WorldWideScience

Sample records for non-equilibrium statistical physics

  1. Non-equilibrium statistical physics with application to disordered systems

    CERN Document Server

    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...

  2. Open problems in non-equilibrium physics

    International Nuclear Information System (INIS)

    Kusnezov, D.

    1997-01-01

    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

  3. 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.

  4. Limiting processes in non-equilibrium classical statistical mechanics

    International Nuclear Information System (INIS)

    Jancel, R.

    1983-01-01

    After a recall of the basic principles of the statistical mechanics, the results of ergodic theory, the transient at the thermodynamic limit and his link with the transport theory near the equilibrium are analyzed. The fundamental problems put by the description of non-equilibrium macroscopic systems are investigated and the kinetic methods are stated. The problems of the non-equilibrium statistical mechanics are analyzed: irreversibility and coarse-graining, macroscopic variables and kinetic description, autonomous reduced descriptions, limit processes, BBGKY hierarchy, limit theorems [fr

  5. Teaching at the edge of knowledge: Non-equilibrium statistical physics

    Science.gov (United States)

    Schmittmann, Beate

    2007-03-01

    As physicists become increasingly interested in biological problems, we frequently find ourselves confronted with complex open systems, involving many interacting constituents and characterized by non-vanishing fluxes of mass or energy. Faced with the task of predicting macroscopic behaviors from microscopic information for these non-equilibrium systems, the familiar Gibbs-Boltzmann framework fails. The development of a comprehensive theoretical characterization of non-equilibrium behavior is one of the key challenges of modern condensed matter physics. In its absence, several approaches have been developed, from master equations to thermostatted molecular dynamics, which provide key insights into the rich and often surprising phenomenology of systems far from equilibrium. In my talk, I will address some of these methods, selecting those that are most relevant for a broad range of interdisciplinary problems from biology to traffic, finance, and sociology. The ``portability'' of these methods makes them valuable for graduate students from a variety of disciplines. To illustrate how different methods can complement each other when probing a problem from, e.g., the life sciences, I will discuss some recent attempts at modeling translation, i.e., the process by which the genetic information encoded on an mRNA is translated into the corresponding protein.

  6. Some recent developments in non-equilibrium statistical physics

    Indian Academy of Sciences (India)

    : ... This canonical prescription is the starting point for studying a system in ... abilistic approach to non-equilibrium dynamics by treating the case of Markovian ..... equation in this network between the incoming flux and the outgoing flux at each.

  7. Physical phenomena in a low-temperature non-equilibrium plasma and in MHD generators with non-equilibrium conductivity

    International Nuclear Information System (INIS)

    Velikhov, E.P.; Golubev, V.S.; Dykhne, A.M.

    1976-01-01

    The paper assesses the position in 1975 of theoretical and experimental work on the physics of a magnetohydrodynamic generator with non-equilibrium plasma conductivity. This research started at the beginning of the 1960s; as work on the properties of thermally non-equilibrium plasma in magnetic fields and also in MHD generator ducts progressed, a number of phenomena were discovered and investigated that had either been unknown in plasma physics or had remained uninvestigated until that time: ionization instability and ionization turbulence of plasma in a magnetic field, acoustic instability of a plasma with anisotropic conductivity, the non-equilibrium ionization wave and the energy balance of a non-equilibrium plasma. At the same time, it was discovered what physical requirements an MHD generator with non-equilibrium conductivity must satisfy to achieve high efficiency in converting the thermal or kinetic energy of the gas flow into electric energy. The experiments on MHD power generation with thermally non-equilibrium plasma carried out up to 1975 indicated that it should be possible to achieve conversion efficiencies of up to 20-30%. (author)

  8. Equilibrium statistical mechanics

    CERN Document Server

    Mayer, J E

    1968-01-01

    The International Encyclopedia of Physical Chemistry and Chemical Physics, Volume 1: Equilibrium Statistical Mechanics covers the fundamental principles and the development of theoretical aspects of equilibrium statistical mechanics. Statistical mechanical is the study of the connection between the macroscopic behavior of bulk matter and the microscopic properties of its constituent atoms and molecules. This book contains eight chapters, and begins with a presentation of the master equation used for the calculation of the fundamental thermodynamic functions. The succeeding chapters highlight t

  9. 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...

  10. Statistical physics

    CERN Document Server

    Sadovskii, Michael V

    2012-01-01

    This volume provides a compact presentation of modern statistical physics at an advanced level. Beginning with questions on the foundations of statistical mechanics all important aspects of statistical physics are included, such as applications to ideal gases, the theory of quantum liquids and superconductivity and the modern theory of critical phenomena. Beyond that attention is given to new approaches, such as quantum field theory methods and non-equilibrium problems.

  11. Non-equilibrium thermodynamics and physical kinetics

    CERN Document Server

    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.

  12. Non-equilibrium phenomena in confined soft matter irreversible adsorption, physical aging and glass transition at the nanoscale

    CERN Document Server

    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...

  13. Statistical fluctuations and correlations in hadronic equilibrium systems

    International Nuclear Information System (INIS)

    Hauer, Michael

    2010-01-01

    This thesis is dedicated to the study of fluctuation and correlation observables of hadronic equilibrium systems. The statistical hadronization model of high energy physics, in its ideal, i.e. non-interacting, gas approximation is investigated in different ensemble formulations. The hypothesis of thermal and chemical equilibrium in high energy interaction is tested against qualitative and quantitative predictions. (orig.)

  14. Statistical fluctuations and correlations in hadronic equilibrium systems

    Energy Technology Data Exchange (ETDEWEB)

    Hauer, Michael

    2010-06-17

    This thesis is dedicated to the study of fluctuation and correlation observables of hadronic equilibrium systems. The statistical hadronization model of high energy physics, in its ideal, i.e. non-interacting, gas approximation is investigated in different ensemble formulations. The hypothesis of thermal and chemical equilibrium in high energy interaction is tested against qualitative and quantitative predictions. (orig.)

  15. The Non-Equilibrium Statistical Distribution Function for Electrons and Holes in Semiconductor Heterostructures in Steady-State Conditions

    Directory of Open Access Journals (Sweden)

    Krzysztof Jόzwikowska

    2015-06-01

    Full Text Available The main goal of this work is to determine a statistical non-equilibrium distribution function for the electron and holes in semiconductor heterostructures in steady-state conditions. Based on the postulates of local equilibrium, as well as on the integral form of the weighted Gyarmati’s variational principle in the force representation, using an alternative method, we have derived general expressions, which have the form of the Fermi–Dirac distribution function with four additional components. The physical interpretation of these components has been carried out in this paper. Some numerical results of a non-equilibrium distribution function for an electron in HgCdTe structures are also presented.

  16. Infinite-mode squeezed coherent states and non-equilibrium statistical mechanics (phase-space-picture approach)

    International Nuclear Information System (INIS)

    Yeh, L.

    1992-01-01

    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

  17. A modern course in statistical physics

    CERN Document Server

    Reichl, Linda E

    2016-01-01

    "A Modern Course in Statistical Physics" is a textbook that illustrates the foundations of equilibrium and non-equilibrium statistical physics, and the universal nature of thermodynamic processes, from the point of view of contemporary research problems. The book treats such diverse topics as the microscopic theory of critical phenomena, superfluid dynamics, quantum conductance, light scattering, transport processes, and dissipative structures, all in the framework of the foundations of statistical physics and thermodynamics. It shows the quantum origins of problems in classical statistical physics. One focus of the book is fluctuations that occur due to the discrete nature of matter, a topic of growing importance for nanometer scale physics and biophysics. Another focus concerns classical and quantum phase transitions, in both monatomic and mixed particle systems. This fourth edition extends the range of topics considered to include, for example, entropic forces, electrochemical processes in biological syste...

  18. Non-equilibrium statistical theory about microscopic fatigue cracks of metal in magnetic field

    International Nuclear Information System (INIS)

    Zhao-Long, Liu; Hai-Yun, Hu; Tian-You, Fan; Xiu-San, Xing

    2010-01-01

    This paper develops the non-equilibrium statistical fatigue damage theory to study the statistical behaviour of micro-crack for metals in magnetic field. The one-dimensional homogeneous crack system is chosen for study. To investigate the effect caused by magnetic field on the statistical distribution of micro-crack in the system, the theoretical analysis on microcrack evolution equation, the average length of micro-crack, density distribution function of micro-crack and fatigue fracture probability have been performed. The derived results relate the changes of some quantities, such as average length, density distribution function and fatigue fracture probability, to the applied magnetic field, the magnetic and mechanical properties of metals. It gives a theoretical explanation on the change of fatigue damage due to magnetic fields observed by experiments, and presents an analytic approach on studying the fatigue damage of metal in magnetic field. (cross-disciplinary physics and related areas of science and technology)

  19. What Can Reinforcement Learning Teach Us About Non-Equilibrium Quantum Dynamics

    Science.gov (United States)

    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.

  20. Non-equilibrium dog-flea model

    Science.gov (United States)

    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.

  1. Non-Equilibrium Thermodynamics in Multiphase Flows

    CERN Document Server

    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...

  2. Classical and Quantum Models in Non-Equilibrium Statistical Mechanics: Moment Methods and Long-Time Approximations

    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.

  3. 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.

  4. Beyond the second law entropy production and non-equilibrium systems

    CERN Document Server

    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, ...

  5. Line radiative transfer and statistical equilibrium

    NARCIS (Netherlands)

    Kamp, Inga

    Atomic and molecular line emission from protoplanetary disks contains key information of their detailed physical and chemical structures. To unravel those structures, we need to understand line radiative transfer in dusty media and the statistical equilibrium, especially of molecules. I describe

  6. The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled.

    Science.gov (United States)

    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.

  7. Non-Equilibrium Thermodynamics of Self-Replicating Protocells

    DEFF Research Database (Denmark)

    Fellermann, Harold; Corominas-Murtra, Bernat; Hansen, Per Lyngs

    2018-01-01

    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....

  8. Line radiative transfer and statistical equilibrium*

    Directory of Open Access Journals (Sweden)

    Kamp Inga

    2015-01-01

    Full Text Available Atomic and molecular line emission from protoplanetary disks contains key information of their detailed physical and chemical structures. To unravel those structures, we need to understand line radiative transfer in dusty media and the statistical equilibrium, especially of molecules. I describe here the basic principles of statistical equilibrium and illustrate them through the two-level atom. In a second part, the fundamentals of line radiative transfer are introduced along with the various broadening mechanisms. I explain general solution methods with their drawbacks and also specific difficulties encountered in solving the line radiative transfer equation in disks (e.g. velocity gradients. I am closing with a few special cases of line emission from disks: Radiative pumping, masers and resonance scattering.

  9. Ordered phase and non-equilibrium fluctuation in stock market

    Science.gov (United States)

    Maskawa, Jun-ichi

    2002-08-01

    We analyze the statistics of daily price change of stock market in the framework of a statistical physics model for the collective fluctuation of stock portfolio. In this model the time series of price changes are coded into the sequences of up and down spins, and the Hamiltonian of the system is expressed by spin-spin interactions as in spin glass models of disordered magnetic systems. Through the analysis of Dow-Jones industrial portfolio consisting of 30 stock issues by this model, we find a non-equilibrium fluctuation mode on the point slightly below the boundary between ordered and disordered phases. The remaining 29 modes are still in disordered phase and well described by Gibbs distribution. The variance of the fluctuation is outlined by the theoretical curve and peculiarly large in the non-equilibrium mode compared with those in the other modes remaining in ordinary phase.

  10. Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces.

    Science.gov (United States)

    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).

  11. Frontier of plasma physics. 'Research network on non-equilibrium and extreme state plasmas'

    International Nuclear Information System (INIS)

    Itoh, Sanae-I.; Fujisawa, Akihide; Kodama, Ryosuke; Sato, Motoyasu; Tanaka, Kazuo A.; Hatakeyama, Rikizo; Itoh, Kimitaka

    2011-01-01

    Plasma physics and fusion science have been applied to a wide variety of plasmas such as nuclear fusion plasmas, high-energy-density plasmas, processing plasmas and nanobio- plasmas. They are pioneering science and technology frontiers such as new energy sources and new functional materials. A large project 'research network on non-equilibrium and extreme state plasmas' is being proposed to reassess individual plasma researches from a common view of the non-equilibrium extreme plasma and to promote collaboration among plasma researchers all over the country. In the present review, recent collaborative works related to this project are being introduced. (T.I.)

  12. Thermodynamic chemical energy transfer mechanisms of non-equilibrium, quasi-equilibrium, and equilibrium chemical reactions

    International Nuclear Information System (INIS)

    Roh, Heui-Seol

    2015-01-01

    Chemical energy transfer mechanisms at finite temperature are explored by a chemical energy transfer theory which is capable of investigating various chemical mechanisms of non-equilibrium, quasi-equilibrium, and equilibrium. Gibbs energy fluxes are obtained as a function of chemical potential, time, and displacement. Diffusion, convection, internal convection, and internal equilibrium chemical energy fluxes are demonstrated. The theory reveals that there are chemical energy flux gaps and broken discrete symmetries at the activation chemical potential, time, and displacement. The statistical, thermodynamic theory is the unification of diffusion and internal convection chemical reactions which reduces to the non-equilibrium generalization beyond the quasi-equilibrium theories of migration and diffusion processes. The relationship between kinetic theories of chemical and electrochemical reactions is also explored. The theory is applied to explore non-equilibrium chemical reactions as an illustration. Three variable separation constants indicate particle number constants and play key roles in describing the distinct chemical reaction mechanisms. The kinetics of chemical energy transfer accounts for the four control mechanisms of chemical reactions such as activation, concentration, transition, and film chemical reactions. - Highlights: • Chemical energy transfer theory is proposed for non-, quasi-, and equilibrium. • Gibbs energy fluxes are expressed by chemical potential, time, and displacement. • Relationship between chemical and electrochemical reactions is discussed. • Theory is applied to explore nonequilibrium energy transfer in chemical reactions. • Kinetics of non-equilibrium chemical reactions shows the four control mechanisms

  13. 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...

  14. Tropical limit and a micro-macro correspondence in statistical physics

    Science.gov (United States)

    Angelelli, Mario

    2017-10-01

    Tropical mathematics is used to establish a correspondence between certain microscopic and macroscopic objects in statistical models. Tropical algebra gives a common framework for macrosystems (subsets) and their elementary constituents (elements) that is well-behaved with respect to composition. This kind of connection is studied with maps that preserve a monoid structure. The approach highlights an underlying order relation that is explored through the concepts of filter and ideal. Particular attention is paid to asymmetry and duality between max- and min-criteria. Physical implementations are presented through simple examples in thermodynamics and non-equilibrium physics. The phenomenon of ultrametricity, the notion of tropical equilibrium and the role of ground energy in non-equilibrium models are discussed. Tropical symmetry, i.e. idempotence, is investigated.

  15. Non-equilibrium phase transition

    International Nuclear Information System (INIS)

    Mottola, E.; Cooper, F.M.; Bishop, A.R.; Habib, S.; Kluger, Y.; Jensen, N.G.

    1998-01-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Non-equilibrium phase transitions play a central role in a very broad range of scientific areas, ranging from nuclear, particle, and astrophysics to condensed matter physics and the material and biological sciences. The aim of this project was to explore the path to a deeper and more fundamental understanding of the common physical principles underlying the complex real time dynamics of phase transitions. The main emphasis was on the development of general theoretical tools to deal with non-equilibrium processes, and of numerical methods robust enough to capture the time-evolving structures that occur in actual experimental situations. Specific applications to Laboratory multidivisional efforts in relativistic heavy-ion physics (transition to a new phase of nuclear matter consisting of a quark-gluon plasma) and layered high-temperature superconductors (critical currents and flux flow at the National High Magnetic Field Laboratory) were undertaken

  16. Problems of a Statistical Ensemble Theory for Systems Far from Equilibrium

    Science.gov (United States)

    Ebeling, Werner

    The development of a general statistical physics of nonequilibrium systems was one of the main unfinished tasks of statistical physics of the 20th century. The aim of this work is the study of a special class of nonequilibrium systems where the formulation of an ensemble theory of some generality is possible. These are the so-called canonical-dissipative systems, where the driving terms are determined by invariants of motion. We construct canonical-dissipative systems which are ergodic on certain surfaces on the phase plane. These systems may be described by a non-equilibrium microcanocical ensemble, corresponding to an equal distribution on the target surface. Next we construct and solve Fokker-Planck equations; this leads to a kind of canonical-dissipative ensemble. In the last part we discuss the thoretical problem how to define bifurcations in the framework of nonequilibrium statistics and several possible applications.

  17. Non-equilibrium dynamics of one-dimensional Bose gases

    International Nuclear Information System (INIS)

    Langen, T.

    2013-01-01

    Understanding the non-equilibrium dynamics of isolated quantum many-body systems is an open problem on vastly different energy, length, and time scales. Examples range from the dynamics of the early universe and heavy-ion collisions to the subtle coherence and transport properties in condensed matter physics. However, realizations of such quantum many-body systems, which are both well isolated from the environment and accessible to experimental study are scarce. This thesis presents a series of experiments with ultracold one-dimensional Bose gases. These gases combine a nearly perfect isolation from the environment with many well-established methods to manipulate and probe their quantum states. This makes them an ideal model system to explore the physics of quantum many body systems out of equilibrium. In the experiments, a well-defined non-equilibrium state is created by splitting a single one-dimensional gas coherently into two parts. The relaxation of this state is probed using matter-wave interferometry. The Observations reveal the emergence of a prethermalized steady state which differs strongly from thermal equilibrium. Such thermal-like states had previously been predicted for a large variety of systems, but never been observed directly. Studying the relaxation process in further detail shows that the thermal correlations of the prethermalized state emerge locally in their final form and propagate through the system in a light-cone-like evolution. This provides first experimental evidence for the local relaxation conjecture, which links relaxation processes in quantum many-body systems to the propagation of correlations. Furthermore, engineering the initial state of the evolution demonstrates that the prethermalized state is described by a generalized Gibbs ensemble, an observation which substantiates the importance of this ensemble as an extension of standard statistical mechanics. Finally, an experiment is presented, where pairs of gases with an atom

  18. Non-equilibrium many body dynamics

    International Nuclear Information System (INIS)

    Creutz, M.; Gyulassy, M.

    1997-01-01

    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

  19. 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.

  20. A new formalism for non extensive physical systems: Tsallis Thermo statistics

    International Nuclear Information System (INIS)

    Tirnakli, U.; Bueyuekkilic, F.; Demirhan, D.

    1999-01-01

    Although Boltzmann-Gibbs (BG) statistics provides a suitable tool which enables us to handle a large number of physical systems satisfactorily, it has some basic restrictions. Recently a non extensive thermo statistics has been proposed by C.Tsallis to handle the non extensive physical systems and up to now, besides the generalization of some of the conventional concepts, the formalism has been prosperous in some of the physical applications. In this study, our effort is to introduce Tsallis thermo statistics in some details and to emphasize its achievements on physical systems by noting the recent developments on this line

  1. Toward a Multi-scale Phase Transition Kinetics Methodology: From Non-Equilibrium Statistical Mechanics to Hydrodynamics

    Science.gov (United States)

    Belof, Jonathan; Orlikowski, Daniel; Wu, Christine; McLaughlin, Keith

    2013-06-01

    Shock and ramp compression experiments are allowing us to probe condensed matter under extreme conditions where phase transitions and other non-equilibrium aspects can now be directly observed, but first principles simulation of kinetics remains a challenge. A multi-scale approach is presented here, with non-equilibrium statistical mechanical quantities calculated by molecular dynamics (MD) and then leveraged to inform a classical nucleation and growth kinetics model at the hydrodynamic scale. Of central interest is the free energy barrier for the formation of a critical nucleus, with direct NEMD presenting the challenge of relatively long timescales necessary to resolve nucleation. Rather than attempt to resolve the time-dependent nucleation sequence directly, the methodology derived here is built upon the non-equilibrium work theorem in order to bias the formation of a critical nucleus and thus construct the nucleation and growth rates. Having determined these kinetic terms from MD, a hydrodynamics implementation of Kolmogorov-Johnson-Mehl-Avrami (KJMA) kinetics and metastabilty is applied to the dynamic compressive freezing of water and compared with recent ramp compression experiments [Dolan et al., Nature (2007)] Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344.

  2. A simple non-equilibrium, statistical-physics toy model of thin-film growth

    International Nuclear Information System (INIS)

    Ochab, Jeremi K; Nagel, Hannes; Janke, Wolfhard; Waclaw, Bartlomiej

    2015-01-01

    We present a simple non-equilibrium model of mass condensation with Lennard–Jones interactions between particles and the substrate. We show that when some number of particles is deposited onto the surface and the system is left to equilibrate, particles condense into an island if the density of particles becomes higher than some critical density. We illustrate this with numerically obtained phase diagrams for three-dimensional systems. We also solve a two-dimensional counterpart of this model analytically and show that not only the phase diagram but also the shape of the cross-sections of three-dimensional condensates qualitatively matches the two-dimensional predictions. Lastly, we show that when particles are being deposited with a constant rate, the system has two phases: a single condensate for low deposition rates, and multiple condensates for fast deposition. The behaviour of our model is thus similar to that of thin film growth processes, and in particular to Stranski–Krastanov growth. (paper)

  3. Stability and equilibrium in quantum statistical mechanics

    International Nuclear Information System (INIS)

    Kastler, Daniel.

    1975-01-01

    A derivation of the Gibbs Ansatz, base of the equilibrium statistical mechanics is provided from a stability requirements, in technical connection with the harmonic analysis of non-commutative dynamical systems. By the same token a relation is established between stability and the positivity of Hamiltonian in the zero temperature case [fr

  4. Spectral-Lagrangian methods for collisional models of non-equilibrium statistical states

    International Nuclear Information System (INIS)

    Gamba, Irene M.; Tharkabhushanam, Sri Harsha

    2009-01-01

    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 d-1 . 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

  5. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    International Nuclear Information System (INIS)

    Zhu, Jian-Zhou; Hammett, Gregory W.

    2011-01-01

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence (T.-D. Lee, 'On some statistical properties of hydrodynamical and magnetohydrodynamical fields,' Q. Appl. Math. 10, 69 (1952)) is taken to study gyrokinetic plasma turbulence: A finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N + 1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  6. Non-Equilibrium Heavy Flavored Hadron Yields from Chemical Equilibrium Strangeness-Rich QGP

    OpenAIRE

    Kuznetsova, Inga; Rafelski, Johann

    2008-01-01

    The yields of heavy flavored hadrons emitted from strangeness-rich QGP are evaluated within chemical non-equilibrium statistical hadronization model, conserving strangeness, charm, and entropy yields at hadronization.

  7. Statistical physics

    CERN Document Server

    Guénault, Tony

    2007-01-01

    In this revised and enlarged second edition of an established text Tony Guénault provides a clear and refreshingly readable introduction to statistical physics, an essential component of any first degree in physics. The treatment itself is self-contained and concentrates on an understanding of the physical ideas, without requiring a high level of mathematical sophistication. A straightforward quantum approach to statistical averaging is adopted from the outset (easier, the author believes, than the classical approach). The initial part of the book is geared towards explaining the equilibrium properties of a simple isolated assembly of particles. Thus, several important topics, for example an ideal spin-½ solid, can be discussed at an early stage. The treatment of gases gives full coverage to Maxwell-Boltzmann, Fermi-Dirac and Bose-Einstein statistics. Towards the end of the book the student is introduced to a wider viewpoint and new chapters are included on chemical thermodynamics, interactions in, for exam...

  8. Statistical physics of non-thermal phase transitions from foundations to applications

    CERN Document Server

    Abaimov, Sergey G

    2015-01-01

    Statistical physics can be used to better understand non-thermal complex systems—phenomena such as stock-market crashes, revolutions in society and in science, fractures in engineered materials and in the Earth’s crust, catastrophes, traffic jams, petroleum clusters, polymerization, self-organized criticality and many others exhibit behaviors resembling those of thermodynamic systems. In particular, many of these systems possess phase transitions identical to critical or spinodal phenomena in statistical physics. The application of the well-developed formalism of statistical physics to non-thermal complex systems may help to predict and prevent such catastrophes as earthquakes, snow-avalanches and landslides, failure of engineering structures, or economical crises. This book addresses the issue step-by-step, from phenomenological analogies between complex systems and statistical physics to more complex aspects, such as correlations, fluctuation-dissipation theorem, susceptibility, the concept of free ener...

  9. Equilibrium statistical mechanics

    CERN Document Server

    Jackson, E Atlee

    2000-01-01

    Ideal as an elementary introduction to equilibrium statistical mechanics, this volume covers both classical and quantum methodology for open and closed systems. Introductory chapters familiarize readers with probability and microscopic models of systems, while additional chapters describe the general derivation of the fundamental statistical mechanics relationships. The final chapter contains 16 sections, each dealing with a different application, ordered according to complexity, from classical through degenerate quantum statistical mechanics. Key features include an elementary introduction t

  10. Analysis of non-equilibrium phenomena in inductively coupled plasma generators

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.; Panesi, M., E-mail: mpanesi@illinois.edu [University of Illinois at Urbana-Champaign, Urbana, Illinois 61822 (United States); Lani, A. [Von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse (Belgium)

    2016-07-15

    This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.

  11. Non-equilibrium synergistic effects in atmospheric pressure plasmas.

    Science.gov (United States)

    Guo, Heng; Zhang, Xiao-Ning; Chen, Jian; Li, He-Ping; Ostrikov, Kostya Ken

    2018-03-19

    Non-equilibrium is one of the important features of an atmospheric gas discharge plasma. It involves complicated physical-chemical processes and plays a key role in various actual plasma processing. In this report, a novel complete non-equilibrium model is developed to reveal the non-equilibrium synergistic effects for the atmospheric-pressure low-temperature plasmas (AP-LTPs). It combines a thermal-chemical non-equilibrium fluid model for the quasi-neutral plasma region and a simplified sheath model for the electrode sheath region. The free-burning argon arc is selected as a model system because both the electrical-thermal-chemical equilibrium and non-equilibrium regions are involved simultaneously in this arc plasma system. The modeling results indicate for the first time that it is the strong and synergistic interactions among the mass, momentum and energy transfer processes that determine the self-consistent non-equilibrium characteristics of the AP-LTPs. An energy transfer process related to the non-uniform spatial distributions of the electron-to-heavy-particle temperature ratio has also been discovered for the first time. It has a significant influence for self-consistently predicting the transition region between the "hot" and "cold" equilibrium regions of an AP-LTP system. The modeling results would provide an instructive guidance for predicting and possibly controlling the non-equilibrium particle-energy transportation process in various AP-LTPs in future.

  12. Foundations of atmospheric pressure non-equilibrium plasmas

    Science.gov (United States)

    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.

  13. Non-equilibrium dynamics of open systems and fluctuation-dissipation theorems

    Czech Academy of Sciences Publication Activity Database

    Špička, Václav; Velický, B.; Kalvová, Anděla

    2017-01-01

    Roč. 65, 6-8 (2017), s. 1-23, č. článku 1700032. ISSN 0015-8208 Institutional support: RVO:68378271 Keywords : non-equilibrium * fluctuation-dissipation theorems * non-equilibrium Greens function * transient and steady state magnetic current * molecular bridge Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics ( physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 2.434, year: 2016

  14. Statistical mechanics

    CERN Document Server

    Schwabl, Franz

    2006-01-01

    The completely revised new edition of the classical book on Statistical Mechanics covers the basic concepts of equilibrium and non-equilibrium statistical physics. In addition to a deductive approach to equilibrium statistics and thermodynamics based on a single hypothesis - the form of the microcanonical density matrix - this book treats the most important elements of non-equilibrium phenomena. Intermediate calculations are presented in complete detail. Problems at the end of each chapter help students to consolidate their understanding of the material. Beyond the fundamentals, this text demonstrates the breadth of the field and its great variety of applications. Modern areas such as renormalization group theory, percolation, stochastic equations of motion and their applications to critical dynamics, kinetic theories, as well as fundamental considerations of irreversibility, are discussed. The text will be useful for advanced students of physics and other natural sciences; a basic knowledge of quantum mechan...

  15. Relation between absorbed dose, charged particle equilibrium and nuclear transformations: A non-equilibrium thermodynamics point of view

    International Nuclear Information System (INIS)

    Alvarez-Romero, J. T.

    2006-01-01

    We present a discussion to show that the absorbed dose D is a time-dependent function. This time dependence is demonstrated based on the concepts of charged particle equilibrium and on radiation equilibrium within the context of thermodynamic non-equilibrium. In the latter, the time dependence is due to changes of the rest mass energy of the nuclei and elementary particles involved in the terms ΣQ and Q that appear in the definitions of energy imparted ε and energy deposit ε i , respectively. In fact, nothing is said about the averaging operation of the non-stochastic quantity mean energy imparted ε-bar, which is used in the definition of D according to ICRU 60. It is shown in this research that the averaging operation necessary to define the ε-bar employed to get D cannot be performed with an equilibrium statistical operator ρ(r) as could be expected. Rather, the operation has to be defined with a time-dependent non-equilibrium statistical operator (r, t) therefore, D is a time-dependent function D(r, t). (authors)

  16. Renyi statistics in equilibrium statistical mechanics

    International Nuclear Information System (INIS)

    Parvan, A.S.; Biro, T.S.

    2010-01-01

    The Renyi statistics in the canonical and microcanonical ensembles is examined both in general and in particular for the ideal gas. In the microcanonical ensemble the Renyi statistics is equivalent to the Boltzmann-Gibbs statistics. By the exact analytical results for the ideal gas, it is shown that in the canonical ensemble, taking the thermodynamic limit, the Renyi statistics is also equivalent to the Boltzmann-Gibbs statistics. Furthermore it satisfies the requirements of the equilibrium thermodynamics, i.e. the thermodynamical potential of the statistical ensemble is a homogeneous function of first degree of its extensive variables of state. We conclude that the Renyi statistics arrives at the same thermodynamical relations, as those stemming from the Boltzmann-Gibbs statistics in this limit.

  17. Gyrokinetic statistical absolute equilibrium and turbulence

    International Nuclear Information System (INIS)

    Zhu Jianzhou; Hammett, Gregory W.

    2010-01-01

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: a finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N+1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  18. Examples of equilibrium and non-equilibrium behavior in evolutionary systems

    Science.gov (United States)

    Soulier, Arne

    With this thesis, we want to shed some light into the darkness of our understanding of simply defined statistical mechanics systems and the surprisingly complex dynamical behavior they exhibit. We will do so by presenting in turn one equilibrium and then one non-equilibrium system with evolutionary dynamics. In part 1, we will present the seceder-model, a newly developed system that cannot equilibrate. We will then study several properties of the system and obtain an idea of the richness of the dynamics of the seceder model, which is particular impressive given the minimal amount of modeling necessary in its setup. In part 2, we will present extensions to the directed polymer in random media problem on a hypercube and its connection to the Eigen model of evolution. Our main interest will be the influence of time-dependent and time-independent changes in the fitness landscape viewed by an evolving population. This part contains the equilibrium dynamics. The stochastic models and the topic of evolution and non-equilibrium in general will allow us to point out similarities to the various lines of thought in game theory.

  19. Statistical physics of human beings in games: Controlled experiments

    International Nuclear Information System (INIS)

    Liang Yuan; Huang Ji-Ping

    2014-01-01

    It is important to know whether the laws or phenomena in statistical physics for natural systems with non-adaptive agents still hold for social human systems with adaptive agents, because this implies whether it is possible to study or understand social human systems by using statistical physics originating from natural systems. For this purpose, we review the role of human adaptability in four kinds of specific human behaviors, namely, normal behavior, herd behavior, contrarian behavior, and hedge behavior. The approach is based on controlled experiments in the framework of market-directed resource-allocation games. The role of the controlled experiments could be at least two-fold: adopting the real human decision-making process so that the system under consideration could reflect the performance of genuine human beings; making it possible to obtain macroscopic physical properties of a human system by tuning a particular factor of the system, thus directly revealing cause and effect. As a result, both computer simulations and theoretical analyses help to show a few counterparts of some laws or phenomena in statistical physics for social human systems: two-phase phenomena or phase transitions, entropy-related phenomena, and a non-equilibrium steady state. This review highlights the role of human adaptability in these counterparts, and makes it possible to study or understand some particular social human systems by means of statistical physics coming from natural systems. (topical review - statistical physics and complex systems)

  20. Non-equilibrium umbrella sampling applied to force spectroscopy of soft matter.

    Science.gov (United States)

    Gao, Y X; Wang, G M; Williams, D R M; Williams, Stephen R; Evans, Denis J; Sevick, E M

    2012-02-07

    Physical systems often respond on a timescale which is longer than that of the measurement. This is particularly true in soft matter where direct experimental measurement, for example in force spectroscopy, drives the soft system out of equilibrium and provides a non-equilibrium measure. Here we demonstrate experimentally for the first time that equilibrium physical quantities (such as the mean square displacement) can be obtained from non-equilibrium measurements via umbrella sampling. Our model experimental system is a bead fluctuating in a time-varying optical trap. We also show this for simulated force spectroscopy on a complex soft molecule--a piston-rotaxane.

  1. Non-extensive statistical effects in nuclear many-body problems

    International Nuclear Information System (INIS)

    Lavagno, A.; Quarati, P.

    2007-01-01

    Density and temperature conditions in many stellar core and in the first stage of relativistic heavy-ion collisions imply the presence of non-ideal plasma effects with memory and long-range interactions between particles. Recent progress in statistical mechanics indicates that Tsallis non-extensive thermostatistics could be the natural generalization of the standard classical and quantum statistics, when memory effects and long range forces are not negligible. In this framework, we show that in weakly non-ideal plasma non-extensive effects should be taken into account to derive the equilibrium distribution functions, the quantum fluctuations and correlations between the particles. The strong influence of these effects is discussed in the context of the solar plasma physics and in the high-energy nuclear-nuclear collision experiments. Although the deviation from Boltzmann-Gibbs statistics, in both cases, is very small, the stellar plasma and the hadronic gas are strongly influenced by the non-extensive feature and the discrepancies between experimental data and theoretical previsions are sensibly reduced. (authors)

  2. Non-equilibrium supramolecular polymerization.

    Science.gov (United States)

    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.

  3. Non-equilibrium thermodynamics

    CERN Document Server

    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

  4. Statistical physics of human beings in games: Controlled experiments

    Science.gov (United States)

    Liang, Yuan; Huang, Ji-Ping

    2014-07-01

    It is important to know whether the laws or phenomena in statistical physics for natural systems with non-adaptive agents still hold for social human systems with adaptive agents, because this implies whether it is possible to study or understand social human systems by using statistical physics originating from natural systems. For this purpose, we review the role of human adaptability in four kinds of specific human behaviors, namely, normal behavior, herd behavior, contrarian behavior, and hedge behavior. The approach is based on controlled experiments in the framework of market-directed resource-allocation games. The role of the controlled experiments could be at least two-fold: adopting the real human decision-making process so that the system under consideration could reflect the performance of genuine human beings; making it possible to obtain macroscopic physical properties of a human system by tuning a particular factor of the system, thus directly revealing cause and effect. As a result, both computer simulations and theoretical analyses help to show a few counterparts of some laws or phenomena in statistical physics for social human systems: two-phase phenomena or phase transitions, entropy-related phenomena, and a non-equilibrium steady state. This review highlights the role of human adaptability in these counterparts, and makes it possible to study or understand some particular social human systems by means of statistical physics coming from natural systems.

