energy differences between hydrate and hydrate formers. Gibbs free energy differences were calculated from changes in chemical potentials, which were obtained using non-equilibrium thermodynamic approach. Further extension of RCB has been implemented in this work through adding on-the-fly thermodynamic calculations. Correspondingly, hydrate phase transitions are calculated directly inside the code as a result of super
Directory of Open Access Journals (Sweden)
Hrubý Jan
2012-04-01
Full Text Available Mathematical modeling of the non-equilibrium condensing transonic steam flow in the complex 3D geometry of a steam turbine is a demanding problem both concerning the physical concepts and the required computational power. Available accurate formulations of steam properties IAPWS-95 and IAPWS-IF97 require much computation time. For this reason, the modelers often accept the unrealistic ideal-gas behavior. Here we present a computation scheme based on a piecewise, thermodynamically consistent representation of the IAPWS-95 formulation. Density and internal energy are chosen as independent variables to avoid variable transformations and iterations. On the contrary to the previous Tabular Taylor Series Expansion Method, the pressure and temperature are continuous functions of the independent variables, which is a desirable property for the solution of the differential equations of the mass, energy, and momentum conservation for both phases.
Khrabry, A.; Kaganovich, I. D.; Nemchinsky, V.; Khodak, A.
2018-01-01
The atmospheric pressure arcs have recently found application in the production of nanoparticles. The distinguishing features of such arcs are small length and hot ablating anode characterized by intensive electron emission and radiation from its surface. We performed a one-dimensional modeling of argon arc, which shows that near-electrode effects of thermal and ionization non-equilibrium play an important role in the operation of a short arc, because the non-equilibrium regions are up to several millimeters long and are comparable to the arc length. The near-anode region is typically longer than the near-cathode region and its length depends more strongly on the current density. The model was extensively verified and validated against previous simulation results and experimental data. The Volt-Ampere characteristic (VAC) of the near-anode region depends on the anode cooling mechanism. The anode voltage is negative. In the case of strong anode cooling (water-cooled anode) when the anode is cold, temperature and plasma density gradients increase with current density, resulting in a decrease of the anode voltage (the absolute value increases). Falling VAC of the near-anode region suggests the arc constriction near the anode. Without anode cooling, the anode temperature increases significantly with the current density, leading to a drastic increase in the thermionic emission current from the anode. Correspondingly, the anode voltage increases to suppress the emission, and the opposite trend in the VAC is observed. The results of simulations were found to be independent of sheath model used: collisional (fluid) or collisionless model gave the same plasma profiles for both near-anode and near-cathode regions.
Hachay, Olga; Khachay, Andrey; Khachay, Oleg
2016-04-01
The processes of oil extraction from deposit are linked with the movement of multi-phase multi-component media, which are characterized by non-equilibrium and non-linear rheological features. The real behavior of layered systems is defined by the complexity of the rheology of moving fluids and the morphology structure of the porous medium, and also by the great variety of interactions between the fluid and the porous medium [Hasanov and Bulgakova, 2003]. It is necessary to take into account these features in order to informatively describe the filtration processes due to the non-linearity, non-equilibrium and heterogeneity that are features of real systems. In this way, new synergetic events can be revealed (namely, a loss of stability when oscillations occur, and the formation of ordered structures). This allows us to suggest new methods for the control and management of complicated natural systems that are constructed on account of these phenomena. Thus the layered system, from which it is necessary to extract the oil, is a complicated dynamical hierarchical system. A comparison is provided of non-equilibrium effects of the influence of independent hydrodynamic and electromagnetic induction on an oil layer and the medium which it surrounds. It is known that by drainage and steeping the hysteresis effect on curves of the relative phase permeability in dependence on the porous medium's water saturation in some cycles of influence (drainage-steep-drainage) is observed. Using the earlier developed 3D method of induction electromagnetic frequency geometric monitoring, we showed the possibility of defining the physical and structural features of a hierarchical oil layer structure and estimating the water saturation from crack inclusions. This effect allows managing the process of drainage and steeping the oil out of the layer by water displacement. An algorithm was constructed for 2D modeling of sound diffraction on a porous fluid-saturated intrusion of a hierarchical
Energy Technology Data Exchange (ETDEWEB)
Yu, Samuel; Kim, Sun Min [Inha University, Incheon (Korea, Republic of)
2011-04-15
In this study, we developed a micromixer based on the non-equilibrium electrokinetics at the junction of a microchannel and nanochannel. Two fluid streams were mixed by an electro-osmotic flow and a vortex flow created as a result of the non-equilibrium electrokinetics at the junction of the microchannel and nanochannel. Initially, the microchannel was fabricated using Polydimethylsiloxane (PDMS) by the general soft lithography process and the nanochannel was created at a specific position on the microchannel by applying a high voltage. To evaluate the mixing performance of the micromixer, fluorescent distribution was analyzed by using the fluorescent dye, Rhodamine B. About 90% mixing was achieved with this novel micromixer, and this micromixer can be used in microsystems for biochemical sample analysis.
Role of interface in forming non-equilibrium hcp phase by ion mixing in an immiscible Au-Co system
Yan, H F; Liu, B X
2003-01-01
In an equilibrium immiscible Au-Co system characterized by a positive heat of formation of +11 kJ mol sup - sup 1 , a non-equilibrium Au-Co phase of hcp structure was formed by 200 keV xenon ion mixing at 77 K in the Au sub 5 sub 0 Co sub 5 sub 0 multilayered films. Based on the free energy calculation, the excess interfacial free energy stored in the Au-Co multilayered films could provide adequate thermodynamic driving force for alloying between Au and Co and forming the non-equilibrium Au-Co hcp phase. Besides, the average magnetic moment per Co atom in the newly formed hcp structure was reduced by 22% of its equilibrium value, within a measuring error of 8%.
Vladimir N. Chuvil’deev; Vladimir I. Kopylov; Aleksey V. Nokhrin; Olga E. Pirozhnikova
2013-01-01
The article presents the results of theoretical analysis of non-equilibrium grain boundaries diffusion properties recovery during ultra-fine grain (UFG) materials annealing, produced by severe plastic deformation (SPD) method. The paper proves that activation energy and grain boundary diffusion coefficient of UFG materials depend on density of defects, cumulated by grain boundary during SPD.Annealing causes diffusion redistribution of defects in grain boundaries, which results in diffusion pr...
Energy Technology Data Exchange (ETDEWEB)
Nag, S. [Department of Physics, Jadavpur University, Kolkata 700032 (India); Bhattacharya, D.P., E-mail: d_p_bhattacharya@rediffmail.co [Department of Physics, Jadavpur University, Kolkata 700032 (India)
2009-11-15
The effect of finite energy of intravalley acoustic phonons on the electric field dependence of the temperature of the non-equilibrium carriers in a quantum surface has been studied here. The calculations have been made, for a rather pure material, at low lattice temperature. Numerical results are obtained for GaAs and Si. The results are interesting being significantly different from what one obtains by neglecting the phonon energy.
Mathematical Modeling of Chemical Stoichiometry
Croteau, Joshua; Fox, William P.; Varazo, Kristofoland
2007-01-01
In beginning chemistry classes, students are taught a variety of techniques for balancing chemical equations. The most common method is inspection. This paper addresses using a system of linear mathematical equations to solve for the stoichiometric coefficients. Many linear algebra books carry the standard balancing of chemical equations as an…
Quantum non-equilibrium and relaxation to equilibrium for a class of de Broglie-Bohm-type theories
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Colin, Samuel [Centre for Quantum Dynamics, Griffith University, Brisbane, QLD 4111 (Australia); Struyve, Ward [Institute of Theoretical Physics, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)], E-mail: s.colin@griffith.edu.au, E-mail: Ward.Struyve@fys.kuleuven.be
2010-04-15
The de Broglie-Bohm theory is about non-relativistic point-particles that move deterministically along trajectories. The theory reproduces the predictions of standard quantum theory, given that the distribution of particles over an ensemble of systems, all described by the same wavefunction {psi}, equals the quantum equilibrium distribution |{psi}|{sup 2}. Numerical simulations done by Valentini and Westman (2005 Proc. R. Soc. A 461 253) have illustrated that non-equilibrium particle distributions may relax to quantum equilibrium after some time. Here we consider non-equilibrium distributions and their relaxation properties for a particular class of trajectory theories (first studied in detail by Deotto and Ghirardi (1998 Found. Phys. 28 1)) that are empirically equivalent to the de Broglie-Bohm theory in quantum equilibrium. In the examples we studied of such theories, we found a speed-up of the relaxation, compared to the ordinary de Broglie-Bohm theory. Hence non-equilibrium predictions that depend strongly on relaxation properties, such as those studied recently by Valentini, may vary across different trajectory theories. As such, these theories might be experimentally distinguishable.
Chemical reactor modeling multiphase reactive flows
Jakobsen, Hugo A
2014-01-01
Chemical Reactor Modeling closes the gap between Chemical Reaction Engineering and Fluid Mechanics. The second edition consists of two volumes: Volume 1: Fundamentals. Volume 2: Chemical Engineering Applications In volume 1 most of the fundamental theory is presented. A few numerical model simulation application examples are given to elucidate the link between theory and applications. In volume 2 the chemical reactor equipment to be modeled are described. Several engineering models are introduced and discussed. A survey of the frequently used numerical methods, algorithms and schemes is provided. A few practical engineering applications of the modeling tools are presented and discussed. The working principles of several experimental techniques employed in order to get data for model validation are outlined. The monograph is based on lectures regularly taught in the fourth and fifth years graduate courses in transport phenomena and chemical reactor modeling, and in a post graduate course in modern reactor m...
Modelling Students' Visualisation of Chemical Reaction
Cheng, Maurice M. W.; Gilbert, John K.
2017-01-01
This paper proposes a model-based notion of "submicro representations of chemical reactions". Based on three structural models of matter (the simple particle model, the atomic model and the free electron model of metals), we suggest there are two major models of reaction in school chemistry curricula: (a) reactions that are simple…
Mars Chemical Kinetic Models: A Short Review
Ndindabahizi, I.; Mazoue, F.; Marraffa, L.
2006-11-01
This study deals with the comparison of available thermo-chemical models for the Martian atmosphere. Ten thermo-chemical models have been investigated: McKenzie et al (1967), Evans et al (1973), Kay et al (1993), Park et al (1994), Gupta et al (1994), Afonina et al (1997), Dikovskaya et al (1998), Losev et al (2000), Kudryavtsev et al (2001) and Afonina et al (2002); A more recent model, from Gökçen (2004) is also shortly reviewed. The influence of chemical modelling on species concentrations and temperatures behind a shock wave has been studied first. Afterwards, radiation has been investigated for different computed results. A large sensitivity of the temperatures near the shock to the chemical model has been found. Some thermo-chemical models are found to be inadequate for studies of Martian entry. Radiation investigations show the importance of some species.
Bader, S.; Kooi, H.