  5. Lattice ellipsoidal statistical BGK model for thermal non-equilibrium flows

    Science.gov (United States)

    Meng, Jianping; Zhang, Yonghao; Hadjiconstantinou, Nicolas G.; Radtke, Gregg A.; Shan, Xiaowen

    2013-03-01

    A thermal lattice Boltzmann model is constructed on the basis of the ellipsoidal statistical Bhatnagar-Gross-Krook (ES-BGK) collision operator via the Hermite moment representation. The resulting lattice ES-BGK model uses a single distribution function and features an adjustable Prandtl number. Numerical simulations show that using a moderate discrete velocity set, this model can accurately recover steady and transient solutions of the ES-BGK equation in the slip-flow and early transition regimes in the small Mach number limit that is typical of microscale problems of practical interest. In the transition regime in particular, comparisons with numerical solutions of the ES-BGK model, direct Monte Carlo and low-variance deviational Monte Carlo simulations show good accuracy for values of the Knudsen number up to approximately 0.5. On the other hand, highly non-equilibrium phenomena characterized by high Mach numbers, such as viscous heating and force-driven Poiseuille flow for large values of the driving force, are more difficult to capture quantitatively in the transition regime using discretizations chosen with computational efficiency in mind such as the one used here, although improved accuracy is observed as the number of discrete velocities is increased.

  6. Non-equilibrium Quasi-Chemical Nucleation Model

    Science.gov (United States)

    Gorbachev, Yuriy E.

    2018-04-01

    Quasi-chemical model, which is widely used for nucleation description, is revised on the basis of recent results in studying of non-equilibrium effects in reacting gas mixtures (Kolesnichenko and Gorbachev in Appl Math Model 34:3778-3790, 2010; Shock Waves 23:635-648, 2013; Shock Waves 27:333-374, 2017). Non-equilibrium effects in chemical reactions are caused by the chemical reactions themselves and therefore these contributions should be taken into account in the corresponding expressions for reaction rates. Corrections to quasi-equilibrium reaction rates are of two types: (a) spatially homogeneous (caused by physical-chemical processes) and (b) spatially inhomogeneous (caused by gas expansion/compression processes and proportional to the velocity divergency). Both of these processes play an important role during the nucleation and are included into the proposed model. The method developed for solving the generalized Boltzmann equation for chemically reactive gases is applied for solving the set of equations of the revised quasi-chemical model. It is shown that non-equilibrium processes lead to essential deviation of the quasi-stationary distribution and therefore the nucleation rate from its traditional form.

  7. PHYSICS OF NON-GAUSSIAN FIELDS AND THE COSMOLOGICAL GENUS STATISTIC

    International Nuclear Information System (INIS)

    James, J. Berian

    2012-01-01

    We report a technique to calculate the impact of distinct physical processes inducing non-Gaussianity on the cosmological density field. A natural decomposition of the cosmic genus statistic into an orthogonal polynomial sequence allows complete expression of the scale-dependent evolution of the topology of large-scale structure, in which effects including galaxy bias, nonlinear gravitational evolution, and primordial non-Gaussianity may be delineated. The relationship of this decomposition to previous methods for analyzing the genus statistic is briefly considered and the following applications are made: (1) the expression of certain systematics affecting topological measurements, (2) the quantification of broad deformations from Gaussianity that appear in the genus statistic as measured in the Horizon Run simulation, and (3) the study of the evolution of the genus curve for simulations with primordial non-Gaussianity. These advances improve the treatment of flux-limited galaxy catalogs for use with this measurement and further the use of the genus statistic as a tool for exploring non-Gaussianity.

  8. Quantum gases finite temperature and non-equilibrium dynamics

    CERN Document Server

    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...

  9. Non-equilibrium coherence dynamics in one-dimensional Bose gases

    DEFF Research Database (Denmark)

    Hofferberth, S.; Lesanovsky, Igor; Fischer, B.

    2007-01-01

    Low-dimensional systems provide beautiful examples of many-body quantum physics. For one-dimensional (1D) systems, the Luttinger liquid approach provides insight into universal properties. Much is known of the equilibrium state, both in the weakly and strongly interacting regimes. However......, the coherence factor is observed to approach a non-zero equilibrium value, as predicted by a Bogoliubov approach. This coupled-system decay to finite coherence is the matter wave equivalent of phase-locking two lasers by injection. The non-equilibrium dynamics of superfluids has an important role in a wide...... range of physical systems, such as superconductors, quantum Hall systems, superfluid helium and spin systems. Our experiments studying coherence dynamics show that 1D Bose gases are ideally suited for investigating this class of phenomena....

  10. Statistical equilibrium equations for trace elements in stellar atmospheres

    OpenAIRE

    Kubat, Jiri

    2010-01-01

    The conditions of thermodynamic equilibrium, local thermodynamic equilibrium, and statistical equilibrium are discussed in detail. The equations of statistical equilibrium and the supplementary equations are shown together with the expressions for radiative and collisional rates with the emphasize on the solution for trace elements.

  11. Non-equilibrium physics and evolution—adaptation, extinction, and ecology: a Key Issues review

    International Nuclear Information System (INIS)

    Kussell, E; Vucelja, M

    2014-01-01

    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. (key issues reviews)

  12. Temperature in non-equilibrium states: a review of open problems and current proposals

    International Nuclear Information System (INIS)

    Casas-Vazquez, J; Jou, D

    2003-01-01

    The conceptual problems arising in the definition and measurement of temperature in non-equilibrium states are discussed in this paper in situations where the local-equilibrium hypothesis is no longer satisfactory. This is a necessary and urgent discussion because of the increasing interest in thermodynamic theories beyond local equilibrium, in computer simulations, in non-linear statistical mechanics, in new experiments, and in technological applications of nanoscale systems and material sciences. First, we briefly review the concept of temperature from the perspectives of equilibrium thermodynamics and statistical mechanics. Afterwards, we explore which of the equilibrium concepts may be extrapolated beyond local equilibrium and which of them should be modified, then we review several attempts to define temperature in non-equilibrium situations from macroscopic and microscopic bases. A wide review of proposals is offered on effective non-equilibrium temperatures and their application to ideal and real gases, electromagnetic radiation, nuclear collisions, granular systems, glasses, sheared fluids, amorphous semiconductors and turbulent fluids. The consistency between the different relativistic transformation laws for temperature is discussed in the new light gained from this perspective. A wide bibliography is provided in order to foster further research in this field

  13. Non-equilibrium fluctuation-induced interactions

    International Nuclear Information System (INIS)

    Dean, David S

    2012-01-01

    We discuss non-equilibrium aspects of fluctuation-induced interactions. While the equilibrium behavior of such interactions has been extensively studied and is relatively well understood, the study of these interactions out of equilibrium is relatively new. We discuss recent results on the non-equilibrium behavior of systems whose dynamics is of the dissipative stochastic type and identify a number of outstanding problems concerning non-equilibrium fluctuation-induced interactions.

  14. Equilibrium and non-equilibrium phenomena in arcs and torches

    NARCIS (Netherlands)

    Mullen, van der J.J.A.M.

    2000-01-01

    A general treatment of non-equilibrium plasma aspects is obtained by relating transport fluxes to equilibrium restoring processes in so-called disturbed Bilateral Relations. The (non) equilibrium stage of a small microwave induced plasma serves as case study.

  15. Non-equilibrium Dynamics, Thermalization and Entropy Production

    International Nuclear Information System (INIS)

    Hinrichsen, Haye; Janotta, Peter; Gogolin, Christian

    2011-01-01

    This paper addresses fundamental aspects of statistical mechanics such as the motivation of a classical state space with spontaneous transitions, the meaning of non-equilibrium in the context of thermalization, and the justification of these concepts from the quantum-mechanical point of view. After an introductory part we focus on the problem of entropy production in non-equilibrium systems. In particular, the generally accepted formula for entropy production in the environment is analyzed from a critical perspective. It is shown that this formula is only valid in the limit of separated time scales of the system's and the environmental degrees of freedom. Finally, we present an alternative simple proof of the fluctuation theorem.

  16. Broken detailed balance and non-equilibrium dynamics in living systems: a review

    Science.gov (United States)

    Gnesotto, F. S.; Mura, F.; Gladrow, J.; Broedersz, C. P.

    2018-06-01

    Living systems operate far from thermodynamic equilibrium. Enzymatic activity can induce broken detailed balance at the molecular scale. This molecular scale breaking of detailed balance is crucial to achieve biological functions such as high-fidelity transcription and translation, sensing, adaptation, biochemical patterning, and force generation. While biological systems such as motor enzymes violate detailed balance at the molecular scale, it remains unclear how non-equilibrium dynamics manifests at the mesoscale in systems that are driven through the collective activity of many motors. Indeed, in several cellular systems the presence of non-equilibrium dynamics is not always evident at large scales. For example, in the cytoskeleton or in chromosomes one can observe stationary stochastic processes that appear at first glance thermally driven. This raises the question how non-equilibrium fluctuations can be discerned from thermal noise. We discuss approaches that have recently been developed to address this question, including methods based on measuring the extent to which the system violates the fluctuation-dissipation theorem. We also review applications of this approach to reconstituted cytoskeletal networks, the cytoplasm of living cells, and cell membranes. Furthermore, we discuss a more recent approach to detect actively driven dynamics, which is based on inferring broken detailed balance. This constitutes a non-invasive method that uses time-lapse microscopy data, and can be applied to a broad range of systems in cells and tissue. We discuss the ideas underlying this method and its application to several examples including flagella, primary cilia, and cytoskeletal networks. Finally, we briefly discuss recent developments in stochastic thermodynamics and non-equilibrium statistical mechanics, which offer new perspectives to understand the physics of living systems.

  17. Broken detailed balance and non-equilibrium dynamics in living systems: a review.

    Science.gov (United States)

    Gnesotto, F S; Mura, F; Gladrow, J; Broedersz, C P

    2018-03-05

    Living systems operate far from thermodynamic equilibrium. Enzymatic activity can induce broken detailed balance at the molecular scale. This molecular scale breaking of detailed balance is crucial to achieve biological functions such as high-fidelity transcription and translation, sensing, adaptation, biochemical patterning, and force generation. While biological systems such as motor enzymes violate detailed balance at the molecular scale, it remains unclear how non-equilibrium dynamics manifests at the mesoscale in systems that are driven through the collective activity of many motors. Indeed, in several cellular systems the presence of non-equilibrium dynamics is not always evident at large scales. For example, in the cytoskeleton or in chromosomes one can observe stationary stochastic processes that appear at first glance thermally driven. This raises the question how non-equilibrium fluctuations can be discerned from thermal noise. We discuss approaches that have recently been developed to address this question, including methods based on measuring the extent to which the system violates the fluctuation-dissipation theorem. We also review applications of this approach to reconstituted cytoskeletal networks, the cytoplasm of living cells, and cell membranes. Furthermore, we discuss a more recent approach to detect actively driven dynamics, which is based on inferring broken detailed balance. This constitutes a non-invasive method that uses time-lapse microscopy data, and can be applied to a broad range of systems in cells and tissue. We discuss the ideas underlying this method and its application to several examples including flagella, primary cilia, and cytoskeletal networks. Finally, we briefly discuss recent developments in stochastic thermodynamics and non-equilibrium statistical mechanics, which offer new perspectives to understand the physics of living systems.

  18. Non-equilibrium Economics

    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.

  19. Non-equilibrium thermodynamics of radiation-induced processes in solids

    International Nuclear Information System (INIS)

    Yurov, V.M.; Eshchanov, A.N.; Kuketaev, A.T.; Sidorenya, Yu.S.

    2005-01-01

    In the paper an item about a defect system response in solids on external action (temperature, pressure, light, etc.) from the point of view of non-equilibrium statistical thermodynamics is considered

  20. The applications of Complexity Theory and Tsallis Non-extensive Statistics at Solar Plasma Dynamics

    Science.gov (United States)

    Pavlos, George

    2015-04-01

    As the solar plasma lives far from equilibrium it is an excellent laboratory for testing complexity theory and non-equilibrium statistical mechanics. In this study, we present the highlights of complexity theory and Tsallis non extensive statistical mechanics as concerns their applications at solar plasma dynamics, especially at sunspot, solar flare and solar wind phenomena. Generally, when a physical system is driven far from equilibrium states some novel characteristics can be observed related to the nonlinear character of dynamics. Generally, the nonlinearity in space plasma dynamics can generate intermittent turbulence with the typical characteristics of the anomalous diffusion process and strange topologies of stochastic space plasma fields (velocity and magnetic fields) caused by the strange dynamics and strange kinetics (Zaslavsky, 2002). In addition, according to Zelenyi and Milovanov (2004) the complex character of the space plasma system includes the existence of non-equilibrium (quasi)-stationary states (NESS) having the topology of a percolating fractal set. The stabilization of a system near the NESS is perceived as a transition into a turbulent state determined by self-organization processes. The long-range correlation effects manifest themselves as a strange non-Gaussian behavior of kinetic processes near the NESS plasma state. The complex character of space plasma can also be described by the non-extensive statistical thermodynamics pioneered by Tsallis, which offers a consistent and effective theoretical framework, based on a generalization of Boltzmann - Gibbs (BG) entropy, to describe far from equilibrium nonlinear complex dynamics (Tsallis, 2009). In a series of recent papers, the hypothesis of Tsallis non-extensive statistics in magnetosphere, sunspot dynamics, solar flares, solar wind and space plasma in general, was tested and verified (Karakatsanis et al., 2013; Pavlos et al., 2014; 2015). Our study includes the analysis of solar plasma time

  1. The non-equilibrium statistical mechanics of a simple geophysical fluid dynamics model

    Science.gov (United States)

    Verkley, Wim; Severijns, Camiel

    2014-05-01

    Lorenz [1] has devised a dynamical system that has proved to be very useful as a benchmark system in geophysical fluid dynamics. The system in its simplest form consists of a periodic array of variables that can be associated with an atmospheric field on a latitude circle. The system is driven by a constant forcing, is damped by linear friction and has a simple advection term that causes the model to behave chaotically if the forcing is large enough. Our aim is to predict the statistics of Lorenz' model on the basis of a given average value of its total energy - obtained from a numerical integration - and the assumption of statistical stationarity. Our method is the principle of maximum entropy [2] which in this case reads: the information entropy of the system's probability density function shall be maximal under the constraints of normalization, a given value of the average total energy and statistical stationarity. Statistical stationarity is incorporated approximately by using `stationarity constraints', i.e., by requiring that the average first and possibly higher-order time-derivatives of the energy are zero in the maximization of entropy. The analysis [3] reveals that, if the first stationarity constraint is used, the resulting probability density function rather accurately reproduces the statistics of the individual variables. If the second stationarity constraint is used as well, the correlations between the variables are also reproduced quite adequately. The method can be generalized straightforwardly and holds the promise of a viable non-equilibrium statistical mechanics of the forced-dissipative systems of geophysical fluid dynamics. [1] E.N. Lorenz, 1996: Predictability - A problem partly solved, in Proc. Seminar on Predictability (ECMWF, Reading, Berkshire, UK), Vol. 1, pp. 1-18. [2] E.T. Jaynes, 2003: Probability Theory - The Logic of Science (Cambridge University Press, Cambridge). [3] W.T.M. Verkley and C.A. Severijns, 2014: The maximum entropy

  2. Stochastic linearization of turbulent dynamics of dispersive waves in equilibrium and non-equilibrium state

    International Nuclear Information System (INIS)

    Jiang, Shixiao W; Lu, Haihao; Zhou, Douglas; Cai, David

    2016-01-01

    Characterizing dispersive wave turbulence in the long time dynamics is central to understanding of many natural phenomena, e.g., in atmosphere ocean dynamics, nonlinear optics, and plasma physics. Using the β -Fermi–Pasta–Ulam nonlinear system as a prototypical example, we show that in thermal equilibrium and non-equilibrium steady state the turbulent state even in the strongly nonlinear regime possesses an effective linear stochastic structure in renormalized normal variables. In this framework, we can well characterize the spatiotemporal dynamics, which are dominated by long-wavelength renormalized waves. We further demonstrate that the energy flux is nearly saturated by the long-wavelength renormalized waves in non-equilibrium steady state. The scenario of such effective linear stochastic dynamics can be extended to study turbulent states in other nonlinear wave systems. (paper)

  3. Non-Equilibrium Properties from Equilibrium Free Energy Calculations

    Science.gov (United States)

    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.

  4. Modelling non-equilibrium thermodynamic systems from the speed-gradient principle.

    Science.gov (United States)

    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).

  5. Non-equilibrium phase transitions

    CERN Document Server

    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.

  6. Evaluating equilibrium and non-equilibrium transport of bromide and isoproturon in disturbed and undisturbed soil columns

    Science.gov (United States)

    Dousset, S.; Thevenot, M.; Pot, V.; Šimunek, J.; Andreux, F.

    2007-12-01

    In this study, displacement experiments of isoproturon were conducted in disturbed and undisturbed columns of a silty clay loam soil under similar rainfall intensities. Solute transport occurred under saturated conditions in the undisturbed soil and under unsaturated conditions in the sieved soil because of a greater bulk density of the compacted undisturbed soil compared to the sieved soil. The objective of this work was to determine transport characteristics of isoproturon relative to bromide tracer. Triplicate column experiments were performed with sieved (structure partially destroyed to simulate conventional tillage) and undisturbed (structure preserved) soils. Bromide experimental breakthrough curves were analyzed using convective-dispersive and dual-permeability (DP) models (HYDRUS-1D). Isoproturon breakthrough curves (BTCs) were analyzed using the DP model that considered either chemical equilibrium or non-equilibrium transport. The DP model described the bromide elution curves of the sieved soil columns well, whereas it overestimated the tailing of the bromide BTCs of the undisturbed soil columns. A higher degree of physical non-equilibrium was found in the undisturbed soil, where 56% of total water was contained in the slow-flow matrix, compared to 26% in the sieved soil. Isoproturon BTCs were best described in both sieved and undisturbed soil columns using the DP model combined with the chemical non-equilibrium. Higher degradation rates were obtained in the transport experiments than in batch studies, for both soils. This was likely caused by hysteresis in sorption of isoproturon. However, it cannot be ruled out that higher degradation rates were due, at least in part, to the adopted first-order model. Results showed that for similar rainfall intensity, physical and chemical non-equilibrium were greater in the saturated undisturbed soil than in the unsaturated sieved soil. Results also suggested faster transport of isoproturon in the undisturbed soil due

  7. The entropy concept for non-equilibrium states.

    Science.gov (United States)

    Lieb, Elliott H; Yngvason, Jakob

    2013-10-08

    In earlier work, we presented a foundation for the second law of classical thermodynamics in terms of the entropy principle. More precisely, we provided an empirically accessible axiomatic derivation of an entropy function defined on all equilibrium states of all systems that has the appropriate additivity and scaling properties, and whose increase is a necessary and sufficient condition for an adiabatic process between two states to be possible. Here, after a brief review of this approach, we address the question of defining entropy for non-equilibrium states. Our conclusion is that it is generally not possible to find a unique entropy that has all relevant physical properties. We do show, however, that one can define two entropy functions, called S - and S + , which, taken together, delimit the range of adiabatic processes that can occur between non-equilibrium states. The concept of comparability of states with respect to adiabatic changes plays an important role in our reasoning.

  8. Non-equilibrium scaling analysis of the Kondo model with voltage bias

    International Nuclear Information System (INIS)

    Fritsch, Peter; Kehrein, Stefan

    2009-01-01

    The quintessential description of Kondo physics in equilibrium is obtained within a scaling picture that shows the buildup of Kondo screening at low temperature. For the non-equilibrium Kondo model with a voltage bias, the key new feature are decoherence effects due to the current across the impurity. In the present paper, we show how one can develop a consistent framework for studying the non-equilibrium Kondo model within a scaling picture of infinitesimal unitary transformations (flow equations). Decoherence effects appear naturally in third order of the β-function and dominate the Hamiltonian flow for sufficiently large voltage bias. We work out the spin dynamics in non-equilibrium and compare it with finite temperature equilibrium results. In particular, we report on the behavior of the static spin susceptibility including leading logarithmic corrections and compare it with the celebrated equilibrium result as a function of temperature.

  9. "Non-equilibrium" block copolymer micelles with glassy cores: a predictive approach based on theory of equilibrium micelles.

    Science.gov (United States)

    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

  10. Physical mechanism for biopolymers to aggregate and maintain in non-equilibrium states.

    Science.gov (United 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.

  11. Modeling of two-phase flow with thermal and mechanical non-equilibrium

    International Nuclear Information System (INIS)

    Houdayer, G.; Pinet, B.; Le Coq, G.; Reocreux, M.; Rousseau, J.C.

    1977-01-01

    To improve two-phase flow modeling by taking into account thermal and mechanical non-equilibrium a joint effort on analytical experiment and physical modeling has been undertaken. A model describing thermal non-equilibrium effects is first presented. A correlation of mass transfer has been developed using steam water critical flow tests. This model has been used to predict in a satisfactory manner blowdown tests. It has been incorporated in CLYSTERE system code. To take into account mechanical non-equilibrium, a six equations model is written. To get information on the momentum transfers special nitrogen-water tests have been undertaken. The first results of these studies are presented

  12. On the definition of equilibrium and non-equilibrium states in dynamical systems

    OpenAIRE

    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.

  13. Important contributions of M.C. Wang and C.S. Wang Chang to non-equilibrium statistical physics

    International Nuclear Information System (INIS)

    Liu Jixing

    2004-01-01

    In the middle of the 20th century two Chinese women physicists, Ming-Chen Wang and Cheng-Shu Wang Chang made great contributions to statistical physics. The famous review article 'On the theory of the Brownian motion II' by Ming-Chen Wang and G.E. Uhlenbeck published in Rev. of Mod. Phys. in 1945 provided a complete scientific classification of stochastic processes which is still adopted by the scientific community as the standard classification. The Wang-Chang-Uhlenbeck (WCU) equation proposed jointly by C.S. Wang-Chang and Uhlenbeck became the fundamental kinetic equation for the treatment of transport properties of multi-atomic gases with internal degrees of freedom in the physics literature. These important scientific contributions are analyzed and reviewed

  14. Ward identity for non-equilibrium Fermi systems

    Czech Academy of Sciences Publication Activity Database

    Velický, B.; Kalvová, Anděla; Špička, Václav

    2008-01-01

    Roč. 77, č. 4 (2008), 041201/1-041201/4 ISSN 1098-0121 R&D Projects: GA ČR GC202/07/J051 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z10100521 Keywords : non-equilibrium * Green’s functions * quantum transport equations * Ward identity Subject RIV: BE - Theoretical Physics Impact factor: 3.322, year: 2008

  15. Non equilibrium atomic processes and plasma spectroscopy

    International Nuclear Information System (INIS)

    Kato, Takako

    2003-01-01

    Along with the technical progress in plasma spectroscopy, non equilibrium ionization processes have been recently observed. We study non local thermodynamic equilibrium and non ionization equilibrium for various kinds of plasmas. Specifically we discuss non equilibrium atomic processes in magnetically confined plasmas, solar flares and laser produced plasmas using a collisional radiative model based on plasma spectroscopic data. (author)

  16. NON-EQUILIBRIUM HELIUM IONIZATION IN AN MHD SIMULATION OF THE SOLAR ATMOSPHERE

    International Nuclear Information System (INIS)

    Golding, Thomas Peter; Carlsson, Mats; Leenaarts, Jorrit

    2016-01-01

    The ionization state of the gas in the dynamic solar chromosphere can depart strongly from the instantaneous statistical equilibrium commonly assumed in numerical modeling. We improve on earlier simulations of the solar atmosphere that only included non-equilibrium hydrogen ionization by performing a 2D radiation-magnetohydrodynamics simulation featuring non-equilibrium ionization of both hydrogen and helium. The simulation includes the effect of hydrogen Lyα and the EUV radiation from the corona on the ionization and heating of the atmosphere. Details on code implementation are given. We obtain helium ion fractions that are far from their equilibrium values. Comparison with models with local thermodynamic equilibrium (LTE) ionization shows that non-equilibrium helium ionization leads to higher temperatures in wavefronts and lower temperatures in the gas between shocks. Assuming LTE ionization results in a thermostat-like behavior with matter accumulating around the temperatures where the LTE ionization fractions change rapidly. Comparison of DEM curves computed from our models shows that non-equilibrium ionization leads to more radiating material in the temperature range 11–18 kK, compared to models with LTE helium ionization. We conclude that non-equilibrium helium ionization is important for the dynamics and thermal structure of the upper chromosphere and transition region. It might also help resolve the problem that intensities of chromospheric lines computed from current models are smaller than those observed

  17. Shape characteristics of equilibrium and non-equilibrium fractal clusters.

    Science.gov (United States)

    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

  18. Non-equilibrium spectroscopy of high-Tc superconductors

    International Nuclear Information System (INIS)

    Krasnov, V M

    2009-01-01

    In superconductors, recombination of two non-equilibrium quasiparticles into a Cooper pair results in emission of excitation that mediates superconductivity. This is the basis of the proposed new type of 'non-equilibrium' spectroscopy of high T c superconductors, which may open a possibility for direct and unambiguous determination of the coupling mechanism of high T c superconductivity. In case of low T c superconductors, the feasibility of such the non-equilibrium spectroscopy was demonstrated in classical phonon generation-detection experiments almost four decades ago. Recently it was demonstrated that a similar technique can be used for high T c superconductors, using natural intrinsic Josephson junctions both for injection of non-equilibrium quasiparticles and for detection of the non-equilibrium radiation. Here I analyze theoretically non-equilibrium phenomena in intrinsic Josephson junctions. It is shown that extreme non-equilibrium state can be achieved at bias equal to integer number of the gap voltage, which can lead to laser-like emission from the stack. I argue that identification of the boson type, constituting this non-equilibrium radiation would unambiguously reveal the coupling mechanism of high Tc superconductors.

  19. Fundamental properties of fracture and seismicity in a non extensive statistical physics framework.

    Science.gov (United States)

    Vallianatos, Filippos

    2010-05-01

    A fundamental challenge in many scientific disciplines concerns upscaling, that is, of determining the regularities and laws of evolution at some large scale, from those known at a lower scale. Earthquake physics is no exception, with the challenge of understanding the transition from the laboratory scale to the scale of fault networks and large earthquakes. In this context, statistical physics has a remarkably successful work record in addressing the upscaling problem in physics. It is natural then to consider that the physics of many earthquakes has to be studied with a different approach than the physics of one earthquake and in this sense we can consider the use of statistical physics not only appropriate but necessary to understand the collective properties of earthquakes [see Corral 2004, 2005a,b,c;]. A significant attempt is given in a series of works [Main 1996; Rundle et al., 1997; Main et al., 2000; Main and Al-Kindy, 2002; Rundle et al., 2003; Vallianatos and Triantis, 2008a] that uses classical statistical physics to describe seismicity. Then a natural question arises. What type of statistical physics is appropriate to commonly describe effects from fracture level to seismicity scale?? The application of non extensive statistical physics offers a consistent theoretical framework, based on a generalization of entropy, to analyze the behavior of natural systems with fractal or multi-fractal distribution of their elements. Such natural systems where long - range interactions or intermittency are important, lead to power law behavior. We note that this is consistent with a classical thermodynamic approach to natural systems that rapidly attain equilibrium, leading to exponential-law behavior. In the frame of non extensive statistical physics approach, the probability function p(X) is calculated using the maximum entropy formulation of Tsallis entropy which involves the introduction of at least two constraints (Tsallis et al., 1998). The first one is the

  20. Statistical mechanics and the physics of fluids

    CERN Document Server

    Tosi, Mario

    This volume collects the lecture notes of a course on statistical mechanics, held at Scuola Normale Superiore di Pisa for third-to-fifth year students in physics and chemistry. Three main themes are covered in the book. The first part gives a compact presentation of the foundations of statistical mechanics and their connections with thermodynamics. Applications to ideal gases of material particles and of excitation quanta are followed by a brief introduction to a real classical gas and to a weakly coupled classical plasma, and by a broad overview on the three states of matter.The second part is devoted to fluctuations around equilibrium and their correlations. Coverage of liquid structure and critical phenomena is followed by a discussion of irreversible processes as exemplified by diffusive motions and by the dynamics of density and heat fluctuations. Finally, the third part is an introduction to some advanced themes: supercooling and the glassy state, non-Newtonian fluids including polymers and liquid cryst...

  1. Experimental approaches for studying non-equilibrium atmospheric plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Shashurin, A., E-mail: ashashur@purdue.edu [School of Aeronautics & Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Keidar, M. [Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, District of Columbia 20052 (United States)

    2015-12-15

    This work reviews recent research efforts undertaken in the area non-equilibrium atmospheric plasma jets with special focus on experimental approaches. Physics of small non-equilibrium atmospheric plasma jets operating in kHz frequency range at powers around few Watts will be analyzed, including mechanism of breakdown, process of ionization front propagation, electrical coupling of the ionization front with the discharge electrodes, distributions of excited and ionized species, discharge current spreading, transient dynamics of various plasma parameters, etc. Experimental diagnostic approaches utilized in the field will be considered, including Rayleigh microwave scattering, Thomson laser scattering, electrostatic streamer scatterers, optical emission spectroscopy, fast photographing, etc.

  2. Stochastic Spatial Models in Ecology: A Statistical Physics Approach

    Science.gov (United States)

    Pigolotti, Simone; Cencini, Massimo; Molina, Daniel; Muñoz, Miguel A.

    2017-11-01

    Ecosystems display a complex spatial organization. Ecologists have long tried to characterize them by looking at how different measures of biodiversity change across spatial scales. Ecological neutral theory has provided simple predictions accounting for general empirical patterns in communities of competing species. However, while neutral theory in well-mixed ecosystems is mathematically well understood, spatial models still present several open problems, limiting the quantitative understanding of spatial biodiversity. In this review, we discuss the state of the art in spatial neutral theory. We emphasize the connection between spatial ecological models and the physics of non-equilibrium phase transitions and how concepts developed in statistical physics translate in population dynamics, and vice versa. We focus on non-trivial scaling laws arising at the critical dimension D = 2 of spatial neutral models, and their relevance for biological populations inhabiting two-dimensional environments. We conclude by discussing models incorporating non-neutral effects in the form of spatial and temporal disorder, and analyze how their predictions deviate from those of purely neutral theories.

  3. Non-equilibrium coherence dynamics in one-dimensional Bose gases.

    Science.gov (United States)

    Hofferberth, S; Lesanovsky, I; Fischer, B; Schumm, T; Schmiedmayer, J

    2007-09-20

    Low-dimensional systems provide beautiful examples of many-body quantum physics. For one-dimensional (1D) systems, the Luttinger liquid approach provides insight into universal properties. Much is known of the equilibrium state, both in the weakly and strongly interacting regimes. However, it remains a challenge to probe the dynamics by which this equilibrium state is reached. Here we present a direct experimental study of the coherence dynamics in both isolated and coupled degenerate 1D Bose gases. Dynamic splitting is used to create two 1D systems in a phase coherent state. The time evolution of the coherence is revealed through local phase shifts of the subsequently observed interference patterns. Completely isolated 1D Bose gases are observed to exhibit universal sub-exponential coherence decay, in excellent agreement with recent predictions. For two coupled 1D Bose gases, the coherence factor is observed to approach a non-zero equilibrium value, as predicted by a Bogoliubov approach. This coupled-system decay to finite coherence is the matter wave equivalent of phase-locking two lasers by injection. The non-equilibrium dynamics of superfluids has an important role in a wide range of physical systems, such as superconductors, quantum Hall systems, superfluid helium and spin systems. Our experiments studying coherence dynamics show that 1D Bose gases are ideally suited for investigating this class of phenomena.

  4. The new physics of non-equilibrium condensates: insights from classical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Eastham, P R [Theory of Condensed Matter, Cavendish Laboratory, Cambridge CB3 0HE (United Kingdom)

    2007-07-25

    We discuss the dynamics of classical Dicke-type models, aiming to clarify the mechanisms by which coherent states could develop in potentially non-equilibrium systems such as semiconductor microcavities. We present simulations of an undamped model which show spontaneous coherent states with persistent oscillations in the magnitude of the order parameter. These states are generalizations of superradiant ringing to the case of inhomogeneous broadening. They correspond to the persistent gap oscillations proposed in fermionic atomic condensates, and arise from a variety of initial conditions. We show that introducing randomness into the couplings can suppress the oscillations, leading to a limiting dynamics with a time-independent order parameter. This demonstrates that non-equilibrium generalizations of polariton condensates can be created even without dissipation. We explain the dynamical origins of the coherence in terms of instabilities of the normal state, and consider how it can additionally develop through scattering and dissipation.

  5. The new physics of non-equilibrium condensates: insights from classical dynamics

    International Nuclear Information System (INIS)

    Eastham, P R

    2007-01-01

    We discuss the dynamics of classical Dicke-type models, aiming to clarify the mechanisms by which coherent states could develop in potentially non-equilibrium systems such as semiconductor microcavities. We present simulations of an undamped model which show spontaneous coherent states with persistent oscillations in the magnitude of the order parameter. These states are generalizations of superradiant ringing to the case of inhomogeneous broadening. They correspond to the persistent gap oscillations proposed in fermionic atomic condensates, and arise from a variety of initial conditions. We show that introducing randomness into the couplings can suppress the oscillations, leading to a limiting dynamics with a time-independent order parameter. This demonstrates that non-equilibrium generalizations of polariton condensates can be created even without dissipation. We explain the dynamical origins of the coherence in terms of instabilities of the normal state, and consider how it can additionally develop through scattering and dissipation

  6. Non-equilibrium dynamics from RPMD and CMD.

    Science.gov (United States)

    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(t 4 ) and O(t 1 ), respectively; for the position-autocorrelation function associated with an initial momentum impulse, RPMD and CMD agree with Matsubara dynamics up to O(t 5 ) and O(t 2 ), 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.

  7. Non-equilibrium thermionic electron emission for metals at high temperatures

    Science.gov (United States)

    Domenech-Garret, J. L.; Tierno, S. P.; Conde, L.

    2015-08-01

    Stationary thermionic electron emission currents from heated metals are compared against an analytical expression derived using a non-equilibrium quantum kappa energy distribution for the electrons. The latter depends on the temperature decreasing parameter κ ( T ) , which decreases with increasing temperature and can be estimated from raw experimental data and characterizes the departure of the electron energy spectrum from equilibrium Fermi-Dirac statistics. The calculations accurately predict the measured thermionic emission currents for both high and moderate temperature ranges. The Richardson-Dushman law governs electron emission for large values of kappa or equivalently, moderate metal temperatures. The high energy tail in the electron energy distribution function that develops at higher temperatures or lower kappa values increases the emission currents well over the predictions of the classical expression. This also permits the quantitative estimation of the departure of the metal electrons from the equilibrium Fermi-Dirac statistics.

  8. 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.

  9. 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

    -equilibrium-induced changes in the solubility control. Despite both physical and chemical non-equilibrium, the Columns were found to provide adequate information for readily soluble compounds (i.e., Na, Cl-, and K) and solubility-controlled elements (i.e., Ca, SO42-, Ba, Si, Al, Zn, and Pb). The leaching Of Cu and Ni...... was shown to depend strongly on DOC leaching, which was likely affected by physical non-equilibrium during flow interruptions. Consequently, the leaching of Cu and Ni in the undisturbed Columns Was shown to be by about one order of magnitude lower compared with the interrupted column. The results indicate...... in turn appeared to be controlled by diffusion from the stagnant zone: no Mo controlling minerals were predicted by the geochemical modeling....