2005-01-01
Theories of osmosis in groundwater flow are increasingly used to explain anomalies of salinity in clayey environments. However, predictive modelling through mathematical analysis can hardly be found in literature. In this paper, a model of chemical osmosis based on non-equilibrium thermodynamics, is
Energy Technology Data Exchange (ETDEWEB)
Patton, Edward G. [Univ. Corporation for Atmospheric Research, Boulder, CO (United States)
2015-07-14
This project used a combination of turbulence-resolving large-eddy simulations, single-column modeling (where turbulence is parameterized), and currently available observations to improve, assess, and develop a parameterization of the impact of non-equilibrium wave states and stratification on the buoy-observed winds to establish reliable wind data at the turbine hub-height level. Analysis of turbulence-resolving simulations and observations illuminates the non-linear coupling between the atmosphere and the undulating sea surface. This analysis guides modification of existing boundary layer parameterizations to include wave influences for upward extrapolation of surface-based observations through the turbine layer. Our surface roughness modifications account for the interaction between stratification and the effects of swell’s amplitude and wavelength as well as swell’s relative motion with respect to the mean wind direction. The single-column version of the open source Weather and Research Forecasting (WRF) model (Skamarock et al., 2008) serves as our platform to test our proposed planetary boundary layer parameterization modifications that account for wave effects on marine atmospheric boundary layer flows. WRF has been widely adopted for wind resource analysis and forecasting. The single column version is particularly suitable to development, analysis, and testing of new boundary layer parameterizations. We utilize WRF’s single-column version to verify and validate our proposed modifications to the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer parameterization (Nakanishi and Niino, 2004). We explore the implications of our modifications for two-way coupling between WRF and wave models (e.g.,Wavewatch III). The newly implemented parameterization accounting for marine atmospheric boundary layer-wave coupling is then tested in three-dimensional WRF simulations at grid sizes near 1 km. These simulations identify the behavior of simulated winds at the
Chemical equilibrium modeling of detonation
Energy Technology Data Exchange (ETDEWEB)
Fried, Laurence E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bastea, Sorin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2010-05-19
Energetic materials are unique for having a strong exothermic reactivity, which has made them desirable for both military and commercial applications. Energetic materials are commonly divided into high explosives, propellants, and pyrotechnics. We will focus on high explosive (HE) materials here, although there is a great deal of commonality between the classes of energetic materials. Furthermore the history of HE materials is long, their condensed-phase chemical properties are poorly understood.
Odagaki, Takashi
2017-08-01
Extending the concept of the Ginzburg-Landau theory of phase transition to non-equilibrium systems, I present a free energy landscape (FEL) formalism of non-equilibrium statistical mechanics and show that the FEL formalism provides a framework for unified description of thermodynamic and dynamic properties of non-equilibrium systems. I first show that a conditional free energy Φ (T,V,N,{ Ri} ) can be defined as a function of configuration {Ri} of a given average position of atoms so that the probability of finding the configuration {Ri} is in proportion to \\exp [ - Φ (T,V,N,{ Ri} )/kBT]. Thermodynamic quantities in quasi-equilibrium states are given by their average over the configuration, and the temperature dependence of the FEL manifests itself in the temperature derivatives of thermodynamic quantities. As an example, I discuss the entropy and the specific heat, focusing on the contributions due to configuration and the temperature dependence of the FEL, and show that an additional contribution due to the temperature dependence of the FEL exists in the specific heat. I generalize the FEL formalism so that time dependent phenomena can be analyzed in a frame work similar to the time-dependent Ginzburg-Landau theory. I introduce a time-dependent probability function of configuration and describe its time dependence by a Fokker-Planck equation which guarantees that the probability function satisfies the initial condition and the proper long-time limit. The time dependence of a physical quantity is given by its average over the time-dependent distribution function. In order to show the robustness of the FEL formalism in explaining thermodynamic and dynamic effects in a unified frame work, I discuss several phenomena found in super-cooled liquids on the basis of the FEL formalism which includes glass transition singularities, slow relaxations, cooling rate dependence of the specific heat, the ac specific heat, temperature dependence of the crystallization time and
Directory of Open Access Journals (Sweden)
Vladimir N. Chuvil’deev
2013-01-01
Full Text Available The article presents the results of theoretical analysis of non-equilibrium grain boundaries diffusion properties recovery during ultra-fine grain (UFG materials annealing, produced by severe plastic deformation (SPD method. The paper proves that activation energy and grain boundary diffusion coefficient of UFG materials depend on density of defects, cumulated by grain boundary during SPD.Annealing causes diffusion redistribution of defects in grain boundaries, which results in diffusion properties change. Diffusion properties recovery rate depends on grain size and it is much higher in UFG materials than in coarse-grained materials.
Non-equilibrium reversible dynamics of work production in four-spin system in a magnetic field
Directory of Open Access Journals (Sweden)
E.A. Ivanchenko
2011-06-01
Full Text Available A closed system of the equations for the local Bloch vectors and spin correlation functions is obtained by decomplexification of the Liouville-von Neumann equation for 4 magnetic particles with the exchange interaction that takes place in an arbitrary time-dependent external magnetic field. The analytical and numerical analysis of the quantum thermodynamic variables is carried out depending on separable mixed initial state and the magnetic field modulation. Under unitary evolution, non-equilibrium reversible dynamics of power production in the finite environment is investigated.
Energy Technology Data Exchange (ETDEWEB)
Miyakawa, M.; Murakami, T.; Suekane, T.; Okuno, Y.; Kabashima, S. [Tokyo Institute of Technology, Tokyo (Japan)
1996-10-20
Structure of non-equilibrium cesium seeded argon plasma excited with microwave power is simulated numerically. The plasmas produced at suitable microwave powers are found to consist of three regimes, that is, the region limited by charged particle loss toward the wall, the full seed ionization and the diffusion limited regions. The fully ionized seed plasma is produced within the skin-depth determined by the electrical conductivity of the plasma, and the thickness of the fully ionized seed plasma depends on the seed fractions gas pressure and microwave power. 15 refs., 6 figs.
Directory of Open Access Journals (Sweden)
Kuznetsov Vladimir V.
2017-01-01
Full Text Available Multiscale processes of self-organization of the flow and non-equilibrium heat and mass transfer during the separation of a binary mixture in a multiphase system formed by a structural packing and a counter-flow vapor-liquid flow are considered. The conditions for the appearance of large-scale convective flow during separation of the binary mixture of refrigerants R21-R114 in a distillation column with Koch 1Y structure packing are obtained. The physical properties of this mixture are similar to the properties of air component at cryogenic temperatures.
Ngo, Son Tung; Nguyen, Minh Tung; Nguyen, Minh Tho
2017-05-01
The absolute binding free energy of an inhibitor to HIV-1 Protease (PR) was determined throughout evaluation of the non-bonded interaction energy difference between the two bound and unbound states of the inhibitor and surrounding molecules by the fast pulling of ligand (FPL) process using non-equilibrium molecular dynamics (NEMD) simulations. The calculated free energy difference terms help clarifying the nature of the binding. Theoretical binding affinities are in good correlation with experimental data, with R = 0.89. The paradigm used is able to rank two inhibitors having the maximum difference of ∼1.5 kcal/mol in absolute binding free energies.
Blankson, Isaiah M.; Foster, John E.; Adamovsky, Grigory
2016-01-01
2016 NASA Glenn Technology Day Panel Presentation on May 24, 2016. The panel description is: Environmental Impact: NASA Glenn Water Capabilities Both global water scarcity and water treatment concerns are two of the most predominant environmental issues of our time. Glenn researchers share insights on a snow sensing technique, hyper spectral imaging of Lake Erie algal blooms, and a discussion on non-equilibrium plasma applications for water purification supporting human spaceflight and terrestrial point-of-use. The panel moderator will be Bryan Stubbs, Executive Director of the Cleveland Water Alliance.
Wang, Weizong; Berthelot, Antonin; Kolev, Stanimir; Tu, Xin; Bogaerts, Annemie
2016-01-01
Abstract: CO2 conversion by a gliding arc plasma is gaining increasing interest, but the underlying mechanisms for an energy-efficient process are still far from understood. Indeed, the chemical complexity of the non-equilibrium plasma poses a challenge for plasma modeling due to the huge computational load. In this paper, a one-dimensional (1D) gliding arc model is developed in a cylindrical frame, with a detailed non-equilibrium CO2 plasma chemistry set, including the CO2 vibrational kineti...
Error estimation and adaptive chemical transport modeling
Directory of Open Access Journals (Sweden)
Malte Braack
2014-09-01
Full Text Available We present a numerical method to use several chemical transport models of increasing accuracy and complexity in an adaptive way. In largest parts of the domain, a simplified chemical model may be used, whereas in certain regions a more complex model is needed for accuracy reasons. A mathematically derived error estimator measures the modeling error and provides information where to use more accurate models. The error is measured in terms of output functionals. Therefore, one has to consider adjoint problems which carry sensitivity information. This concept is demonstrated by means of ozone formation and pollution emission.
Tellurium molecular model and chemical bond
Directory of Open Access Journals (Sweden)
Azcheulov A. A.
2010-10-01
Full Text Available The molecular model of tellurium was considered which explains the complex structure of the chemical bond. Its force bearing and energy characteristics which stipulated the appearance the number of technological solutions of new materials obtaining are defined.
Gerving, C S; Hoang, T M; Land, B J; Anquez, M; Hamley, C D; Chapman, M S
2012-01-01
A pendulum prepared perfectly inverted and motionless is a prototype of unstable equilibrium and corresponds to an unstable hyperbolic fixed point in the dynamical phase space. Here, we measure the non-equilibrium dynamics of a spin-1 Bose-Einstein condensate initialized as a minimum uncertainty spin-nematic state to a hyperbolic fixed point of the phase space. Quantum fluctuations lead to non-linear spin evolution along a separatrix and non-Gaussian probability distributions that are measured to be in good agreement with exact quantum calculations up to 0.25 s. At longer times, atomic loss due to the finite lifetime of the condensate leads to larger spin oscillation amplitudes, as orbits depart from the separatrix. This demonstrates how decoherence of a many-body system can result in apparent coherent behaviour. This experiment provides new avenues for studying macroscopic spin systems in the quantum limit and for investigations of important topics in non-equilibrium quantum dynamics.
Eltayeb, I. A.; Elbashir, T. B. A.
2017-08-01
The linear and nonlinear stabilities of second sound waves in a rotating porous Darcy-Brinkman layer in local thermal non-equilibrium are studied when the heat flux in the solid obeys the Cattaneo law. The simultaneous action of the Brinkman effect (effective viscosity) and rotation is shown to destabilise the layer, as compared to either of them acting alone, for both stationary and overstable modes. The effective viscosity tends to favour overstable modes while rotation tends to favour stationary convection. Rapid rotation invokes a negative viscosity effect that suppresses the stabilising effect of porosity so that the stability characteristics resemble those of the classical rotating Benard layer. A formal weakly nonlinear analysis yields evolution equations of the Landau-Stuart type governing the slow time development of the amplitudes of the unstable waves. The equilibrium points of the evolution equations are analysed and the overall development of the amplitudes is examined. Both overstable and stationary modes can exhibit supercritical stability; supercritical instability, subcritical instability and stability are not possible. The dependence of the supercritical stability on the relative values of the six dimensionless parameters representing thermal non-equilibrium, rotation, porosity, relaxation time, thermal diffusivities and Brinkman effect is illustrated as regions in regime diagrams in the parameter space. The dependence of the heat transfer and the mean heat flux on the parameters of the problem is also discussed.
Chemical vapor infiltration process modeling and optimization
Energy Technology Data Exchange (ETDEWEB)
Besmann, T.M.; Stinton, D.P. [Oak Ridge National Lab., TN (United States); Matlin, W.M. [Tennessee Univ., Knoxville, TN (United States). Dept. of Materials Science and Engineering
1995-12-31
Chemical vapor infiltration is a unique method for preparing continuous fiber ceramic composites that spares the strong but relatively fragile fibers from damaging thermal, mechanical, and chemical degradation. The process is relatively complex and modeling requires detailed phenomenological knowledge of the chemical kinetics and mass and heat transport. An overview of some of the current understanding and modeling of CVI and examples of efforts to optimize the processes is given. Finally, recent efforts to scale-up the process to produce tubular forms are described.
Molecule-based approach for computing chemical-reaction rates in upper atmosphere hypersonic flows.
Energy Technology Data Exchange (ETDEWEB)
Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert
2009-08-01
This report summarizes the work completed during FY2009 for the LDRD project 09-1332 'Molecule-Based Approach for Computing Chemical-Reaction Rates in Upper-Atmosphere Hypersonic Flows'. The goal of this project was to apply a recently proposed approach for the Direct Simulation Monte Carlo (DSMC) method to calculate chemical-reaction rates for high-temperature atmospheric species. The new DSMC model reproduces measured equilibrium reaction rates without using any macroscopic reaction-rate information. Since it uses only molecular properties, the new model is inherently able to predict reaction rates for arbitrary nonequilibrium conditions. DSMC non-equilibrium reaction rates are compared to Park's phenomenological non-equilibrium reaction-rate model, the predominant model for hypersonic-flow-field calculations. For near-equilibrium conditions, Park's model is in good agreement with the DSMC-calculated reaction rates. For far-from-equilibrium conditions, corresponding to a typical shock layer, the difference between the two models can exceed 10 orders of magnitude. The DSMC predictions are also found to be in very good agreement with measured and calculated non-equilibrium reaction rates. Extensions of the model to reactions typically found in combustion flows and ionizing reactions are also found to be in very good agreement with available measurements, offering strong evidence that this is a viable and reliable technique to predict chemical reaction rates.
Using chemical kinetics to model biochemical pathways.
Le Novère, Nicolas; Endler, Lukas
2013-01-01
Chemical kinetics is the study of the rate of reactions transforming some chemical entities into other chemical entities. Over the twentieth century it has become one of the cornerstones of biochemistry. When in the second half of the century basic knowledge of cellular processes became sufficient to understand quantitatively metabolic networks, chemical kinetics associated with systems theory led to the development of what would become an important branch of systems biology. In this chapter we introduce basic concepts of chemical and enzyme kinetics, and show how the temporal evolution of a reaction system can be described by ordinary differential equations. Finally we present a method to apply this type of approach to model any regulatory network.
Chemical Kinetic Models for Advanced Engine Combustion
Energy Technology Data Exchange (ETDEWEB)
Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2014-10-22
The objectives for this project are as follows: Develop detailed chemical kinetic models for fuel components used in surrogate fuels for compression ignition (CI), homogeneous charge compression ignition (HCCI) and reactivity-controlled compression-ignition (RCCI) engines; and Combine component models into surrogate fuel models to represent real transportation fuels. Use them to model low-temperature combustion strategies in HCCI, RCCI, and CI engines that lead to low emissions and high efficiency.
Supramolecular gel phase crystallization: orthogonal self-assembly under non-equilibrium conditions.
Kumar, D Krishna; Steed, Jonathan W
2014-04-07
This tutorial review charts the history of gel phase crystallization from its origins in Liesegang ring formation to current research in the generation of new pharmaceutical solid forms in low molecular weight organogels. The growth of molecular crystals under a supersaturation gradient within the same space and timescale as the formation of a gel phase material is placed into context as an example of orthogonal self-assembly. Such multi-component, weakly coupled orthogonal self-assembly processes occurring far from equilibrium represent a powerful conceptual paradigm for generating fascinating emergent behaviour in chemical systems.
Mathematical modeling a chemical engineer's perspective
Rutherford, Aris
1999-01-01
Mathematical modeling is the art and craft of building a system of equations that is both sufficiently complex to do justice to physical reality and sufficiently simple to give real insight into the situation. Mathematical Modeling: A Chemical Engineer's Perspective provides an elementary introduction to the craft by one of the century's most distinguished practitioners.Though the book is written from a chemical engineering viewpoint, the principles and pitfalls are common to all mathematical modeling of physical systems. Seventeen of the author's frequently cited papers are reprinted to illus
Bahlman, Joseph W.; Swartz, Sharon M.; Riskin, Daniel K.; Breuer, Kenneth S.
2013-01-01
Gliding is an efficient form of travel found in every major group of terrestrial vertebrates. Gliding is often modelled in equilibrium, where aerodynamic forces exactly balance body weight resulting in constant velocity. Although the equilibrium model is relevant for long-distance gliding, such as soaring by birds, it may not be realistic for shorter distances between trees. To understand the aerodynamics of inter-tree gliding, we used direct observation and mathematical modelling. We used vi...
Chemical Kinetic Modeling of Hydrogen Combustion Limits
Energy Technology Data Exchange (ETDEWEB)
Pitz, W J; Westbrook, C K
2008-04-02
A detailed chemical kinetic model is used to explore the flammability and detonability of hydrogen mixtures. In the case of flammability, a detailed chemical kinetic mechanism for hydrogen is coupled to the CHEMKIN Premix code to compute premixed, laminar flame speeds. The detailed chemical kinetic model reproduces flame speeds in the literature over a range of equivalence ratios, pressures and reactant temperatures. A series of calculation were performed to assess the key parameters determining the flammability of hydrogen mixtures. Increased reactant temperature was found to greatly increase the flame speed and the flammability of the mixture. The effect of added diluents was assessed. Addition of water and carbon dioxide were found to reduce the flame speed and thus the flammability of a hydrogen mixture approximately equally well and much more than the addition of nitrogen. The detailed chemical kinetic model was used to explore the detonability of hydrogen mixtures. A Zeldovich-von Neumann-Doring (ZND) detonation model coupled with detailed chemical kinetics was used to model the detonation. The effectiveness on different diluents was assessed in reducing the detonability of a hydrogen mixture. Carbon dioxide was found to be most effective in reducing the detonability followed by water and nitrogen. The chemical action of chemical inhibitors on reducing the flammability of hydrogen mixtures is discussed. Bromine and organophosphorus inhibitors act through catalytic cycles that recombine H and OH radicals in the flame. The reduction in H and OH radicals reduces chain branching in the flame through the H + O{sub 2} = OH + O chain branching reaction. The reduction in chain branching and radical production reduces the flame speed and thus the flammability of the hydrogen mixture.
Methane Incorporation into Liquid Fuel by Non-Equilibrium Plasma Discharges
Liu, Chong; Ji, Hai-Feng; Smith, Joshua; Rabinovich, Alexander; Dobrynin, Danil; Fridman, Alexander
2016-01-01
The conventional ways of processing natural gas into more efficient and economical fuels usually either have low conversion rate or low energy efficiency. In this work, a new approach of methane liquefaction is proposed. Instead of direct treatment of only natural gas, plasma activated methane is reacting with liquid fuel. In this way, methane molecules are directly incorporated onto liquid fuel to achieve liquefaction. Nanosecond-pulsed dielectric barrier discharge and atmospheric pressure glow discharge are used here to ensure no local heating in gas bubbles. Effects of both discharges on methane reaction with liquid fuel are investigated, mass and chemical changes in liquid are observed. Preliminary results show fixation of methane in liquid fuel.
Transport spectroscopy of non-equilibrium many-particle spin states in self-assembled quantum dots.
Marquardt, B; Geller, M; Baxevanis, B; Pfannkuche, D; Wieck, A D; Reuter, D; Lorke, A
2011-02-22
Self-assembled quantum dots (QDs) are prominent candidates for solid-state quantum information processing. For these systems, great progress has been made in addressing spin states by optical means. In this study, we introduce an all-electrical measurement technique to prepare and detect non-equilibrium many-particle spin states in an ensemble of self-assembled QDs at liquid helium temperature. The excitation spectra of the one- (QD hydrogen), two- (QD helium) and three- (QD lithium) electron configuration are shown and compared with calculations using the exact diagonalization method. An exchange splitting of 10 meV between the excited triplet and singlet spin states is observed in the QD helium spectrum. These experiments are a starting point for an all-electrical control of electron spin states in self-assembled QDs above liquid helium temperature.
Directory of Open Access Journals (Sweden)
Seung Jun Lee
2016-07-01
Full Text Available We describe a quantitative study of vortex generation due to non-equilibrium electrokinetics near a micro/nanochannel interface. The microfluidic device is comprised of a microchannel with a set of nanochannels. These perm-selective nanochannels induce flow instability and thereby produce strong vortex generation. We performed tracking visualization of fluorescent microparticles to obtain velocity fields. Particle tracking enables the calculation of an averaged velocity field and the velocity fluctuations. We characterized the effect of applied voltages and electrolyte concentrations on vortex formation. The experimental results show that an increasing voltage or decreasing concentration results in a larger vortex region and a strong velocity fluctuation. We calculate the normalized velocity fluctuation—whose meaning is comparable to turbulent intensity—and we found that it is as high as 0.12. This value is indicative of very efficient mixing, albeit with a small Reynolds number.
Energy Technology Data Exchange (ETDEWEB)
Balat-Pichelin, M., E-mail: marianne.balat@promes.cnrs.fr [Laboratoire Procedes, Materiaux et Energie Solaire, PROMES-CNRS, UPR 8521, 7 rue du four solaire, 66120 Font-Romeu Odeillo (France); Passarelli, M.; Vesel, A. [Laboratoire Procedes, Materiaux et Energie Solaire, PROMES-CNRS, UPR 8521, 7 rue du four solaire, 66120 Font-Romeu Odeillo (France)
2010-09-01
High temperature ceramic materials are necessary for the design of primary heat shields for future re-usable space vehicles re-entering atmospheric planet at hypersonic velocity. During the re-entry phase on earth, one of the most important phenomena occurring on the heat shield is the recombination of atomic oxygen and this phenomenon is more or less catalyzed by the material of the heat shield. This paper presents some experimental results for the recombination coefficient of atomic oxygen {gamma} based on experiments performed on the MESOX facility using optical emission spectroscopy and actinometry techniques. Experimental results on the recombination coefficient are presented for three types of sintered ZrO{sub 2} in the temperature range 900-2500 K for 200 Pa total air pressure. These three zirconia ceramics differ essentially by the chemical nature of the sintering additives (Y{sub 2}O{sub 3}, CaO or MgO). A great different behavior of the recombination coefficient versus temperature is observed according to the crystalline structure of zirconia (monoclinic and tetragonal phases) and few influence of the additive is shown.
Non-equilibrium thermodynamical framework for rate- and state-dependent friction
Ván, P; Hatano, T
2015-01-01
Rate- and state-dependent friction law for velocity-step and healing are analysed from a thermodynamic point of view. Assuming a logarithmic deviation from steady-state a unification of the classical Dieterich and Ruina models of rock friction is proposed.
A non-equilibrium simulation of thermal constriction in a cascaded arc hydrogen plasma
Peerenboom, K. S. C.; van Dijk, J.; W. J. Goedheer,; Kroesen, G. M. W.
2014-01-01
The cascaded arc hydrogen plasma of Pilot-PSI is studied in a non-LTE model. We demonstrate that the effect of vibrationally excited molecules on the heavy-particle-assisted dissociation is crucial for obtaining thermal constriction. To the best of our knowledge, thermal constriction has not been
Non-Equilibrium Patterns in the Space of the Stock Market Prices
Gligor, M.; Ignat, M.
2002-11-01
Using a phenomenological approach, we analyse the formation and the propagation of the patterns (or ‘dissipative structures’) in the stock market, the spatial coordinate being the bid-offer spread y, as a function of which the spectrum φ of deals is modelled. The stock market will be considered a distributed active medium that is a set of active elements (the brokers) interacting with others through deals (typically a diffusion process). The physical model used is the reaction-diffusion model. The reactive part of the reaction-diffusion equation is developed from a hot-spot mechanism, with a characteristic jump when φ passes the critical value φc. Solving the stationary equation according to the Dirichlet boundary conditions, we find the ‘hot deals’ regions, meaning regions of speculative transactions which can be considered ‘dissipation’ as they do not contribute to the gross national product. The time propagation of these patterns in the one-dimensional space considered could explain the evolution of markets towards speculative bubbles. These are frequently met in the frame of emerging stock markets. Financial data, which illustrate the physical model refer to Romania's stock market, Bucharest S.E.