  10. Nonideal plasmas as non-equilibrium media

    International Nuclear Information System (INIS)

    Morozov, I V; Norman, G E; Valuev, A A; Valuev, I A

    2003-01-01

    Various aspects of the collective behaviour of non-equilibrium nonideal plasmas are studied. The relaxation of kinetic energy to the equilibrium state is simulated by the molecular dynamics (MD) method for two-component non-degenerate strongly non-equilibrium plasmas. The initial non-exponential stage, its duration and the subsequent exponential stage of the relaxation process are studied for a wide range of ion charge, nonideality parameter and ion mass. A simulation model of the nonideal plasma excited by an electron beam is proposed. An approach is developed to calculate the dynamic structure factor in non-stationary conditions. Instability increment is obtained from MD simulations

  11. Energy flow in non-equilibrium conformal field theory

    Science.gov (United States)

    Bernard, Denis; Doyon, Benjamin

    2012-09-01

    We study the energy current and its fluctuations in quantum gapless 1d systems far from equilibrium modeled by conformal field theory, where two separated halves are prepared at distinct temperatures and glued together at a point contact. We prove that these systems converge towards steady states, and give a general description of such non-equilibrium steady states in terms of quantum field theory data. We compute the large deviation function, also called the full counting statistics, of energy transfer through the contact. These are universal and satisfy fluctuation relations. We provide a simple representation of these quantum fluctuations in terms of classical Poisson processes whose intensities are proportional to Boltzmann weights.

  12. Non-equilibrium statistical thermodynamics of neutron gas in reactor

    International Nuclear Information System (INIS)

    Hayasaka, Hideo

    1977-01-01

    The thermodynamic structures of non-equilibrium steady states of highly rarefied neutron gas in various media are considered for the irreversible processes owing to creative and destructive reactions of neutrons with nuclei of these media and supply from the external sources. Under the so-called clean and cold condition in reactor, the medium is regarded virtually as offering the different chemical potential fields for each subsystem of a steady neutron gas system. The fluctuations around a steady state are considered in a Markovian-Gaussian process. The generalized Einstein relations are derived for stationary neutron gas systems. The forces and flows of neutron gases in a medium are defined upon the general stationary solution of the Fokker-Planck equation. There exist the symmetry of the kinetic coefficients, and the minimum entropy production upon neutron-nuclear reactions. The distribution functions in various media are determined by each corresponding extremum condition under the vanishing of changes of the respective total entropies in the Gibbs equation. (auth.)

  13. Physics of far-from-equilibrium systems and self-organization

    International Nuclear Information System (INIS)

    Nicolis, G.

    1993-01-01

    The status of self-organization phenomena from the stand point of the physical sciences are analyzed. Non linear dynamics and the presence of constraints maintaining the system far from equilibrium are shown to be the basic mechanism involved in the emergence of these phenomena. Some particularly representative experiments are first presented: thermal conversion, chemical reactions (Benard problem), biological systems, and their explanation through order, disorder, non-linearity, irreversibility, stability, bifurcation, symmetry breaking, etc., concepts. Then it is shown how the self-organization paradigm allows to model problems outside the traditional realm of the physical sciences. 29 figs., 27 refs

  14. Aerospace Applications of Non-Equilibrium Plasma

    Science.gov (United States)

    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.).

  15. Non-equilibrium versus equilibrium emission of complex fragments from hot nuclei

    International Nuclear Information System (INIS)

    Viola, V.E.; Kwiatkowski, K.; Yennello, S.; Fields, D.E.

    1989-01-01

    The relative contributions of equilibrium and non-equilibrium mechanisms for intermediate-mass fragment emission have been deduced for Z=3-14 fragments formed in 3 He- and 14 N-induced reactions on Ag and Au targets. Complete inclusive excitation function measurements have been performed for 3 He projectiles from E/A=67 to 1,200 MeV and for 14 N from E/A=20 to 50 MeV. The data are consistent with a picture in which equilibrated emission is important at the lowest energies, but with increasing bombarding energy the cross sections are increasingly dominated by non-equilibrium processes. Non-equilibrium emission is also shown to be favored for light fragments relative to heavy fragments. These results are supported by coincidence studies of intermediate-mass fragments tagged by linear momentum transfer measurements

  16. Non-equilibrium thermodynamical description of rhythmic motion patterns of active systems: a canonical-dissipative approach.

    Science.gov (United States)

    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.

  17. 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

  18. Equilibrium statistical mechanics for self-gravitating systems: local ergodicity and extended Boltzmann-Gibbs/White-Narayan statistics

    Science.gov (United States)

    He, Ping

    2012-01-01

    The long-standing puzzle surrounding the statistical mechanics of self-gravitating systems has not yet been solved successfully. We formulate a systematic theoretical framework of entropy-based statistical mechanics for spherically symmetric collisionless self-gravitating systems. We use an approach that is very different from that of the conventional statistical mechanics of short-range interaction systems. We demonstrate that the equilibrium states of self-gravitating systems consist of both mechanical and statistical equilibria, with the former characterized by a series of velocity-moment equations and the latter by statistical equilibrium equations, which should be derived from the entropy principle. The velocity-moment equations of all orders are derived from the steady-state collisionless Boltzmann equation. We point out that the ergodicity is invalid for the whole self-gravitating system, but it can be re-established locally. Based on the local ergodicity, using Fermi-Dirac-like statistics, with the non-degenerate condition and the spatial independence of the local microstates, we rederive the Boltzmann-Gibbs entropy. This is consistent with the validity of the collisionless Boltzmann equation, and should be the correct entropy form for collisionless self-gravitating systems. Apart from the usual constraints of mass and energy conservation, we demonstrate that the series of moment or virialization equations must be included as additional constraints on the entropy functional when performing the variational calculus; this is an extension to the original prescription by White & Narayan. Any possible velocity distribution can be produced by the statistical-mechanical approach that we have developed with the extended Boltzmann-Gibbs/White-Narayan statistics. Finally, we discuss the questions of negative specific heat and ensemble inequivalence for self-gravitating systems.

  19. From statistic mechanic outside equilibrium to transport equations

    International Nuclear Information System (INIS)

    Balian, R.

    1995-01-01

    This lecture notes give a synthetic view on the foundations of non-equilibrium statistical mechanics. The purpose is to establish the transport equations satisfied by the relevant variables, starting from the microscopic dynamics. The Liouville representation is introduced, and a projection associates with any density operator , for given choice of relevant observables, a reduced density operator. An exact integral-differential equation for the relevant variables is thereby derived. A short-memory approximation then yields the transport equations. A relevant entropy which characterizes the coarseness of the description is associated with each level of description. As an illustration, the classical gas, with its three levels of description and with the Chapman-Enskog method, is discussed. (author). 3 figs., 5 refs

  20. Non-Extensive Statistical Analysis of Magnetic Field and SEPs during the March 2012 ICME event, using a multi-spacecraft approach

    Science.gov (United States)

    Pavlos, George; Malandraki, Olga; Pavlos, Evgenios; Iliopoulos, Aggelos; Karakatsanis, Leonidas

    2017-04-01

    -entropy principle can explain the emergence of a series of new and significant physical characteristics in distributed systems as well as in space plasmas. Such characteristics are: non-Gaussian statistics and anomalous diffusion processes, strange and fractional dynamics, multifractal, percolating and intermittent turbulence structures, multiscale and long spatio-temporal correlations, fractional acceleration and Non-Equilibrium Stationary States (NESS) or non-equilibrium self-organization process and non-equilibrium phase transition and topological phase transition processes according to Zelenyi and Milovanov (2004). In this direction, our results reveal clearly strong self-organization and development of macroscopic ordering of plasma system related to strengthen of non-extensivity, multifractality and intermittency everywhere in the space plasmas region during the CME event. Acknowledgements: This project has received funding form the European Union's Horizon 2020 research and innovation program under grant agreement No 637324.

  1. New exponential, logarithm and q-probability in the non-extensive statistical physics

    OpenAIRE

    Chung, Won Sang

    2013-01-01

    In this paper, a new exponential and logarithm related to the non-extensive statistical physics is proposed by using the q-sum and q-product which satisfy the distributivity. And we discuss the q-mapping from an ordinary probability to q-probability. The q-entropy defined by the idea of q-probability is shown to be q-additive.

  2. Critical dynamics a field theory approach to equilibrium and non-equilibrium scaling behavior

    CERN Document Server

    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...

  3. Isospin equilibrium and non-equilibrium in heavy-ion collisions at intermediate energies

    International Nuclear Information System (INIS)

    Chen Liewen; Ge Lingxiao; Zhang Xiaodong; Zhang Fengshou

    1997-01-01

    The equilibrium and non-equilibrium of the isospin degree of freedom are studied in terms of an isospin-dependent QMD model, which includes isospin-dependent symmetry energy, Coulomb energy, N-N cross sections and Pauli blocking. It is shown that there exists a transition from the isospin equilibrium to non-equilibrium as the incident energy from below to above a threshold energy in central, asymmetric heavy-ion collisions. Meanwhile, it is found that the phenomenon results from the co-existence and competition of different reaction mechanisms, namely, the isospin degree of freedom reaches an equilibrium if the incomplete fusion (ICF) component is dominant and does not reach equilibrium if the fragmentation component is dominant. Moreover, it is also found that the isospin-dependent N-N cross sections and symmetry energy are crucial for the equilibrium of the isospin degree of freedom in heavy-ion collisions around the Fermi energy. (author)

  4. Planar-channeling spatial density under statistical equilibrium

    International Nuclear Information System (INIS)

    Ellison, J.A.; Picraux, S.T.

    1978-01-01

    The phase-space density for planar channeled particles has been derived for the continuum model under statistical equilibrium. This is used to obtain the particle spatial probability density as a function of incident angle. The spatial density is shown to depend on only two parameters, a normalized incident angle and a normalized planar spacing. This normalization is used to obtain, by numerical calculation, a set of universal curves for the spatial density and also for the channeled-particle wavelength as a function of amplitude. Using these universal curves, the statistical-equilibrium spatial density and the channeled-particle wavelength can be easily obtained for any case for which the continuum model can be applied. Also, a new one-parameter analytic approximation to the spatial density is developed. This parabolic approximation is shown to give excellent agreement with the exact calculations

  5. Extended irreversible thermodynamics and non-equilibrium temperature

    Directory of Open Access Journals (Sweden)

    Casas-Vazquez, Jose'

    2008-02-01

    Full Text Available We briefly review the concept of non-equilibrium temperature from the perspectives of extended irreversible thermodynamics, fluctuation theory, and statistical mechanics. The relations between different proposals are explicitly examined in two especially simple systems: an ideal gas in steady shear flow and a forced harmonic oscillator in a thermal bath. We examine with special detail temperatures related to the average molecular kinetic energy along different spatial directions, to the average configurational energy, to the derivative of the entropy with respect to internal energy, to fluctuation-dissipation relation and discuss their measurement.

  6. Discussions on the non-equilibrium effects in the quantitative phase field model of binary alloys

    International Nuclear Information System (INIS)

    Zhi-Jun, Wang; Jin-Cheng, Wang; Gen-Cang, Yang

    2010-01-01

    All the quantitative phase field models try to get rid of the artificial factors of solutal drag, interface diffusion and interface stretch in the diffuse interface. These artificial non-equilibrium effects due to the introducing of diffuse interface are analysed based on the thermodynamic status across the diffuse interface in the quantitative phase field model of binary alloys. Results indicate that the non-equilibrium effects are related to the negative driving force in the local region of solid side across the diffuse interface. The negative driving force results from the fact that the phase field model is derived from equilibrium condition but used to simulate the non-equilibrium solidification process. The interface thickness dependence of the non-equilibrium effects and its restriction on the large scale simulation are also discussed. (cross-disciplinary physics and related areas of science and technology)

  7. Many-body current formula and current conservation for non-equilibrium fully interacting nanojunctions

    International Nuclear Information System (INIS)

    Ness, H; Dash, L K

    2012-01-01

    We consider the electron transport properties through fully interacting nanoscale junctions beyond the linear-response regime. We calculate the current flowing through an interacting region connected to two interacting leads, with interaction crossing at the left and right contacts, by using a non-equilibrium Green function technique. The total current at one interface (the left one for example) is made of several terms which can be regrouped into two sets. The first set corresponds to a very generalized Landauer-like current formula with physical quantities defined only in the interacting central region and with renormalized lead self-energies. The second set characterizes inelastic scattering events occurring in the left lead. We show how this term can be negligible or even vanish due to the pseudo-equilibrium statistical properties of the lead in the thermodynamic limit. The expressions for the different Green functions needed for practical calculations of the current are also provided. We determine the constraints imposed by the physical condition of current conservation. The corresponding equation imposed on the different self-energy quantities arising from the current conservation is derived. We discuss in detail its physical interpretation and its relation with previously derived expressions. Finally several important key features are discussed in relation to the implementation of our formalism for calculations of quantum transport in realistic systems. (paper)

  8. 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.

  9. Non-dissipative effects in nonequilibrium systems

    CERN Document Server

    Maes, Christian

    2018-01-01

    This book introduces and discusses both the fundamental aspects and the measurability of applications of time-symmetric kinetic quantities, outlining the features that constitute the non-dissipative branch of non-equilibrium physics. These specific features of non-equilibrium dynamics have largely been ignored in standard statistical mechanics texts. This introductory-level book offers novel material that does not take the traditional line of extending standard thermodynamics to the irreversible domain. It shows that although stationary dissipation is essentially equivalent with steady non-equilibrium and ubiquitous in complex phenomena, non-equilibrium is not determined solely by the time-antisymmetric sector of energy-entropy considerations. While this should not be very surprising, this book provides timely, simple reminders of the role of time-symmetric and kinetic aspects in the construction of non-equilibrium statistical mechanics.

  10. Non-equilibrium modelling of distillation

    NARCIS (Netherlands)

    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

  11. Statistical mechanics of driven diffusive systems

    CERN Document Server

    Schmittmann, B

    1995-01-01

    Far-from-equilibrium phenomena, while abundant in nature, are not nearly as well understood as their equilibrium counterparts. On the theoretical side, progress is slowed by the lack of a simple framework, such as the Boltzmann-Gbbs paradigm in the case of equilibrium thermodynamics. On the experimental side, the enormous structural complexity of real systems poses serious obstacles to comprehension. Similar difficulties have been overcome in equilibrium statistical mechanics by focusing on model systems. Even if they seem too simplistic for known physical systems, models give us considerable insight, provided they capture the essential physics. They serve as important theoretical testing grounds where the relationship between the generic physical behavior and the key ingredients of a successful theory can be identified and understood in detail. Within the vast realm of non-equilibrium physics, driven diffusive systems form a subset with particularly interesting properties. As a prototype model for these syst...

  12. Statistical approach to partial equilibrium analysis

    Science.gov (United States)

    Wang, Yougui; Stanley, H. E.

    2009-04-01

    A statistical approach to market equilibrium and efficiency analysis is proposed in this paper. One factor that governs the exchange decisions of traders in a market, named willingness price, is highlighted and constitutes the whole theory. The supply and demand functions are formulated as the distributions of corresponding willing exchange over the willingness price. The laws of supply and demand can be derived directly from these distributions. The characteristics of excess demand function are analyzed and the necessary conditions for the existence and uniqueness of equilibrium point of the market are specified. The rationing rates of buyers and sellers are introduced to describe the ratio of realized exchange to willing exchange, and their dependence on the market price is studied in the cases of shortage and surplus. The realized market surplus, which is the criterion of market efficiency, can be written as a function of the distributions of willing exchange and the rationing rates. With this approach we can strictly prove that a market is efficient in the state of equilibrium.

  13. Exploring Chemical and Thermal Non-equilibrium in Nitrogen Arcs

    International Nuclear Information System (INIS)

    Ghorui, S; Das, A K

    2012-01-01

    Plasma torches operating with nitrogen are of special importance as they can operate with usual tungsten based refractory electrodes and offer radical rich non-oxidizing high temperature environment for plasma chemistry. Strong gradients in temperature as well as species densities and huge convective fluxes lead to varying degrees of chemical non-equilibrium in associated regions. An axi-symmetric two-temperature chemical non-equilibrium model of a nitrogen plasma torch has been developed to understand the effects of thermal and chemical non-equilibrium in arcs. A 2-D finite volume CFD code in association with a non-equilibrium property routine enabled extraction of steady state self-consistent distributions of various plasma quantities inside the torch under various thermal and chemical non-equilibrium conditions. Chemical non-equilibrium has been incorporated through computation of diffusive and convective fluxes in each finite volume cell in every iteration and associating corresponding thermodynamic and transport properties through the scheme of 'chemical non-equilibrium parameter' introduced by Ghorui et. al. Recombination coefficient data from Nahar et. al. and radiation data from Krey and Morris have been used in the simulation. Results are presented for distributions of temperature, pressure, velocity, current density, electric potential, species densities and chemical non-equilibrium effects. Obtained results are compared with similar results under LTE.

  14. Composition and partition functions of partially ionized hydrogen plasma in Non-Local Thermal Equilibrium (Non-LThE) and Non-Local Chemical Equilibrium (Non-LChE)

    International Nuclear Information System (INIS)

    Chen Kuan; Eddy, T.L.

    1993-01-01

    A GTME (Generalized MultiThermodynamic Equilibrium) plasma model is developed for plasmas in both Non-LThE (Non-Local Thermal Equilibrium) and Non-LChE (Non-Local Chemical Equilibrium). The model uses multitemperatures for thermal nonequilibrium and non-zero chemical affinities as a measure of the deviation from chemical equilibrium. The plasma is treated as an ideal gas with the Debye-Hueckel approximation employed for pressure correction. The proration method is used when the cutoff energy level is between two discrete levels. The composition and internal partition functions of a hydrogen plasma are presented for electron temperatures ranging from 5000 to 35000 K and pressures from 0.1 to 1000 kPa. Number densities of 7 different species of hydrogen plasma and internal partition functions of different energy modes (rotational, vibrational, and electronic excitation) are computed for three affinity values. The results differ from other plasma properties in that they 1) are not based on equilibrium properties; and 2) are expressed as a function of different energy distribution parameters (temperatures) within each energy mode of each species as appropriate. The computed number densities and partition functions are applicable to calculating the thermodynamic, transport, and radiation properties of a hydrogen plasma not in thermal and chemical equilibria. The nonequilibrium plasma model and plasma compositions presented in this paper are very useful to the diagnosis of high-speed and/or low-pressure plasma flows in which the assumptions of local thermal and chemical equilibrium are invalid. (orig.)

  15. Small angle neutron scattering (SANS) under non-equilibrium conditions

    International Nuclear Information System (INIS)

    Oberthur, R.C.

    1984-01-01

    The use of small angle neutron scattering (SANS) for the study of systems under non-equilibrium conditions is illustrated by three types of experiments in the field of polymer research: - the relaxation of a system from an initial non-equilibrium state towards equilibrium, - the cyclic or repetitive installation of a series of non-equilibrium states in a system, - the steady non-equilibrium state maintained by a constant dissipation of energy within the system. Characteristic times obtained in these experiments with SANS are compared with the times obtained from quasi-elastic neutron and light scattering, which yield information about the equilibrium dynamics of the system. The limits of SANS applied to non-equilibrium systems for the measurement of relaxation times at different length scales are shown and compared to the limits of quasielastic neutron and light scattering

  16. Achieving Radiation Tolerance through Non-Equilibrium Grain Boundary Structures.

    Science.gov (United States)

    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.

  17. The non-equilibrium nature of culinary evolution

    Science.gov (United States)

    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.

  18. Non-equilibrium QCD of high-energy multi-gluon dynamics

    International Nuclear Information System (INIS)

    Geiger, K.

    1996-01-01

    A non-equilibrium QCD description of multiparticle dynamics in space-time is of both fundamental and phenomenological interest. Here the authors discusses an attempt to derive from first principles, a real-time formalism to study the dynamical interplay of quantum and statistical-kinetic properties of non-equilibrium multi-parton systems produced in high-energy QCD processes. The ultimate goal (from which one is still far away) is to have a practically applicable description of the space-time evolution of a general initial system of gluons and quarks, characterized by some large energy or momentum scale, that expands, diffuses and dissipates according to the self- and mutual-interactions, and eventually converts dynamically into final state hadrons. For example, the evolution of parton showers in the mechanism of parton-hadron conversion in high-energy hadronic collisions, or, the description of formation, evolution and freezeout of a quark-gluon plasma, in ultra-relativistic heavy-ion collisions

  19. Brownian quasi-particles in statistical physics

    International Nuclear Information System (INIS)

    Tellez-Arenas, A.; Fronteau, J.; Combis, P.

    1979-01-01

    The idea of a Brownian quasi-particle and the associated differentiable flow (with nonselfadjoint forces) are used here in the context of a stochastic description of the approach towards statistical equilibrium. We show that this quasi-particle flow acquires, at equilibrium, the principal properties of a conservative Hamiltonian flow. Thus the model of Brownian quasi-particles permits us to establish a link between the stochastic description and the Gibbs description of statistical equilibrium

  20. Two-proton correlation functions for equilibrium and non-equilibrium emission

    International Nuclear Information System (INIS)

    Gong, W.G.; Gelbke, C.K.; Carlin, N.; De Souza, R.T.; Kim, Y.D.; Lynch, W.G.; Murakami, T.; Poggi, G.; Sanderson, D.; Tsang, M.B.; Xu, H.M.; Michigan State Univ., East Lansing; Fields, D.E.; Kwiatkowski, K.; Planeta, R.; Viola, V.E. Jr.; Yennello, S.J.; Indiana Univ., Bloomington; Indiana Univ., Bloomington; Pratt, S.

    1990-01-01

    Two-proton correlation functions are compared for equilibrium and non-equilibrium emission processes investigated, respectively, in ''reverse kinematics'' for the reactions 129 Xe+ 27 Al and 129 Xe+ 122 Sn at E/A=31 MeV and in ''forward kinematics'' for the reaction 14 N+ 197 Au at E/A=75 MeV. Observed differences in the shapes of the correlation functions are understood in terms of the different time scales for equilibrium and preequilibrium emission. Transverse and longitudinal correlation functions are very similar. (orig.)

  1. Equilibrium and non equilibrium in fragmentation

    International Nuclear Information System (INIS)

    Dorso, C.O.; Chernomoretz, A.; Lopez, J.A.

    2001-01-01

    Full text: In this communication we present recent results regarding the interplay of equilibrium and non equilibrium in the process of fragmentation of excited finite Lennard Jones drops. Because the general features of such a potential resemble the ones of the nuclear interaction (fact that is reinforced by the similarity between the EOS of both systems) these studies are not only relevant from a fundamental point of view but also shed light on the problem of nuclear multifragmentation. We focus on the microscopic analysis of the state of the fragmenting system at fragmentation time. We show that the Caloric Curve (i e. the functional relationship between the temperature of the system and the excitation energy) is of the type rise plateau with no vapor branch. The usual rise plateau rise pattern is only recovered when equilibrium is artificially imposed. This result puts a serious question on the validity of the freeze out hypothesis. This feature is independent of the dimensionality or excitation mechanism. Moreover we explore the behavior of magnitudes which can help us determine the degree of the assumed phase transition. It is found that no clear cut criteria is presently available. (Author)

  2. Molecular-dynamics study of propane-hydrate dissociation: Fluctuation-dissipation and non-equilibrium analysis.

    Science.gov (United States)

    Ghaani, Mohammad Reza; English, Niall J

    2018-03-21

    Equilibrium and non-equilibrium molecular-dynamics (MD) simulations have been performed to investigate thermal-driven break-up of planar propane-hydrate interfaces in contact with liquid water over the 260-320 K range. Two types of hydrate-surface water-lattice molecular termination were adopted, at the hydrate edge with water, for comparison: a 001-direct surface cleavage and one with completed cages. Statistically significant differences in melting temperatures and initial break-up rates were observed between both interface types. Dissociation rates were observed to be strongly dependent on temperature, with higher rates at larger over-temperatures vis-à-vis melting. A simple coupled mass and heat transfer model, developed previously, was applied to fit the observed dissociation profiles, and this helps us to identify clearly two distinct hydrate-decomposition régimes; following a highly temperature-dependent break-up phase, a second well-defined stage is essentially independent of temperature, in which the remaining nanoscale, de facto two-dimensional system's lattice framework is intrinsically unstable. Further equilibrium MD-analysis of the two-phase systems at their melting point, with consideration of the relaxation times gleaned from the auto-correlation functions of fluctuations in a number of enclathrated guest molecules, led to statistically significant differences between the two surface-termination cases; a consistent correlation emerged in both cases between the underlying, non-equilibrium, thermal-driven dissociation rates sampled directly from melting with that from an equilibrium-MD fluctuation-dissipation approach.

  3. Nonequilibrium statistical physics a modern perspective

    CERN Document Server

    Livi, Roberto

    2017-01-01

    Statistical mechanics has been proven to be successful at describing physical systems at thermodynamic equilibrium. Since most natural phenomena occur in nonequilibrium conditions, the present challenge is to find suitable physical approaches for such conditions: this book provides a pedagogical pathway that explores various perspectives. The use of clear language, and explanatory figures and diagrams to describe models, simulations and experimental findings makes the book a valuable resource for undergraduate and graduate students, and also for lecturers organizing teaching at varying levels of experience in the field. Written in three parts, it covers basic and traditional concepts of nonequilibrium physics, modern aspects concerning nonequilibrium phase transitions, and application-orientated topics from a modern perspective. A broad range of topics is covered, including Langevin equations, Levy processes, directed percolation, kinetic roughening and pattern formation.

  4. Basics of statistical physics

    CERN Document Server

    Müller-Kirsten, Harald J W

    2013-01-01

    Statistics links microscopic and macroscopic phenomena, and requires for this reason a large number of microscopic elements like atoms. The results are values of maximum probability or of averaging. This introduction to statistical physics concentrates on the basic principles, and attempts to explain these in simple terms supplemented by numerous examples. These basic principles include the difference between classical and quantum statistics, a priori probabilities as related to degeneracies, the vital aspect of indistinguishability as compared with distinguishability in classical physics, the differences between conserved and non-conserved elements, the different ways of counting arrangements in the three statistics (Maxwell-Boltzmann, Fermi-Dirac, Bose-Einstein), the difference between maximization of the number of arrangements of elements, and averaging in the Darwin-Fowler method. Significant applications to solids, radiation and electrons in metals are treated in separate chapters, as well as Bose-Eins...

  5. Worldwide seismicity in view of non-extensive statistical physics

    Science.gov (United States)

    Chochlaki, Kaliopi; Vallianatos, Filippos; Michas, George

    2014-05-01

    In the present work we study the distribution of worldwide shallow seismic events occurred from 1981 to 2011 extracted from the CMT catalog, with magnitude equal or greater than Mw 5.0. Our analysis based on the subdivision of the Earth surface into seismic zones that are homogeneous with regards to seismic activity and orientation of the predominant stress field. To this direction we use the Flinn-Engdahl regionalization (Flinn and Engdahl, 1965), which consists of 50 seismic zones as modified by Lombardi and Marzocchi (2007), where grouped the 50 FE zones into larger tectonically homogeneous ones, utilizing the cumulative moment tensor method. As a result Lombardi and Marzocchi (2007), limit the initial 50 regions to 39 ones, in which we apply the non- extensive statistical physics approach. The non-extensive statistical physics seems to be the most adequate and promising methodological tool for analyzing complex systems, such as the Earth's interior. In this frame, we introduce the q-exponential formulation as the expression of probability distribution function that maximizes the Sq entropy as defined by Tsallis, (1988). In the present work we analyze the interevent time distribution between successive earthquakes by a q-exponential function in each of the seismic zones defined by Lombardi and Marzocchi (2007).confirming the importance of long-range interactions and the existence of a power-law approximation in the distribution of the interevent times. Our findings supports the ideas of universality within the Tsallis approach to describe Earth's seismicity and present strong evidence on temporal clustering of seismic activity in each of the tectonic zones analyzed. Our analysis as applied in worldwide seismicity with magnitude equal or greater than Mw 5.5 and 6.) is presented and the dependence of our result on the cut-off magnitude is discussed. This research has been funded by the European Union (European Social Fund) and Greek national resources under the

  6. Homogeneous non-equilibrium two-phase critical flow model

    International Nuclear Information System (INIS)

    Schroeder, J.J.; Vuxuan, N.

    1987-01-01

    An important aspect of nuclear and chemical reactor safety is the ability to predict the maximum or critical mass flow rate from a break or leak in a pipe system. At the beginning of such a blowdown, if the stagnation condition of the fluid is subcooled or slightly saturated thermodynamic non-equilibrium exists in the downstream, e.g. the fluid becomes superheated to a degree determined by the liquid pressure. A simplified non-equilibrium model, explained in this report, is valid for rapidly decreasing pressure along the flow path. It presumes that fluid has to be superheated by an amount governed by physical principles before it starts to flash into steam. The flow is assumed to be homogeneous, i.e. the steam and liquid velocities are equal. An adiabatic flow calculation mode (Fanno lines) is employed to evaluate the critical flow rate for long pipes. The model is found to satisfactorily describe critical flow tests. Good agreement is obtained with the large scale Marviken tests as well as with small scale experiments. (orig.)

  7. Transition from equilibrium ignition to non-equilibrium burn for ICF capsules surrounded by a high-Z pusher

    International Nuclear Information System (INIS)

    Li, Ji W.; Chang, Lei; Li, Yun S.; Li, Jing H.

    2011-01-01

    For the ICF capsule surrounded by a high-Z pusher which traps the radiation and confines the hot fuel, the fuel will first be ignited in thermal equilibrium with radiation at a much lower temperature than hot-spot ignition, which is also the low temperature ignition. Because of the lower areal density for ICF capsules, the equilibrium ignition must be developed into a non-equilibrium burn to shorten the reaction time and lower the drive energy. In this paper, the transition from the equilibrium ignition to non-equilibrium burn is discussed and the energy deposited by α particles required for the equilibrium ignition and non-equilibrium burn to occur is estimated.

  8. Molecular dynamics study of CO2 hydrate dissociation: Fluctuation-dissipation and non-equilibrium analysis.

    Science.gov (United States)

    English, Niall J; Clarke, Elaine T

    2013-09-07

    Equilibrium and non-equilibrium molecular dynamics (MD) simulations have been performed to investigate thermal-driven break-up of planar CO2 hydrate interfaces in liquid water at 300-320 K. Different guest compositions, at 85%, 95%, and 100% of maximum theoretical occupation, led to statistically-significant differences in the observed initial dissociation rates. The melting temperatures of each interface were estimated, and dissociation rates were observed to be strongly dependent on temperature, with higher dissociation rates at larger over-temperatures vis-à-vis melting. A simple coupled mass and heat transfer model developed previously was applied to fit the observed dissociation profiles, and this helps to identify clearly two distinct régimes of break-up; a second well-defined region is essentially independent of composition and temperature, in which the remaining nanoscale, de facto two-dimensional system's lattice framework is intrinsically unstable. From equilibrium MD of the two-phase systems at their melting point, the relaxation times of the auto-correlation functions of fluctuations in number of enclathrated guest molecules were used as a basis for comparison of the variation in the underlying, non-equilibrium, thermal-driven dissociation rates via Onsager's hypothesis, and statistically significant differences were found, confirming the value of a fluctuation-dissipation approach in this case.

  9. Isotope effects in the equilibrium and non-equilibrium vaporization of tritiated water and ice

    International Nuclear Information System (INIS)

    Baumgaertner, F.; Kim, M.-A.

    1990-01-01

    The vaporization isotope effect of the HTO/H 2 O system has been measured at various temperatures and pressures under equilibrium as well as non-equilibrium conditions. The isotope effect values measured in equilibrium sublimation or distillation are in good agreement with the theoretical values based on the harmonic oscillator model. In non-equilibrium vaporization at low temperatures ( 0 C), the isotope effect decreases rapidly with decreasing system pressure and becomes negligible when the system pressure is lowered more than one tenth of the equilibrium vapor pressure. At higher temperatures, the isotope effect decreases very slowly with decreasing system pressure. Discussion is extended for the application of the present results to the study of biological enrichment of tritium. (author)

  10. Non-equilibrium transport in the quantum dot: quench dynamics and non-equilibrium steady state

    Science.gov (United States)

    Culver, Adrian; Andrei, Natan

    We present an exact method of calculating the non-equilibrium current driven by a voltage drop across a quantum dot. The system is described by the two lead Anderson model at zero temperature with on-site Coulomb repulsion and non-interacting, linearized leads. We prepare the system in an initial state consisting of a free Fermi sea in each lead with the voltage drop given as the difference between the two Fermi levels. We quench the system by coupling the dot to the leads at t = 0 and following the time evolution of the wavefunction. In the long time limit a new type of Bethe Ansatz wavefunction emerges, which satisfies the Lippmann-Schwinger equation with the two Fermi seas serving as the boundary conditions. This exact, non-perturbative solution describes the non-equilibrium steady state of the system. We describe how to use this solution to compute the infinite time limit of the expectation value of the current operator at a given voltage, which would yield the I-V characteristic of the dot. Research supported by NSF Grant DMR 1410583.

  11. Non-equilibrium physics at a holographic chiral phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Nick; Kim, Keun-young [Southampton Univ. (United Kingdom). School of Physics and Astronomy; Kavli Institute for Theoretical Physics China, Beijing (China); Kalaydzhyan, Tigran; Kirsch, Ingo [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-11-15

    The D3/D7 system holographically describes an N=2 gauge theory which spontaneously breaks a chiral symmetry by the formation of a quark condensate in the presence of a magnetic field. At finite temperature it displays a first order phase transition. We study out of equilibrium dynamics associated with this transition by placing probe D7 branes in a geometry describing a boost-invariant expanding or contracting plasma. We use an adiabatic approximation to track the evolution of the quark condensate in a heated system and reproduce the phase structure expected from equilibrium dynamics. We then study solutions of the full partial differential equation that describes the evolution of out of equilibrium configurations to provide a complete description of the phase transition including describing aspects of bubble formation. (orig.)

  12. Paths to equilibrium in non-conformal collisions

    Directory of Open Access Journals (Sweden)

    Attems Maximilian

    2018-01-01

    Full Text Available Ever since fast hydrodynamization has been observed in heavy ion collisions the understanding of the hot early out-of-equilibrium stage of such collisions has been a topic of intense research. We use the gauge/gravity duality to model the creation of a strongly coupled Quark-Gluon plasma in a non-conformal gauge theory. This numerical relativity study is the first non-conformal holographic simulation of a heavy ion collision and reveals the existence of new relaxation channels due to the presence of non-vanishing bulk viscosity. We study shock wave collisions at different energies in gauge theories with different degrees of non-conformality and compare three relaxation times which can occur in different orderings: the hydrodynamization time (when hydrodynamics becomes applicable, the EoSization time (when the average pressure approaches its equilibrium value and the condensate relaxation time (when the expectation value of a scalar operator approaches its equilibrium value. We find that these processes can occur in several different orderings. In particular, the condensate can remain far from equilibrium even long after the plasma has hydrodynamized and EoSized.

  13. Non-equilibrium effects upon the non-Markovian Caldeira-Leggett quantum master equation

    International Nuclear Information System (INIS)

    Bolivar, A.O.

    2011-01-01

    Highlights: → Classical Brownian motion described by a non-Markovian Fokker-Planck equation. → Quantization process. → Quantum Brownian motion described by a non-Markovian Caldeira-Leggett equation. → A non-equilibrium quantum thermal force is predicted. - Abstract: We obtain a non-Markovian quantum master equation directly from the quantization of a non-Markovian Fokker-Planck equation describing the Brownian motion of a particle immersed in a generic environment (e.g. a non-thermal fluid). As far as the especial case of a heat bath comprising of quantum harmonic oscillators is concerned, we derive a non-Markovian Caldeira-Leggett master equation on the basis of which we work out the concept of non-equilibrium quantum thermal force exerted by the harmonic heat bath upon the Brownian motion of a free particle. The classical limit (or dequantization process) of this sort of non-equilibrium quantum effect is scrutinized, as well.

  14. Non-equilibrium solid-to-plasma transition dynamics using XANES diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Dorchies, F., E-mail: dorchies@celia.u-bordeaux1.fr [Univ. Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33400 Talence (France); Recoules, V. [CEA-DAM-DIF, F-91297 Arpajon (France)

    2016-10-31

    The advent of femtosecond lasers has shed new light on non-equilibrium high energy density physics. The ultrafast energy absorption by electrons and the finite rate of their energy transfer to the lattice creates non-equilibrium states of matter, triggering a new class of non-thermal processes from the ambient solid up to extreme conditions of temperature and pressure, referred as the warm dense matter regime. The dynamical interplay between electron and atomic structures is the key issue that drives the ultrafast phase transitions dynamics. Bond weakening or bond hardening are predicted, but strongly depends on the material considered. Many studies have been conducted but this physics is still poorly understood. The experimental tools used up-to-now have provided an incomplete insight. Pure optical techniques measure only indirectly atomic motion through changes in the dielectric function whereas X-ray or electron diffraction only probes the average long-range order. This review is dedicated to recent developments in time-resolved X-ray absorption near-edge spectroscopy, which is expected to give a more complete picture by probing simultaneously the modifications of the near-continuum electron and local atomic structures. Results are reported for three different types of metals (simple, transition and noble metals) in which a confrontation has been carried out between measurements and ab initio simulations.

  15. Non-equilibrium hydrogen ionization in 2D simulations of the solar atmosphere

    Science.gov (United States)

    Leenaarts, J.; Carlsson, M.; Hansteen, V.; Rutten, R. J.

    2007-10-01

    Context: The ionization of hydrogen in the solar chromosphere and transition region does not obey LTE or instantaneous statistical equilibrium because the timescale is long compared with important hydrodynamical timescales, especially of magneto-acoustic shocks. Since the pressure, temperature, and electron density depend sensitively on hydrogen ionization, numerical simulation of the solar atmosphere requires non-equilibrium treatment of all pertinent hydrogen transitions. The same holds for any diagnostic application employing hydrogen lines. Aims: To demonstrate the importance and to quantify the effects of non-equilibrium hydrogen ionization, both on the dynamical structure of the solar atmosphere and on hydrogen line formation, in particular Hα. Methods: We implement an algorithm to compute non-equilibrium hydrogen ionization and its coupling into the MHD equations within an existing radiation MHD code, and perform a two-dimensional simulation of the solar atmosphere from the convection zone to the corona. Results: Analysis of the simulation results and comparison to a companion simulation assuming LTE shows that: a) non-equilibrium computation delivers much smaller variations of the chromospheric hydrogen ionization than for LTE. The ionization is smaller within shocks but subsequently remains high in the cool intershock phases. As a result, the chromospheric temperature variations are much larger than for LTE because in non-equilibrium, hydrogen ionization is a less effective internal energy buffer. The actual shock temperatures are therefore higher and the intershock temperatures lower. b) The chromospheric populations of the hydrogen n = 2 level, which governs the opacity of Hα, are coupled to the ion populations. They are set by the high temperature in shocks and subsequently remain high in the cool intershock phases. c) The temperature structure and the hydrogen level populations differ much between the chromosphere above photospheric magnetic elements

  16. Non-equilibrium phase transitions in complex plasma

    International Nuclear Information System (INIS)

    Suetterlin, K R; Raeth, C; Ivlev, A V; Thomas, H M; Khrapak, S; Zhdanov, S; Rubin-Zuzic, M; Morfill, G E; Wysocki, A; Loewen, H; Goedheer, W J; Fortov, V E; Lipaev, A M; Molotkov, V I; Petrov, O F

    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 separation. Using the permanent microgravity laboratory PK-3 Plus, operating onboard the International Space Station, we performed unique experiments with binary mixtures of complex plasmas that showed both lane formation and phase separation. These observations have been augmented by comprehensive numerical and theoretical studies. In this paper we present an overview of our most important results. In addition we put our results in context with research of complex plasmas, binary systems and non-equilibrium phase transitions. Necessary and promising future complex plasma experiments on phase separation and lane formation are briefly discussed.

  17. Towards the unified non-classical physics: account for quantum fluctuations in equilibrium thermodynamics via the effective temperature

    Directory of Open Access Journals (Sweden)

    Yu.G.Rudoy

    2005-01-01

    Full Text Available The concept of effective temperature (ET T*(T0, T is used in order to approximately "quantize" the thermodynamic functions of the dynamical object which is in the thermal equilibrium with thermal bath being at constant temperature T (T0=E0/kB, where E0 is the ground-state energy, kB - Boltzmann constant, is the characteristic ``quantum'' temperature of the system itself. On these grounds the extensive comparative investigation is carried out for the ``standard model'' of statistical mechanics - the one-dimensional harmonic oscillator (HO. Three well-known approaches are considered and their thermodynamic consequences thoroughly studied. These are: the exact quantum, or non-classical Planck-Einstein approach, intermediate, or semiclassical Bloch-Wigner approach and, finally, the pure classical, or Maxwell-Boltzmann approach.

  18. Non-grey benchmark results for two temperature non-equilibrium radiative transfer

    International Nuclear Information System (INIS)

    Su, B.; Olson, G.L.

    1999-01-01

    Benchmark solutions to time-dependent radiative transfer problems involving non-equilibrium coupling to the material temperature field are crucial for validating time-dependent radiation transport codes. Previous efforts on generating analytical solutions to non-equilibrium radiative transfer problems were all restricted to the one-group grey model. In this paper, a non-grey model, namely the picket-fence model, is considered for a two temperature non-equilibrium radiative transfer problem in an infinite medium. The analytical solutions, as functions of space and time, are constructed in the form of infinite integrals for both the diffusion description and transport description. These expressions are evaluated numerically and the benchmark results are generated. The asymptotic solutions for large and small times are also derived in terms of elementary functions and are compared with the exact results. Comparisons are given between the transport and diffusion solutions and between the grey and non-grey solutions. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. Advancing non-equilibrium ARPES experiments by a 9.3 eV coherent ultrafast photon source

    Energy Technology Data Exchange (ETDEWEB)

    Cilento, F., E-mail: federico.cilento@elettra.eu [Elettra – Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste 34149 (Italy); C.N.R. – I.O.M., Strada Statale 14, km 163.5, Trieste 34149 (Italy); Crepaldi, A. [Elettra – Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste 34149 (Italy); Manzoni, G.; Sterzi, A. [Universitá degli Studi di Trieste, Via A. Valerio 2, Trieste 34127 (Italy); Zacchigna, M. [C.N.R. – I.O.M., Strada Statale 14, km 163.5, Trieste 34149 (Italy); Bugnon, Ph.; Berger, H. [Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Parmigiani, F. [Elettra – Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste 34149 (Italy); Universitá degli Studi di Trieste, Via A. Valerio 2, Trieste 34127 (Italy); International Faculty, University of Köln, 50937 Köln (Germany)

    2016-02-15

    The quest for investigating the non-equilibrium dynamics of the band structure of strongly-correlated materials over their entire Brillouin zone is a primary objective. However, the actual ultrafast UV light sources are not suitable for addressing several critical questions in the field. Here we report on a novel light source generating sub-250 fs, 9.3 eV photon energy light pulses at 250 kHz repetition rate, obtained via third-harmonic generation in Xe of frequency-doubled 50 fs laser pulses at 1.55 eV. By reporting the measured band dispersion of a Cu(111) crystal and the non-equilibrium dynamics of the Bi{sub 2}Se{sub 3} topological insulator, we prove that this source is suitable for studying the non-equilibrium dynamics of the entire Fermi surface of several complex materials, with high signal statistics and limited space-charge effect.

  20. Modification of surfaces and surface layers by non equilibrium processes

    International Nuclear Information System (INIS)

    Beamson, G.; Brennan, W.J.; Clark, D.T.; Howard, J.

    1988-01-01

    Plasmas are examples of non-equilibrium phenomena which are being used increasingly for the synthesis and modification of materials impossible by conventional routes. This paper introduces methods available by describing the construction and characteristics of some equipment used for the production of different types of plasmas and other non-equilibrium phenomena. This includes high energy ion beams. The special features, advantages and disadvantages of the techniques will be described. There are a multitude of potential application relevant to electronic, metallic, ceramic, and polymeric materials. However, scale-up from the laboratory to production equipment depends on establishing a better understanding of both the physics and chemistry of plasma as well as plasma-solid interactions. Examples are given of how such an understanding can be gained. The chemical analysis of polymer surfaces undergoing modification by inert gas, hydrogen or oxygen plasmas is shown to give physical information regarding the relative roles of diffusion of active species, and direct and radiative energy transfer from the plasma. Surface modification by plasma depositing a new material onto an existing substrate is discussed with particular reference to the deposition of amorphous carbon films. Applications of the unique properties of these films are outlined together with our current understanding of these properties based on chemical and physical methods of analysis of both the films and the plasmas producing them. Finally, surface modification by ion beams is briefly illustrated using examples from the electronics and metals industries where the modification has had a largely physical rather than chemical effect on the starting material. (orig.)

  1. The effect of non-equilibrium metal cooling on the interstellar medium

    Science.gov (United States)

    Capelo, Pedro R.; Bovino, Stefano; Lupi, Alessandro; Schleicher, Dominik R. G.; Grassi, Tommaso

    2018-04-01

    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 10 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 10 to 100 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 that link star formation rate to metal emission lines.

  2. Non-equilibrium quantum heat machines

    Science.gov (United States)

    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.

  3. Non-equilibrium quantum heat machines

    International Nuclear Information System (INIS)

    Alicki, Robert; Gelbwaser-Klimovsky, 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) 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. (paper)

  4. Equilibrium and non-equilibrium extraction separation of rare earth metals in presence of diethylenetriaminepentaacetic acid in aqueous phase

    International Nuclear Information System (INIS)

    Azis, Abdul; Teramoto, Masaaki; Matsuyama, Hideto.

    1995-01-01

    Equilibrium and non-equilibrium extraction separations of rare earth metals were carried out in the presence of chelating agent in the aqueous phase. The separation systems of the rare earth metal mixtures used were Y/Dy, Y/Ho, Y/Er and Y/Tm, and the chelating agent and the extractant were diethylenetriaminepentaacetic acid (DTPA) and bis (2,4,4-trimethylpentyl) phosphinic acid (CYANEXR 272), respectively. For Y/Dy and Y/Ho systems, higher selectivities were obtained in equilibrium separation compared with those in non-equilibrium separation. On the other hand, the selectivities in non-equilibrium separation were higher for Y/Er and Y/Tm systems. In the separation condition suitable to each system, the addition of DTPA to the aqueous phase was found to be very effective for obtaining higher selectivities. The distribution ratios of the rare earth metals and the selectivities in the equilibrium separations obtained experimentally were thoroughly analyzed by considering various equilibria such as the extraction equilibrium and the complex formation equilibrium between rare earth metals and DTPA in the aqueous phase. Moreover, the extraction rates and the selectivities in the non-equilibrium separations were also analyzed by the extraction model considering the dissociation reactions of the rare earth metal-DTPA complexes in the aqueous stagnant layer. Based on these analyses, we presented an index which is useful for selecting the optimum operation mode. Using this index, we can predict that the selectivities under equilibrium conditions are higher than those under non-equilibrium conditions for Y/Dy and Y/Ho systems, while for Y/Er and Y/Tm systems, higher selectivities are obtained under non-equilibrium conditions. The experimental results were in agreement with predictions by this index. Further, the selectivities in various systems including other chelating agents and extractants were discussed based on this index. (J.P.N.)

  5. Theoretical investigation of shock stand-off distance for non-equilibrium flows over spheres

    KAUST Repository

    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.

  6. Strong magnetic fields and non equilibrium dynamics in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Niklas

    2017-06-21

    and topology is intriguing and often mysterious, yet central to many of the fundamental mechanisms of nature. As the anomalous violation of classical symmetries in the earliest stages of the universe is conjectured to be responsible for the dominance of matter over anti-matter, researchers attempt to recreate the dynamics of matter under extreme conditions at heavy ion collider experiments and thus understand these challenging mechanisms. In the early universe as well as in present day experiments the emergence of quantum anomalies is tied to out-of-equilibrium systems. In this thesis we focus on a comprehensive attempt at establishing the theoretical foundations of the non-equilibrium description of anomalous and topological dynamics. To this end we present a selection of different techniques and approximation schemes, which are motivated by the properties of the space-time evolution of QCD matter in ultra-relativistic heavy ion collisions. Most importantly we aim to illustrate that the techniques, which are presented here, are applicable to a number of systems in nature, starting from strong-field laser physics to cosmology. The nature of topological effects is much richer in out-of-equilibrium systems and in accord with present progress in the experimental study of anomalous effects, we hope to contribute to the establishment of a novel view on anomalies and topology beyond the previous equilibrium paradigm.

  7. Statistical Physics

    CERN Document Server

    Wannier, Gregory Hugh

    1966-01-01

    Until recently, the field of statistical physics was traditionally taught as three separate subjects: thermodynamics, statistical mechanics, and kinetic theory. This text, a forerunner in its field and now a classic, was the first to recognize the outdated reasons for their separation and to combine the essentials of the three subjects into one unified presentation of thermal physics. It has been widely adopted in graduate and advanced undergraduate courses, and is recommended throughout the field as an indispensable aid to the independent study and research of statistical physics.Designed for

  8. Combined equilibrium and non-equilibrium phosphorus segregation to grain boundaries in a 2.25Cr1Mo steel

    International Nuclear Information System (INIS)

    Song, S.-H.; Shen, D.-D.; Yuan, Z.-X.; Liu, J.; Xu, T.-D.; Weng, L.-Q.

    2003-01-01

    Grain boundary segregation of phosphorus in a P-doped 2.25Cr1Mo steel during ageing at 540 deg. C after quenching from 980 deg. C is examined by Auger electron spectroscopy. The segregation is a combined effect of equilibrium segregation and non-equilibrium segregation. The effect of phosphorus non-equilibrium segregation is to enhance the kinetics of its equilibrium segregation

  9. Understanding Non-equilibrium Thermodynamics Foundations, Applications, Frontiers

    CERN Document Server

    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...

  10. Statistical Physics

    CERN Document Server

    Mandl, Franz

    1988-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition E. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A. C. Phillips Computing for Scient

  11. Path-space variational inference for non-equilibrium coarse-grained systems

    International Nuclear Information System (INIS)

    Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plecháč, Petr

    2016-01-01

    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.

  12. Path-space variational inference for non-equilibrium coarse-grained systems

    Energy Technology Data Exchange (ETDEWEB)

    Harmandaris, Vagelis, E-mail: harman@uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete (Greece); Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), IACM/FORTH, GR-71110 Heraklion (Greece); Kalligiannaki, Evangelia, E-mail: ekalligian@tem.uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete (Greece); Katsoulakis, Markos, E-mail: markos@math.umass.edu [Department of Mathematics and Statistics, University of Massachusetts at Amherst (United States); Plecháč, Petr, E-mail: plechac@math.udel.edu [Department of Mathematical Sciences, University of Delaware, Newark, Delaware (United States)

    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.

  13. Equilibrium statistical mechanics of lattice models

    CERN Document Server

    Lavis, David A

    2015-01-01

    Most interesting and difficult problems in equilibrium statistical mechanics concern models which exhibit phase transitions. For graduate students and more experienced researchers this book provides an invaluable reference source of approximate and exact solutions for a comprehensive range of such models. Part I contains background material on classical thermodynamics and statistical mechanics, together with a classification and survey of lattice models. The geometry of phase transitions is described and scaling theory is used to introduce critical exponents and scaling laws. An introduction is given to finite-size scaling, conformal invariance and Schramm—Loewner evolution. Part II contains accounts of classical mean-field methods. The parallels between Landau expansions and catastrophe theory are discussed and Ginzburg—Landau theory is introduced. The extension of mean-field theory to higher-orders is explored using the Kikuchi—Hijmans—De Boer hierarchy of approximations. In Part III the use of alge...

  14. Statistical equilibrium and symplectic geometry in general relativity

    International Nuclear Information System (INIS)

    Iglesias, P.

    1981-09-01

    A geometrical construction is given of the statistical equilibrium states of a system of particles in the gravitational field in general relativity. By a method of localization variables, the expression of thermodynamic values is given and the compatibility of this description is shown with a macroscopic model of a relativistic continuous medium for a given value of the free-energy function [fr

  15. Statistical Thermodynamics of Disperse Systems

    DEFF Research Database (Denmark)

    Shapiro, Alexander

    1996-01-01

    Principles of statistical physics are applied for the description of thermodynamic equilibrium in disperse systems. The cells of disperse systems are shown to possess a number of non-standard thermodynamic parameters. A random distribution of these parameters in the system is determined....... On the basis of this distribution, it is established that the disperse system has an additional degree of freedom called the macro-entropy. A large set of bounded ideal disperse systems allows exact evaluation of thermodynamic characteristics. The theory developed is applied to the description of equilibrium...

  16. Physics-based preconditioning and the Newton-Krylov method for non-equilibrium radiation diffusion

    International Nuclear Information System (INIS)

    Mousseau, V.A.; Knoll, D.A.; Rider, W.J.

    2000-01-01

    An algorithm is presented for the solution of the time dependent reaction-diffusion systems which arise in non-equilibrium radiation diffusion applications. This system of nonlinear equations is solved by coupling three numerical methods, Jacobian-free Newton-Krylov, operator splitting, and multigrid linear solvers. An inexact Newton's method is used to solve the system of nonlinear equations. Since building the Jacobian matrix for problems of interest can be challenging, the authors employ a Jacobian-free implementation of Newton's method, where the action of the Jacobian matrix on a vector is approximated by a first order Taylor series expansion. Preconditioned generalized minimal residual (PGMRES) is the Krylov method used to solve the linear systems that come from the iterations of Newton's method. The preconditioner in this solution method is constructed using a physics-based divide and conquer approach, often referred to as operator splitting. This solution procedure inverts the scalar elliptic systems that make up the preconditioner using simple multigrid methods. The preconditioner also addresses the strong coupling between equations with local 2 x 2 block solves. The intra-cell coupling is applied after the inter-cell coupling has already been addressed by the elliptic solves. Results are presented using this solution procedure that demonstrate its efficiency while incurring minimal memory requirements

  17. Phase Equilibrium, Chemical Equilibrium, and a Test of the Third Law: Experiments for Physical Chemistry.

    Science.gov (United States)

    Dannhauser, Walter

    1980-01-01

    Described is an experiment designed to provide an experimental basis for a unifying point of view (utilizing theoretical framework and chemistry laboratory experiments) for physical chemistry students. Three experiments are described: phase equilibrium, chemical equilibrium, and a test of the third law of thermodynamics. (Author/DS)

  18. On the establishment of thermal equilibrium in simplest mechanical systems

    International Nuclear Information System (INIS)

    Kotsinyan, Ar.M.

    1987-01-01

    The process of the establishment of thermal equilibrium of the damping oscillators and a ''free'' particle in interaction with the blackbody radiation field is considered. A special attention is payed to the principal role of non-closedness of real systems as well as to the irreversibility of the microscopic equations of motion in the question of grounding of the statistical physics

  19. PREFACE: International Symposium on Non-Equilibrium Soft Matter 2010 International Symposium on Non-Equilibrium Soft Matter 2010

    Science.gov (United States)

    Kawakatsu, T.; Matsuyama, A.; Ohta, T.; Tanaka, H.; Tanaka, S.

    2011-07-01

    Soft matter is a rapidly growing interdisciplinary research field covering a range of subject areas including physics, chemistry, biology, mathematics and engineering. Some of the important universal features of these materials are their mesoscopic structures and their dynamics. Due to the existence of such large-scale structures, which nevertheless exhibit interactions of the order of the thermal energy, soft matter can readily be taken out of equilibrium by imposing a weak external field such as an electric field, a mechanical stress or a shear flow. The importance of the coexistence of microscopic molecular dynamics and the mesoscopic/macroscopic structures and flows requires us to develop hierarchical approaches to understand the nonlinear and nonequilibrium phenomena, which is one of the central issues of current soft matter research. This special section presents selected contributions from the 'International Symposium on Non-Equilibrium Soft Matter 2010' held from 17-20 August 2010 in Nara, Japan, which aimed to describe recent advances in soft matter research focusing especially on its nonequilibrium aspects. The topics discussed cover statics and dynamics of a wide variety of materials ranging from traditional soft matter like polymers, gels, emulsions, liquid crystals and colloids to biomaterials such as biopolymers and biomembranes. Among these studies, we highlighted the physics of biomembranes and vesicles, which has attracted great attention during the last decade; we organized a special session for this active field. The work presented in this issue deals with (1) structure formation in biomembranes and vesicles, (2) rheology of polymers and gels, (3) mesophases in block copolymers, (4) mesoscopic structures in liquid crystals and ionic liquids, and (5) nonequilibrium dynamics. This symposium was organized as part of a research project supported by the Grant-in-Aid for the priority area 'Soft Matter Physics' (2006-2010) from the Ministry of Education

  20. Investigation of Non-Equilibrium Radiation for Earth Entry

    Science.gov (United States)

    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

  1. Theoretical physics 8 statistical physics

    CERN Document Server

    Nolting, Wolfgang

    2018-01-01

    This textbook offers a clear and comprehensive introduction to statistical physics, one of the core components of advanced undergraduate physics courses. It follows on naturally from the previous volumes in this series, using methods of probability theory and statistics to solve physical problems. The first part of the book gives a detailed overview on classical statistical physics and introduces all mathematical tools needed. The second part of the book covers topics related to quantized states, gives a thorough introduction to quantum statistics, followed by a concise treatment of quantum gases. Ideally suited to undergraduate students with some grounding in quantum mechanics, the book is enhanced throughout with learning features such as boxed inserts and chapter summaries, with key mathematical derivations highlighted to aid understanding. The text is supported by numerous worked examples and end of chapter problem sets. About the Theoretical Physics series Translated from the renowned and highly successf...

  2. Statistical mechanics of two-dimensional and geophysical flows

    International Nuclear Information System (INIS)

    Bouchet, Freddy; Venaille, Antoine

    2012-01-01

    The theoretical study of the self-organization of two-dimensional and geophysical turbulent flows is addressed based on statistical mechanics methods. This review is a self-contained presentation of classical and recent works on this subject; from the statistical mechanics basis of the theory up to applications to Jupiter’s troposphere and ocean vortices and jets. Emphasize has been placed on examples with available analytical treatment in order to favor better understanding of the physics and dynamics. After a brief presentation of the 2D Euler and quasi-geostrophic equations, the specificity of two-dimensional and geophysical turbulence is emphasized. The equilibrium microcanonical measure is built from the Liouville theorem. Important statistical mechanics concepts (large deviations and mean field approach) and thermodynamic concepts (ensemble inequivalence and negative heat capacity) are briefly explained and described. On this theoretical basis, we predict the output of the long time evolution of complex turbulent flows as statistical equilibria. This is applied to make quantitative models of two-dimensional turbulence, the Great Red Spot and other Jovian vortices, ocean jets like the Gulf-Stream, and ocean vortices. A detailed comparison between these statistical equilibria and real flow observations is provided. We also present recent results for non-equilibrium situations, for the studies of either the relaxation towards equilibrium or non-equilibrium steady states. In this last case, forces and dissipation are in a statistical balance; fluxes of conserved quantity characterize the system and microcanonical or other equilibrium measures no longer describe the system.

  3. SRB states and nonequilibrium statistical mechanics close to equilibrium

    OpenAIRE

    Gallavotti, Giovannni; Ruelle, David

    1996-01-01

    Nonequilibrium statistical mechanics close to equilibrium is studied using SRB states and a formula for their derivatives with respect to parameters. We write general expressions for the thermodynamic fluxes (or currents) and the transport coefficients, generalizing previous results. In this framework we give a general proof of the Onsager reciprocity relations.

  4. Potential and flux field landscape theory. I. Global stability and dynamics of spatially dependent non-equilibrium systems.

    Science.gov (United States)

    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.

  5. Experimental benchmark of non-local-thermodynamic-equilibrium plasma atomic physics codes

    International Nuclear Information System (INIS)

    Nagels-Silvert, V.

    2004-09-01

    The main purpose of this thesis is to get experimental data for the testing and validation of atomic physics codes dealing with non-local-thermodynamical-equilibrium plasmas. The first part is dedicated to the spectroscopic study of xenon and krypton plasmas that have been produced by a nanosecond laser pulse interacting with a gas jet. A Thomson scattering diagnostic has allowed us to measure independently plasma parameters such as electron temperature, electron density and the average ionisation state. We have obtained time integrated spectra in the range between 5 and 10 angstroms. We have identified about one hundred xenon rays between 8.6 and 9.6 angstroms via the use of the Relac code. We have discovered unknown rays for the krypton between 5.2 and 7.5 angstroms. In a second experiment we have extended the wavelength range to the X UV domain. The Averroes/Transpec code has been tested in the ranges from 9 to 15 angstroms and from 10 to 130 angstroms, the first range has been well reproduced while the second range requires a more complex data analysis. The second part is dedicated to the spectroscopic study of aluminium, selenium and samarium plasmas in femtosecond operating rate. We have designed an interferometry diagnostic in the frequency domain that has allowed us to measure the expanding speed of the target's backside. Via the use of an adequate isothermal model this parameter has led us to know the plasma electron temperature. Spectra and emission times of various rays from the aluminium and selenium plasmas have been computed satisfactorily with the Averroes/Transpec code coupled with Film and Multif hydrodynamical codes. (A.C.)

  6. On non-equilibrium states in QFT model with boundary interaction

    International Nuclear Information System (INIS)

    Bazhanov, Vladimir V.; Lukyanov, Sergei L.; Zamolodchikov, Alexander B.

    1999-01-01

    We prove that certain non-equilibrium expectation values in the boundary sine-Gordon model coincide with associated equilibrium-state expectation values in the systems which differ from the boundary sine-Gordon in that certain extra boundary degrees of freedom (q-oscillators) are added. Applications of this result to actual calculation of non-equilibrium characteristics of the boundary sine-Gordon model are also discussed

  7. Non-equilibrium mean-field theories on scale-free networks

    International Nuclear Information System (INIS)

    Caccioli, Fabio; Dall'Asta, Luca

    2009-01-01

    Many non-equilibrium processes on scale-free networks present anomalous critical behavior that is not explained by standard mean-field theories. We propose a systematic method to derive stochastic equations for mean-field order parameters that implicitly account for the degree heterogeneity. The method is used to correctly predict the dynamical critical behavior of some binary spin models and reaction–diffusion processes. The validity of our non-equilibrium theory is further supported by showing its relation with the generalized Landau theory of equilibrium critical phenomena on networks

  8. On the forces and fluxes in non-equilibrium thermodynamics

    International Nuclear Information System (INIS)

    Kitahara, Kazuo

    1986-01-01

    A formulation of non-equilibrium thermodynamics of continuum systems based on local equilibrium assumption is reported. Thermodynamic forces are defined from a generalized local entropy and irreversible fluxes are defined as non-advective parts of fluxes of conservative quantities. The validity of the general evolution criterion and its generalization is discussed. (author)

  9. The universal statistical distributions of the affinity, equilibrium constants, kinetics and specificity in biomolecular recognition.

    Directory of Open Access Journals (Sweden)

    Xiliang Zheng

    2015-04-01

    Full Text Available We uncovered the universal statistical laws for the biomolecular recognition/binding process. We quantified the statistical energy landscapes for binding, from which we can characterize the distributions of the binding free energy (affinity, the equilibrium constants, the kinetics and the specificity by exploring the different ligands binding with a particular receptor. The results of the analytical studies are confirmed by the microscopic flexible docking simulations. The distribution of binding affinity is Gaussian around the mean and becomes exponential near the tail. The equilibrium constants of the binding follow a log-normal distribution around the mean and a power law distribution in the tail. The intrinsic specificity for biomolecular recognition measures the degree of discrimination of native versus non-native binding and the optimization of which becomes the maximization of the ratio of the free energy gap between the native state and the average of non-native states versus the roughness measured by the variance of the free energy landscape around its mean. The intrinsic specificity obeys a Gaussian distribution near the mean and an exponential distribution near the tail. Furthermore, the kinetics of binding follows a log-normal distribution near the mean and a power law distribution at the tail. Our study provides new insights into the statistical nature of thermodynamics, kinetics and function from different ligands binding with a specific receptor or equivalently specific ligand binding with different receptors. The elucidation of distributions of the kinetics and free energy has guiding roles in studying biomolecular recognition and function through small-molecule evolution and chemical genetics.

  10. Wall ablation of heated compound-materials into non-equilibrium discharge plasmas

    Science.gov (United States)

    Wang, Weizong; Kong, Linghan; Geng, Jinyue; Wei, Fuzhi; Xia, Guangqing

    2017-02-01

    The discharge properties of the plasma bulk flow near the surface of heated compound-materials strongly affects the kinetic layer parameters modeled and manifested in the Knudsen layer. This paper extends the widely used two-layer kinetic ablation model to the ablation controlled non-equilibrium discharge due to the fact that the local thermodynamic equilibrium (LTE) approximation is often violated as a result of the interaction between the plasma and solid walls. Modifications to the governing set of equations, to account for this effect, are derived and presented by assuming that the temperature of the electrons deviates from that of the heavy particles. The ablation characteristics of one typical material, polytetrafluoroethylene (PTFE) are calculated with this improved model. The internal degrees of freedom as well as the average particle mass and specific heat ratio of the polyatomic vapor, which strongly depends on the temperature, pressure and plasma non-equilibrium degree and plays a crucial role in the accurate determination of the ablation behavior by this model, are also taken into account. Our assessment showed the significance of including such modifications related to the non-equilibrium effect in the study of vaporization of heated compound materials in ablation controlled arcs. Additionally, a two-temperature magneto-hydrodynamic (MHD) model accounting for the thermal non-equilibrium occurring near the wall surface is developed and applied into an ablation-dominated discharge for an electro-thermal chemical launch device. Special attention is paid to the interaction between the non-equilibrium plasma and the solid propellant surface. Both the mass exchange process caused by the wall ablation and plasma species deposition as well as the associated momentum and energy exchange processes are taken into account. A detailed comparison of the results of the non-equilibrium model with those of an equilibrium model is presented. The non-equilibrium results

  11. A statistical method for evaluation of the experimental phase equilibrium data of simple clathrate hydrates

    DEFF Research Database (Denmark)

    Eslamimanesh, Ali; Gharagheizi, Farhad; Mohammadi, Amir H.

    2012-01-01

    We, herein, present a statistical method for diagnostics of the outliers in phase equilibrium data (dissociation data) of simple clathrate hydrates. The applied algorithm is performed on the basis of the Leverage mathematical approach, in which the statistical Hat matrix, Williams Plot, and the r......We, herein, present a statistical method for diagnostics of the outliers in phase equilibrium data (dissociation data) of simple clathrate hydrates. The applied algorithm is performed on the basis of the Leverage mathematical approach, in which the statistical Hat matrix, Williams Plot...... in exponential form is used to represent/predict the hydrate dissociation pressures for three-phase equilibrium conditions (liquid water/ice–vapor-hydrate). The investigated hydrate formers are methane, ethane, propane, carbon dioxide, nitrogen, and hydrogen sulfide. It is interpreted from the obtained results...

  12. A statistical mechanical model for equilibrium ionization

    International Nuclear Information System (INIS)

    Macris, N.; Martin, P.A.; Pule, J.

    1990-01-01

    A quantum electron interacts with a classical gas of hard spheres and is in thermal equilibrium with it. The interaction is attractive and the electron can form a bound state with the classical particles. It is rigorously shown that in a well defined low density and low temperature limit, the ionization probability for the electron tends to the value predicted by the Saha formula for thermal ionization. In this regime, the electron is found to be in a statistical mixture of a bound and a free state. (orig.)

  13. 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.

  14. Step-wise pulling protocols for non-equilibrium dynamics

    Science.gov (United States)

    Ngo, Van Anh

    The fundamental laws of thermodynamics and statistical mechanics, and the deeper understandings of quantum mechanics have been rebuilt in recent years. It is partly because of the increasing power of computing resources nowadays, that allow shedding direct insights into the connections among the thermodynamics laws, statistical nature of our world, and the concepts of quantum mechanics, which have not yet been understood. But mostly, the most important reason, also the ultimate goal, is to understand the mechanisms, statistics and dynamics of biological systems, whose prevailing non-equilibrium processes violate the fundamental laws of thermodynamics, deviate from statistical mechanics, and finally complicate quantum effects. I believe that investigations of the fundamental laws of non-equilibrium dynamics will be a frontier research for at least several more decades. One of the fundamental laws was first discovered in 1997 by Jarzynski, so-called Jarzynski's Equality. Since then, different proofs, alternative descriptions of Jarzynski's Equality, and its further developments and applications have been quickly accumulated. My understandings, developments and applications of an alternative theory on Jarzynski's Equality form the bulk of this dissertation. The core of my theory is based on stepwise pulling protocols, which provide deeper insight into how fluctuations of reaction coordinates contribute to free-energy changes along a reaction pathway. We find that the most optimal pathways, having the largest contribution to free-energy changes, follow the principle of detailed balance. This is a glimpse of why the principle of detailed balance appears so powerful for sampling the most probable statistics of events. In a further development on Jarzynski's Equality, I have been trying to use it in the formalism of diagonal entropy to propose a way to extract useful thermodynamic quantities such temperature, work and free-energy profiles from far-from-equilibrium

  15. Progress in Non-equilibrium Green's Functions (PNGF VI)

    International Nuclear Information System (INIS)

    2016-01-01

    The sixth interdisciplinary conference 'Progress in Non-equilibrium Green's Functions' (PNGF6) took place at Lund University, Sweden, on 17-21 August 2015. The conference was attended by 60 scientists, from Europe and overseas, sharing an interest in Green's function methods and/or non-equilibrium phenomena. At the conference, 34 invited and contributed talks were given, together with a poster session with 17 contributions. As its predecessors (Rostock 1999, Dresden 2002, Kiel 2005, Glasgow 2009, Jyväskylä 2012) did, the conference succeeded in gathering different communities for the exchange of recent developments and results. Among the topics of the conference, we mention approaches for strongly correlated systems, improvements of existing perturbative many-body schemes, electron-phonon/-photon interactions in time-dependent treatments, numerical scalability of NEGF approaches, connections with other non-equilibrium methods and concrete physical applications. For the latter, we mention quantum transport, semiconductor kinetics, multiply excited states in atoms and ions, nuclear reactions, high energy physics, quantum cascade lasers, strongly correlated model systems, graphene-nanostructures, optoelectronics, superconductors, spin-dynamics, photovoltaics, excitations in atoms and ions and time-resolved spectroscopy. The present volume contains 20 articles from participants of PNGF6, devoted to these topics. Compared to previous conferences, a completely novel and successful aspect of PNGF6 was the participation of experimentalists among the invited speakers, to establish a connection between emerging experimental techniques (for example, time-dependent spectroscopies) and the theoretical NEGF community. As at the previous PNGF conferences, the atmosphere was friendly and exciting at the same time, favoring vivid and stimulating discussions among experienced scientists, young researchers and students. The conference would not have been

  16. Statistical Physics of Colloidal Dispersions.

    Science.gov (United States)

    Canessa, E.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis is concerned with the equilibrium statistical mechanics of colloidal dispersions which represent useful model systems for the study of condensed matter physics; namely, charge stabilized colloidal dispersions and polymer stabilized colloidal dispersions. A one-component macroparticle approach is adopted in order to treat the macroscopic and microscopic properties of these systems in a simple and comprehensive manner. The thesis opens with the description of the nature of the colloidal state before reviewing some basic definitions and theory in Chapter II. In Chapter III a variational theory of phase equilibria based on the Gibbs-Bogolyobov inequality is applied to sterically stabilized colloidal dispersions. Hard spheres are chosen as the reference system for the disordered phases while an Einstein model is used for the ordered phases. The new choice of pair potential, taken for mathematical convenience, is a superposition of two Yukawa functions. By matching a double Yukawa potential to the van der Waals attractive potential at different temperatures and introducing a purely temperature dependent coefficient to the repulsive part, a rich variety of observed phase separation phenomena is qualitatively described. The behaviour of the potential is found to be consistent with a small decrease of the polymer layer thickness with increasing temperature. Using the same concept of a collapse transition the non-monotonic second virial coefficient is also explained and quantified. It is shown that a reduction of the effective macroparticle diameter with increasing temperature can only be partially examined from the point of view of a (binary-) polymer solution theory. This chapter concludes with the description of the observed, reversible, depletion flocculation behaviour. This is accomplished by using the variational formalism and by invoking the double Yukawa potential to allow

  17. Non-equilibrium spin and charge transport in superconducting heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Thalmann, Marcel; Rudolf, Marcel; Braun, Julian; Pietsch, Torsten; Scheer, Elke [Department of Physics, University of Konstanz, Universitaetsstrasse 10, 78464 Konstanz (Germany)

    2015-07-01

    Ferromagnet Superconductance (F/S) junctions are rich in exciting quantum-physical-phenomena, which are still poorly understood but may provide bright prospects for new applications. In contrast to conventional normal-metal proximity systems, Andreev reflection is suppressed for singlet cooper pairs in F/S heterostructures. However, long-range triplet pairing may be observed in S/F systems with non-collinear magnetization or spin-active interfaces. Herein, we investigate non-equilibrium transport properties of lateral S/F heterojunctions, defined via electron beam lithography. In particular we focus microwave- and magneto-transport spectroscopy on conventional type-I (Al, Pb, Zn) and type-II (Nb) superconductors in combination with strong transition metal ferromagnets (Ni, Co, Fe). A cryogenic HF readout platform and advanced electronic filtering is developed and results on Al-based heterojunctions are shown.