A grand model for chemical product design
DEFF Research Database (Denmark)
Fung, Ka Y.; Ng, Ka M.; Zhang, Lei
2016-01-01
Chemical engineering has been expanding its focus from primarily business-to-business products (B2B) to business-to-consumer (B2C) products. The production of B2B products generally emphasizes on process design and optimization, whereas the production of B2C products focuses on product quality......, ingredients and structure. Market and competitive analysis, government policies and regulations have to be explicitly considered in product design. All these considerations are accounted for in the Grand Product Design Model, which consists of a process model, a property model, a quality model, a cost model...
Chemical Kinetic Modeling of 2-Methylhexane Combustion
Mohamed, Samah Y.
2015-03-30
Accurate chemical kinetic combustion models of lightly branched alkanes (e.g., 2-methylalkanes) are important for investigating the combustion behavior of diesel, gasoline, and aviation fuels. Improving the fidelity of existing kinetic models is a necessity, as new experiments and advanced theories show inaccuracy in certain portions of the models. This study focuses on updating thermodynamic data and kinetic model for a gasoline surrogate fuel, 2-methylhexane, with recently published group values and rate rules. These update provides a better agreement with rapid compression machine measurements of ignition delay time, while also strengthening the fundamental basis of the model.
The non-equilibrium Green's function method for nanoscale device simulation
Pourfath, Mahdi
2014-01-01
For modeling the transport of carriers in nanoscale devices, a Green-function formalism is the most accurate approach. Due to the complexity of the formalism, one should have a deep understanding of the underlying principles and use smart approximations and numerical methods for solving the kinetic equations at a reasonable computational time. In this book the required concepts from quantum and statistical mechanics and numerical methods for calculating Green functions are presented. The Green function is studied in detail for systems both under equilibrium and under nonequilibrium conditions. Because the formalism enables rigorous modeling of different scattering mechanisms in terms of self-energies, but an exact evaluation of self-energies for realistic systems is not possible, their approximation and inclusion in the quantum kinetic equations of the Green functions are elaborated. All the elements of the kinetic equations, which are the device Hamiltonian, contact self-energies, and scattering self-energie...
Targeting Bayes factors with direct-path non-equilibrium thermodynamic integration
Grzegorczyk, Marco; Aderhold, Andrej; Husmeier, Dirk
2017-01-01
Thermodynamic integration (TI) for computing marginal likelihoods is based on an inverse annealing path from the prior to the posterior distribution. In many cases, the resulting estimator suffers from high variability, which particularly stems from the prior regime. When comparing complex models with differences in a comparatively small number of parameters, intrinsic errors from sampling fluctuations may outweigh the differences in the log marginal likelihood estimates. In the present artic...
Non-equilibrium Thermodynamical Description of Superfluid Transition in Liquid Helium
Ardizzone, Lucia; Stella Mongiovì, Maria; Saluto, Lidia
2017-10-01
In previous papers a phase field model for λ-transition in 4He was proposed, which is able to describe the influence of the heat flux on the temperature transition. The model presented here generalizes previous results taking into account of a homogeneous presence of quantized vortices below the λ-transition. As parameter that controls the transition, a dimensionless field f linked to the modulus of the condensate wave function is used. In addition to the field f, the resulting model chooses the following field variables: density, velocity, temperature and heat flux. Nonlocal terms to describe inhomogeneities in the field variables and dissipative effects of mechanical and thermal origin are also taken into account. Under the hypothesis that the liquid is at rest, the second sound propagation near the superfluid transition is studied. It is seen that the order parameter modifies the speed and the attenuation of the second sound, as well as the presence of a small tangle of vortices. This shows that the influence of the order parameter is not restricted to the description of the lambda transition, but its presence influences also other features, as the second sound speed and attenuation. In addition to the second sound a new mode is present, corresponding to a perturbation in the order parameter f, which is attenuated within a short number of wavelengths.
Bahlman, Joseph W; Swartz, Sharon M; Riskin, Daniel K; Breuer, Kenneth S
2013-03-06
Gliding is an efficient form of travel found in every major group of terrestrial vertebrates. Gliding is often modelled in equilibrium, where aerodynamic forces exactly balance body weight resulting in constant velocity. Although the equilibrium model is relevant for long-distance gliding, such as soaring by birds, it may not be realistic for shorter distances between trees. To understand the aerodynamics of inter-tree gliding, we used direct observation and mathematical modelling. We used videography (60-125 fps) to track and reconstruct the three-dimensional trajectories of northern flying squirrels (Glaucomys sabrinus) in nature. From their trajectories, we calculated velocities, aerodynamic forces and force coefficients. We determined that flying squirrels do not glide at equilibrium, and instead demonstrate continuously changing velocities, forces and force coefficients, and generate more lift than needed to balance body weight. We compared observed glide performance with mathematical simulations that use constant force coefficients, a characteristic of equilibrium glides. Simulations with varying force coefficients, such as those of live squirrels, demonstrated better whole-glide performance compared with the theoretical equilibrium state. Using results from both the observed glides and the simulation, we describe the mechanics and execution of inter-tree glides, and then discuss how gliding behaviour may relate to the evolution of flapping flight.
Adsorption of NH4+-N on Chinese loess: Non-equilibrium and equilibrium investigations.
Xie, Haijian; Wang, Shaoyi; Qiu, Zhanhong; Jiang, Jianqun
2017-11-01
NH 4 + -N is a crucial pollutant in landfill leachate and can be in high concentrations for a long period of time due to anaerobic condition of landfills. The adsorption properties of NH 4 + -N on the Chinese loess were investigated using Batch test. The influences of ammonium concentration, temperature, reaction time, slurry concentration, and pH on the adsorption process are evaluated. Adsorption kinetics and isotherm behaviors were studied by applying different models to the test data to determine the adsorption parameters. The equilibrating duration was shown to be less than 60 min. The data on adsorption kinetics can be well fitted by the pseudo-second-order kinetics model. According to the Langmuir isotherm model, the adsorption capacity of Chinese loess about NH 4 + -N was predicted to be 72.30 mg g -1 . The uptake of NH 4 + -N by Chinese loess was considered to be the type of physical adsorption on the basis of D-R isotherm analysis. The optimal pH and slurry concentration are 4 and 2 g/50 ml, respectively. According to the calculated values of free energy, enthalpy and entropy change, the adsorption process is determined to be exothermic. The disorder of the system appeared lowest at temperature of 308.15 K. The predicted Gibb's free energies also indicate the adsorption process is endothermic and spontaneous. The FTIR spectrum and EDX analysis showed the adsorption process of NH 4 + involves cation exchange and dissolution of calcite. Copyright © 2017 Elsevier Ltd. All rights reserved.
Heat transfer in porous medium embedded with vertical plate: Non-equilibrium approach - Part B
Energy Technology Data Exchange (ETDEWEB)
Quadir, G. A., E-mail: Irfan-magami@Rediffmail.com, E-mail: gaquadir@gmail.com [School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis (Malaysia); Badruddin, Irfan Anjum [Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia)
2016-06-08
This work is continuation of the paper Part A. Due to large number of results, the paper is divided into two section with section-A (Part A) discussing the effect of various parameters such as heat transfer coefficient parameter, thermal conductivity ratio etc. on streamlines and isothermal lines. Section-B highlights the heat transfer characteristics in terms of Nusselt number The Darcy model is employed to simulate the flow inside the medium. It is assumed that the heat transfer takes place by convection and radiation. The governing partial differential equations are converted into non-dimensional form and solved numerically using finite element method.
Non-equilibrium trajectory dynamics and the kinematics of gliding in a flying snake
Energy Technology Data Exchange (ETDEWEB)
Socha, John J; Jafari, Farid [Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States); Miklasz, Kevin [Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 (United States); Vlachos, Pavlos P, E-mail: jjsocha@vt.ed [Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061 (United States)
2010-12-15
Given sufficient space, it is possible for gliding animals to reach an equilibrium state with no net forces acting on the body. In contrast, every gliding trajectory must begin with a non-steady component, and the relative importance of this phase is not well understood. Of any terrestrial animal glider, snakes exhibit the greatest active movements, which may affect their trajectory dynamics. Our primary aim was to determine the characteristics of snake gliding during the transition to equilibrium, quantifying changes in velocity, acceleration, and body orientation in the late phase of a glide sequence. We launched 'flying' snakes (Chrysopelea paradisi) from a 15 m tower and recorded the mid-to-end portion of trajectories with four videocameras to reconstruct the snake's body position with mm to cm accuracy. Additionally, we developed a simple analytical model of gliding assuming only steady-state forces of lift, drag and weight acting on the body and used it to explore effects of wing loading, lift-to-drag ratio, and initial velocity on trajectory dynamics. Despite the vertical space provided to transition to steady-state gliding, snakes did not exhibit equilibrium gliding and in fact displayed a net positive acceleration in the vertical axis, an effect also predicted by the analytical model.
Two-step ionization in non-equilibrium SF sub 6 discharges at high current density
Bychkov, Yu A; Lacour, B; Pasquiers, S; Puech, V; Yastremski, A
2003-01-01
In the pressure range 10-100 mbar, the discharge development in SF sub 6 has been investigated in the photo-triggered excitation scheme for current density in the range 10-1000 A cm sup - sup 2 and pulse duration of about 60 ns. Thanks to the homogeneity of the photo-triggered discharge, a self-consistent zero-dimensional model can be used to predict the temporal evolution of the electrical parameters. From a detailed comparison between the experimental results and the modelling predictions, evidence for the occurrence of a two-step ionization process in high current density discharges in SF sub 6 is reported and the corresponding collision cross-section is estimated. Moreover, it is shown that the amount of the two-step ionization is directly correlated to the density of the electrical charge transferred to the plasma per unit surface. This two-step ionization becomes the main source of electron multiplication whenever the transferred charge per unit surface is higher than 15 mu C cm sup - sup 2.
Brownian motion in non-equilibrium systems and the Ornstein-Uhlenbeck stochastic process.
Donado, F; Moctezuma, R E; López-Flores, L; Medina-Noyola, M; Arauz-Lara, J L
2017-10-03
The Ornstein-Uhlenbeck stochastic process is an exact mathematical model providing accurate representations of many real dynamic processes in systems in a stationary state. When applied to the description of random motion of particles such as that of Brownian particles, it provides exact predictions coinciding with those of the Langevin equation but not restricted to systems in thermal equilibrium but only conditioned to be stationary. Here, we investigate experimentally single particle motion in a two-dimensional granular system in a stationary state, consisting of 1 mm stainless balls on a plane circular surface. The motion of the particles is produced by an alternating magnetic field applied perpendicular to the surface of the container. The mean square displacement of the particles is measured for a range of low concentrations and it is found that following an appropriate scaling of length and time, the short-time experimental curves conform a master curve covering the range of particle motion from ballistic to diffusive in accordance with the description of the Ornstein-Uhlenbeck model.
Crema, Enrico R.; Kandler, Anne; Shennan, Stephen
2016-12-01
A long tradition of cultural evolutionary studies has developed a rich repertoire of mathematical models of social learning. Early studies have laid the foundation of more recent endeavours to infer patterns of cultural transmission from observed frequencies of a variety of cultural data, from decorative motifs on potsherds to baby names and musical preferences. While this wide range of applications provides an opportunity for the development of generalisable analytical workflows, archaeological data present new questions and challenges that require further methodological and theoretical discussion. Here we examine the decorative motifs of Neolithic pottery from an archaeological assemblage in Western Germany, and argue that the widely used (and relatively undiscussed) assumption that observed frequencies are the result of a system in equilibrium conditions is unwarranted, and can lead to incorrect conclusions. We analyse our data with a simulation-based inferential framework that can overcome some of the intrinsic limitations in archaeological data, as well as handle both equilibrium conditions and instances where the mode of cultural transmission is time-variant. Results suggest that none of the models examined can produce the observed pattern under equilibrium conditions, and suggest. instead temporal shifts in the patterns of cultural transmission.