  18. Spectral non-equilibrium property in homogeneous isotropic turbulence and its implication in subgrid-scale modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Le [Laboratory of Mathematics and Physics, Ecole Centrale de Pékin, Beihang University, Beijing 100191 (China); Zhu, Ying [Laboratory of Mathematics and Physics, Ecole Centrale de Pékin, Beihang University, Beijing 100191 (China); National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing 100191 (China); Liu, Yangwei, E-mail: liuyangwei@126.com [National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing 100191 (China); Lu, Lipeng [National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing 100191 (China)

    2015-10-09

    The non-equilibrium property in turbulence is a non-negligible problem in large-eddy simulation but has not yet been systematically considered. The generalization from equilibrium turbulence to non-equilibrium turbulence requires a clear recognition of the non-equilibrium property. As a preliminary step of this recognition, the present letter defines a typical non-equilibrium process, that is, the spectral non-equilibrium process, in homogeneous isotropic turbulence. It is then theoretically investigated by employing the skewness of grid-scale velocity gradient, which permits the decomposition of resolved velocity field into an equilibrium one and a time-reversed one. Based on this decomposition, an improved Smagorinsky model is proposed to correct the non-equilibrium behavior of the traditional Smagorinsky model. The present study is expected to shed light on the future studies of more generalized non-equilibrium turbulent flows. - Highlights: • A spectral non-equilibrium process in isotropic turbulence is defined theoretically. • A decomposition method is proposed to divide a non-equilibrium turbulence field. • An improved Smagorinsky model is proposed to correct the non-equilibrium behavior.

  19. Non-equilibrium concentration fluctuations in binary liquids with realistic boundary conditions.

    Science.gov (United States)

    Ortiz de Zárate, J M; Kirkpatrick, T R; Sengers, J V

    2015-09-01

    Because of the spatially long-ranged nature of spontaneous fluctuations in thermal non-equilibrium systems, they are affected by boundary conditions for the fluctuating hydrodynamic variables. In this paper we consider a liquid mixture between two rigid and impervious plates with a stationary concentration gradient resulting from a temperature gradient through the Soret effect. For liquid mixtures with large Lewis and Schmidt numbers, we are able to obtain explicit analytical expressions for the intensity of the non-equilibrium concentration fluctuations as a function of the frequency ω and the wave number q of the fluctuations. In addition we elucidate the spatial dependence of the intensity of the non-equilibrium fluctuations responsible for a non-equilibrium Casimir effect.

  20. Force-dominated non-equilibrium oxidation kinetics of tantalum

    International Nuclear Information System (INIS)

    Kar, Prasenjit; Wang, Ke; Liang, Hong

    2008-01-01

    Using a combined electrochemical and mechanical manipulation technique, we compared the equilibrium and non-equilibrium oxidation processes and states of tantalum. Experimentally, a setup was developed with an electrochemical system attached to a sliding mechanical configuration capable of friction force measurement. The surface chemistry of a sliding surface, i.e., tantalum, was modified through the electrolyte. The mechanically applied force was fixed and the dynamics of the surface was monitored in situ through a force sensor. The formation of non-equilibrium oxidation states of tantalum was found in oxidation limiting environment of acetic acid. An oxidative environment of deionized water saturated with KCl was used as comparison. We proposed a modified Arrhenius-Eyring equation in which the mechanical factor was considered. We found that the mechanical energy induced the non-stable-state reactions leading to metastable oxidation states of tantalum. This equation can be used to predict mechanochemical reactions that are important in many industrial applications

  1. Local equilibrium in bird flocks

    Science.gov (United States)

    Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    2016-12-01

    The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

  2. Statistical physics and computational methods for evolutionary game theory

    CERN Document Server

    Javarone, Marco Alberto

    2018-01-01

    This book presents an introduction to Evolutionary Game Theory (EGT) which is an emerging field in the area of complex systems attracting the attention of researchers from disparate scientific communities. EGT allows one to represent and study several complex phenomena, such as the emergence of cooperation in social systems, the role of conformity in shaping the equilibrium of a population, and the dynamics in biological and ecological systems. Since EGT models belong to the area of complex systems, statistical physics constitutes a fundamental ingredient for investigating their behavior. At the same time, the complexity of some EGT models, such as those realized by means of agent-based methods, often require the implementation of numerical simulations. Therefore, beyond providing an introduction to EGT, this book gives a brief overview of the main statistical physics tools (such as phase transitions and the Ising model) and computational strategies for simulating evolutionary games (such as Monte Carlo algor...

  3. Decay of non-equilibrium polariton condensate in semiconductors

    International Nuclear Information System (INIS)

    Beloussov, I.V.; Shvera, Y.M.

    1993-08-01

    Excitation dynamics of polariton quantum fluctuations arising in direct-gap semi-conductor as a result of parametric decay of non-equilibrium polariton condensate with non-zero wave vector is studied. The predominant mechanism of polariton scattering is supposed to be exciton-exciton interaction. Steady state which corresponds to the case of dynamic equilibrium between the polariton condensate and quantum fluctuations is obtained. Distribution functions of non-condensate polaritons are localized in the resonant regions, corresponding to two-particle excitation of polaritons from the condensate. The spectrum of elementary excitations in steady state coincides with usual polariton energy with the shift proportional to initial density of polariton condensate. (author). 25 refs

  4. A two-temperature chemical non-equilibrium modeling of DC arc plasma

    International Nuclear Information System (INIS)

    Qian Haiyang; Wu Bin

    2011-01-01

    To a better understanding of non-equilibrium characteristics of DC arc plasma,a two-dimensional axisymmetric two-temperature chemical non-equilibrium (2T-NCE) model is applied for direct current arc argon plasma generator with water-cooled constrictor at atmospheric pressure. The results show that the electron temperature and heavy particle temperature has a relationship under different working parameters, indicating that DC arc plasma has a strong non-equilibrium characteristic, and the variation is obvious. (authors)

  5. Statistical equilibrium of copper in the solar atmosphere

    International Nuclear Information System (INIS)

    Shi, J. R.; Mashonkina, L.; Zhao, G.; Gehren, T.; Zeng, J. L.

    2014-01-01

    Non-local thermodynamic equilibrium (NLTE) line formation for neutral copper in the one-dimensional solar atmospheres is presented for the atomic model, including 96 terms of Cu I and the ground state of Cu II. The accurate oscillator strengths for all the line transitions in model atom and photoionization cross sections were calculated using the R-matrix method in the Russell-Saunders coupling scheme. The main NLTE mechanism for Cu I is the ultraviolet overionization. We find that NLTE leads to systematically depleted total absorption in the Cu I lines and, accordingly, positive abundance corrections. Inelastic collisions with neutral hydrogen atoms produce minor effects on the statistical equilibrium of Cu I in the solar atmosphere. For the solar Cu I lines, the departures from LTE are found to be small, the mean NLTE abundance correction of ∼0.01 dex. It was found that the six low-excitation lines, with excitation energy of the lower level E exc ≤ 1.64 eV, give a 0.14 dex lower mean solar abundance compared to that from the six E exc > 3.7 eV lines, when applying experimental gf-values of Kock and Richter. Without the two strong resonance transitions, the solar mean NLTE abundance from 10 lines of Cu I is log ε ☉ (Cu) = 4.19 ± 0.10, which is consistent within the error bars with the meteoritic value 4.25 ± 0.05 of Lodders et al. The discrepancy between E exc = 1.39-1.64 eV and E exc > 3.7 eV lines can be removed when the calculated gf-values are adopted and a mean solar abundance of log ε ☉ (Cu) = 4.24 ± 0.08 is derived.

  6. Post-CHF heat transfer: a non-equilibrium, relaxation model

    International Nuclear Information System (INIS)

    Jones, O.C. Jr.; Zuber, N.

    1977-01-01

    Existing phenomenological models of heat transfer in the non-equilibrium, liquid-deficient, dispersed flow regime can sometimes predict the thermal behavior fairly well but are quite complex, requiring coupled simultaneous differential equations to describe the axial gradients of mass and energy along with those of droplet acceleration and size. In addition, empirical relations are required to express the droplet breakup and increased effective heat transfer due to holdup. This report describes the development of a different approach to the problem. It is shown that the non-equilibrium component of the total energy can be expressed as a first order, inhomogeneous relaxation equation in terms of one variable coefficient termed the Superheat Relaxation number. A demonstration is provided to show that this relaxation number can be correlated using local variables in such a manner to allow the single non-equilibrium equation to accurately calculate the effects of mass velocity and heat flux along with tube length, diameter, and critical quality for equilibrium qualities from 0.13 to over 3.0

  7. Non-equilibrium plasma chemistry at high pressure and its applications

    International Nuclear Information System (INIS)

    Bai Xiyao; Zhang Zhitao; Bai Mindong; Zhu Qiaoying

    2000-01-01

    A review is presented of research and development of gas discharge and non-equilibrium plasma including, new ideas of non-equilibrium plasma at high gas pressure. With special technology, strong electric fields (>400 Td) can be achieved by which electrons are accelerated suddenly, becoming high energy electrons (> 10 eV) at high pressure. On impact with the electrons, the gas molecules dissociate into ions, atomic ions, atoms and free radicals, and new substances or molecules can be synthesized through custom design. Chemical reaction difficult to achieve by conventional method can be realized or accelerated. Non-equilibrium plasma chemistry at high pressure has wide application prospects

  8. X-ray scattering studies of non-equilibrium ordering processes

    International Nuclear Information System (INIS)

    Nagler, S.E.

    1990-01-01

    We report on the progress of our project entitled ''X-ray Scattering of Non-Equilibrium Ordering Processes.'' During the past year we have made the first synchrotron measurements of ordering in Cu 3 Au have revealed the presence of an intermediate, non-equilibrium ordered state. Preliminary work involving x-ray magnetic scattering has been carried out. Work is continuing in these areas as well as on related problems. 5 refs

  9. Influence of arc current and pressure on non-chemical equilibrium air arc behavior

    Science.gov (United States)

    Yi, WU; Yufei, CUI; Jiawei, DUAN; Hao, SUN; Chunlin, WANG; Chunping, NIU

    2018-01-01

    The influence of arc current and pressure on the non-chemical equilibrium (non-CE) air arc behavior of a nozzle structure was investigated based on the self-consistent non-chemical equilibrium model. The arc behavior during both the arc burning and arc decay phases were discussed at different currents and different pressures. We also devised the concept of a non-equilibrium parameter for a better understanding of non-CE effects. During the arc burning phase, the increasing current leads to a decrease of the non-equilibrium parameter of the particles in the arc core, while the increasing pressure leads to an increase of the non-equilibrium parameter of the particles in the arc core. During the arc decay phase, the non-CE effect will decrease by increasing the arc burning current and the nozzle pressure. Three factors together—convection, diffusion and chemical reactions—influence non-CE behavior.

  10. Stochastic optimal control as non-equilibrium statistical mechanics: calculus of variations over density and current

    Science.gov (United States)

    Chernyak, Vladimir Y.; Chertkov, Michael; Bierkens, Joris; Kappen, Hilbert J.

    2014-01-01

    In stochastic optimal control (SOC) one minimizes the average cost-to-go, that consists of the cost-of-control (amount of efforts), cost-of-space (where one wants the system to be) and the target cost (where one wants the system to arrive), for a system participating in forced and controlled Langevin dynamics. We extend the SOC problem by introducing an additional cost-of-dynamics, characterized by a vector potential. We propose derivation of the generalized gauge-invariant Hamilton-Jacobi-Bellman equation as a variation over density and current, suggest hydrodynamic interpretation and discuss examples, e.g., ergodic control of a particle-within-a-circle, illustrating non-equilibrium space-time complexity.

  11. The Rate-Controlled Constrained-Equilibrium Approach to Far-From-Local-Equilibrium Thermodynamics

    Directory of Open Access Journals (Sweden)

    Hameed Metghalchi

    2012-01-01

    Full Text Available The Rate-Controlled Constrained-Equilibrium (RCCE method for the description of the time-dependent behavior of dynamical systems in non-equilibrium states is a general, effective, physically based method for model order reduction that was originally developed in the framework of thermodynamics and chemical kinetics. A generalized mathematical formulation is presented here that allows including nonlinear constraints in non-local equilibrium systems characterized by the existence of a non-increasing Lyapunov functional under the system’s internal dynamics. The generalized formulation of RCCE enables to clarify the essentials of the method and the built-in general feature of thermodynamic consistency in the chemical kinetics context. In this paper, we work out the details of the method in a generalized mathematical-physics framework, but for definiteness we detail its well-known implementation in the traditional chemical kinetics framework. We detail proofs and spell out explicit functional dependences so as to bring out and clarify each underlying assumption of the method. In the standard context of chemical kinetics of ideal gas mixtures, we discuss the relations between the validity of the detailed balance condition off-equilibrium and the thermodynamic consistency of the method. We also discuss two examples of RCCE gas-phase combustion calculations to emphasize the constraint-dependent performance of the RCCE method.

  12. Transient magnetic currents through a molecular bridge: limits to reduction of non-equilibrium Green's functions to a generalized master equation

    Czech Academy of Sciences Publication Activity Database

    Kalvová, Anděla; Velický, B.; Špička, Václav

    2017-01-01

    Roč. 30, č. 3 (2017), s. 807-811 ISSN 1557-1939 Institutional support: RVO:68378271 Keywords : non-equilibrium * initial conditions * transient currents * molecular islands Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.180, year: 2016

  13. Light-induced electronic non-equilibrium in plasmonic particles.

    Science.gov (United States)

    Kornbluth, Mordechai; Nitzan, Abraham; Seideman, Tamar

    2013-05-07

    We consider the transient non-equilibrium electronic distribution that is created in a metal nanoparticle upon plasmon excitation. Following light absorption, the created plasmons decohere within a few femtoseconds, producing uncorrelated electron-hole pairs. The corresponding non-thermal electronic distribution evolves in response to the photo-exciting pulse and to subsequent relaxation processes. First, on the femtosecond timescale, the electronic subsystem relaxes to a Fermi-Dirac distribution characterized by an electronic temperature. Next, within picoseconds, thermalization with the underlying lattice phonons leads to a hot particle in internal equilibrium that subsequently equilibrates with the environment. Here we focus on the early stage of this multistep relaxation process, and on the properties of the ensuing non-equilibrium electronic distribution. We consider the form of this distribution as derived from the balance between the optical absorption and the subsequent relaxation processes, and discuss its implication for (a) heating of illuminated plasmonic particles, (b) the possibility to optically induce current in junctions, and (c) the prospect for experimental observation of such light-driven transport phenomena.

  14. Equilibrium and non-equilibrium metal-ceramic interfaces

    International Nuclear Information System (INIS)

    Gao, Y.; Merkle, K.L.

    1992-01-01

    Metal-ceramic interfaces in thermodynamic equilibrium (Au/ZrO 2 ) and non-equilibrium (Au/MgO) have been studied by TEM and HREM. In the Au/ZrO 2 system, ZrO 2 precipitates formed by internal oxidation of a 7%Zr-Au alloy show a cubic ZrO 2 phase. It appears that formation of the cubic ZrO 2 is facilitated by alignment with the Au matrix. Most of the ZrO 2 precipitates have a perfect cube-on-cube orientation relationship with the Au matrix. The large number of interfacial steps observed in a short-time annealing experiment indicate that the precipitates are formed by the ledge growth mechanism. The lowest interfacial energy is indicated by the dominance of closed-packed [111] Au/ZrO 2 interfaces. In the Au/MgO system, composite films with small MgO smoke particles embedded in a Au matrix were prepared by a thin film technique. HREM observations show that most of the Au/MgO interfaces have a strong tendency to maintain a dense lattice structure across the interfaces irrespective of whether the interfaces are incoherent or semi-coherent. This paper reports that this indicates that there may be a relatively strong bond between MgO and Au

  15. Fragmentation function in non-equilibrium QCD using closed-time path integral formalism

    International Nuclear Information System (INIS)

    Nayak, Gouranga C.

    2009-01-01

    In this paper we implement the Schwinger-Keldysh closed-time path integral formalism in non-equilibrium QCD in accordance to the definition of the Collins-Soper fragmentation function. We consider a high-p T parton in QCD medium at initial time τ 0 with an arbitrary non-equilibrium (non-isotropic) distribution function f(vector (p)) fragmenting to a hadron. We formulate the parton-to-hadron fragmentation function in non-equilibrium QCD in the light-cone quantization formalism. It may be possible to include final-state interactions with the medium via a modification of the Wilson lines in this definition of the non-equilibrium fragmentation function. This may be relevant to the study of hadron production from a quark-gluon plasma at RHIC and LHC. (orig.)

  16. Electrolytes: transport properties and non-equilibrium thermodynamics

    International Nuclear Information System (INIS)

    Miller, D.G.

    1980-12-01

    This paper presents a review on the application of non-equilibrium thermodynamics to transport in electrolyte solutions, and some recent experimental work and results for mutual diffusion in electrolyte solutions

  17. Investigation on non-equilibrium performance of composite adsorbent for resorption refrigeration

    International Nuclear Information System (INIS)

    Jiang, L.; Wang, L.W.; Zhou, Z.S.; Zhu, F.Q.; Wang, R.Z.

    2016-01-01

    Highlights: • Performance of resorption refrigeration is analyzed based on non-equilibrium reaction process. • The porous matrix improves the heat and mass performance of composite adsorbent. • The actual desorption process has the significant hysteresis phenomenon. • The highest energy efficiency of Manganese and Calcium chloride working pair is 0.272. - Abstract: The aims of this paper is to indicate that the non-equilibrium adsorption testing results is more suitable for prediction of real refrigeration performance than equilibrium data. Therefore, a test unit is constructed to test the non-equilibrium performance of different composite adsorbents. The adsorption and desorption quantity are measured and calculated by smart differential pressure transmitter. The non-equilibrium adsorption performances of working pair of Manganese chloride–ammonia, Calcium chloride–ammonia and Ammonium chloride–ammonia are investigated respectively. Results show that hysteresis phenomena happens obviously in non-equilibrium desorption process, which is related with dual variables rather than single variable. Based on the testing results, resorption refrigeration performance is analyzed, in which Manganese chloride is used as high temperature salt (HTS), and Calcium chloride, Ammonium chloride are selected as low temperature salt (LTS) for comparison. Results show that the highest COP and SCP for resorption refrigeration are about 0.272 and 45.6 W/kg, respectively. Performance of Manganese chloride–Calcium chloride and Manganese chloride–Ammonium chloride working pairs are much lower when compared with theoretical data.

  18. Statistical physics of hard optimization problems

    International Nuclear Information System (INIS)

    Zdeborova, L.

    2009-01-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an non-deterministic polynomial-complete problem the practically arising instances might, in fact, be easy to solve. The principal the question we address in the article is: How to recognize if an non-deterministic polynomial-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named 'locked' constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability (Authors)

  19. Non-equilibrium coupling of protein structure and function to translation-elongation kinetics.

    Science.gov (United States)

    Sharma, Ajeet K; O'Brien, Edward P

    2018-04-01

    Protein folding research has been dominated by the assumption that thermodynamics determines protein structure and function. And that when the folding process is compromised in vivo the proteostasis machinery-chaperones, deaggregases, the proteasome-work to restore proteins to their soluble, functional form or degrade them to maintain the cellular pool of proteins in a quasi-equilibrium state. During the past decade, however, more and more proteins have been identified for which altering only their speed of synthesis alters their structure and function, the efficiency of the down-stream processes they take part in, and cellular phenotype. Indeed, evidence has emerged that evolutionary selection pressures have encoded translation-rate information into mRNA molecules to coordinate diverse co-translational processes. Thus, non-equilibrium physics can play a fundamental role in influencing nascent protein behavior, mRNA sequence evolution, and disease. Here, we discuss how our understanding of this phenomenon is being advanced by the application of theoretical tools from the physical sciences. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Initial conditions of non-equilibrium quark-gluon plasma evolution

    International Nuclear Information System (INIS)

    Shmatov, S.V.

    2002-01-01

    In accordance with the hydrodynamic Bjorken limit, the initial energy density and temperature for a chemical non-equilibrium quark-gluon system formed in the heavy ion collisions at the LHC are computed. The dependence of this value on the type of colliding nuclei and the collision impact parameter is studied. The principle possibility of the non-equilibrium quark-gluon plasma (QGP) formation in the light nuclei collisions is shown. The life time of QGP is calculated. (author)

  1. I. Dissociation free energies of drug-receptor systems via non-equilibrium alchemical simulations: a theoretical framework.

    Science.gov (United States)

    Procacci, Piero

    2016-06-01

    In this contribution I critically revise the alchemical reversible approach in the context of the statistical mechanics theory of non-covalent bonding in drug-receptor systems. I show that most of the pitfalls and entanglements for the binding free energy evaluation in computer simulations are rooted in the equilibrium assumption that is implicit in the reversible method. These critical issues can be resolved by using a non-equilibrium variant of the alchemical method in molecular dynamics simulations, relying on the production of many independent trajectories with a continuous dynamical evolution of an externally driven alchemical coordinate, completing the decoupling of the ligand in a matter of a few tens of picoseconds rather than nanoseconds. The absolute binding free energy can be recovered from the annihilation work distributions by applying an unbiased unidirectional free energy estimate, on the assumption that any observed work distribution is given by a mixture of normal distributions, whose components are identical in either direction of the non-equilibrium process, with weights regulated by the Crooks theorem. I finally show that the inherent reliability and accuracy of the unidirectional estimate of the decoupling free energies, based on the production of a few hundreds of non-equilibrium independent sub-nanosecond unrestrained alchemical annihilation processes, is a direct consequence of the funnel-like shape of the free energy surface in molecular recognition. An application of the technique to a real drug-receptor system is presented in the companion paper.

  2. A non-equilibrium simulation of thermal constriction in a cascaded arc hydrogen plasma

    International Nuclear Information System (INIS)

    Peerenboom, K S C; Goedheer, W J; Van Dijk, J; 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 obtained before in a non-LTE simulation. Probably, realistic numerical studies of this type of plasma were hindered by numerical problems, preventing the non-LTE simulations to show characteristic physical mechanisms such as thermal constriction. In this paper we show that with the help of appropriate numerical strategies thermal constriction can be obtained in a non-LTE simulation. To this end, a new source term linearization technique is developed, which ensures physical solutions even near chemical equilibrium where the composition is dominated by chemical source terms. Results of the model are compared with experiments on Pilot-PSI and show good agreement with pressure and voltage measurements in the source. (paper)

  3. Self-assembly and transformation of hybrid nano-objects and nanostructures under equilibrium and non-equilibrium conditions

    Science.gov (United States)

    Mann, Stephen

    2009-10-01

    Understanding how chemically derived processes control the construction and organization of matter across extended and multiple length scales is of growing interest in many areas of materials research. Here we review present equilibrium and non-equilibrium self-assembly approaches to the synthetic construction of discrete hybrid (inorganic-organic) nano-objects and higher-level nanostructured networks. We examine a range of synthetic modalities under equilibrium conditions that give rise to integrative self-assembly (supramolecular wrapping, nanoscale incarceration and nanostructure templating) or higher-order self-assembly (programmed/directed aggregation). We contrast these strategies with processes of transformative self-assembly that use self-organizing media, reaction-diffusion systems and coupled mesophases to produce higher-level hybrid structures under non-equilibrium conditions. Key elements of the constructional codes associated with these processes are identified with regard to existing theoretical knowledge, and presented as a heuristic guideline for the rational design of hybrid nano-objects and nanomaterials.

  4. Experimental determination of order in non-equilibrium solids using colloidal gels

    International Nuclear Information System (INIS)

    Gao Yongxiang; Kilfoil, Maria

    2004-01-01

    The idea of quantifying order in disordered systems has been introduced recently by Torquato and co-workers (2000 Phys. Rev. E 62 993-1001). We are interested in the application of this idea to measure structure in non-equilibrium systems. Here we focus on gels, using as a model system colloidal gels formed from hard spheres with polymer added to the systems to induce a controlled, weak attraction. To describe the structure of the gels we use real space imaging via confocal microscopy to obtain the full three-dimensional structure. We measure experimentally both translational order and bond angle correlations, defining a new (refined) translational order parameter that is sensitive to long range order in these non-random packings. This metric is also sensitive to anisotropy, which should be important in the many physical situations where an external force is present. The bond angle distribution shows coordinated organization. To give a clearer physical picture for gels, we compare the experimental data to computer generated hard sphere systems

  5. Statistical Physics An Introduction

    CERN Document Server

    Yoshioka, Daijiro

    2007-01-01

    This book provides a comprehensive presentation of the basics of statistical physics. The first part explains the essence of statistical physics and how it provides a bridge between microscopic and macroscopic phenomena, allowing one to derive quantities such as entropy. Here the author avoids going into details such as Liouville’s theorem or the ergodic theorem, which are difficult for beginners and unnecessary for the actual application of the statistical mechanics. In the second part, statistical mechanics is applied to various systems which, although they look different, share the same mathematical structure. In this way readers can deepen their understanding of statistical physics. The book also features applications to quantum dynamics, thermodynamics, the Ising model and the statistical dynamics of free spins.

  6. Speed of sound in hadronic matter using non-extensive Tsallis statistics

    International Nuclear Information System (INIS)

    Khuntia, Arvind; Sahoo, Pragati; Garg, Prakhar; Sahoo, Raghunath; Cleymans, Jean

    2016-01-01

    The speed of sound (c_s) is studied to understand the hydrodynamical evolution of the matter created in heavy-ion collisions. The quark-gluon plasma (QGP) formed in heavy-ion collisions evolves from an initial QGP to the hadronic phase via a possible mixed phase. Due to the system expansion in a first-order phase transition scenario, the speed of sound reduces to zero as the specific heat diverges. We study the speed of sound for systems which deviate from a thermalized Boltzmann distribution using non-extensive Tsallis statistics. In the present work, we calculate the speed of sound as a function of temperature for different q-values for a hadron resonance gas. We observe a similar mass cut-off behaviour in the non-extensive case for c"2_s by including heavier particles, as is observed in the case of a hadron resonance gas following equilibrium statistics. Also, we explicitly show that the temperature where the mass cut-off starts varies with the q-parameter which hints at a relation between the degree of non-equilibrium and the limiting temperature of the system. It is shown that for values of q above approximately 1.13 all criticality disappears in the speed of sound, i.e. the decrease in the value of the speed of sound, observed at lower values of q, disappears completely. (orig.)

  7. Speed of sound in hadronic matter using non-extensive Tsallis statistics

    Energy Technology Data Exchange (ETDEWEB)

    Khuntia, Arvind; Sahoo, Pragati; Garg, Prakhar; Sahoo, Raghunath [Indian Institute of Technology Indore, Discipline of Physics, School of Basic Science, Simrol, M.P. (India); Cleymans, Jean [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa)

    2016-09-15

    The speed of sound (c{sub s}) is studied to understand the hydrodynamical evolution of the matter created in heavy-ion collisions. The quark-gluon plasma (QGP) formed in heavy-ion collisions evolves from an initial QGP to the hadronic phase via a possible mixed phase. Due to the system expansion in a first-order phase transition scenario, the speed of sound reduces to zero as the specific heat diverges. We study the speed of sound for systems which deviate from a thermalized Boltzmann distribution using non-extensive Tsallis statistics. In the present work, we calculate the speed of sound as a function of temperature for different q-values for a hadron resonance gas. We observe a similar mass cut-off behaviour in the non-extensive case for c{sup 2}{sub s} by including heavier particles, as is observed in the case of a hadron resonance gas following equilibrium statistics. Also, we explicitly show that the temperature where the mass cut-off starts varies with the q-parameter which hints at a relation between the degree of non-equilibrium and the limiting temperature of the system. It is shown that for values of q above approximately 1.13 all criticality disappears in the speed of sound, i.e. the decrease in the value of the speed of sound, observed at lower values of q, disappears completely. (orig.)

  8. Non-equilibrium thermodynamics, maximum entropy production and Earth-system evolution.

    Science.gov (United States)

    Kleidon, Axel

    2010-01-13

    The present-day atmosphere is in a unique state far from thermodynamic equilibrium. This uniqueness is for instance reflected in the high concentration of molecular oxygen and the low relative humidity in the atmosphere. Given that the concentration of atmospheric oxygen has likely increased throughout Earth-system history, we can ask whether this trend can be generalized to a trend of Earth-system evolution that is directed away from thermodynamic equilibrium, why we would expect such a trend to take place and what it would imply for Earth-system evolution as a whole. The justification for such a trend could be found in the proposed general principle of maximum entropy production (MEP), which states that non-equilibrium thermodynamic systems maintain steady states at which entropy production is maximized. Here, I justify and demonstrate this application of MEP to the Earth at the planetary scale. I first describe the non-equilibrium thermodynamic nature of Earth-system processes and distinguish processes that drive the system's state away from equilibrium from those that are directed towards equilibrium. I formulate the interactions among these processes from a thermodynamic perspective and then connect them to a holistic view of the planetary thermodynamic state of the Earth system. In conclusion, non-equilibrium thermodynamics and MEP have the potential to provide a simple and holistic theory of Earth-system functioning. This theory can be used to derive overall evolutionary trends of the Earth's past, identify the role that life plays in driving thermodynamic states far from equilibrium, identify habitability in other planetary environments and evaluate human impacts on Earth-system functioning. This journal is © 2010 The Royal Society

  9. A nested-LES wall-modeling approach for computation of high Reynolds number equilibrium and non-equilibrium wall-bounded turbulent flows

    Science.gov (United States)

    Tang, Yifeng; Akhavan, Rayhaneh

    2014-11-01

    A nested-LES wall-modeling approach for high Reynolds number, wall-bounded turbulence is presented. In this approach, a coarse-grained LES is performed in the full-domain, along with a nested, fine-resolution LES in a minimal flow unit. The coupling between the two domains is achieved by renormalizing the instantaneous LES velocity fields to match the profiles of kinetic energies of components of the mean velocity and velocity fluctuations in both domains to those of the minimal flow unit in the near-wall region, and to those of the full-domain in the outer region. The method is of fixed computational cost, independent of Reτ , in homogenous flows, and is O (Reτ) in strongly non-homogenous flows. The method has been applied to equilibrium turbulent channel flows at 1000 shear-driven, 3D turbulent channel flow at Reτ ~ 2000 . In equilibrium channel flow, the friction coefficient and the one-point turbulence statistics are predicted in agreement with Dean's correlation and available DNS and experimental data. In shear-driven, 3D channel flow, the evolution of turbulence statistics is predicted in agreement with experimental data of Driver & Hebbar (1991) in shear-driven, 3D boundary layer flow.

  10. The second-order description of rotational non-equilibrium effects in polyatomic gases

    Science.gov (United States)

    Myong, Rho Shin

    2017-11-01

    The conventional description of gases is based on the physical laws of conservation (mass, momentum, and energy) in conjunction with the first-order constitutive laws, the two-century old so-called Navier-Stokes-Fourier (NSF) equation based on a critical assumption made by Stokes in 1845 that the bulk viscosity vanishes. While the Stokes' assumption is certainly legitimate in the case of dilute monatomic gases, ever increasing evidences, however, now indicate that such is not the case, in particular, in the case of polyatomic gases-like nitrogen and carbon dioxide-far-from local thermal equilibrium. It should be noted that, from room temperature acoustic attenuation data, the bulk viscosity for carbon dioxide is three orders of magnitude larger than its shear viscosity. In this study, this fundamental issue in compressible gas dynamics is revisited and the second-order constitutive laws are derived by starting from the Boltzmann-Curtiss kinetic equation. Then the topology of the second-order nonlinear coupled constitutive relations in phase space is investigated. Finally, the shock-vortex interaction problem where the strong interaction of two important thermal (translational and rotational) non-equilibrium phenomena occurs is considered in order to highlight the rotational non-equilibrium effects in polyatomic gases. This work was supported by the National Research Foundation of South Korea (NRF 2017-R1A2B2-007634).

  11. Simulations of NMR pulse sequences during equilibrium and non-equilibrium chemical exchange

    International Nuclear Information System (INIS)

    Helgstrand, Magnus; Haerd, Torleif; Allard, Peter

    2000-01-01

    The McConnell equations combine the differential equations for a simple two-state chemical exchange process with the Bloch differential equations for a classical description of the behavior of nuclear spins in a magnetic field. This equation system provides a useful starting point for the analysis of slow, intermediate and fast chemical exchange studied using a variety of NMR experiments. The McConnell equations are in the mathematical form of an inhomogeneous system of first-order differential equations. Here we rewrite the McConnell equations in a homogeneous form in order to facilitate fast and simple numerical calculation of the solution to the equation system. The McConnell equations can only treat equilibrium chemical exchange. We therefore also present a homogeneous equation system that can handle both equilibrium and non-equilibrium chemical processes correctly, as long as the kinetics is of first-order. Finally, the same method of rewriting the inhomogeneous form of the McConnell equations into a homogeneous form is applied to a quantum mechanical treatment of a spin system in chemical exchange. In order to illustrate the homogeneous McConnell equations, we have simulated pulse sequences useful for measuring exchange rates in slow, intermediate and fast chemical exchange processes. A stopped-flow NMR experiment was simulated using the equations for non-equilibrium chemical exchange. The quantum mechanical treatment was tested by the simulation of a sensitivity enhanced 15 N-HSQC with pulsed field gradients during slow chemical exchange and by the simulation of the transfer efficiency of a two-dimensional heteronuclear cross-polarization based experiment as a function of both chemical shift difference and exchange rate constants

  12. Note: Local thermal conductivities from boundary driven non-equilibrium molecular dynamics simulations

    International Nuclear Information System (INIS)

    Bresme, F.; Armstrong, J.

    2014-01-01

    We report non-equilibrium molecular dynamics simulations of heat transport in models of molecular fluids. We show that the “local” thermal conductivities obtained from non-equilibrium molecular dynamics simulations agree within numerical accuracy with equilibrium Green-Kubo computations. Our results support the local equilibrium hypothesis for transport properties. We show how to use the local dependence of the thermal gradients to quantify the thermal conductivity of molecular fluids for a wide range of thermodynamic states using a single simulation

  13. Conceptual Integration of Chemical Equilibrium by Prospective Physical Sciences Teachers

    Science.gov (United States)

    Ganaras, Kostas; Dumon, Alain; Larcher, Claudine

    2008-01-01

    This article describes an empirical study concerning the mastering of the chemical equilibrium concept by prospective physical sciences teachers. The main objective was to check whether the concept of chemical equilibrium had become an integrating and unifying concept for them, that is to say an operational and functional knowledge to explain and…

  14. Supersymmetric Field Theory of Non-Equilibrium Thermodynamic System

    OpenAIRE

    Olemskoi, Alexander I.; Brazhnyi, Valerii A.

    1998-01-01

    On the basis of Langevin equation the optimal SUSY field scheme is formulated to discribe a non-equilibrium thermodynamic system with quenched disorder and non-ergodicity effects. Thermodynamic and isothermal susceptibilities, memory parameter and irreversible response are determined at different temperatures and quenched disorder intensities.

  15. The statistical mechanics of financial markets

    CERN Document Server

    Voit, Johannes

    2003-01-01

    From the reviews of the first edition - "Provides an excellent introduction for physicists interested in the statistical properties of financial markets. Appropriately early in the book the basic financial terms such as shorts, limit orders, puts, calls, and other terms are clearly defined. Examples, often with graphs, augment the reader’s understanding of what may be a plethora of new terms and ideas… [This is] an excellent starting point for the physicist interested in the subject. Some of the book’s strongest features are its careful definitions, its detailed examples, and the connection it establishes to physical systems." PHYSICS TODAY "This book is excellent at illustrating the similarities of financial markets with other non-equilibrium physical systems. [...] In summary, a very good book that offers more than just qualitative comparisons of physics and finance." (www.quantnotes.com) This highly-praised introductory treatment describes parallels between statistical physics and finance - both thos...

  16. Thermodynamics and statistical physics. 2. rev. ed.

    International Nuclear Information System (INIS)

    Schnakenberg, J.

    2002-01-01

    This textbook covers tthe following topics: Thermodynamic systems and equilibrium, irreversible thermodynamics, thermodynamic potentials, stability, thermodynamic processes, ideal systems, real gases and phase transformations, magnetic systems and Landau model, low temperature thermodynamics, canonical ensembles, statistical theory, quantum statistics, fermions and bosons, kinetic theory, Bose-Einstein condensation, photon gas

  17. Coronal emission-line polarization from the statistical equilibrium of magnetic sublevels. I. Fe XII

    International Nuclear Information System (INIS)

    House, L.L.

    1977-01-01

    A general formulation for the polarization of coronal emission lines is presented, and the physics is illustrated through application of the formulation to the lines of Fe XIII at 10747 and 10798 A. The goal is to present a foundation for the determination of the orientation of coronal magnetic fields from emission-line polarization measurements. The physics of emission-line polarization is discussed using the statistical equilibrium equations for the magnetic sublevels of a coronal ion. The formulation of these equations, which describe the polarization of the radiation field in terms of Stokes parameters, is presented; and the various rate parameters: both radiative and collisional: are considered. The emission Stokes vector is constructed from the solution of the equilibrium equations for a point in the corona where the magnetic field has an arbitrary orientation. On the basis of a model, a computer code for the calculation of emission-line polarization is briefly described and illustrated with a number of sample calculations for Fe XIII. Calculations are carried out for three-dimensional models that demonstrate the physics of the formation of emission-line polarization and illustrate how the degree of polarization and angle of polarization and their variations over the corona are related to the density and magnetic field structure. The models considered range from simple cases in which the density distribution with height is spherically symmetric and the field is radial or dipole to a complex case in which both the density and magnetic field distributions are derived from realistic three-dimensional distributions for the 1973 eclipse on the basis of K-coronameter measurements for the density and potential-field extrapolation of surface magnetic fields in the corona

  18. Two-temperature chemically non-equilibrium modelling of an air supersonic ICP

    Energy Technology Data Exchange (ETDEWEB)

    El Morsli, Mbark; Proulx, Pierre [Laboratoire de Modelisation de Procedes Chimiques par Ordinateur Oppus, Departement de Genie Chimique, Universite de Sherbrooke (Ciheam) J1K 2R1 (Canada)

    2007-08-21

    In this work, a non-equilibrium mathematical model for an air inductively coupled plasma torch with a supersonic nozzle is developed without making thermal and chemical equilibrium assumptions. Reaction rate equations are written, and two coupled energy equations are used, one for the calculation of the translational-rotational temperature T{sub hr} and one for the calculation of the electro-vibrational temperature T{sub ev}. The viscous dissipation is taken into account in the translational-rotational energy equation. The electro-vibrational energy equation also includes the pressure work of the electrons, the Ohmic heating power and the exchange due to elastic collision. 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 collisions integrals available in the literature. The results obtained are compared with those obtained using a chemical equilibrium model and a one-temperature chemical non-equilibrium model. The influence of the power and the pressure chamber on the chemical and thermal non-equilibrium is investigated.

  19. Forces and energy dissipation in inhomogeneous non-equilibrium superconductors

    International Nuclear Information System (INIS)

    Poluehktov, Yu.M.; Slezov, V.V.

    1987-01-01

    The phenomenological theory of volume forces and dissipation processes in inhomogeneous non-equilibrium superconductors near temperature transition from the normal to superconducting state is constructed. The approach is based on application of dynamic equations of superconductivity formulated on the basis of the Lagrangian formalism. These equations are generalized the Ginzburg-Landau theory in the nonstationary non-equilibrium case for ''foul'' superconductors. The value estimations of volume forces arising in inhomogeneities during relaxation of an order parameter and when the electrical field is penetrated into the superconductor, are given

  20. Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands.

    Science.gov (United States)

    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.

  1. Conceptual developments of non-equilibrium statistical mechanics in the early days of Japan

    Science.gov (United States)

    Ichiyanagi, Masakazu

    1995-11-01

    This paper reviews the research in nonequilibrium statistical mechanics made in Japan in the period between 1930 and 1960. Nearly thirty years have passed since the discovery of the exact formula for the electrical conductivity. With the rise of the linear response theory, the methods and results of which are quickly grasped by anyone, its rationale was pushed aside and even at the stage where the formulation was still incomplete some authors hurried to make physical applications. Such an attitude robbed it of most of its interest for the average physicist, who would approach an understanding of some basic concept, not through abstract and logical analysis but by simply increasing his technical experiences with the concept. The purpose of this review is to rescue the linear response theory from being labeled a mathematical tool and to show that it has considerable physical content. Many key papers, originally written in Japanese, are reproduced.

  2. Thermal equilibrium and statistical thermometers in special relativity.

    Science.gov (United States)

    Cubero, David; Casado-Pascual, Jesús; Dunkel, Jörn; Talkner, Peter; Hänggi, Peter

    2007-10-26

    There is an intense debate in the recent literature about the correct generalization of Maxwell's velocity distribution in special relativity. The most frequently discussed candidate distributions include the Jüttner function as well as modifications thereof. Here we report results from fully relativistic one-dimensional molecular dynamics simulations that resolve the ambiguity. The numerical evidence unequivocally favors the Jüttner distribution. Moreover, our simulations illustrate that the concept of "thermal equilibrium" extends naturally to special relativity only if a many-particle system is spatially confined. They make evident that "temperature" can be statistically defined and measured in an observer frame independent way.

  3. Non-equilibrium plasma reactor for natrual gas processing

    International Nuclear Information System (INIS)

    Shair, F.H.; Ravimohan, A.L.

    1974-01-01

    A non-equilibrium plasma reactor for natural gas processing into ethane and ethylene comprising means of producing a non-equilibrium chemical plasma wherein selective conversion of the methane in natural gas to desired products of ethane and ethylene at a pre-determined ethane/ethylene ratio in the chemical process may be intimately controlled and optimized at a high electrical power efficiency rate by mixing with a recycling gas inert to the chemical process such as argon, helium, or hydrogen, reducing the residence time of the methane in the chemical plasma, selecting the gas pressure in the chemical plasma from a wide range of pressures, and utilizing pulsed electrical discharge producing the chemical plasma. (author)

  4. Improvement of characteristic statistic algorithm and its application on equilibrium cycle reloading optimization

    International Nuclear Information System (INIS)

    Hu, Y.; Liu, Z.; Shi, X.; Wang, B.

    2006-01-01

    A brief introduction of characteristic statistic algorithm (CSA) is given in the paper, which is a new global optimization algorithm to solve the problem of PWR in-core fuel management optimization. CSA is modified by the adoption of back propagation neural network and fast local adjustment. Then the modified CSA is applied to PWR Equilibrium Cycle Reloading Optimization, and the corresponding optimization code of CSA-DYW is developed. CSA-DYW is used to optimize the equilibrium cycle of 18 month reloading of Daya bay nuclear plant Unit 1 reactor. The results show that CSA-DYW has high efficiency and good global performance on PWR Equilibrium Cycle Reloading Optimization. (authors)

  5. Final Report on DTRA Basic Research Project #BRCALL08-Per3-C-2-0006 "High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser Targets"

    Energy Technology Data Exchange (ETDEWEB)

    Colvin, Jeffrey D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-06-01

    This project had two major goals. Final Goal: obtain spectrally resolved, absolutely calibrated x-ray emission data from uniquely uniform mm-scale near-critical-density high-Z plasmas not in local thermodynamic equilibrium (LTE) to benchmark modern detailed atomic physics models. Scientific significance: advance understanding of non-LTE atomic physics. Intermediate Goal: develop new nano-fabrication techniques to make suitable laser targets that form the required highly uniform non-LTE plasmas when illuminated by high-intensity laser light. Scientific significance: advance understanding of nano-science. The new knowledge will allow us to make x-ray sources that are bright at the photon energies of most interest for testing radiation hardening technologies, the spectral energy range where current x-ray sources are weak. All project goals were met.

  6. Non-equilibrium effects in the plasmas

    International Nuclear Information System (INIS)

    Einfeld, D.

    1975-01-01

    Radial dependences of non-equilibrium effects of a He plasma were studied in a wall-stabilized short-time discharge. The electron density (nsub(e) = 2.5 x 10 22 m -3 ), the electron temperature and the equilibrium shift were determined by calculations of the continuum beam density and the beam densities of one He-I and one He-II line, respectively. In the discharge axis, the overpopulation factors of the ground state of He-I and He-II are about 75. As the distance to the axis increases, they increase for He-I and decrease for He-II. Except for the usual errors of measurement, the overpopulation factors found here correspond to those calculated from the balance equations (Drawin). (orig./AK) [de

  7. Theory of stellar atmospheres an introduction to astrophysical non-equilibrium quantitative spectroscopic analysis

    CERN Document Server

    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.

  8. Memory loss process and non-Gibbsian equilibrium solutions of master equations

    International Nuclear Information System (INIS)

    Cataldo, H.M.; Hernandez, E.S.

    1988-01-01

    The phonon dynamics of a harmonic oscillator coupled to a steady reservoir is studied. In the Markovian limit, the equilibrium is reached through a progressive loss of memory process which involves the moments of the initial distribution. The relationship to the non-Markovian equations of motion and its resolvent poles is settled. As a particular model of the coupling mechanism is adopted, the possibility of non-Gibbsian equilibrium distribution arises, which is analyzed focusing upon the dependence of various parameters of the system on an effective equilibrium temperature

  9. Thermodynamics, Gibbs Method and Statistical Physics of Electron Gases Gibbs Method and Statistical Physics of Electron Gases

    CERN Document Server

    Askerov, Bahram M

    2010-01-01

    This book deals with theoretical thermodynamics and the statistical physics of electron and particle gases. While treating the laws of thermodynamics from both classical and quantum theoretical viewpoints, it posits that the basis of the statistical theory of macroscopic properties of a system is the microcanonical distribution of isolated systems, from which all canonical distributions stem. To calculate the free energy, the Gibbs method is applied to ideal and non-ideal gases, and also to a crystalline solid. Considerable attention is paid to the Fermi-Dirac and Bose-Einstein quantum statistics and its application to different quantum gases, and electron gas in both metals and semiconductors is considered in a nonequilibrium state. A separate chapter treats the statistical theory of thermodynamic properties of an electron gas in a quantizing magnetic field.

  10. Quantum physics and statistical physics. 5. ed.

    International Nuclear Information System (INIS)

    Alonso, Marcelo; Finn, Edward J.

    2012-01-01

    By logical and uniform presentation this recognized introduction in modern physics treats both the experimental and theoretical aspects. The first part of the book deals with quantum mechanics and their application to atoms, molecules, nuclei, solids, and elementary particles. The statistical physics with classical statistics, thermodynamics, and quantum statistics is theme of the second part. Alsonso and Finn avoid complicated mathematical developments; by numerous sketches and diagrams as well as many problems and examples they make the reader early and above all easily understandably familiar with the formations of concepts of modern physics.

  11. Integral Method for the Assessment of U-RANS Effectiveness in Non-Equilibrium Flows and Heat Transfer

    Science.gov (United States)

    Pond, Ian; Edabi, Alireza; Dubief, Yves; White, Christopher

    2015-11-01

    Reynolds Average Navier Stokes (RANS) modeling has established itself as a critical design tool in many engineering applications, thanks to its superior computational efficiency. The drawbacks of RANS models are well known, but not necessarily well understood: poor prediction of transition, non equilibrium flows, mixing and heat transfer, to name the ones relevant to our study. In the present study, we use a DNS of a reciprocating channel flow driven by an oscillating pressure gradient to test several low- and high-Reynolds RANS models. Temperature is introduced as a passive scalar to study heat transfer modeling. Low-Reynolds models manage to capture the overall physics of wall shear and heat flux well, yet with some phase discrepancies, whereas high Reynolds models fail. Under the microscope of the integral method for wall shear and wall heat flux, the qualitative agreement appears more serendipitous than driven by the ability of the models to capture the correct physics. The integral method is shown to be more insightful in the benchmarking of RANS models than the typical comparisons of statistical quantities. The authors acknowledges the support of NSF and DOE under grant NSF/DOE 1258697 (VT) and 1258702 (NH).

  12. Non-canonical distribution and non-equilibrium transport beyond weak system-bath coupling regime: A polaron transformation approach

    Science.gov (United States)

    Xu, Dazhi; Cao, Jianshu

    2016-08-01

    The concept of polaron, emerged from condense matter physics, describes the dynamical interaction of moving particle with its surrounding bosonic modes. This concept has been developed into a useful method to treat open quantum systems with a complete range of system-bath coupling strength. Especially, the polaron transformation approach shows its validity in the intermediate coupling regime, in which the Redfield equation or Fermi's golden rule will fail. In the polaron frame, the equilibrium distribution carried out by perturbative expansion presents a deviation from the canonical distribution, which is beyond the usual weak coupling assumption in thermodynamics. A polaron transformed Redfield equation (PTRE) not only reproduces the dissipative quantum dynamics but also provides an accurate and efficient way to calculate the non-equilibrium steady states. Applications of the PTRE approach to problems such as exciton diffusion, heat transport and light-harvesting energy transfer are presented.

  13. Convection with local thermal non-equilibrium and microfluidic effects

    CERN Document Server

    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.

  14. Replacing leads by self-energies using non-equilibrium Green's functions

    International Nuclear Information System (INIS)

    Michael, Fredrick; Johnson, M.D.

    2003-01-01

    Open quantum systems consist of semi-infinite leads which transport electrons to and from the device of interest. We show here that within the non-equilibrium Green's function technique for continuum systems, the leads can be replaced by simple c-number self-energies. Our starting point is an approach for continuum systems developed by Feuchtwang. The reformulation developed here is simpler to understand and carry out than the somewhat unwieldly manipulations typical in the Feuchtwang method. The self-energies turn out to have a limited variability: the retarded self-energy Σ r depends on the arbitrary choice of internal boundary conditions, but the non-equilibrium self-energy or scattering function Σ which determines transport is invariant for a broad class of boundary conditions. Expressed in terms of these self-energies, continuum non-equilibrium transport calculations take a particularly simple form similar to that developed for discrete systems

  15. Continuum model of non-equilibrium solvation and solvent effect on ultra-fast processes

    International Nuclear Information System (INIS)

    Li Xiangyuan; Fu Kexiang; Zhu Quan

    2006-01-01

    In the past 50 years, non-equilibrium solvation theory for ultra-fast processes such as electron transfer and light absorption/emission has attracted particular interest. A great deal of research efforts was made in this area and various models which give reasonable qualitative descriptions for such as solvent reorganization energy in electron transfer and spectral shift in solution, were developed within the framework of continuous medium theory. In a series of publications by the authors, we clarified that the expression of the non-equilibrium electrostatic free energy that is at the dominant position of non-equilibrium solvation and serves as the basis of various models, however, was incorrectly formulated. In this work, the authors argue that reversible charging work integration was inappropriately applied in the past to an irreversible path linking the equilibrium or the non-equilibrium state. Because the step from the equilibrium state to the nonequilibrium state is factually thermodynamically irreversible, the conventional expression for non-equilibrium free energy that was deduced in different ways is unreasonable. Here the authors derive the non-equilibrium free energy to a quite different form according to Jackson integral formula. Such a difference throws doubts to the models including the famous Marcus two-sphere model for solvent reorganization energy of electron transfer and the Lippert-Mataga equation for spectral shift. By introducing the concept of 'spring energy' arising from medium polarizations, the energy constitution of the non-equilibrium state is highlighted. For a solute-solvent system, the authors separate the total electrostatic energy into different components: the self-energies of solute charge and polarized charge, the interaction energy between them and the 'spring energy' of the solvent polarization. With detailed reasoning and derivation, our formula for non-equilibrium free energy can be reached through different ways. Based on the

  16. Non-equilibrium reaction rates in chemical kinetic equations

    Science.gov (United States)

    Gorbachev, Yuriy

    2018-05-01

    Within the recently proposed asymptotic method for solving the Boltzmann equation for chemically reacting gas mixture, the chemical kinetic equations has been derived. Corresponding one-temperature non-equilibrium reaction rates are expressed in terms of specific heat capacities of the species participate in the chemical reactions, bracket integrals connected with the internal energy transfer in inelastic non-reactive collisions and energy transfer coefficients. Reactions of dissociation/recombination of homonuclear and heteronuclear diatomic molecules are considered. It is shown that all reaction rates are the complex functions of the species densities, similarly to the unimolecular reaction rates. For determining the rate coefficients it is recommended to tabulate corresponding bracket integrals, additionally to the equilibrium rate constants. Correlation of the obtained results with the irreversible thermodynamics is established.

  17. Dynamical Cooper pairing in non-equilibrium electron-phonon systems

    Energy Technology Data Exchange (ETDEWEB)

    Knap, Michael [Technical University of Munich (Germany); Harvard University (United States); Babadi, Mehrtash; Refael, Gil [Caltech (United States); Martin, Ivar [Argonne National Laboratory (United States); Demler, Eugene [Harvard University (United States)

    2016-07-01

    Ultrafast laser pulses have been used to manipulate complex quantum materials and to induce dynamical phase transitions. One of the most striking examples is the transient enhancement of superconductivity in several classes of materials upon irradiating them with high intensity pulses of terahertz light. Motivated by these experiments we analyze the Cooper pairing instabilities in non-equilibrium electron-phonon systems. We demonstrate that the light induced non-equilibrium state of phonons results in a simultaneous increase of the superconducting coupling constant and the electron scattering. We analyze the competition between these effects and show that in a broad range of parameters the dynamic enhancement of Cooper pair formation dominates over the increase in the scattering rate. This opens the possibility of transient light induced superconductivity at temperatures that are considerably higher than the equilibrium transition temperatures. Our results pave new pathways for engineering high-temperature light-induced superconducting states.

  18. Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry.

    Science.gov (United States)

    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.

  19. Pre-equilibrium assumptions and statistical model parameters effects on reaction cross-section calculations

    International Nuclear Information System (INIS)

    Avrigeanu, M.; Avrigeanu, V.

    1992-02-01

    A systematic study on effects of statistical model parameters and semi-classical pre-equilibrium emission models has been carried out for the (n,p) reactions on the 56 Fe and 60 Co target nuclei. The results obtained by using various assumptions within a given pre-equilibrium emission model differ among them more than the ones of different models used under similar conditions. The necessity of using realistic level density formulas is emphasized especially in connection with pre-equilibrium emission models (i.e. with the exciton state density expression), while a basic support could be found only by replacement of the Williams exciton state density formula with a realistic one. (author). 46 refs, 12 figs, 3 tabs

  20. Statistical physics of complex systems a concise introduction

    CERN Document Server

    Bertin, Eric

    2016-01-01

    This course-tested primer provides graduate students and non-specialists with a basic understanding of the concepts and methods of statistical physics and demonstrates their wide range of applications to interdisciplinary topics in the field of complex system sciences, including selected aspects of theoretical modeling in biology and the social sciences. Generally speaking, the goals of statistical physics may be summarized as follows: on the one hand to study systems composed of a large number of interacting units, and on the other to predict the macroscopic, collective behavior of the system considered from the perspective of the microscopic laws governing the dynamics of the individual entities. These two goals are essentially also shared by what is now called 'complex systems science', and as such, systems studied in the framework of statistical physics may be considered to be among the simplest examples of complex systems – while also offering a rather well developed mathematical treatment. The second ...

  1. One-loop calculation in time-dependent non-equilibrium thermo field dynamics

    International Nuclear Information System (INIS)

    Umezawa, H.; Yamanaka, Y.

    1989-01-01

    This paper is a review on the structure of thermo field dynamics (TFD) in which the basic concepts such as the thermal doublets, the quasi-particles and the self-consistent renormalization are presented in detail. A strong emphasis is put on the computational scheme. A detailed structure of this scheme is illustrated by the one-loop calculation in a non-equilibrium time-dependent process. A detailed account of the one-loop calculation has never been reported anywhere. The role of the self-consistent renormalization is explained. The equilibrium TFD is obtained as the long-time limit of non-equilibrium TFD. (author)

  2. Coherent application of a contact structure to formulate Classical Non-Equilibrium Thermodynamics

    NARCIS (Netherlands)

    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

  3. Non-equilibrium reactive flux: A unified framework for slow and fast reaction kinetics.

    Science.gov (United States)

    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.

  4. Proceedings of RIKEN BNL research center workshop, equilibrium and non-equilibrium aspects of hot, dense QCD, Vol. 28

    International Nuclear Information System (INIS)

    De Vega, H.J.; Boyanovsky, D.

    2000-01-01

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven, beginning operation this year, and the Large Hadron Collider (LHC) at CERN, beginning operation ∼2005, will provide an unprecedented range of energies and luminosities that will allow us to probe the Gluon-Quark plasma. At RHIC and LHC, at central rapidity typical estimates of energy densities and temperatures are e * 1-10 GeV/fm3 and T0 * 300 - 900 MeV. Such energies are well above current estimates for the GQ plasma. Initially, this hot, dense plasma is far from local thermal equilibrium, making the theoretical study of transport phenomena, kinetic and chemical equilibration in dense and hot plasmas, and related issues a matter of fundamental importance. During the last few years a consistent framework to study collective effects in the Gluon-Quark plasma, and a microscopic description of transport in terms of the hard thermal (and dense) loops resummation program has emerged. This approach has the potential of providing a microscopic formulation of transport, in the regime of temperatures and densities to be achieved at RHIC and LHC. A parallel development over the last few years has provided a consistent formulation of non-equilibrium quantum field theory that provides a real-time description of phenomena out of equilibrium. Novel techniques including non-perturbative approaches and the dynamical renormalization group techniques lead to new insights into transport and relaxation. A deeper understanding of collective.excitations and transport phenomena in the GQ plasma could lead to recognize novel potential experimental signatures. New insights into small-c physics reveals a striking similarity between small-c and hard thermal loops, and novel real-time numerical simulations have recently studied the parton distributions and their thermalizations in the initial stages of a heavy ion collision

  5. Temperature control in molecular dynamic simulations of non-equilibrium processes

    International Nuclear Information System (INIS)

    Toton, Dawid; Lorenz, Christian D; Rompotis, Nikolaos; Martsinovich, Natalia; Kantorovich, Lev

    2010-01-01

    Thermostats are often used in various condensed matter problems, e.g. when a biological molecule undergoes a transformation in a solution, a crystal surface is irradiated with energetic particles, a crack propagates in a solid upon applied stress, two surfaces slide with respect to each other, an excited local phonon dissipates its energy into a crystal bulk, and so on. In all of these problems, as well as in many others, there is an energy transfer between different local parts of the entire system kept at a constant temperature. Very often, when modelling such processes using molecular dynamics simulations, thermostatting is done using strictly equilibrium approaches serving to describe the NVT ensemble. In this paper we critically discuss the applicability of such approaches to non-equilibrium problems, including those mentioned above, and stress that the correct temperature control can only be achieved if the method is based on the generalized Langevin equation (GLE). Specifically, we emphasize that a meaningful compromise between computational efficiency and a physically appropriate implementation of the NVT thermostat can be achieved, at least for solid state and surface problems, if the so-called stochastic boundary conditions (SBC), recently derived from the GLE (Kantorovich and Rompotis 2008 Phys. Rev. B 78 094305), are used. For SBC, the Langevin thermostat is only applied to the outer part of the simulated fragment of the entire system which borders the surrounding environment (not considered explicitly) serving as a heat bath. This point is illustrated by comparing the performance of the SBC and some of the equilibrium thermostats in two problems: (i) irradiation of the Si(001) surface with an energetic CaF 2 molecule using an ab initio density functional theory based method, and (ii) the tribology of two amorphous SiO 2 surfaces coated with self-assembled monolayers of methyl-terminated hydrocarbon alkoxylsilane molecules using a classical atomistic

  6. Nakedly singular non-vacuum gravitating equilibrium states

    Science.gov (United States)

    Woszczyna, Andrzej; Kutschera, Marek; Kubis, Sebastian; Czaja, Wojciech; Plaszczyk, Piotr; Golda, Zdzisław A.

    2016-01-01

    Non-vacuum static spherically symmetric spacetimes with central point-like repulsive gravity sources are investigated. Both the symmetries of spacetime and the degree of irregularity of curvature invariants, are the same as for the Schwarzschild case. The equilibrium configurations are modelled using the neutron star polytrope equation of state.

  7. New Hybrid Monte Carlo methods for efficient sampling. From physics to biology and statistics

    International Nuclear Information System (INIS)

    Akhmatskaya, Elena; Reich, Sebastian

    2011-01-01

    We introduce a class of novel hybrid methods for detailed simulations of large complex systems in physics, biology, materials science and statistics. These generalized shadow Hybrid Monte Carlo (GSHMC) methods combine the advantages of stochastic and deterministic simulation techniques. They utilize a partial momentum update to retain some of the dynamical information, employ modified Hamiltonians to overcome exponential performance degradation with the system’s size and make use of multi-scale nature of complex systems. Variants of GSHMCs were developed for atomistic simulation, particle simulation and statistics: GSHMC (thermodynamically consistent implementation of constant-temperature molecular dynamics), MTS-GSHMC (multiple-time-stepping GSHMC), meso-GSHMC (Metropolis corrected dissipative particle dynamics (DPD) method), and a generalized shadow Hamiltonian Monte Carlo, GSHmMC (a GSHMC for statistical simulations). All of these are compatible with other enhanced sampling techniques and suitable for massively parallel computing allowing for a range of multi-level parallel strategies. A brief description of the GSHMC approach, examples of its application on high performance computers and comparison with other existing techniques are given. Our approach is shown to resolve such problems as resonance instabilities of the MTS methods and non-preservation of thermodynamic equilibrium properties in DPD, and to outperform known methods in sampling efficiency by an order of magnitude. (author)

  8. Non-equilibrium magnetic interactions in strongly correlated systems

    Energy Technology Data Exchange (ETDEWEB)

    Secchi, A., E-mail: a.secchi@science.ru.nl [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands); Brener, S.; Lichtenstein, A.I. [Institut für Theoretische Physik, Universitat Hamburg, Jungiusstraße 9, D-20355 Hamburg (Germany); Katsnelson, M.I. [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands)

    2013-06-15

    We formulate a low-energy theory for the magnetic interactions between electrons in the multi-band Hubbard model under non-equilibrium conditions determined by an external time-dependent electric field which simulates laser-induced spin dynamics. We derive expressions for dynamical exchange parameters in terms of non-equilibrium electronic Green functions and self-energies, which can be computed, e.g., with the methods of time-dependent dynamical mean-field theory. Moreover, we find that a correct description of the system requires, in addition to exchange, a new kind of magnetic interaction, that we name twist exchange, which formally resembles Dzyaloshinskii–Moriya coupling, but is not due to spin–orbit, and is actually due to an effective three-spin interaction. Our theory allows the evaluation of the related time-dependent parameters as well. -- Highlights: •We develop a theory for magnetism of strongly correlated systems out of equilibrium. •Our theory is suitable for laser-induced ultrafast magnetization dynamics. •We write time-dependent exchange parameters in terms of electronic Green functions. •We find a new magnetic interaction, a “twist exchange”. •We give general expressions for magnetic noise in itinerant-electron systems.

  9. Nuclear Statistical Equilibrium for compact stars: modelling the nuclear energy functional

    International Nuclear Information System (INIS)

    Aymard, Francois

    2015-01-01

    and beyond. At densities above two-three times saturation, other degrees of freedom are expected to appear, which potentially lead to other consistency problems but this issue will not be treated in this thesis. The thesis is divided into three parts. In part I, we present the Nuclear Statistical Equilibrium model based on the grand canonical statistics and non-relativistic Skyrme interactions. Results at β-equilibrium are shown and the importance of the clusters distribution as well as a realistic treatment for the free energy model is discussed. Part II investigates the functional behavior of the baryonic energy in the Wigner-Seitz cell within the Extended-Thomas-Fermi approximation. In particular, both bulk and surface in-medium effects are studied, and their dependence on cluster size and asymmetry as well as gas densities and asymmetry is investigated. A preliminary result of in-medium surface effects is presented within some approximations in the case of β-equilibrated matter. In part III, we develop approximations in order to obtain a reliable analytical expression of the mass formula, directly linked to the functional form and parameters of the Skyrme interaction. In this part, we mainly focus on nuclei in vacuum, and analyse the different binding energy components in terms of bulk and surface properties, as well as isovector and isoscalar properties. (author)

  10. A numerical model of non-equilibrium thermal plasmas. I. Transport properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhang XiaoNing; Xia WeiDong [Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026 (China); Li HePing [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Murphy, Anthony B. [CSIRO Materials Science and Engineering, PO Box 218, Lindfield NSW 2070 (Australia)

    2013-03-15

    A self-consistent and complete numerical model for investigating the fundamental processes in a non-equilibrium thermal plasma system consists of the governing equations and the corresponding physical properties of the plasmas. In this paper, a new kinetic theory of the transport properties of two-temperature (2-T) plasmas, based on the solution of the Boltzmann equation using a modified Chapman-Enskog method, is presented. This work is motivated by the large discrepancies between the theories for the calculation of the transport properties of 2-T plasmas proposed by different authors in previous publications. In the present paper, the coupling between electrons and heavy species is taken into account, but reasonable simplifications are adopted, based on the physical fact that m{sub e}/m{sub h} Much-Less-Than 1, where m{sub e} and m{sub h} are, respectively, the masses of electrons and heavy species. A new set of formulas for the transport coefficients of 2-T plasmas is obtained. The new theory has important physical and practical advantages over previous approaches. In particular, the diffusion coefficients are complete and satisfy the mass conversation law due to the consideration of the coupling between electrons and heavy species. Moreover, this essential requirement is satisfied without increasing the complexity of the transport coefficient formulas. Expressions for the 2-T combined diffusion coefficients are obtained. The expressions for the transport coefficients can be reduced to the corresponding well-established expressions for plasmas in local thermodynamic equilibrium for the case in which the electron and heavy-species temperatures are equal.

  11. A numerical model of non-equilibrium thermal plasmas. I. Transport properties

    Science.gov (United States)

    Zhang, Xiao-Ning; Li, He-Ping; Murphy, Anthony B.; Xia, Wei-Dong

    2013-03-01

    A self-consistent and complete numerical model for investigating the fundamental processes in a non-equilibrium thermal plasma system consists of the governing equations and the corresponding physical properties of the plasmas. In this paper, a new kinetic theory of the transport properties of two-temperature (2-T) plasmas, based on the solution of the Boltzmann equation using a modified Chapman-Enskog method, is presented. This work is motivated by the large discrepancies between the theories for the calculation of the transport properties of 2-T plasmas proposed by different authors in previous publications. In the present paper, the coupling between electrons and heavy species is taken into account, but reasonable simplifications are adopted, based on the physical fact that me/mh ≪ 1, where me and mh are, respectively, the masses of electrons and heavy species. A new set of formulas for the transport coefficients of 2-T plasmas is obtained. The new theory has important physical and practical advantages over previous approaches. In particular, the diffusion coefficients are complete and satisfy the mass conversation law due to the consideration of the coupling between electrons and heavy species. Moreover, this essential requirement is satisfied without increasing the complexity of the transport coefficient formulas. Expressions for the 2-T combined diffusion coefficients are obtained. The expressions for the transport coefficients can be reduced to the corresponding well-established expressions for plasmas in local thermodynamic equilibrium for the case in which the electron and heavy-species temperatures are equal.

  12. 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.

  13. A model for non-equilibrium, non-homogeneous two-phase critical flow

    International Nuclear Information System (INIS)

    Bassel, Wageeh Sidrak; Ting, Daniel Kao Sun

    1999-01-01

    Critical two phase flow is a very important phenomena in nuclear reactor technology for the analysis of loss of coolant accident. Several recent papers, Lee and Shrock (1990), Dagan (1993) and Downar (1996) , among others, treat the phenomena using complex models which require heuristic parameters such as relaxation constants or interfacial transfer models. In this paper a mathematical model for one dimensional non equilibrium and non homogeneous two phase flow in constant area duct is developed. The model is constituted of three conservation equations type mass ,momentum and energy. Two important variables are defined in the model: equilibrium constant in the energy equation and the impulse function in the momentum equation. In the energy equation, the enthalpy of the liquid phase is determined by a linear interpolation function between the liquid phase enthalpy at inlet condition and the saturated liquid enthalpy at local pressure. The interpolation coefficient is the equilibrium constant. The momentum equation is expressed in terms of the impulse function. It is considered that there is slip between the liquid and vapor phases, the liquid phase is in metastable state and the vapor phase is in saturated stable state. The model is not heuristic in nature and does not require complex interface transfer models. It is proved numerically that for the critical condition the partial derivative of two phase pressure drop with respect to the local pressure or to phase velocity must be zero.This criteria is demonstrated by numerical examples. The experimental work of Fauske (1962) and Jeandey (1982) were analyzed resulting in estimated numerical values for important parameters like slip ratio, equilibrium constant and two phase frictional drop. (author)

  14. Statistical equilibrium calculations for silicon in early-type model stellar atmospheres

    International Nuclear Information System (INIS)

    Kamp, L.W.

    1976-02-01

    Line profiles of 36 multiplets of silicon (Si) II, III, and IV were computed for a grid of model atmospheres covering the range from 15,000 to 35,000 K in effective temperature and 2.5 to 4.5 in log (gravity). The computations involved simultaneous solution of the steady-state statistical equilibrium equations for the populations and of the equation of radiative transfer in the lines. The variables were linearized, and successive corrections were computed until a minimal accuracy of 1/1000 in the line intensities was reached. The common assumption of local thermodynamic equilibrium (LTE) was dropped. The model atmospheres used also were computed by non-LTE methods. Some effects that were incorporated into the calculations were the depression of the continuum by free electrons, hydrogen and ionized helium line blocking, and auto-ionization and dielectronic recombination, which later were found to be insignificant. Use of radiation damping and detailed electron (quadratic Stark) damping constants had small but significant effects on the strong resonance lines of Si III and IV. For weak and intermediate-strength lines, large differences with respect to LTE computations, the results of which are also presented, were found in line shapes and strengths. For the strong lines the differences are generally small, except for the models at the hot, low-gravity extreme of the range. These computations should be useful in the interpretation of the spectra of stars in the spectral range B0--B5, luminosity classes III, IV, and V

  15. Extension of CE/SE method to non-equilibrium dissociating flows

    KAUST Repository

    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.