Designing high specificity anti-cancer nanocarriers by exploiting non-equilibrium effects
Tsekouras, Konstantinos; Goncharenko, Igor; Colvin, Michael; Huang, Kerwyn; Gopinathan, Ajay
2012-11-01
Although targeting of cancer cells using drug-delivering nanocarriers holds promise for improving therapeutic agent specificity, the strategy of maximizing ligand affinity for receptors overexpressed on cancer cells is suboptimal. To determine design principles that maximize nanocarrier specificity for cancer cells, we studied a generalized kinetics-based theoretical model of nanocarriers with one or more ligands that specifically bind these overexpressed receptors. We show that kinetics inherent to the system play an important role in determining specificity and can in fact be exploited to attain orders of magnitude improvement in specificity. In contrast to the current trend of therapeutic design, we show that these specificity increases can generally be achieved by a combination of low rates of endocytosis and nanocarriers with multiple low-affinity ligands. These results are broadly robust across endocytosis mechanisms and drug-delivery protocols, suggesting the need for a paradigm shift in receptor- targeted drug-delivery design.
Relationship between Population Dynamics and the Self-Energy in Driven Non-Equilibrium Systems
Directory of Open Access Journals (Sweden)
Alexander F. Kemper
2016-05-01
Full Text Available We compare the decay rates of excited populations directly calculated within a Keldysh formalism to the equation of motion of the population itself for a Hubbard-Holstein model in two dimensions. While it is true that these two approaches must give the same answer, it is common to make a number of simplifying assumptions, within the differential equation for the populations, that allows one to interpret the decay in terms of hot electrons interacting with a phonon bath. Here, we show how care must be taken to ensure an accurate treatment of the equation of motion for the populations due to the fact that there are identities that require cancellations of terms that naively look like they contribute to the decay rates. In particular, the average time dependence of the Green’s functions and self-energies plays a pivotal role in determining these decay rates.
Non-equilibrium differential conductance through a quantum dot in a magnetic field
Energy Technology Data Exchange (ETDEWEB)
Hewson, A C [Department of Mathematics, Imperial College, London SW7 2AZ (United Kingdom); Bauer, J [Department of Mathematics, Imperial College, London SW7 2AZ (United Kingdom); Oguri, A [Department of Material Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan)
2005-09-07
We derive an exact expression for the differential conductance for a quantum dot in an arbitrary magnetic field for small bias voltage. The derivation is based on the symmetric Anderson model using renormalized perturbation theory and is valid for all values of the on-site interaction U including the Kondo regime. We calculate the critical magnetic field for the splitting of the Kondo resonance to be seen in the differential conductivity as a function of bias voltage. Our calculations for small field show that the peak positions of the component resonances in the differential conductance are reduced substantially from estimates using the equilibrium Green function. We conclude that it is important to take the voltage dependence of the local retarded Green function into account in interpreting experimental results.
DEFF Research Database (Denmark)
Jørgensen, Jacob Lykkebo
, which is characterised by destructive quantum interference. The molecules are cross-conjugated, which means that the two parts of the molecules are conjugated to a third part, but not to each other. This gives rise to an anti-resonance in the trans- mission. In the low bias and low temperature regime......-resonance in the transmission. We then go on to study current induced heating and cooling, and nd that there is a basis for using quantum interference to design molecules that can be cooling by the tunnelling current. The basic idea is to align the incoming and the outgoing transmission channels such that absorption...... of a phonon is favoured over emission of a phonon. The incoming and outgoing channels are usually very alike, but by separating them using quantum interference it is possible to tune the system to observe a cooling eect. The basis is illus- trated in a simple tight-binding model, and the subsequent cooling...
Measurement of Vibrational Non-Equilibrium in a Supersonic Freestream Using Dual-Pump CARS
Cutler, Andrew D.; Magnotti, Gaetano; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Danehy, Paul M.; Burle, Rob; Rockwell, Robert; Goyne, Christopher; McDaniel, James
2012-01-01
Measurements have been conducted at the University of Virginia Supersonic Combustion Facility of the flow in a constant area duct downstream of a Mach 2 nozzle, where the airflow has first been heated to approximately 1200 K. Dual-pump CARS was used to acquire rotational and vibrational temperatures of N2 and O2 at two planes in the duct at different downstream distances from the nozzle exit. Wall static pressures in the nozzle are also reported. With a flow of clean air, the vibrational temperature of N2 freezes at close to the heater stagnation temperature, while the O2 vibrational temperature is about 1000 K. The results are well predicted by computational fluid mechanics models employing separate "lumped" vibrational and translational/rotational temperatures. Experimental results are also reported for a few percent steam addition to the air and the effect of the steam is to bring the flow to thermal equilibrium.
NON-EQUILIBRIUM DYNAMICS OF MANY-BODY QUANTUM SYSTEMS: FUNDAMENTALS AND NEW FRONTIER
Energy Technology Data Exchange (ETDEWEB)
DeMille, David; LeHur, Karyn
2013-11-27
Rapid progress in nanotechnology and naofabrication techniques has ushered in a new era of quantum transport experiments. This has in turn heightened the interest in theoretical understanding of nonequilibrium dynamics of strongly correlated quantum systems. This project has advanced the frontiers of understanding in this area along several fronts. For example, we showed that under certain conditions, quantum impurities out of equilibrium can be reformulated in terms of an effective equilibrium theory; this makes it possible to use the gamut of tools available for quantum systems in equilibrium. On a different front, we demonstrated that the elastic power of a transmitted microwave photon in circuit QED systems can exhibit a many-body Kondo resonance. We also showed that under many circumstances, bipartite fluctuations of particle number provide an effective tool for studying many-body physics—particularly the entanglement properties of a many-body system. This implies that it should be possible to measure many-body entanglement in relatively simple and tractable quantum systems. In addition, we studied charge relaxation in quantum RC circuits with a large number of conducting channels, and elucidated its relation to Kondo models in various regimes. We also extended our earlier work on the dynamics of driven and dissipative quantum spin-boson impurity systems, deriving a new formalism that makes it possible to compute the full spin density matrix and spin-spin correlation functions beyond the weak coupling limit. Finally, we provided a comprehensive analysis of the nonequilibrium transport near a quantum phase transition in the case of a spinless dissipative resonant-level model. This project supported the research of two Ph.D. students and two postdoctoral researchers, whose training will allow them to further advance the field in coming years.
PROTOTYPING NON-EQUILIBRIUM VISCOUS-TIMESCALE ACCRETION THEORY USING LMC X-3
Energy Technology Data Exchange (ETDEWEB)
Cambier, Hal J.; Smith, David M. [Physics Department, University of California, Santa Cruz, CA 95064 (United States)
2013-04-10
Explaining variability observed in the accretion flows of black hole X-ray binary systems remains challenging, especially concerning timescales less than, or comparable to, the viscous timescale but much larger than the inner orbital period despite decades of research identifying numerous relevant physical mechanisms. We take a simplified but broad approach to study several mechanisms likely relevant to patterns of variability observed in the persistently high-soft Roche-lobe overflow system LMC X-3. Based on simple estimates and upper bounds, we find that physics beyond varying disk/corona bifurcation at the disk edge, Compton-heated winds, modulation of total supply rate via irradiation of the companion, and the likely extent of the partial hydrogen ionization instability is needed to explain the degree, and especially the pattern, of variability in LMC X-3 largely due to viscous dampening. We then show how evaporation-condensation may resolve or compound the problem given the uncertainties associated with this complex mechanism and our current implementation. We briefly mention our plans to resolve the question, refine and extend our model, and alternatives we have not yet explored.
Non-equilibrium phase stabilization versus bubble nucleation at a nanoscale-curved Interface
Schiffbauer, Jarrod; Luo, Tengfei
Using continuum dynamic van der Waals theory in a radial 1D geometry with a Lennard-Jones fluid model, we investigate the nature of vapor bubble nucleation near a heated, nanoscale-curved convex interface. Vapor bubble nucleation and growth are observed for interfaces with sufficiently large radius of curvature while phase stabilization of a superheated fluid layer occurs at interfaces with smaller radius. The hypothesis that the high Laplace pressure required for stable equilibrium of very small bubbles is responsible for phase stability is tested by effectively varying the parameter which controls liquid-vapor surface tension. In doing so, the liquid-vapor surface tension- hence Laplace pressure-is shown to have limited effect on phase stabilization vs. bubble nucleation. However, the strong dependence of nucleation on leading-order momentum transport, i.e. viscous dissipation, near the heated inner surface is demonstrated. We gratefully acknowledge ND Energy for support through the ND Energy Postdoctoral Fellowship program and the Army Research Office, Grant No. W911NF-16-1-0267, managed by Dr. Chakrapani Venanasi.
Leggett, S. K.; Tremblin, P.; Saumon, D.; Marley, M. S.; Morley, Caroline V.; Amundsen, D. S.; Baraffe, I.; Chabrier, G.
2016-01-01
We present new near-infrared spectra, obtained at Gemini Observatory, for two Y dwarfs: WISE J035000.32-565830.2 (W0350) and WISEP J173835.52+273258.9 (W1738). A FLAMINGOS-2 R = 540 spectrum was obtained for W0350, covering 1.0 < ? micrometer < 1.7, and a cross-dispersed GNIRS R = 2800 spectrum was obtained for W1738, covering 0.993 - 1.087 micrometer, 1.191 - 1.305 micrometer, 1.589 - 1.631 micrometer, and 1.985 - 2.175 micrometer, in four orders. We also present revised Y JH photometry for W1738, using new NIRI Y and J imaging, and a re-analysis of the previously published NIRI H band images. We compare these data, together with previously published data for late-T and Y dwarfs, to cloud-free models of solar metallicity, calculated both in chemical equilibrium and with disequilibrium driven by vertical transport. We find that for the Y dwarfs the non-equilibrium models reproduce the near-infrared data better than the equilibrium models. The remaining discrepancies suggest that fine-tuning the CH4/CO and NH3/N2 balance is needed. Improved trigonometric parallaxes would improve the analysis. Despite the uncertainties and discrepancies, the models reproduce the observed near-infrared spectra well. We find that for the Y0, W1738, T(sub eff) = 425 +/- 25K and log g = 4.0 +/- 0.25, and for the Y1, W0350, T(sub eff) = 350 +/- 25K and log g = 4.0 +/- 0.25. W1738 may be metal-rich. Based on evolutionary models, these temperatures and gravities correspond to a mass range for both Y dwarfs of 3 - 9 Jupiter masses, with W0350 being a cooler, slightly older, version of W1738; the age of W0350 is 0.3 - 3 Gyr, and the age of W1738 is 0.15 - 1 Gyr.
Chemical kinetics and modeling of planetary atmospheres
Yung, Yuk L.
1990-01-01
A unified overview is presented for chemical kinetics and chemical modeling in planetary atmospheres. The recent major advances in the understanding of the chemistry of the terrestrial atmosphere make the study of planets more interesting and relevant. A deeper understanding suggests that the important chemical cycles have a universal character that connects the different planets and ultimately link together the origin and evolution of the solar system. The completeness (or incompleteness) of the data base for chemical kinetics in planetary atmospheres will always be judged by comparison with that for the terrestrial atmosphere. In the latter case, the chemistry of H, O, N, and Cl species is well understood. S chemistry is poorly understood. In the atmospheres of Jovian planets and Titan, the C-H chemistry of simple species (containing 2 or less C atoms) is fairly well understood. The chemistry of higher hydrocarbons and the C-N, P-N chemistry is much less understood. In the atmosphere of Venus, the dominant chemistry is that of chlorine and sulfur, and very little is known about C1-S coupled chemistry. A new frontier for chemical kinetics both in the Earth and planetary atmospheres is the study of heterogeneous reactions. The formation of the ozone hole on Earth, the ubiquitous photochemical haze on Venus and in the Jovian planets and Titan all testify to the importance of heterogeneous reactions. It remains a challenge to connect the gas phase chemistry to the production of aerosols.