  16. A Comparison of the Computation Times of Thermal Equilibrium and Non-equilibrium Models of Droplet Field in a Two-Fluid Three-Field Model

    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.

  17. Comparing two non-equilibrium approaches to modelling of a free-burning arc

    International Nuclear Information System (INIS)

    Baeva, M; Uhrlandt, D; Benilov, M S; Cunha, M D

    2013-01-01

    Two models of high-pressure arc discharges are compared with each other and with experimental data for an atmospheric-pressure free-burning arc in argon for arc currents of 20–200 A. The models account for space-charge effects and thermal and ionization non-equilibrium in somewhat different ways. One model considers space-charge effects, thermal and ionization non-equilibrium in the near-cathode region and thermal non-equilibrium in the bulk plasma. The other model considers thermal and ionization non-equilibrium in the entire arc plasma and space-charge effects in the near-cathode region. Both models are capable of predicting the arc voltage in fair agreement with experimental data. Differences are observed in the arc attachment to the cathode, which do not strongly affect the near-cathode voltage drop and the total arc voltage for arc currents exceeding 75 A. For lower arc currents the difference is significant but the arc column structure is quite similar and the predicted bulk plasma characteristics are relatively close to each other. (paper)

  18. Non-equilibrium assembly of microtubules: from molecules to autonomous chemical robots.

    Science.gov (United States)

    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.

  19. A statistical physics perspective on criticality in financial markets

    International Nuclear Information System (INIS)

    Bury, Thomas

    2013-01-01

    Stock markets are complex systems exhibiting collective phenomena and particular features such as synchronization, fluctuations distributed as power-laws, non-random structures and similarity to neural networks. Such specific properties suggest that markets operate at a very special point. Financial markets are believed to be critical by analogy to physical systems, but little statistically founded evidence has been given. Through a data-based methodology and comparison to simulations inspired by the statistical physics of complex systems, we show that the Dow Jones and index sets are not rigorously critical. However, financial systems are closer to criticality in the crash neighborhood. (paper)

  20. Thermal non-equilibrium in porous medium adjacent to vertical plate: ANN approach

    Science.gov (United States)

    Ahmed, N. J. Salman; Ahamed, K. S. Nazim; Al-Rashed, Abdullah A. A. A.; Kamangar, Sarfaraz; Athani, Abdulgaphur

    2018-05-01

    Thermal non-equilibrium in porous medium is a condition that refers to temperature discrepancy in solid matrix and fluid of porous medium. This type of flow is complex flow requiring complex set of partial differential equations that govern the flow behavior. The current work is undertaken to predict the thermal non-equilibrium behavior of porous medium adjacent to vertical plate using artificial neural network. A set of neurons in 3 layers are trained to predict the heat transfer characteristics. It is found that the thermal non-equilibrium heat transfer behavior in terms of Nusselt number of fluid as well as solid phase can be predicted accurately by using well-trained neural network.

  1. Elements of non-equilibrium (ℎ, k)-dynamics at zero and finite temperatures

    International Nuclear Information System (INIS)

    Golubeva, O.N.; Sukhanov, A.D.

    2011-01-01

    We suggest a method which allows developing some elements of non-equilibrium (ℎ, k)-dynamics without use of Schroedinger equation. It is based on the generalization pf Fokker-Planck and Hamilton-Jacobi equations. Sequential considering of stochastic influence of vacuum is realized in the quantum heat bath model. We show that at the presence of quantum-thermal diffusion non-equilibrium wave functions describe the process of nearing to generalized state of thermal equilibrium at zero and finite temperatures. They can be used as a ground for universal description of transport phenomena

  2. Non-equilibrium properties of Josephson critical current in Nb-based three terminal superconducting tunnel devices

    International Nuclear Information System (INIS)

    Ammendola, G.; Parlato, L.; Peluso, G.; Pepe, G.

    1998-01-01

    Tunnel quasi-particle injection into a superconducting film provides useful information on the non-equilibrium state inside the perturbed superconductor as well as on the potential application to electronic devices. Three terminal injector-detector superconducting devices have a long history in non-equilibrium superconductivity. In the recent past non-equilibrium phenomena have attracted again considerable attention because of many superconducting based detectors involve processes substantially non-equilibrium in nature. The possibility of using a stacked double tunnel junction to study the influence of non-equilibrium superconductivity on the Josephson critical current is now considered. An experimental study of the effect of quasi-particle injection on the Josephson current both in steady-state and pulsed experiments down to T=1.2 K is presented using 3 terminal Nb-based stacked double tunnel devices. The feasibility of a new class of particle detectors based on the direct measurement of the change in the Josephson current following the absorption of a X-ray quantum is also discussed in terms of non-equilibrium theories. (orig.)

  3. A field-theoretic approach to non-equilibrium work identities

    International Nuclear Information System (INIS)

    Mallick, Kirone; Orland, Henri; Moshe, Moshe

    2011-01-01

    We study non-equilibrium work relations for a space-dependent field with stochastic dynamics (model A). Jarzynski's equality is obtained through symmetries of the dynamical action in the path-integral representation. We derive a set of exact identities that generalize the fluctuation-dissipation relations to non-stationary and far-from-equilibrium situations. These identities are prone to experimental verification. Furthermore, we show that a well-studied invariance of the Langevin equation under supersymmetry, which is known to be broken when the external potential is time dependent, can be partially restored by adding to the action a term which is precisely Jarzynski's work. The work identities can then be retrieved as consequences of the associated Ward-Takahashi identities.

  4. Partition Function and Configurational Entropy in Non-Equilibrium States: A New Theoretical Model

    Directory of Open Access Journals (Sweden)

    Akira Takada

    2018-03-01

    Full Text Available A new model of non-equilibrium thermodynamic states has been investigated on the basis of the fact that all thermodynamic variables can be derived from partition functions. We have thus attempted to define partition functions for non-equilibrium conditions by introducing the concept of pseudo-temperature distributions. These pseudo-temperatures are configurational in origin and distinct from kinetic (phonon temperatures because they refer to the particular fragments of the system with specific energies. This definition allows thermodynamic states to be described either for equilibrium or non-equilibrium conditions. In addition; a new formulation of an extended canonical partition function; internal energy and entropy are derived from this new temperature definition. With this new model; computational experiments are performed on simple non-interacting systems to investigate cooling and two distinct relaxational effects in terms of the time profiles of the partition function; internal energy and configurational entropy.

  5. Introductory statistical mechanics for electron storage rings

    International Nuclear Information System (INIS)

    Jowett, J.M.

    1986-07-01

    These lectures introduce the beam dynamics of electron-positron storage rings with particular emphasis on the effects due to synchrotron radiation. They differ from most other introductions in their systematic use of the physical principles and mathematical techniques of the non-equilibrium statistical mechanics of fluctuating dynamical systems. A self-contained exposition of the necessary topics from this field is included. Throughout the development, a Hamiltonian description of the effects of the externally applied fields is maintained in order to preserve the links with other lectures on beam dynamics and to show clearly the extent to which electron dynamics in non-Hamiltonian. The statistical mechanical framework is extended to a discussion of the conceptual foundations of the treatment of collective effects through the Vlasov equation

  6. Methods of statistical physics

    CERN Document Server

    Akhiezer, Aleksandr I

    1981-01-01

    Methods of Statistical Physics is an exposition of the tools of statistical mechanics, which evaluates the kinetic equations of classical and quantized systems. The book also analyzes the equations of macroscopic physics, such as the equations of hydrodynamics for normal and superfluid liquids and macroscopic electrodynamics. The text gives particular attention to the study of quantum systems. This study begins with a discussion of problems of quantum statistics with a detailed description of the basics of quantum mechanics along with the theory of measurement. An analysis of the asymptotic be

  7. Choking flow modeling with mechanical and thermal non-equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, H.J.; Ishii, M.; Revankar, S.T. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2006-01-15

    The mechanistic model, which considers the mechanical and thermal non-equilibrium, is described for two-phase choking flow. The choking mass flux is obtained from the momentum equation with the definition of choking. The key parameter for the mechanical non-equilibrium is a slip ratio. The dependent parameters for the slip ratio are identified. In this research, the slip ratio which is defined in the drift flux model is used to identify the impact parameters on the slip ratio. Because the slip ratio in the drift flux model is related to the distribution parameter and drift velocity, the adequate correlations depending on the flow regime are introduced in this study. For the thermal non-equilibrium, the model is developed with bubble conduction time and Bernoulli choking model. In case of highly subcooled water compared to the inlet pressure, the Bernoulli choking model using the pressure undershoot is used because there is no bubble generation in the test section. When the phase change happens inside the test section, two-phase choking model with relaxation time calculates the choking mass flux. According to the comparison of model prediction with experimental data shows good agreement. The developed model shows good prediction in both low and high pressure ranges. (author)

  8. Non-equilibrium and band tailing in organic conductors

    Indian Academy of Sciences (India)

    . Non-equilibrium ... Introduction. Study of organic conductors and semiconductors continues to generate interest with the ... Band tailing reduces band gap or the acti- ..... (9), we can identify Eg(0) with the focal point and is proportional to P2. 1 .

  9. Calculating zeros: Non-equilibrium free energy calculations

    International Nuclear Information System (INIS)

    Oostenbrink, Chris; Gunsteren, Wilfred F. van

    2006-01-01

    Free energy calculations on three model processes with theoretically known free energy changes have been performed using short simulation times. A comparison between equilibrium (thermodynamic integration) and non-equilibrium (fast growth) methods has been made in order to assess the accuracy and precision of these methods. The three processes have been chosen to represent processes often observed in biomolecular free energy calculations. They involve a redistribution of charges, the creation and annihilation of neutral particles and conformational changes. At very short overall simulation times, the thermodynamic integration approach using discrete steps is most accurate. More importantly, reasonable accuracy can be obtained using this method which seems independent of the overall simulation time. In cases where slow conformational changes play a role, fast growth simulations might have an advantage over discrete thermodynamic integration where sufficient sampling needs to be obtained at every λ-point, but only if the initial conformations do properly represent an equilibrium ensemble. From these three test cases practical lessons can be learned that will be applicable to biomolecular free energy calculations

  10. Non-Equilibrium Turbulence and Two-Equation Modeling

    Science.gov (United States)

    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.

  11. Non-equilibrium between ions and electrons inside hot spots from National Ignition Facility experiments

    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.

  12. Lateral interactions and non-equilibrium in surface kinetics

    Science.gov (United States)

    Menzel, Dietrich

    2016-08-01

    Work modelling reactions between surface species frequently use Langmuir kinetics, assuming that the layer is in internal equilibrium, and that the chemical potential of adsorbates corresponds to that of an ideal gas. Coverage dependences of reacting species and of site blocking are usually treated with simple power law coverage dependences (linear in the simplest case), neglecting that lateral interactions are strong in adsorbate and co-adsorbate layers which may influence kinetics considerably. My research group has in the past investigated many co-adsorbate systems and simple reactions in them. We have collected a number of examples where strong deviations from simple coverage dependences exist, in blocking, promoting, and selecting reactions. Interactions can range from those between next neighbors to larger distances, and can be quite complex. In addition, internal equilibrium in the layer as well as equilibrium distributions over product degrees of freedom can be violated. The latter effect leads to non-equipartition of energy over molecular degrees of freedom (for products) or non-equal response to those of reactants. While such behavior can usually be described by dynamic or kinetic models, the deeper reasons require detailed theoretical analysis. Here, a selection of such cases is reviewed to exemplify these points.

  13. Two-temperature chemically non-equilibrium modelling of transferred arcs

    International Nuclear Information System (INIS)

    Baeva, M; Kozakov, R; Gorchakov, S; Uhrlandt, D

    2012-01-01

    A two-temperature chemically non-equilibrium model describing in a self-consistent manner the heat transfer, the plasma chemistry, the electric and magnetic field in a high-current free-burning arc in argon has been developed. The model is aimed at unifying the description of a thermionic tungsten cathode, a flat copper anode, and the arc plasma including the electrode sheath regions. The heat transfer in the electrodes is coupled to the plasma heat transfer considering the energy fluxes onto the electrode boundaries with the plasma. The results of the non-equilibrium model for an arc current of 200 A and an argon flow rate of 12 slpm are presented along with results obtained from a model based on the assumption of local thermodynamic equilibrium (LTE) and from optical emission spectroscopy. The plasma shows a near-LTE behaviour along the arc axis and in a region surrounding the axis which becomes wider towards the anode. In the near-electrode regions, a large deviation from LTE is observed. The results are in good agreement with experimental findings from optical emission spectroscopy. (paper)

  14. Non-statistical behavior of coupled optical systems

    International Nuclear Information System (INIS)

    Perez, G.; Pando Lambruschini, C.; Sinha, S.; Cerdeira, H.A.

    1991-10-01

    We study globally coupled chaotic maps modeling an optical system, and find clear evidence of non-statistical behavior: the mean square deviation (MSD) of the mean field saturates with respect to increase in the number of elements coupled, after a critical value, and its distribution is clearly non-Gaussian. We also find that the power spectrum of the mean field displays well defined peaks, indicating a subtle coherence among different elements, even in the ''turbulent'' phase. This system is a physically realistic model that may be experimentally realizable. It is also a higher dimensional example (as each individual element is given by a complex map). Its study confirms that the phenomena observed in a wide class of coupled one-dimensional maps are present here as well. This gives more evidence to believe that such non-statistical behavior is probably generic in globally coupled systems. We also investigate the influence of parametric fluctuations on the MSD. (author). 10 refs, 7 figs, 1 tab

  15. Non-extensive statistical aspects of clustering and nuclear multi-fragmentation

    International Nuclear Information System (INIS)

    Calboreanu, A.

    2002-01-01

    Recent developments concerning an application of the non-extensive Tsalis statistics to describe clustering phenomena is briefly presented. Cluster formation is a common feature of a large number of physical phenomena encountered in molecular and nuclear physics, astrophysics, condensed matter and biophysics. Common to all these is the large number of degrees of freedom, thus justifying a statistical approach. However the conventional statistical mechanics paradigm seems to fail in dealing with clustering. Whether this is due to the prevalence of complex dynamical constrains, or it is a manifestation of new statistics is a subject of considerable interest, which was intensively debated during the last few years. Tsalis conjecture has proved extremely appealing due to its rather elegant and transparent basic arguments. We present here evidence for its adequacy for the study of a large class of physical phenomena related to cluster formation. An application to nuclear multi-fragmentation is presented. (author)

  16. Thermodynamic evolution far from equilibrium

    Science.gov (United States)

    Khantuleva, Tatiana A.

    2018-05-01

    The presented model of thermodynamic evolution of an open system far from equilibrium is based on the modern results of nonequilibrium statistical mechanics, the nonlocal theory of nonequilibrium transport developed by the author and the Speed Gradient principle introduced in the theory of adaptive control. Transition to a description of the system internal structure evolution at the mesoscopic level allows a new insight at the stability problem of non-equilibrium processes. The new model is used in a number of specific tasks.

  17. Adaptive Chemical Networks under Non-Equilibrium Conditions: The Evaporating Droplet.

    Science.gov (United States)

    Armao, Joseph J; Lehn, Jean-Marie

    2016-10-17

    Non-volatile solutes in an evaporating drop experience an out-of-equilibrium state due to non-linear concentration effects and complex flow patterns. Here, we demonstrate a small molecule chemical reaction network that undergoes a rapid adaptation response to the out-of-equilibrium conditions inside the droplet leading to control over the molecular constitution and spatial arrangement of the deposition pattern. Adaptation results in a pronounced coffee stain effect and coupling to chemical concentration gradients within the drop is demonstrated. Amplification and suppression of network species are readily identifiable with confocal fluorescence microscopy. We anticipate that these observations will contribute to the design and exploration of out-of-equilibrium chemical systems, as well as be useful towards the development of point-of-care medical diagnostics and controlled deposition of small molecules through inkjet printing. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Entropy generation of viscous dissipative flow in thermal non-equilibrium porous media with thermal asymmetries

    International Nuclear Information System (INIS)

    Chee, Yi Shen; Ting, Tiew Wei; Hung, Yew Mun

    2015-01-01

    The effect of thermal asymmetrical boundaries on entropy generation of viscous dissipative flow of forced convection in thermal non-equilibrium porous media is analytically studied. The two-dimensional temperature, Nusselt number and entropy generation contours are analysed comprehensively to provide insights into the underlying physical significance of the effect on entropy generation. By incorporating the effects of viscous dissipation and thermal non-equilibrium, the first-law and second-law characteristics of porous-medium flow are investigated via various pertinent parameters, i.e. heat flux ratio, effective thermal conductivity ratio, Darcy number, Biot number and averaged fluid velocity. For the case of symmetrical wall heat flux, an optimum condition with a high Nusselt number and a low entropy generation is identified at a Darcy number of 10 −4 , providing an ideal operating condition from the second-law aspect. This type of heat and fluid transport in porous media covers a wide range of engineering applications, involving porous insulation, packed-bed catalytic process in nuclear reactors, filtration transpiration cooling, and modelling of transport phenomena of microchannel heat sinks. - Highlights: • Effects of thermal asymmetries on convection in porous-medium are studied. • Exergetic effectiveness of porous media with thermal asymmetries is investigated. • 2-D temperature, Nusselt number and entropy generation contours are analyzed. • Significance of viscous dissipation in entropy generation is scrutinized. • Significance of thermal non-equilibrium in entropy generation is studied

  19. Stochastic pumping of non-equilibrium steady-states: how molecules adapt to a fluctuating environment.

    Science.gov (United States)

    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.

  20. Self-assembled materials and supramolecular chemistry within microfluidic environments: from common thermodynamic states to non-equilibrium structures.

    Science.gov (United States)

    Sevim, S; Sorrenti, A; Franco, C; Furukawa, S; Pané, S; deMello, A J; Puigmartí-Luis, J

    2018-05-01

    Self-assembly is a crucial component in the bottom-up fabrication of hierarchical supramolecular structures and advanced functional materials. Control has traditionally relied on the use of encoded building blocks bearing suitable moieties for recognition and interaction, with targeting of the thermodynamic equilibrium state. On the other hand, nature leverages the control of reaction-diffusion processes to create hierarchically organized materials with surprisingly complex biological functions. Indeed, under non-equilibrium conditions (kinetic control), the spatio-temporal command of chemical gradients and reactant mixing during self-assembly (the creation of non-uniform chemical environments for example) can strongly affect the outcome of the self-assembly process. This directly enables a precise control over material properties and functions. In this tutorial review, we show how the unique physical conditions offered by microfluidic technologies can be advantageously used to control the self-assembly of materials and of supramolecular aggregates in solution, making possible the isolation of intermediate states and unprecedented non-equilibrium structures, as well as the emergence of novel functions. Selected examples from the literature will be used to confirm that microfluidic devices are an invaluable toolbox technology for unveiling, understanding and steering self-assembly pathways to desired structures, properties and functions, as well as advanced processing tools for device fabrication and integration.

  1. Statistical symmetries in physics

    International Nuclear Information System (INIS)

    Green, H.S.; Adelaide Univ., SA

    1994-01-01

    Every law of physics is invariant under some group of transformations and is therefore the expression of some type of symmetry. Symmetries are classified as geometrical, dynamical or statistical. At the most fundamental level, statistical symmetries are expressed in the field theories of the elementary particles. This paper traces some of the developments from the discovery of Bose statistics, one of the two fundamental symmetries of physics. A series of generalizations of Bose statistics is described. A supersymmetric generalization accommodates fermions as well as bosons, and further generalizations, including parastatistics, modular statistics and graded statistics, accommodate particles with properties such as 'colour'. A factorization of elements of ggl(n b ,n f ) can be used to define truncated boson operators. A general construction is given for q-deformed boson operators, and explicit constructions of the same type are given for various 'deformed' algebras. A summary is given of some of the applications and potential applications. 39 refs., 2 figs

  2. Proton-rich nuclear statistical equilibrium

    International Nuclear Information System (INIS)

    Seitenzahl, I.R.; Timmes, F.X.; Marin-Lafleche, A.; Brown, E.; Magkotsios, G.; Truran, J.

    2008-01-01

    Proton-rich material in a state of nuclear statistical equilibrium (NSE) is one of the least studied regimes of nucleosynthesis. One reason for this is that after hydrogen burning, stellar evolution proceeds at conditions of an equal number of neutrons and protons or at a slight degree of neutron-richness. Proton-rich nucleosynthesis in stars tends to occur only when hydrogen-rich material that accretes onto a white dwarf or a neutron star explodes, or when neutrino interactions in the winds from a nascent proto-neutron star or collapsar disk drive the matter proton-rich prior to or during the nucleosynthesis. In this Letter we solve the NSE equations for a range of proton-rich thermodynamic conditions. We show that cold proton-rich NSE is qualitatively different from neutron-rich NSE. Instead of being dominated by the Fe-peak nuclei with the largest binding energy per nucleon that have a proton-to-nucleon ratio close to the prescribed electron fraction, NSE for proton-rich material near freezeout temperature is mainly composed of 56Ni and free protons. Previous results of nuclear reaction network calculations rely on this nonintuitive high-proton abundance, which this Letter explains. We show how the differences and especially the large fraction of free protons arises from the minimization of the free energy as a result of a delicate competition between the entropy and nuclear binding energy.

  3. Speed of Sound in Hadronic matter using Non-extensive Statistics

    CERN Document Server

    Khuntia, Arvind; Garg, Prakhar; Sahoo, Raghunath; Cleymans, Jean

    2016-01-01

    The speed of sound ($c_s$) is studied to understand the hydrodynamical evolution of the matter created in heavy-ion collisions. The quark gluon plasma (QGP) formed in heavy-ion collisions evolves from an initial QGP to the hadronic phase via a possible mixed phase. Due to the system expansion in a first order phase transition scenario, the speed of sound reduces to zero as the specific heat diverges. We study the speed of sound for systems, which deviate from a thermalized Boltzmann distribution using non-extensive Tsallis statistics. In the present work, we calculate the speed of sound as a function of temperature for different $q$-values for a hadron resonance gas. We observe a similar mass cut-off behaviour in non-extensive case for $c^{2}_s$ by including heavier particles, as is observed in the case of a hadron resonance gas following equilibrium statistics. Also, we explicitly present that the temperature where the mass cut-off starts, varies with the $q$-parameter which hints at a relation between the d...

  4. The scientifiv way of thinking in statistics, statistical physics and quantum mechanics

    OpenAIRE

    Săvoiu, Gheorghe

    2008-01-01

    This paper focuses on the way of thinking in both classical and modern Physics and Statistics, Statistical Mechanics or Statistical Physics and Quantum Mechanics. These different statistical ways of thinking and their specific methods have generated new fields for new activities and new scientific disciplines, like Econophysics (between Economics and Physics), Sociophysics (between Sociology and Physics), Mediaphysics (between all media and comunication sciences), etc. After describing some r...

  5. The scientific way of thinking in statistics, statistical physics and quantum mechanics

    OpenAIRE

    Săvoiu, Gheorghe

    2008-01-01

    This paper focuses on the way of thinking in both classical and modern Physics and Statistics, Statistical Mechanics or Statistical Physics and Quantum Mechanics. These different statistical ways of thinking and their specific methods have generated new fields for new activities and new scientific disciplines, like Econophysics (between Economics and Physics), Sociophysics (between Sociology and Physics), Mediaphysics (between all media and comunication sciences), etc. After describing some r...

  6. X-RAY SIGNATURES OF NON-EQUILIBRIUM IONIZATION EFFECTS IN GALAXY CLUSTER ACCRETION SHOCK REGIONS

    International Nuclear Information System (INIS)

    Wong, Ka-Wah; Sarazin, Craig L.; Ji Li

    2011-01-01

    The densities in the outer regions of clusters of galaxies are very low, and the collisional timescales are very long. As a result, heavy elements will be under-ionized after they have passed through the accretion shock. We have studied systematically the effects of non-equilibrium ionization for relaxed clusters in the ΛCDM cosmology using one-dimensional hydrodynamic simulations. We found that non-equilibrium ionization effects do not depend on cluster mass, but depend strongly on redshift which can be understood by self-similar scaling arguments. The effects are stronger for clusters at lower redshifts. We present X-ray signatures such as surface brightness profiles and emission lines in detail for a massive cluster at low redshift. In general, soft emission (0.3-1.0 keV) is enhanced significantly by under-ionization, and the enhancement can be nearly an order of magnitude near the shock radius. The most prominent non-equilibrium ionization signature we found is the O VII and O VIII line ratio. The ratios for non-equilibrium ionization and collisional ionization equilibrium models are different by more than an order of magnitude at radii beyond half of the shock radius. These non-equilibrium ionization signatures are equally strong for models with different non-adiabatic shock electron heating efficiencies. We have also calculated the detectability of the O VII and O VIII lines with the future International X-ray Observatory (IXO). Depending on the line ratio measured, we conclude that an exposure of ∼130-380 ks on a moderate-redshift, massive regular cluster with the X-ray Microcalorimeter Spectrometer (XMS) on the IXO will be sufficient to provide a strong test for the non-equilibrium ionization model.

  7. Statistical methods in radiation physics

    CERN Document Server

    Turner, James E; Bogard, James S

    2012-01-01

    This statistics textbook, with particular emphasis on radiation protection and dosimetry, deals with statistical solutions to problems inherent in health physics measurements and decision making. The authors begin with a description of our current understanding of the statistical nature of physical processes at the atomic level, including radioactive decay and interactions of radiation with matter. Examples are taken from problems encountered in health physics, and the material is presented such that health physicists and most other nuclear professionals will more readily understand the application of statistical principles in the familiar context of the examples. Problems are presented at the end of each chapter, with solutions to selected problems provided online. In addition, numerous worked examples are included throughout the text.

  8. Conjugate pair of non-extensive statistics in quantum scattering

    International Nuclear Information System (INIS)

    Ion, D.B.; Ion, M.L.D.

    1999-01-01

    In this paper, by defining the Fourier transform of the scattering amplitudes as a bounded linear mapping from the space L 2p to the space L 2q when 1/(2p)+1/(2q)=1, we introduced a new concept in quantum physics in terms of Tsallis-like entropies S J (p) and S θ (q), namely, that of conjugate pair of non-extensive statistics. This new concept is experimentally illustrated by using 88 + 49 sets of pion-nucleon and pion-nucleus phase shifts. From the experimental determination of the (p,q) - non-extensivity indices by choosing the pairs for which the [χ L 2 (p) + χ θ 2 (q min )] - optimal - test function is minimum we get the conjugate pair of [(p min ,J),(q min , θ)]- non-extensive statistics with 0.50 ≤ p min ≤ 0.60. This new non-extensive statistical effect is experimentally evidenced with high degree of accuracy (CL≥ 99%). Moreover, it is worth to mention that the modification of the statistics has been more efficient than the modification of the PMD-SQS-optimum principle in obtaining the best overall fitting to the experimental data. (authors)

  9. Critical pressure of non-equilibrium two-phase critical flow

    Energy Technology Data Exchange (ETDEWEB)

    Minzer, U [Israel Electric Corp. Ltd., Haifa (Israel)

    1996-12-01

    Critical pressure is defined as the pressure existing at the exit edge of the piping, when it remains constant despite a decrease in the back. According to this definition the critical pressure is larger than the back pressure and for two-phase conditions below saturation pressure. The two-phase critical pressure has a major influence on the two-phase critical flow characteristics. Therefore it is of High significance in calculations of critical mass flux and critical depressurization rate, which are important in the fields of Nuclear Reactor Safety and Industrial Safety. At the Nuclear Reactor Safety field is useful for estimations of the Reactor Cooling System depressurization, the core coolant level, and the pressure build-up in the containment. In the Industrial Safety field it is helpful for estimating the leakage rate of toxic gases Tom liquefied gas pressure vessels, depressurization of pressure vessels, and explosion conditions due to liquefied gas release. For physical description of non-equilibrium two-phase critical flow it would be convenient to divide the flow into two stages. The first stage is the flow of subcooled liquid at constant temperature and uniform pressure drop (i.e., the case of incompressible fluid and uniform piping cross section). The rapid flow of the liquid causes a delay in the boiling of the liquid, which begins to boil below saturation pressure, at thermal non-equilibrium. The boiling is the beginning of the second stage, characterized by a sharp increase of the pressure drop. The liquid temperature on the second stage is almost constant because most of the energy for vaporization is supplied from the large pressure drop The present work will focus on the two-phase critical pressure of water, since water serves as coolant in the vast majority of nuclear power reactors throughout the world. (author).

  10. Critical pressure of non-equilibrium two-phase critical flow

    International Nuclear Information System (INIS)

    Minzer, U.

    1996-01-01

    Critical pressure is defined as the pressure existing at the exit edge of the piping, when it remains constant despite a decrease in the back. According to this definition the critical pressure is larger than the back pressure and for two-phase conditions below saturation pressure. The two-phase critical pressure has a major influence on the two-phase critical flow characteristics. Therefore it is of High significance in calculations of critical mass flux and critical depressurization rate, which are important in the fields of Nuclear Reactor Safety and Industrial Safety. At the Nuclear Reactor Safety field is useful for estimations of the Reactor Cooling System depressurization, the core coolant level, and the pressure build-up in the containment. In the Industrial Safety field it is helpful for estimating the leakage rate of toxic gases Tom liquefied gas pressure vessels, depressurization of pressure vessels, and explosion conditions due to liquefied gas release. For physical description of non-equilibrium two-phase critical flow it would be convenient to divide the flow into two stages. The first stage is the flow of subcooled liquid at constant temperature and uniform pressure drop (i.e., the case of incompressible fluid and uniform piping cross section). The rapid flow of the liquid causes a delay in the boiling of the liquid, which begins to boil below saturation pressure, at thermal non-equilibrium. The boiling is the beginning of the second stage, characterized by a sharp increase of the pressure drop. The liquid temperature on the second stage is almost constant because most of the energy for vaporization is supplied from the large pressure drop The present work will focus on the two-phase critical pressure of water, since water serves as coolant in the vast majority of nuclear power reactors throughout the world. (author)

  11. Non-equilibrium flow and sediment transport distribution over mobile river dunes

    Science.gov (United States)

    Hoitink, T.; Naqshband, S.; McElroy, B. J.

    2017-12-01

    Flow and sediment transport are key processes in the morphodynamics of river dunes. During floods in several rivers (e.g., the Elkhorn, Missouri, Niobrara, and Rio Grande), dunes are observed to grow rapidly as flow strength increases, undergoing an unstable transition regime, after which they are washed out in what is called upper stage plane bed. This morphological evolution of dunes to upper stage plane bed is the strongest bed-form adjustment during non-equilibrium flows and is associated with a significant change in hydraulic roughness and water levels. Detailed experimental investigations, however, have mostly focused on fixed dunes limited to equilibrium flow and bed conditions that are rare in natural channels. Our understanding of the underlying sedimentary processes that result into the washing out of dunes is therefore very limited. In the present study, using the Acoustic Concentration and Velocity Profiler (ACVP), we were able to quantify flow structure and sediment transport distribution over mobile non-equilibrium dunes. Under these non-equilibrium flow conditions average dune heights were decreasing while dune lengths were increasing. Preliminary results suggest that this morphological behaviour is due to a positive phase lag between sediment transport maximum and topographic maximum leading to a larger erosion on the dune stoss side compared to deposition on dune lee side.

  12. Principles of classical statistical mechanics: A perspective from the notion of complementarity

    International Nuclear Information System (INIS)

    Velazquez Abad, Luisberis

    2012-01-01

    Quantum mechanics and classical statistical mechanics are two physical theories that share several analogies in their mathematical apparatus and physical foundations. In particular, classical statistical mechanics is hallmarked by the complementarity between two descriptions that are unified in thermodynamics: (i) the parametrization of the system macrostate in terms of mechanical macroscopic observablesI=(I i ), and (ii) the dynamical description that explains the evolution of a system towards the thermodynamic equilibrium. As expected, such a complementarity is related to the uncertainty relations of classical statistical mechanics ΔI i Δη i ≥k. Here, k is the Boltzmann constant, η i =∂S(I|θ)/∂I i are the restituting generalized forces derived from the entropy S(I|θ) of a closed system, which is found in an equilibrium situation driven by certain control parameters θ=(θ α ). These arguments constitute the central ingredients of a reformulation of classical statistical mechanics from the notion of complementarity. In this new framework, Einstein postulate of classical fluctuation theory dp(I|θ)∼exp[S(I|θ)/k]dI appears as the correspondence principle between classical statistical mechanics and thermodynamics in the limit k→0, while the existence of uncertainty relations can be associated with the non-commuting character of certain operators. - Highlights: ► There exists a direct analogy between quantum and classical statistical mechanics. ► Statistical form of Le Chatellier principle leads to the uncertainty principle. ► Einstein postulate is simply the correspondence principle. ► Complementary quantities are associated with non-commuting operators.

  13. MAGNETIC RECONNECTION IN NON-EQUILIBRIUM IONIZATION PLASMA

    International Nuclear Information System (INIS)

    Imada, S.; Shimizu, T.; Murakami, I.; Watanabe, T.; Hara, H.

    2011-01-01

    We have studied the effect of time-dependent ionization and the recombination processes on magnetic reconnection in the solar corona. Petschek-type steady reconnection, in which the magnetic energy is mainly converted at the slow-mode shocks, was assumed. We carried out the time-dependent ionization calculation in the magnetic reconnection structure. We only calculated the transient ionization of iron; the other species were assumed to be in ionization equilibrium. The intensity of line emissions at specific wavelengths was also calculated for comparison with Hinode or other observations in future. We found the following: (1) iron is mostly in non-equilibrium ionization in the reconnection region; (2) the intensity of line emission estimated by the time-dependent ionization calculation is significantly different from that determined from the ionization equilibrium assumption; (3) the effect of time-dependent ionization is sensitive to the electron density in the case where the electron density is less than 10 10 cm –3 ; (4) the effect of thermal conduction lessens the time-dependent ionization effect; and (5) the effect of radiative cooling is negligibly small even if we take into account time-dependent ionization.

  14. 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.

  15. A statistical physics of stationary and metastable states

    International Nuclear Information System (INIS)

    Cabo, A; González, A; Curilef, S; Cabo-Bizet, N G; Vera, C A

    2011-01-01

    We present a generalization of Gibbs statistical mechanics designed to describe a general class of stationary and metastable equilibrium states. It is assumed that the physical system maximizes the entropy functional S subject to the standard conditions plus an extra conserved constraint function F, imposed to force the system to remain in the metastable configuration. After requiring additivity for two quasi-independent subsystems, and the commutation of the new constraint with the density matrix ρ, it is argued that F should be a homogeneous function of ρ, at least for systems in which the spectrum is sufficiently dense to be considered as continuous. Therefore, surprisingly, the analytic form of F turns out to be of the kind F(p i ) = p i q , where the p i are the eigenvalues of the density matrix and q is a real number to be determined. Thus, the discussion identifies the physical relevance of Lagrange multiplier constraints of the Tsallis kind and their q parameter, as enforced by the additivity of the constraint F which fixes the metastable state. An approximate analytic solution for the probability density is found for q close to unity. The procedure is applied to describe the results from the plasma experiment of Huang and Driscoll. For small and medium values of the radial distance, the measured density is predicted with a precision similar to that achieved by minimal enstrophy and Tsallis procedures. Also, the particle density is predicted at all the radial positions. Thus, the discussion gives a solution to the conceptual difficulties of the two above mentioned approaches as applied to this problem, which both predict a non-analytic abrupt vanishing of the density above a critical radial distance

  16. Self-organization of dissipative and coherent vortex structures in non-equilibrium magnetized two-dimensional plasmas

    International Nuclear Information System (INIS)

    Bystrenko, O; Bystrenko, T

    2010-01-01

    The properties of non-equilibrium magnetized plasmas confined in planar geometry are studied on the basis of first-principle microscopic Langevin dynamics computer simulations. The non-equilibrium state of plasmas is maintained due to the recombination and generation of charges. The intrinsic microscopic structure of non-equilibrium steady-state magnetized plasmas, in particular the inter-particle correlations and self-organization of vortex structures, are examined. The simulations have been performed for a wide range of parameters including strong plasma coupling, high charge recombination and generation rates and intense magnetic field. As is shown in simulations, the non-equilibrium recombination and generation processes trigger the formation of ordered dissipative or coherent drift vortex states in 2D plasmas with distinctly spatially separated components, which are far from thermal equilibrium. This is evident from the unusual properties of binary distributions and behavior of the Coulomb energy of the system, which turn out to be quite different from the ones typical for the equilibrium state of plasmas under the same conditions.