Models and Modelling Tools for Chemical Product and Process Design
DEFF Research Database (Denmark)
Gani, Rafiqul
2016-01-01
The design, development and reliability of a chemical product and the process to manufacture it, need to be consistent with the end-use characteristics of the desired product. One of the common ways to match the desired product-process characteristics is through trial and error based experiments......-based framework is that in the design, development and/or manufacturing of a chemical product-process, the knowledge of the applied phenomena together with the product-process design details can be provided with diverse degrees of abstractions and details. This would allow the experimental resources......, are the needed models for such a framework available? Or, are modelling tools that can help to develop the needed models available? Can such a model-based framework provide the needed model-based work-flows matching the requirements of the specific chemical product-process design problems? What types of models...
Modeling the Thermal Destruction of Chemical Warfare ...
Symposium Paper In the event of a terrorist attack with chemical warfare agents (CWAs), large quantities of materials, both indoor and outdoor, may be treated with thermal incineration during the site remediation process. This paper reports on a study to examine the thermal decomposition of surrogate CWAs and formation of decomposition by-products bound in model building materials (in this case, ceiling tile) in a pilot-scale rotary kiln incinerator simulator.
Modelling Chemical Preservation of Plantain Hybrid Fruits
Directory of Open Access Journals (Sweden)
Ogueri Nwaiwu
2017-08-01
Full Text Available New plantain hybrids plants have been developed but not much has been done on the post-harvest keeping quality of the fruits and how they are affected by microbial colonization. Hence fruits from a tetraploid hybrid PITA 2 (TMPx 548-9 obtained by crossing plantain varieties Obino l’Ewai and Calcutta 4 (AA and two local triploid (AAB plantain landraces Agbagba and Obino l’Ewai were subjected to various concentrations of acetic, sorbic and propionic acid to determine the impact of chemical concentration, chemical type and plantain variety on ripening and weight loss of plantain fruits. Analysis of titratable acidity, moisture content and total soluble solids showed that there were no significant differences between fruits of hybrid and local varieties. The longest time to ripening from harvest (24 days was achieved with fruits of Agbagba treated with 3% propionic acid. However, fruits of PITA 2 hybrid treated with propionic and sorbic acid at 3% showed the longest green life which indicated that the chemicals may work better at higher concentrations. The Obino l’Ewai cultivar had the highest weight loss for all chemical types used. Modelling data obtained showed that plantain variety had the most significant effect on ripening and indicates that ripening of the fruits may depend on the plantain variety. It appears that weight loss of fruits from the plantain hybrid and local cultivars was not affected by the plantain variety, chemical type. The chemicals at higher concentrations may have an effect on ripening of the fruits and will need further investigation.
Wu, Zeng-Qiang; Du, Wen-Bin; Li, Jin-Yi; Xia, Xing-Hua; Fang, Qun
2015-08-01
Numerical simulation can provide valuable insights for complex microfluidic phenomena coupling mixing and diffusion processes. Herein, a novel finite element model (FEM) has been established to extract chemical reaction kinetics in a microfluidic flow injection analysis (micro-FIA) system using high throughput sample introduction. To reduce the computation burden, the finite element mesh generation is performed with different scales based on the different geometric sizes of micro-FIA. In order to study the contribution of chemical reaction kinetics under non-equilibrium condition, a pseudo-first-order chemical kinetics equation is adopted in the numerical simulations. The effect of reactants diffusion on reaction products is evaluated, and the results demonstrate that the Taylor dispersion plays a determining role in the micro-FIA system. In addition, the effects of flow velocity and injection volume on the reaction product are also simulated. The simulated results agree well with the ones from experiments. Although gravity driven flow is used to the numerical model in the present study, the FEM model also can be applied into the systems with other driving forces such as pressure. Therefore, the established FEM model will facilitate the understanding of reaction mechanism in micro-FIA systems and help us to optimize the manifold of micro-FIA systems. Copyright © 2015 Elsevier B.V. All rights reserved.
Non-equilibrium dynamics of hard-core bosons on 1D lattices: short vs large time results
Rigol, Marcos; Muramatsu, Alejandro
2005-03-01
Based on an exact treatment we study the non-equilibrium dynamics of hard-core bosons on one-dimensional lattices. Starting from a pure Fock state we find that quasi-long range correlations develop very fast in the system, and they lead to the emergence of quasi-condensates at finite momentum [1]. The exponent observed in the power-law decay of the one-particle density matrix, which develops dynamically, is the same that has been proven to be universal in the equilibrium case [2]. We also study the time evolution of clouds of hard-core bosons when they are released from a harmonic trap. In this case we show that the momentum distribution of the free expanding hard-core bosons approaches to the one of noninteracting fermions [3], in contrast to the known behavior in equilibrium systems. [1] M. Rigol and A. Muramatsu, cond-mat/0403387, to appear in Phys. Rev. Lett. (2004). [2] M. Rigol and A. Muramatsu, Phys. Rev. A 70, 031603(R) (2004); ibid. cond-mat/0409132. [3] M. Rigol and A. Muramatsu, cond-mat/0410683.
Rigol, Marcos; Muramatsu, Alejandro
2004-03-01
We study by means of an exact approach, a gas of hard core bosons (HCB) confined on optical lattices. The ground state properties of such systems are analyzed. Local incompressible phases appear in the system, like in the case of interacting soft-core bosons [1] and fermions [2,3]. The changes in momentum distribution function and in the natural orbitals (effective single particle states) introduced by the formation of such phases are analyzed. We also study non-equilibrium properties for those systems, which within our numerical approach can be obtained exactly for systems with 200 particles on lattices with 3000 sites. In particular we analyze the free expansion of the gas when it is released from the trap turning off the confining potential. We show that the expansion is non-trivial (as opposed to the fermionic case) and new features to be observed in the experiments are analyzed. [1] G. G. Batrouni, V. Rousseau, R. T. Scalettar, M. Rigol, A. Muramatsu, P. J. H. Denteneer, and M. Troyer, Phys. Rev. Lett. 89, 117203 (2002). [2] M. Rigol, A. Muramatsu, G. G. Batrouni, and R. T. Scalettar, Phys. Rev. Lett. 91, 130403 (2003). [3] M. Rigol and A. Muramatsu, cond-mat/0309670 (2003).
Bhattacharyya, Sirshendu; Dasgupta, Subinay; Das, Arnab
2015-11-16
Understanding phase transitions in quantum matters constitutes a significant part of present day condensed matter physics. Quantum phase transitions concern ground state properties of many-body systems, and hence their signatures are expected to be pronounced in low-energy states. Here we report signature of a quantum critical point manifested in strongly out-of-equilibrium states with finite energy density with respect to the ground state and extensive (subsystem) entanglement entropy, generated by an external pulse. These non-equilibrium states are evidently completely disordered (e.g., paramagnetic in case of a magnetic ordering transition). The pulse is applied by switching a coupling of the Hamiltonian from an initial value (λI) to a final value (λF) for sufficiently long time and back again. The signature appears as non-analyticities (kinks) in the energy absorbed by the system from the pulse as a function of λF at critical-points (i.e., at values of λF corresponding to static critical-points of the system). As one excites higher and higher eigenstates of the final Hamiltonian H(λF) by increasing the pulse height (|λF - λI|), the non-analyticity grows stronger monotonically with it. This implies adding contributions from higher eigenstates help magnifying the non-analyticity, indicating strong imprint of the critical-point on them. Our findings are grounded on exact analytical results derived for Ising and XY chains in transverse field.
Bag, Biplab; Shaw, Gorky; Banerjee, S S; Majumdar, Sayantan; Sood, A K; Grover, A K
2017-07-17
Under the influence of a constant drive the moving vortex state in 2H-NbS2 superconductor exhibits a negative differential resistance (NDR) transition from a steady flow to an immobile state. This state possesses a high depinning current threshold ([Formula: see text]) with unconventional depinning characteristics. At currents well above [Formula: see text], the moving vortex state exhibits a multimodal velocity distribution which is characteristic of vortex flow instabilities in the NDR regime. However at lower currents which are just above [Formula: see text], the velocity distribution is non-Gaussian with a tail extending to significant negative velocity values. These unusual negative velocity events correspond to vortices drifting opposite to the driving force direction. We show that this distribution obeys the Gallavotti-Cohen Non-Equilibrium Fluctuation Relation (GC-NEFR). Just above [Formula: see text], we also find a high vortex density fluctuating driven state not obeying the conventional GC-NEFR. The GC-NEFR analysis provides a measure of an effective energy scale (E eff ) associated with the driven vortex state. The E eff corresponds to the average energy dissipated by the fluctuating vortex state above [Formula: see text]. We propose the high E eff value corresponds to the onset of high energy dynamic instabilities in this driven vortex state just above [Formula: see text].
Directory of Open Access Journals (Sweden)
Chao Zhang
2016-11-01
Full Text Available We investigate the non-equilibrium quantum transport through a single-molecule magnet embedded in a tunnel junction with ferromagnetic electrodes, which generate spin-polarized electrons. The lead magnetization direction is non-collinear with the uniaxial anisotropy easy-axis of molecule-magnet. Based on the Pauli rate-equation approach we demonstrate the magnetization reversion of molecule-magnet induced by the back action of spin-polarized current in the sequential tunnel regime. The asymptotic magnetization of molecular magnet and spin-polarization of transport current are obtained as functions of time by means of time-dependent solution of the rate equation. It is found that the antiparallel configuration of the ferromagnetic electrodes and molecular anisotropy easy-axis is an effective structure to reverse both the magnetization of molecule-magnet and spin-polarization of the transport current. Particularly the non-collinear angle dependence provides useful knowledge for the quantum manipulation of molecule-magnet and spin polarized electron-transport.
Levi, Emanuele; Gutiérrez, Ricardo; Lesanovsky, Igor
2016-09-01
In the presence of strong dephasing noise the dynamics of Rydberg gases becomes effectively classical, due to the rapid decay of quantum superpositions between atomic levels. Recently a great deal of attention has been devoted to the stochastic dynamics that emerges in that limit, revealing several interesting features, including kinetically constrained glassy behaviour, self-similarity and aggregation effects. However, the non-equilibrium physics of these systems, in particular in the regime where coherent and dissipative processes contribute on equal footing, is yet far from being understood. To explore this we study the dynamics of a small one-dimensional Rydberg lattice gas subject to dephasing noise by numerically integrating the quantum master equation. We interpolate between the coherent and the strongly dephased regime by defining a generalised concept of a blockade length. We find indications that the main features observed in the strongly dissipative limit persist when the dissipation is not strong enough to annihilate quantum coherences at the dynamically relevant time scales. These features include the existence of a time-dependent Rydberg blockade radius, and a growth of the density of excitations which is compatible with the power-law behaviour expected in the classical limit.
Zhang, Chao; Yao, Hui; Nie, Yi-Hang; Liang, J.-Q.
2016-11-01
We investigate the non-equilibrium quantum transport through a single-molecule magnet embedded in a tunnel junction with ferromagnetic electrodes, which generate spin-polarized electrons. The lead magnetization direction is non-collinear with the uniaxial anisotropy easy-axis of molecule-magnet. Based on the Pauli rate-equation approach we demonstrate the magnetization reversion of molecule-magnet induced by the back action of spin-polarized current in the sequential tunnel regime. The asymptotic magnetization of molecular magnet and spin-polarization of transport current are obtained as functions of time by means of time-dependent solution of the rate equation. It is found that the antiparallel configuration of the ferromagnetic electrodes and molecular anisotropy easy-axis is an effective structure to reverse both the magnetization of molecule-magnet and spin-polarization of the transport current. Particularly the non-collinear angle dependence provides useful knowledge for the quantum manipulation of molecule-magnet and spin polarized electron-transport.
Kemp, G. Elijah; Mariscal, D. A.; Williams, G. J.; Blue, B. E.; Colvin, J. D.; Fears, T. M.; Kerr, S. M.; May, M. J.; Moody, J. D.; Strozzi, D. J.; Lefevre, H. J.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Gautier, D. C.; Montgomery, D. S.
2017-10-01
We present experimental and simulation results from a study of thermal transport inhibition in laser-driven, mid-Z, non-equilibrium plasmas in the presence external magnetic fields. The experiments were performed at the Jupiter Laser Facility at LLNL, where x-ray spectroscopy, proton radiography, and Brillouin backscatter data were simultaneously acquired from sub-critical-density, Ti-doped silica aerogel foams driven by a 2 ω laser at 5 ×1014 W /cm2 . External B-field strengths up to 20 T (aligned antiparallel to the laser propagation axis) were provided by a capacitor-bank-driven Helmholtz coil. Pre-shot simulations with Hydra, a radiation-magnetohydrodyanmics code, showed increasing electron plasma temperature with increasing B-field strength - the result of thermal transport inhibition perpendicular to the B-field. The influence of this thermal transport inhibition on the experimental observables as a function of external field strength and target density will be shown and compared with simulations. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344 and funded by LDRD project 17-ERD-027.
Thai students' mental model of chemical bonding
Sarawan, Supawadee; Yuenyong, Chokchai
2018-01-01
This Research was finding the viewing about concept of chemical bonding is fundamental to subsequent learning of various other topics related to this concept in chemistry. Any conceptions about atomic structures that students have will be shown their further learning. The purpose of this study is to interviews conceptions held by high school chemistry students about metallic bonding and to reveal mental model of atomic structures show according to the educational level. With this aim, the questionnaire prepared making use of the literature and administered for analysis about mental model of chemical bonding. It was determined from the analysis of answers of questionnaire the 10th grade, 11th grade and 12th grade students. Finally, each was shown prompts in the form of focus cards derived from curriculum material that showed ways in which the bonding in specific metallic substances had been depicted. Students' responses revealed that learners across all three levels prefer simple, realistic mental models for metallic bonding and reveal to chemical bonding.
Modeling two-phase flow in a micro-model with local thermal non-equilibrium on the Darcy scale
Nuske, Philipp; Ronneberger, Olaf; Karadimitriou, Nikolaos K.; Helmig, Rainer; Hassanizadeh, S. Majid
2015-01-01
Loosening local equilibrium assumptions in two-phase flow in porous media gives rise to new, unknown variables. More specifically, when loosening the local thermal equilibrium assumption, one has to describe the heat transfer between multiple phases, present at the same mathematical point. In this
Using chemical organization theory for model checking.
Kaleta, Christoph; Richter, Stephan; Dittrich, Peter
2009-08-01
The increasing number and complexity of biomodels makes automatic procedures for checking the models' properties and quality necessary. Approaches like elementary mode analysis, flux balance analysis, deficiency analysis and chemical organization theory (OT) require only the stoichiometric structure of the reaction network for derivation of valuable information. In formalisms like Systems Biology Markup Language (SBML), however, information about the stoichiometric coefficients required for an analysis of chemical organizations can be hidden in kinetic laws. First, we introduce an algorithm that uncovers stoichiometric information that might be hidden in the kinetic laws of a reaction network. This allows us to apply OT to SBML models using modifiers. Second, using the new algorithm, we performed a large-scale analysis of the 185 models contained in the manually curated BioModels Database. We found that for 41 models (22%) the set of organizations changes when modifiers are considered correctly. We discuss one of these models in detail (BIOMD149, a combined model of the ERK- and Wnt-signaling pathways), whose set of organizations drastically changes when modifiers are considered. Third, we found inconsistencies in 5 models (3%) and identified their characteristics. Compared with flux-based methods, OT is able to identify those species and reactions more accurately [in 26 cases (14%)] that can be present in a long-term simulation of the model. We conclude that our approach is a valuable tool that helps to improve the consistency of biomodels and their repositories. All data and a JAVA applet to check SBML-models is available from http://www.minet.uni-jena.de/csb/prj/ot/tools. Supplementary data are available at Bioinformatics online.
Chemical Dense Gas Modeling in Cities
Brown, M. J.; Williams, M. D.; Nelson, M. A.; Streit, G. E.
2007-12-01
Many industrial facilities have on-site storage of chemicals and are within a few kilometers of residential population. Chemicals are transported around the country via trains and trucks and often go through populated areas on their journey. Many of the chemicals, like chlorine and phosgene, are toxic and when released into the air are heavier-than-air dense gases that hug the ground and result in high airborne concentrations at breathing level. There is considerable concern about the vulnerability of these stored and transported chemicals to terrorist attack and the impact a release could have on highly-populated urban areas. There is the possibility that the impacts of a dense gas release within a city would be exacerbated since the buildings might act to trap the toxic cloud at street level and channel it over a large area down side streets. However, no one is quite sure what will happen for a release in cities since there is a dearth of experimental data. There are a number of fast-running dense gas models used in the air pollution and emergency response community, but there are none that account for the complex flow fields and turbulence generated by buildings. As part of this presentation, we will discuss current knowledge regarding dense gas releases around buildings and other obstacles. We will present information from wind tunnel and field experiments, as well as computational fluid dynamics modeling. We will also discuss new fast response modeling efforts which are trying to account for dense gas transport and dispersion in cities.
Directory of Open Access Journals (Sweden)
Ming-guo Xie
2017-05-01
Full Text Available Most lost-foam casting processes involve non-equilibrium solidification dominated by kinetic factors, while construction of a common dynamic solidification curve is based on pure thermodynamics, not applicable for analyses and research of non-equilibrium macro-solidification processes, and the construction mode can not be applied to non-equilibrium solidification process. In this study, the construction of the dynamic solidification curve (DSC for the non-equilibrium macro-solidification process included: a modified method to determine the start temperature of primary austenite precipitation (TAL and the start temperature of eutectic solidification (TES; double curves method to determine the temperature of the dendrite coherency point of primary austenite (TAC and the temperature of eutectic cells collision point (TEC; the “technical solidus” method to determine the end temperature of eutectic reaction (TEN. For this purpose, a comparative testing of the non-equilibrium solidification temperature fields in lost-foam casting and green sand mold casting hypoeutectic gray iron was carried out. The thermal analysis results were used to construct the DSCs of both these casting methods under non-equilibrium solidification conditions. The results show that the transformation rate of non-equilibrium solidification in hypoeutectic gray cast iron is greater than that of equilibrium solidification. The eutectic solidification region presents a typical mushy solidification mode. The results also indicate that the primary austenite precipitation zone of lost-foam casting is slightly larger than that of green sand casting. At the same time, the solid fraction (fs of the dendrite coherency points in lost-foam casting is greater than that in the green sand casting. Therefore, from these two points, lost-foam casting is more preferable for reduction of shrinkage and mechanical burnt-in sand tendency of the hypoeutectic gray cast iron. Due to the fact that
Joekar-Niasar, Vahid
2012-02-23
The capillary pressure-saturation (P c-S w) relationship is one of the central constitutive relationships used in two-phase flow simulations. There are two major concerns regarding this relation. These concerns are partially studied in a hypothetical porous medium using a dynamic pore-network model called DYPOSIT, which has been employed and extended for this study: (a) P c-S w relationship is measured empirically under equilibrium conditions. It is then used in Darcy-based simulations for all dynamic conditions. This is only valid if there is a guarantee that this relationship is unique for a given flow process (drainage or imbibition) independent of dynamic conditions; (b) It is also known that P c-S w relationship is flow process dependent. Depending on drainage and imbibition, different curves can be achieved, which are referred to as "hysteresis". A thermodynamically derived theory (Hassanizadeh and Gray, Water Resour Res 29: 3389-3904, 1993a) suggests that, by introducing a new state variable, called the specific interfacial area (a nw, defined as the ratio of fluid-fluid interfacial area to the total volume of the domain), it is possible to define a unique relation between capillary pressure, saturation, and interfacial area. This study investigates these two aspects of capillary pressure-saturation relationship using a dynamic pore-network model. The simulation results imply that P c-S w relation not only depends on flow process (drainage and imbibition) but also on dynamic conditions for a given flow process. Moreover, this study attempts to obtain the first preliminary insights into the global functionality of capillary pressure-saturation-interfacial area relationship under equilibrium and non-equilibrium conditions and the uniqueness of P c-S w-a nw relationship. © 2012 The Author(s).
Cumulus parameterizations in chemical transport models
Mahowald, Natalie M.; Rasch, Philip J.; Prinn, Ronald G.
1995-12-01
Global three-dimensional chemical transport models (CTMs) are valuable tools for studying processes controlling the distribution of trace constituents in the atmosphere. A major uncertainty in these models is the subgrid-scale parametrization of transport by cumulus convection. This study seeks to define the range of behavior of moist convective schemes and point toward more reliable formulations for inclusion in chemical transport models. The emphasis is on deriving convective transport from meteorological data sets (such as those from the forecast centers) which do not routinely include convective mass fluxes. Seven moist convective parameterizations are compared in a column model to examine the sensitivity of the vertical profile of trace gases to the parameterization used in a global chemical transport model. The moist convective schemes examined are the Emanuel scheme [Emanuel, 1991], the Feichter-Crutzen scheme [Feichter and Crutzen, 1990], the inverse thermodynamic scheme (described in this paper), two versions of a scheme suggested by Hack [Hack, 1994], and two versions of a scheme suggested by Tiedtke (one following the formulation used in the ECMWF (European Centre for Medium-Range Weather Forecasting) and ECHAM3 (European Centre and Hamburg Max-Planck-Institut) models [Tiedtke, 1989], and one formulated as in the TM2 (Transport Model-2) model (M. Heimann, personal communication, 1992). These convective schemes vary in the closure used to derive the mass fluxes, as well as the cloud model formulation, giving a broad range of results. In addition, two boundary layer schemes are compared: a state-of-the-art nonlocal boundary layer scheme [Holtslag and Boville, 1993] and a simple adiabatic mixing scheme described in this paper. Three tests are used to compare the moist convective schemes against observations. Although the tests conducted here cannot conclusively show that one parameterization is better than the others, the tests are a good measure of the
Energy Technology Data Exchange (ETDEWEB)
Sergey G Kalyakin; Andrey V Morozov; Oleg V Remizov; Alexandr A Tzyganok [State Scientific Center of Russian Federation - Institute for Physics and Power Engineering by A.I. Leypunsky, IPPE, 1, Bondarenko sq., Obninsk, 249030 (Russian Federation)
2005-07-01
Full text of publication follows: In the systems of passive reactor cooling and core reflooding from above under accident conditions, the cold water flows out into countercurrent steam flow; that is, the direct contact between steam and liquid occurs simultaneously over all cross-sections of pipes/closed spaces. The process is complicated by additional effect of steam condensation and droplet flow towards the steam flow. The processes of heat and mass transfer proceed simultaneously at variable liquid level. These factors give rise to a nonsteady, non-equilibrium two-phase flow. The operating conditions of such a non-steady process, the main of which being the time of closed water volume dump (or the flow coefficient), can be obtained only experimentally. The present work is devoted to the experimental investigations of the interaction of saturated steam with cold water at its flowing out from a closed space with a variable level and some characteristics of dynamic two-phase layer at the steam/liquid interface. With reference to the system of passive heat removal from VVER core, the processes of interaction of saturated steam, steam-water mixture, and air with cold water at its flowing out from a vertical plugged pipe with an internal diameter of 50 and 100 mm have been studied at a pressure of 0.5 MPa. It has been stated experimentally that the dump rate of subcooled water from a plugged pipe into steam is nearly an order of magnitude less than that into non-condensable gas media. The semi-empirical correlation describing the processes of water outflow from plugged pipes into steam is of the form of: W-bar = C{sub 0} {radical}(gd), where C{sub 0} is the dimensionless constant, d is the pipe internal diameter, m, g = 9.81 m/s{sup 2}. (authors)
Wang, Jin
Cognitive behaviors are determined by underlying neural networks. Many brain functions, such as learning and memory, can be described by attractor dynamics. We developed a theoretical framework for global dynamics by quantifying the landscape associated with the steady state probability distributions and steady state curl flux, measuring the degree of non-equilibrium through detailed balance breaking. We found the dynamics and oscillations in human brains responsible for cognitive processes and physiological rhythm regulations are determined not only by the landscape gradient but also by the flux. We found that the flux is closely related to the degrees of the asymmetric connections in neural networks and is the origin of the neural oscillations. The neural oscillation landscape shows a closed-ring attractor topology. The landscape gradient attracts the network down to the ring. The flux is responsible for coherent oscillations on the ring. We suggest the flux may provide the driving force for associations among memories. Both landscape and flux determine the kinetic paths and speed of decision making. The kinetics and global stability of decision making are explored by quantifying the landscape topography through the barrier heights and the mean first passage time. The theoretical predictions are in agreement with experimental observations: more errors occur under time pressure. We quantitatively explored two mechanisms of the speed-accuracy tradeoff with speed emphasis and further uncovered the tradeoffs among speed, accuracy, and energy cost. Our results show an optimal balance among speed, accuracy, and the energy cost in decision making. We uncovered possible mechanisms of changes of mind and how mind changes improve performance in decision processes. Our landscape approach can help facilitate an understanding of the underlying physical mechanisms of cognitive processes and identify the key elements in neural networks.
Brasseur, G. P.; Hauglustaine, D. A.; Walters, S.; Rasch, P. J.; Müller, J.-F.; Granier, C.; Tie, X. X.
1998-11-01
We present a new global three-dimensional chemical-transport model (called MOZART) developed in the framework of the NCAR Community Climate Model (CCM) and aimed at studying the distribution and budget of tropospheric ozone and its precursors. The model, developed with a horizontal resolution of 2.8° in longitude and latitude, includes 25 levels in the vertical between the Earth's surface and an upper boundary located at approximately 35 km altitude. In its present configuration the model calculates the global distribution of 56 chemical constituents with a timestep of 20 min, and accounts for surface emission and deposition, large-scale advective transport, subscale convective and boundary layer exchanges, chemical and photochemical transformations, as well as wet scavenging. Transport is simulated "off line" from CCM with dynamical variables provided every 3 hours from preestablished history tapes. Advection is calculated using the semi-Lagrangian transport scheme [Rasch and Williamson, 1990] developed for the MATCH model of Rasch et al. [1997]. Convective and boundary layer transports are expressed according to Hack [1994] and Holtslag and Boville [1993], respectively. A detailed evaluation of the model results is provided in a companion paper [Hauglustaine et al., this issue]. An analysis of the spatial and temporal variability in the chemical fields predicted by the model suggests that regional events such as summertime ozone episodes in polluted areas can be simulated by MOZART.
Chemically induced mouse models of intestinal inflammation.
Wirtz, Stefan; Neufert, Clemens; Weigmann, Benno; Neurath, Markus F
2007-01-01
Animal models of intestinal inflammation are indispensable for our understanding of the pathogenesis of Crohn disease and ulcerative colitis, the two major forms of inflammatory bowel disease in humans. Here, we provide protocols for establishing murine 2,4,6-trinitro benzene sulfonic acid (TNBS)-, oxazolone- and both acute and chronic dextran sodium sulfate (DSS) colitis, the most widely used chemically induced models of intestinal inflammation. In the former two models, colitis is induced by intrarectal administration of the covalently reactive reagents TNBS/oxazolone, which are believed to induce a T-cell-mediated response against hapten-modified autologous proteins/luminal antigens. In the DSS model, mice are subjected several days to drinking water supplemented with DSS, which seems to be directly toxic to colonic epithelial cells of the basal crypts. The procedures for the hapten models of colitis and acute DSS colitis can be accomplished in about 2 weeks but the protocol for chronic DSS colitis takes about 2 months.
Chen, Yih-Kanq; Milos, Frank S.
2011-01-01
The Fully Implicit Ablation and Thermal Response code, FIAT, simulates pyrolysis and ablation of thermal protection materials and systems. The governing equations, which include energy conservation, a three-component decomposition model, and a surface energy balance, are solved with a moving grid. This work describes new modeling capabilities that are added to a special version of FIAT. These capabilities include a time-dependent pyrolysis gas flow momentum equation with Darcy-Forchheimer terms and pyrolysis gas species conservation equations with finite-rate homogeneous chemical reactions. The total energy conservation equation is also enhanced for consistency with these new additions. Parametric studies are performed using this enhanced version of FIAT. Two groups of analyses of Phenolic Impregnated Carbon Ablator (PICA) are presented. In the first group, an Orion flight environment for a proposed Lunar-return trajectory is considered. In the second group, various test conditions for arcjet models are examined. The central focus of these parametric studies is to understand the effect of pyrolysis gas momentum transfer on PICA material in-depth thermal responses with finite-rate, equilibrium, or frozen homogeneous gas chemistry. Results are presented, discussed, and compared with those predicted by the baseline PICA/FIAT ablation and thermal response model developed by the Orion Thermal Protection System Advanced Development Project.
Energy Technology Data Exchange (ETDEWEB)
Hanai, R.; Littlewood, P. B.; Ohashi, Y.
2016-03-01
We theoretically investigate a Bose-condensed exciton gas out of equilibrium. Within the framework of the combined BCS-Leggett strong-coupling theory with the non-equilibrium Keldysh formalism, we show how the Bose-Einstein condensation (BEC) of excitons is suppressed to eventually disappear, when the system is in the non-equilibrium steady state. The supply of electrons and holes from the bath is shown to induce quasi-particle excitations, leading to the partial occupation of the upper branch of Bogoliubov single-particle excitation spectrum. We also discuss how this quasi-particle induction is related to the suppression of exciton BEC, as well as the stability of the steady state.
Kurake, Naoyuki; Tanaka, Hiromasa; Ishikawa, Kenji; Nakamura, Kae; Kajiyama, Hiroaki; Kikkawa, Fumitaka; Mizuno, Masaaki; Ikehara, Yuzuru; Hori, Masaru
2017-10-01
Oxalate was synthesized in the glucose solution by irradiation with non-equilibrium atmospheric pressure plasma (NEAPP), in which the NEAPP plume contacted the solution surface, via the generation of several intermediate organic products such as gluconic acid. A thermodynamically unstable phase of calcium oxalate dihydrate crystallized rapidly during incubation of a NEAPP-irradiated glucose solution that contained calcium ions and was buffered at neutral pH. Longer irradiation times increased the growth rate and the number of seed crystals.
DEFF Research Database (Denmark)
Kutchinsky, Jonatan; Taboryski, Rafael Jozef; Sørensen, C B
2001-01-01
We report measurements on three-terminal superconductor-semiconductor-superconductor injection devices demonstrating enhancement of the supercurrent by injection from a superconducting injector electrode. Two other electrodes were used to form the detector junction. Applying a small voltage to th...... of enhancement of the supercurrent by non-equilibrium injection into bound supercurrent-carrying Andreev states. The effect persists to temperatures where the equilibrium supercurrent has vanished. (C) 2001 Elsevier Science B.V. All rights reserved....
Nayak, Gouranga C.
2017-09-01
Recently we have proved the factorization of NRQCD S-wave heavy quarkonium production at all orders in coupling constant. In this paper we extend this to prove the factorization of infrared divergences in χ _{cJ} production from color singlet c{\\bar{c}} pair in non-equilibrium QCD at RHIC and LHC at all orders in coupling constant. This can be relevant to study the quark-gluon plasma at RHIC and LHC.
Energy Technology Data Exchange (ETDEWEB)
Choi, Seung Min [GyeongBuk Technopark, Gyeongsan (Korea, Republic of); Kang, Hui Bo; Kwon, Young Doo; Kwon, Soon Bum [Kyungpook Nat’l Univ., Daegu (Korea, Republic of)
2016-12-15
In the present study, the effects of non-equilibrium condensation on the drag divergence Mach number with the angle of attack in a transonic 2D moist air flow of NACA0012 are investigated using the TVD finite difference scheme. For the same α, the maximum upstream Mach number of the shock wave, Mmax, and the size of supersonic bubble decrease with the increase in Φ{sub 0}. For the same M{sub ∞}, Φ{sub 0}, and T{sub 0}, the length of the non-equilibrium condensation zone Δ{sub z} decreases with increasing Φ{sub 0}. On the other hand, because of the attenuating effect of non-equilibrium condensation on wave drag, which is related to the interaction between the shock wave and the boundary layer, the drag coefficient C{sub D} decreases with an increase in Φ{sub 0} for the same M{sub ∞} and α. For the same α, M{sub D} increases with increasing Φ{sub 0}, while M{sub D} decreases with an increase in α.
Chao, S.-P.; Palacios, G.
2010-01-01
We derive the transport properties of a quantum dot subject to a source-drain bias voltage at zero temperature and magnetic field. Using the Scattering Bethe Anstaz, a generalization of the traditional Thermodynamic Bethe Ansatz to open systems out of equilibrium, we derive exact results for the
Dutta, P.S.; Kooi, B.W.; Feudel, U.
2014-01-01
During the last two decades, the simple view of resource limitation by a single resource has been changed due to the realization that co-limitation by multiple resources is often an important determinant of species growth. Hence, the multiple resource limitation hypothesis needs to be taken into
Chemical Mechanism Solvers in Air Quality Models
Directory of Open Access Journals (Sweden)
John C. Linford
2011-09-01
Full Text Available The solution of chemical kinetics is one of the most computationally intensivetasks in atmospheric chemical transport simulations. Due to the stiff nature of the system,implicit time stepping algorithms which repeatedly solve linear systems of equations arenecessary. This paper reviews the issues and challenges associated with the construction ofefficient chemical solvers, discusses several families of algorithms, presents strategies forincreasing computational efficiency, and gives insight into implementing chemical solverson accelerated computer architectures.
A mesoscale chemical transport model (MEDIUM) nested in a global chemical transport model (MEDIANTE)
Energy Technology Data Exchange (ETDEWEB)
Claveau, J.; Ramaroson, R. [Office National d`Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)
1997-12-31
The lower stratosphere and upper troposphere (UT-LS) are frequently subject to mesoscale or local scale exchange of air masses occurring along discontinuities. This exchange (e.g. downward) can constitute one of the most important source of ozone from the stratosphere down to the middle troposphere where strong mixing dilutes the air mass and competing the non-linear chemistry. The distribution of the chemical species in the troposphere and the lower stratosphere depends upon various source emissions, e.g. from polluted boundary layer or from aircraft emissions. Global models, as well as chemical transport models describe the climatological state of the atmosphere and are not able to describe correctly the stratosphere and troposphere exchange. Mesoscale models go further in the description of smaller scales and can reasonably include a rather detailed chemistry. They can be used to assess the budget of NO{sub x} from aircraft emissions in a mesoscale domain. (author) 4 refs.