  17. Monte Carlo estimates of interfacial tension in the two-dimensional Ising model from non-equilibrium methods

    International Nuclear Information System (INIS)

    Híjar, Humberto; Sutmann, Godehard

    2008-01-01

    Non-equilibrium methods for estimating free energy differences are used in order to calculate the interfacial tension between domains with opposite magnetizations in two-dimensional Ising lattices. Non-equilibrium processes are driven by changing the boundary conditions for two opposite sides of the lattice from periodic to antiperiodic and vice versa. This mechanism, which promotes the appearance and disappearance of the interface, is studied by means of Monte Carlo simulations performed at different rates and using different algorithms, thus allowing for testing the applicability of non-equilibrium methods for processes driven far from or close to equilibrium. Interfaces in lattices with different widths and heights are studied and the interface tension as a function of these quantities is obtained. It is found that the estimates of the interfacial tension from non-equilibrium procedures are in good agreement with previous reports as well as with exact results. The efficiency of the different procedures used is analyzed and the dynamics of the interface under these perturbations is briefly discussed. A method for determining the efficiency of non-equilibrium methods as regards thermodynamic perturbation is also presented. It is found that for all cases studied, the Crooks non-equilibrium method for estimating free energy differences is the most efficient one

  18. Statistical thermodynamics of equilibrium polymers at interfaces

    NARCIS (Netherlands)

    Gucht, van der J.; Besseling, N.A.M.

    2002-01-01

    The behavior of a solution of equilibrium polymers (or living polymers) at an interface is studied, using a Bethe-Guggenheim lattice model for molecules with orientation dependent interactions. The density profile of polymers and the chain length distribution are calculated. For equilibrium polymers

  19. Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity.

    Science.gov (United States)

    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).

  20. Non-equilibrium phase transition in a spreading process on a timeline

    International Nuclear Information System (INIS)

    Barato, Andre C; Hinrichsen, Haye

    2009-01-01

    We consider a non-equilibrium process on a timeline with discrete sites which evolves following a non-Markovian update rule in such a way that an active site at time t activates one or several sites in the future at time t+Δt. The time intervals Δt are distributed algebraically as (Δt) −1−κ , where 0<κ<1 is a control parameter. Depending on the activation rate, the system displays a non-equilibrium phase transition which may be interpreted as directed percolation transition driven by temporal Lévy flights in the limit of zero space dimensions. The critical properties are investigated by means of extensive numerical simulations and compared with field-theoretic predictions

  1. Influence of condensed species on thermo-physical properties of LTE and non-LTE SF6-Cu mixture

    Science.gov (United States)

    Chen, Zhexin; Wu, Yi; Yang, Fei; Sun, Hao; Rong, Mingzhe; Wang, Chunlin

    2017-10-01

    SF6-Cu mixture is frequently formed in high-voltage circuit breakers due to the electrode erosion and metal vapor diffusion. During the interruption process, the multiphase effect and deviation from local thermal equilibrium (non-LTE assumption) can both affect the thermo-physical of the arc plasma and further influence the performance of circuit breaker. In this paper, thermo-physical properties, namely composition, thermodynamic properties and transport coefficients are calculated for multiphase SF6-Cu mixture with and without LTE assumption. The composition is confirmed by combining classical two-temperature mass action law with phase equilibrium condition deduced from second law of thermodynamics. The thermodynamic properties and transport coefficients are calculated using the multiphase composition result. The influence of condensed species on thermo-physical properties is discussed at different temperature, pressure (0.1-10 atm), non-equilibrium degrees (1-10), and copper molar proportions (0-50%). It is found that the multiphase effect has significant influence on specific enthalpy, specific heat and heavy species thermal conductivity in both LTE and non-LTE SF6-Cu system. This paper provides a more accurate database for computational fluid dynamic calculation.

  2. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model

    Science.gov (United States)

    Fan, Zhengfeng; Liu, Jie

    2016-10-01

    We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot rhoR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot rhoR requirement is remarkably reduced for achieving self-heating. In NIF high-foot implosions, it is observed that the x-ray enhancement factors are less than unity, which is not self-consistent and is caused by assuming Te =Ti. And from this non-consistency, we could infer that ion-electron non-equilibrium exists in the high-foot implosions and the ion temperature could be 9% larger than the equilibrium temperature.

  3. Asymptotic analysis of discrete schemes for non-equilibrium radiation diffusion

    International Nuclear Information System (INIS)

    Cui, Xia; Yuan, Guang-wei; Shen, Zhi-jun

    2016-01-01

    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. - Highlights: • Provide AP fully discrete schemes for non-equilibrium radiation diffusion. • Propose second order accurate schemes by asymmetric approach for boundary flux-limiter. • Show first order AP property of spatially and fully discrete schemes with IB evolution. • Devise subtle artificial solutions; verify accuracy and AP property quantitatively. • Ideas can be generalized to 3-dimensional problems and higher order implicit schemes.

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

    International Nuclear Information System (INIS)

    Wu, Wei; Wang, Jin

    2014-01-01

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

  5. Modeling chromatographic columns. Non-equilibrium packed-bed adsorption with non-linear adsorption isotherms

    NARCIS (Netherlands)

    Özdural, A.R.; Alkan, A.; Kerkhof, P.J.A.M.

    2004-01-01

    In this work a new mathematical model, based on non-equilibrium conditions, describing the dynamic adsorption of proteins in columns packed with spherical adsorbent particles is used to study the performance of chromatographic systems. Simulations of frontal chromatography, including axial

  6. A Tightly Coupled Non-Equilibrium Magneto-Hydrodynamic Model for Inductively Coupled RF Plasmas

    Science.gov (United States)

    2016-02-29

    development a tightly coupled magneto-hydrodynamic model for Inductively Coupled Radio- Frequency (RF) Plasmas. Non Local Thermodynamic Equilibrium (NLTE...for Inductively Coupled Radio-Frequency (RF) Plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State...Inductively Coupled Plasma (ICP) torches have wide range of possible applications which include deposition of metal coatings, synthesis of ultra-fine powders

  7. Physics colloquium: Electron counting in quantum dots in and out of equilibrium

    CERN Multimedia

    Geneva University

    2011-01-01

    GENEVA UNIVERSITY Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92olé   Lundi 31 octobre 2011 17h00 - Ecole de Physique, Auditoire Stueckelberg PHYSICS COLLOQUIUM « Electron counting in quantum dots in and out of equilibrium » Prof. Klaus Ensslin Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland   Electron transport through quantum dots is governed by Coulomb blockade. Using a nearby quantum point contact the time-dependent charge flow through quantum dots can be monitored on the basis of single electrons. This way electron transport has been investigated in equilibrium as well as out of equilibrium. Recently it has become possible to experimentally verify the fluctuation theorem. The talk will also address electron counting experiments in grapheme. Une verrée ...

  8. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yen, E-mail: yen.liu@nasa.gov; Vinokur, Marcel [NASA Ames Research Center, Moffett Field, California 94035 (United States); Panesi, Marco; Sahai, Amal [University of Illinois, Urbana-Champaign, Illinois 61801 (United States)

    2015-04-07

    This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model’s accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy

  9. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures

    Science.gov (United States)

    Liu, Yen; Panesi, Marco; Sahai, Amal; Vinokur, Marcel

    2015-04-01

    This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model's accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy

  10. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures.

    Science.gov (United States)

    Liu, Yen; Panesi, Marco; Sahai, Amal; Vinokur, Marcel

    2015-04-07

    This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model's accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy

  11. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures

    International Nuclear Information System (INIS)

    Liu, Yen; Vinokur, Marcel; Panesi, Marco; Sahai, Amal

    2015-01-01

    This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model’s accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy

  12. A Novel Derivation of the Time Evolution of the Entropy for Macroscopic Systems in Thermal Non-Equilibrium

    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.

  13. Kinetic equations within the formalism of non-equilibrium thermo field dynamics

    International Nuclear Information System (INIS)

    Arimitsu, Toshihico

    1988-01-01

    After reviewing the real-time formalism of dissipative quantum field theory, i.e. non-equilibrium thermo field dynamics (NETFD), a kinetic equation, a self-consistent equation for the dissipation coefficient and a ''mass'' or ''chemical potential'' renormalization equation for non-equilibrium transient situations are extracted out of the two-point Green's function of the Heisenberg field, in their most general forms upon the basic requirements of NETFD. The formulation is applied to the electron-phonon system, as an example, where the gradient expansion and the quasi-particle approximation are performed. The formalism of NETFD is reinvestigated in connection with the kinetic equations. (orig.)

  14. Enhanced configurational sampling with hybrid non-equilibrium molecular dynamics-Monte Carlo propagator

    Science.gov (United States)

    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

  15. Fluctuation relations in non-equilibrium stationary states of Ising models

    Energy Technology Data Exchange (ETDEWEB)

    Piscitelli, A; Gonnella, G [Dipartimento di Fisica, Universita di Bari and Istituto Nazionale di Fisica Nucleare, Sezione di Bari, via Amendola 173, 70126 Bari (Italy); Corberi, F [Dipartimento di Matematica ed Informatica, via Ponte don Melillo, Universita di Salerno, 84084 Fisciano (Italy); Pelizzola, A [Dipartimento di Fisica and Istituto Nazionale di Fisica Nucleare, Sezione di Torino, and CNISM, Politecnico di Torino, c. Duca degli Abruzzi 24, 10129 Torino (Italy)

    2009-01-15

    Fluctuation relations for the entropy production in non-equilibrium stationary states of Ising models are investigated by means of Monte Carlo simulations. Systems in contact with heat baths at two different temperatures or subject to external driving will be studied. In the first case, considering different kinetic rules and couplings with the baths, the behaviors of the probability distributions of the heat exchanged in time {tau} with the thermostats, both in the disordered phase and in the low temperature phase, are discussed. The fluctuation relation is always followed in the large {tau} limit and deviations from linear response theory are observed. Finite {tau} corrections are shown to obey a scaling behavior. In the other case the system is in contact with a single heat bath, but work is done by shearing it. Also for this system, using the statistics collected for the mechanical work we show the validity of the fluctuation relation and the preasymptotic corrections behave analogously to those for the case with two baths.

  16. Modular reweighting software for statistical mechanical analysis of biased equilibrium data

    Science.gov (United States)

    Sindhikara, Daniel J.

    2012-07-01

    Here a simple, useful, modular approach and software suite designed for statistical reweighting and analysis of equilibrium ensembles is presented. Statistical reweighting is useful and sometimes necessary for analysis of equilibrium enhanced sampling methods, such as umbrella sampling or replica exchange, and also in experimental cases where biasing factors are explicitly known. Essentially, statistical reweighting allows extrapolation of data from one or more equilibrium ensembles to another. Here, the fundamental separable steps of statistical reweighting are broken up into modules - allowing for application to the general case and avoiding the black-box nature of some “all-inclusive” reweighting programs. Additionally, the programs included are, by-design, written with little dependencies. The compilers required are either pre-installed on most systems, or freely available for download with minimal trouble. Examples of the use of this suite applied to umbrella sampling and replica exchange molecular dynamics simulations will be shown along with advice on how to apply it in the general case. New version program summaryProgram title: Modular reweighting version 2 Catalogue identifier: AEJH_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJH_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 179 118 No. of bytes in distributed program, including test data, etc.: 8 518 178 Distribution format: tar.gz Programming language: C++, Python 2.6+, Perl 5+ Computer: Any Operating system: Any RAM: 50-500 MB Supplementary material: An updated version of the original manuscript (Comput. Phys. Commun. 182 (2011) 2227) is available Classification: 4.13 Catalogue identifier of previous version: AEJH_v1_0 Journal reference of previous version: Comput. Phys. Commun. 182 (2011) 2227 Does the new

  17. Thermal transport in low dimensions from statistical physics to nanoscale heat transfer

    CERN Document Server

    2016-01-01

    Understanding non-equilibrium properties of classical and quantum many-particle systems is one of the goals of contemporary statistical mechanics. Besides its own interest for the theoretical foundations of irreversible thermodynamics(e.g. of the Fourier's law of heat conduction), this topic is also relevant to develop innovative ideas for nanoscale thermal management with possible future applications to nanotechnologies and effective energetic resources. The first part of the volume (Chapters 1-6) describes the basic models, the phenomenology and the various theoretical approaches to understand heat transport in low-dimensional lattices (1D e 2D). The methods described will include equilibrium and nonequilibrium molecular dynamics simulations, hydrodynamic and kinetic approaches and the solution of stochastic models. The second part (Chapters 7-10) deals with applications to nano and microscale heat transfer, as for instance phononic transport in carbon-based nanomaterials, including the prominent case of na...

  18. Equilibrium and non-equilibrium charge-state distributions of 2.0 MeV/u carbon ions passing through carbon foils

    International Nuclear Information System (INIS)

    Imai, M.; Sataka, M.; Matsuda, M.; Okayasu, S.; Kawatsura, K.; Takahiro, K.; Komaki, K.; Shibata, H.; Nishio, K.

    2015-01-01

    Both equilibrium and non-equilibrium charge-state distributions were studied experimentally for 2.0 MeV/u carbon ions after passing through carbon foils. Measured charge-state distribution established the equilibrium at a target thickness of 10 μg/cm 2 and this remained unchanged until a maximum target thickness of 98 μg/cm 2 . The equilibrium charge-state distribution, the equilibrium mean charge-state, and the width and skewness of the equilibrium distribution were compared with predictions using existing semi-empirical formulae as well as simulation results, including the ETACHA code. It was found that charge-state distributions, mean charge states, and distribution widths for C 2+ , C 3+ , and C 4+ incident ions merged into quasi-equilibrium values at a target thickness of 5.7 μg/cm 2 in the pre-equilibrium region and evolved simultaneously to the ‘real equilibrium’ values for all of the initial charge states, including C 5+ and C 6+ ions, as previously demonstrated for sulfur projectile ions at the same velocity (Imai et al., 2009). Two kinds of simulation, ETACHA and solution of rate equations taking only single electron transfers into account, were used, and both of them reproduced the measured charge evolution qualitatively. The quasi-equilibrium behavior could be reproduced with the ETACHA code, but not with solution of elementary rate equations

  19. Near-equilibrium dumb-bell-shaped figures for cohesionless small bodies

    Science.gov (United States)

    Descamps, Pascal

    2016-02-01

    In a previous paper (Descamps, P. [2015]. Icarus 245, 64-79), we developed a specific method aimed to retrieve the main physical characteristics (shape, density, surface scattering properties) of highly elongated bodies from their rotational lightcurves through the use of dumb-bell-shaped equilibrium figures. The present work is a test of this method. For that purpose we introduce near-equilibrium dumb-bell-shaped figures which are base dumb-bell equilibrium shapes modulated by lognormal statistics. Such synthetic irregular models are used to generate lightcurves from which our method is successfully applied. Shape statistical parameters of such near-equilibrium dumb-bell-shaped objects are in good agreement with those calculated for example for the Asteroid (216) Kleopatra from its dog-bone radar model. It may suggest that such bilobed and elongated asteroids can be approached by equilibrium figures perturbed be the interplay with a substantial internal friction modeled by a Gaussian random sphere.

  20. Applications of non-equilibrium plasma in chemical processes

    International Nuclear Information System (INIS)

    Patino, P.; Castro, A.

    2003-01-01

    By means of optical emission spectroscopy the population of O( 3 P) in a non-equilibrium, high voltage, oxygen plasma, and O( 3 P), H and OH in another of steam in radio frequency, have been followed. Reactions of both plasmas with liquid hydrocarbons have produced oxidation and/or hydrogenation, depending on the conditions of each one. (Author)

  1. Dynamic implicit 3D adaptive mesh refinement for non-equilibrium radiation diffusion

    Science.gov (United States)

    Philip, B.; Wang, Z.; Berrill, M. A.; Birke, M.; Pernice, M.

    2014-04-01

    The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered often exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multi-physics systems: implicit time integration for efficient long term time integration of stiff multi-physics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

  2. Dynamic implicit 3D adaptive mesh refinement for non-equilibrium radiation diffusion

    International Nuclear Information System (INIS)

    Philip, B.; Wang, Z.; Berrill, M.A.; Birke, M.; Pernice, M.

    2014-01-01

    The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered often exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multi-physics systems: implicit time integration for efficient long term time integration of stiff multi-physics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton–Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence

  3. Influence of condensed species on thermo-physical properties of LTE and non-LTE SF6–Cu mixture

    International Nuclear Information System (INIS)

    Chen, Zhexin; Wu, Yi; Yang, Fei; Sun, Hao; Rong, Mingzhe; Wang, Chunlin

    2017-01-01

    SF 6 –Cu mixture is frequently formed in high-voltage circuit breakers due to the electrode erosion and metal vapor diffusion. During the interruption process, the multiphase effect and deviation from local thermal equilibrium (non-LTE assumption) can both affect the thermo-physical of the arc plasma and further influence the performance of circuit breaker. In this paper, thermo-physical properties, namely composition, thermodynamic properties and transport coefficients are calculated for multiphase SF 6 –Cu mixture with and without LTE assumption. The composition is confirmed by combining classical two-temperature mass action law with phase equilibrium condition deduced from second law of thermodynamics. The thermodynamic properties and transport coefficients are calculated using the multiphase composition result. The influence of condensed species on thermo-physical properties is discussed at different temperature, pressure (0.1–10 atm), non-equilibrium degrees (1–10), and copper molar proportions (0–50%). It is found that the multiphase effect has significant influence on specific enthalpy, specific heat and heavy species thermal conductivity in both LTE and non-LTE SF 6 –Cu system. This paper provides a more accurate database for computational fluid dynamic calculation. (paper)

  4. MEASURING NEBULAR TEMPERATURES: THE EFFECT OF NEW COLLISION STRENGTHS WITH EQUILIBRIUM AND {kappa}-DISTRIBUTED ELECTRON ENERGIES

    Energy Technology Data Exchange (ETDEWEB)

    Nicholls, David C.; Dopita, Michael A.; Sutherland, Ralph S.; Kewley, Lisa J. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Rd., Weston ACT 2611 (Australia); Palay, Ethan, E-mail: david@mso.anu.edu.au [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

    2013-08-15

    In this paper we develop tools for observers to use when analyzing nebular spectra for temperatures and metallicities, with two goals: to present a new, simple method to calculate equilibrium electron temperatures for collisionally excited line flux ratios, using the latest atomic data; and to adapt current methods to include the effects of possible non-equilibrium ''{kappa}'' electron energy distributions. Adopting recent collision strength data for [O III], [S III], [O II], [S II], and [N II], we find that existing methods based on older atomic data seriously overestimate the electron temperatures, even when considering purely Maxwellian statistics. If {kappa} distributions exist in H II regions and planetary nebulae as they do in solar system plasmas, it is important to investigate the observational consequences. This paper continues our previous work on the {kappa} distribution. We present simple formulaic methods that allow observers to (1) measure equilibrium electron temperatures and atomic abundances using the latest atomic data, and (2) to apply simple corrections to existing equilibrium analysis techniques to allow for possible non-equilibrium effects. These tools should lead to better consistency in temperature and abundance measurements, and a clearer understanding of the physics of H II regions and planetary nebulae.

  5. State-to-state modeling of non-equilibrium air nozzle flows

    Science.gov (United States)

    Nagnibeda, E.; Papina, K.; Kunova, O.

    2018-05-01

    One-dimensional non-equilibrium air flows in nozzles are studied on the basis of the state-to-state description of vibrational-chemical kinetics. Five-component mixture N2/O2/NO/N/O is considered taking into account Zeldovich exchange reactions of NO formation, dissociation, recombination and vibrational energy transitions. The equations for vibrational and chem-ical kinetics in a flow are coupled to the conservation equations of momentum and total energy and solved numerically for different conditions in a nozzle throat. The vibrational distributions of nitrogen and oxygen molecules, number densities of species as well as the gas temperature and flow velocity along a nozzle axis are analysed using the detailed state-to-state flow description and in the frame of the simplified one-temperature thermal equilibrium kinetic model. The comparison of the results showed the influence of non-equilibrium kinetics on macroscopic nozzle flow parameters. In the state-to-state approach, non-Boltzmann vibrational dis-tributions of N2 and O2 molecules with a plateau part at intermediate levels are found. The results are found with the use of the complete and simplified schemes of reactions and the impact of exchange reactions, dissociation and recombination on variation of vibrational level populations, mixture composition, gas velocity and temperature along a nozzle axis is shown.

  6. Characterization of non equilibrium effects on high quality critical flows

    International Nuclear Information System (INIS)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J.

    1995-01-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness

  7. Characterization of non equilibrium effects on high quality critical flows

    Energy Technology Data Exchange (ETDEWEB)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J. [Commissariat a l Energie Atomique, Grenoble (France)] [and others

    1995-09-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness.

  8. 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.

  9. Emergence of an enslaved phononic bandgap in a non-equilibrium pseudo-crystal

    Science.gov (United States)

    Bachelard, Nicolas; Ropp, Chad; Dubois, Marc; Zhao, Rongkuo; Wang, Yuan; Zhang, Xiang

    2017-08-01

    Material systems that reside far from thermodynamic equilibrium have the potential to exhibit dynamic properties and behaviours resembling those of living organisms. Here we realize a non-equilibrium material characterized by a bandgap whose edge is enslaved to the wavelength of an external coherent drive. The structure dynamically self-assembles into an unconventional pseudo-crystal geometry that equally distributes momentum across elements. The emergent bandgap is bestowed with lifelike properties, such as the ability to self-heal to perturbations and adapt to sudden changes in the drive. We derive an exact analytical solution for both the spatial organization and the bandgap features, revealing the mechanism for enslavement. This work presents a framework for conceiving lifelike non-equilibrium materials and emphasizes the potential for the dynamic imprinting of material properties through external degrees of freedom.

  10. Emergence of an enslaved phononic bandgap in a non-equilibrium pseudo-crystal.

    Science.gov (United States)

    Bachelard, Nicolas; Ropp, Chad; Dubois, Marc; Zhao, Rongkuo; Wang, Yuan; Zhang, Xiang

    2017-08-01

    Material systems that reside far from thermodynamic equilibrium have the potential to exhibit dynamic properties and behaviours resembling those of living organisms. Here we realize a non-equilibrium material characterized by a bandgap whose edge is enslaved to the wavelength of an external coherent drive. The structure dynamically self-assembles into an unconventional pseudo-crystal geometry that equally distributes momentum across elements. The emergent bandgap is bestowed with lifelike properties, such as the ability to self-heal to perturbations and adapt to sudden changes in the drive. We derive an exact analytical solution for both the spatial organization and the bandgap features, revealing the mechanism for enslavement. This work presents a framework for conceiving lifelike non-equilibrium materials and emphasizes the potential for the dynamic imprinting of material properties through external degrees of freedom.

  11. Fast non-linear extraction of plasma equilibrium parameters using a neural network mapping

    International Nuclear Information System (INIS)

    Lister, J.B.; Schnurrenberger, H.

    1990-07-01

    The shaping of non-circular plasmas requires a non-linear mapping between the measured diagnostic signals and selected equilibrium parameters. The particular configuration of Neural Network known as the multi-layer perceptron provides a powerful and general technique for formulating an arbitrary continuous non-linear multi-dimensional mapping. This technique has been successfully applied to the extraction of equilibrium parameters from measurements of single-null diverted plasmas in the DIII-D tokamak; the results are compared with a purely linear mapping. The method is promising, and hardware implementation is straightforward. (author) 15 refs., 7 figs

  12. Development of a Thermo-chemical Non-equilibrium Solver for Hypervelocity Flows

    Science.gov (United States)

    Balasubramanian, R.; Anandhanarayanan, K.

    2015-04-01

    In the present study, a three dimensional flowsolver is indigenously developed to numerically simulate hypervelocity thermal and chemical non equilibrium reactive air flow past flight vehicles. The two-temperature, five species, seventeen reactions, thermo-chemical non equilibrium, non-ionizing, air-chemistry model of Park is implemented in a compressible viscous code CERANS and solved in the finite volume framework. The energy relaxation is addressed by a conservation equation for the vibrational energy of the gas mixture resulting in the evaluation of its vibrational temperature. The AUSM-PW+ numerical flux function has been used for modeling the convective fluxes and a central differencing approximation is used for modeling the diffusive fluxes. The flowsolver had been validated for specifically chosen test cases with inherent flow complexities of non-ionizing hypervelocity thermochemical nonequilibrium flows and results obtained are in good agreement with results available in open literature.

  13. Transonic flow of steam with non-equilibrium and homogenous condensation

    Science.gov (United States)

    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.

  14. Non-equilibrium mass transfer absorption model for the design of boron isotopes chemical exchange column

    International Nuclear Information System (INIS)

    Bai, Peng; Fan, Kaigong; Guo, Xianghai; Zhang, Haocui

    2016-01-01

    Highlights: • We propose a non-equilibrium mass transfer absorption model instead of a distillation equilibrium model to calculate boron isotopes separation. • We apply the model to calculate the needed column height to meet prescribed separation requirements. - Abstract: To interpret the phenomenon of chemical exchange in boron isotopes separation accurately, the process is specified as an absorption–reaction–desorption hybrid process instead of a distillation equilibrium model, the non-equilibrium mass transfer absorption model is put forward and a mass transfer enhancement factor E is introduced to find the packing height needed to meet the specified separation requirements with MATLAB.

  15. Statistical physics of hard optimization problems

    International Nuclear Information System (INIS)

    Zdeborova, L.

    2009-01-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfy ability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named ”locked” constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfy ability.

  16. Statistical physics of hard optimization problems

    Science.gov (United States)

    Zdeborová, Lenka

    2009-06-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named "locked" constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability.

  17. Colloidal dispersions in external fields: from equilibrium to non-equilibrium

    Science.gov (United States)

    Lowen, Hartmut

    2010-03-01

    Dispersions of colloidal particles are excellent model systems of classical statistical mechanics in order to understand the principles of self-organization processes. Using an external field (e.g. electric or magnetic field) the effective interaction between the colloidal particles can be tailored and the system can be brought into non-equilibrium in a controlled way. Glass formation after an ultrafast quench in a two-dimensional superparamagnetic binary colloidal mixture [1,2] will be discussed as well as lane [3,4,5,6,7] and band [8] formation in mixtures of charged suspensions and dusty plasmas driven by an electric field. [4pt] References:[0pt] [1] L. Assoud, F. Ebert, P. Keim, R. Messina, G. Maret, H. Lowen, Phys. Rev. Letters 102, 238301 (2009). [0pt] [2] L. Assoud, F. Ebert, P. Keim, R. Messina, G. Maret, H. Lowen, J. Phys.: Condensed Matter 21, 464114 (2009). [0pt] [3] J. Dzubiella, G. P. Hoffmann, H. Lowen, Phys. Rev. E 65, 021402 (1-8) (2002). [0pt] [4] M. E. Leunissen, C. G. Christova, A. P. Hynninen, C. P. Royall, A. I. Campbell, A. Imhof, M. Dijkstra, R. van Roij, A. van Blaaderen, Nature 437, 235 (2005). [0pt] [5] M. Rex, H. Lowen, Phys. Rev. E 75, 051402 (2007). [0pt] [6] M. Rex, C. P. Royall, A. van Blaaderen, H. Lowen, Lane formation in driven colloidal mixtures: is it continuous or discontinuous?, http://arxiv.org/abs/0812.0908 [0pt] [7] K. R. Sutterlin, A. Wysocki, A. V. Ivlev, C. Rath, H. M. Thomas, M. Rubin-Zuzic, W. J. Goedheer, V. E. Fortov, A. M. Lipaev, V. I. Molotkov, O. F. Petrov, G. E. Morfill, H. Lowen, Phys. Rev. Letters 102, 085003 (2009). [0pt] [8] A. Wysocki, H. Lowen, Phys. Rev. E 79, 041408 (2009).

  18. The role of nonequilibrium thermo-mechanical statistics in modern technologies and industrial processes: an overview

    OpenAIRE

    Rodrigues, Clóves G.; Silva, Antônio A. P.; Silva, Carlos A. B.; Vasconcellos, Áurea R.; Ramos, J. Galvão; Luzzi, Roberto

    2010-01-01

    The nowadays notable development of all the modern technology, fundamental for the progress and well being of world society, imposes a great deal of stress in the realm of basic Physics, more precisely on Thermo-Statistics. We do face situations in electronics and optoelectronics involving physical-chemical systems far-removed-from equilibrium, where ultrafast (in pico- and femto-second scale) and non-linear processes are present. Further, we need to be aware of the rapid unfolding of nano-te...

  19. Non-local thermodynamic equilibrium effects on isentropic coefficient in argon and helium thermal plasmas

    International Nuclear Information System (INIS)

    Sharma, Rohit; Singh, Kuldip

    2014-01-01

    In the present work, two cases of thermal plasma have been considered; the ground state plasma in which all the atoms and ions are assumed to be in the ground state and the excited state plasma in which atoms and ions are distributed over various possible excited states. The variation of Zγ, frozen isentropic coefficient and the isentropic coefficient with degree of ionization and non-equilibrium parameter θ(= T e /T h ) has been investigated for the ground and excited state helium and argon plasmas at pressures 1 atm, 10 atm, and 100 atm in the temperature range from 6000 K to 60 000 K. For a given value of non-equilibrium parameter, the relationship of Zγ with degree of ionization does not show any dependence on electronically excited states in helium plasma whereas in case of argon plasma this dependence is not appreciable till degree of ionization approaches 2. The minima of frozen isentropic coefficient shifts toward lower temperature with increase of non-equilibrium parameter for both the helium and argon plasmas. The lowering of non-equilibrium parameter decreases the frozen isentropic coefficient more emphatically in helium plasma at high pressures in comparison to argon plasma. The increase of pressure slightly reduces the ionization range over which isentropic coefficient almost remains constant and it does not affect appreciably the dependence of isentropic coefficient on non-equilibrium parameter

  20. Simulation and experimental investigation of mechanical and thermal non-equilibrium effect on choking flow at low pressure

    International Nuclear Information System (INIS)

    Yoon, H.J.; Ishii, M.; Revankar, S.T.

    2004-01-01

    The prediction of two-phase choking flow at low pressure (<1MPa) is much more difficult than at relatively higher pressure due to the large density ratio and relatively large thermal and mechanical non-equilibrium between the phases. At low pressure currently available choking flow models are not reliable and satisfactory. In view of this, separate effect tests were conducted to systematically investigate the effects of mechanical and thermal non-equilibrium on the two-phase choking flow in a pipe. The systematic studies is not available in literature, therefore no clear understanding of these effects has been attained until now. A scaled integral facility called PUMA was used for these tests with specific boundary condition with several unique in-;line instruments. The mechanical non-equilibrium effect was studied with air-water choking flow. Subcooled water two-phase choking flow was studied to identify the effects of mechanical and thermal non-equilibrium. A typical nozzle and orifice were used as the choking flow section to evaluate the degree of non-equilibrium due to geometry. The slip ratio, which is a key parameter to express the mechanical non-equilibrium, is obtained upstream of the choking section in the air-water test. The measured choking mass flux for the nozzle was higher than the orifice at low flow quality (<0.05) for the same upstream flow quality indicating that there is a strong mechanical non-equilibrium at the choking plane. The thermal non-equilibrium effect was very strong at low pressure, however, no major influence of the geometry on this effect was observed. Experimental data were compared with RELAP5/MOD3.2.1.2, MOD3.3 beta and TRAC-M code predictions. The code predictions in general were not in agreement with the air-water choking flow test data. This indicated that the mechanical non-equilibrium effects were not properly modeled in the codes. The test data for subcooled water showed moderate decrease of choking mass flux with decrease

  1. Generalized ensemble theory with non-extensive statistics

    Science.gov (United States)

    Shen, Ke-Ming; Zhang, Ben-Wei; Wang, En-Ke

    2017-12-01

    The non-extensive canonical ensemble theory is reconsidered with the method of Lagrange multipliers by maximizing Tsallis entropy, with the constraint that the normalized term of Tsallis' q -average of physical quantities, the sum ∑ pjq, is independent of the probability pi for Tsallis parameter q. The self-referential problem in the deduced probability and thermal quantities in non-extensive statistics is thus avoided, and thermodynamical relationships are obtained in a consistent and natural way. We also extend the study to the non-extensive grand canonical ensemble theory and obtain the q-deformed Bose-Einstein distribution as well as the q-deformed Fermi-Dirac distribution. The theory is further applied to the generalized Planck law to demonstrate the distinct behaviors of the various generalized q-distribution functions discussed in literature.

  2. Corrosion of cast and non equilibrium magnesium alloys

    International Nuclear Information System (INIS)

    Mathieu, S.; Rapin, C.; Steinmetz, P.; Hazan, J.

    1999-01-01

    Due to their low density, magnesium alloys arc very promising as regards applications in the automotive or aeronautical industry. Their corrosion resistance has however to be increased, particularly for cast alloys which are very often two-phased and thus suffer from internal galvanic corrosion. With use of sputtering methods of elaboration, homogeneous magnesium alloys containing far from equilibrium Al, Zr or valve metals contents can be prepared. Corrosion data for Mg-Al-Zn-Sn alloys and MgZr alloys obtained by sputtering, have been determined and compared to those of cast and thixocast AZ91 alloy. Electrochemical tests have evidenced a significantly better behaviour of non equilibrium alloys which, thanks to XPS measurements, could be correlated to the composition of the superficial oxide scale formed on these alloys. (author)

  3. Information theory explanation of the fluctuation theorem, maximum entropy production and self-organized criticality in non-equilibrium stationary states

    CERN Document Server

    Dewar, R

    2003-01-01

    Jaynes' information theory formalism of statistical mechanics is applied to the stationary states of open, non-equilibrium systems. First, it is shown that the probability distribution p subGAMMA of the underlying microscopic phase space trajectories GAMMA over a time interval of length tau satisfies p subGAMMA propor to exp(tau sigma subGAMMA/2k sub B) where sigma subGAMMA is the time-averaged rate of entropy production of GAMMA. Three consequences of this result are then derived: (1) the fluctuation theorem, which describes the exponentially declining probability of deviations from the second law of thermodynamics as tau -> infinity; (2) the selection principle of maximum entropy production for non-equilibrium stationary states, empirical support for which has been found in studies of phenomena as diverse as the Earth's climate and crystal growth morphology; and (3) the emergence of self-organized criticality for flux-driven systems in the slowly-driven limit. The explanation of these results on general inf...

  4. Elementary statistical physics

    CERN Document Server

    Kittel, C

    1965-01-01

    This book is intended to help physics students attain a modest working knowledge of several areas of statistical mechanics, including stochastic processes and transport theory. The areas discussed are among those forming a useful part of the intellectual background of a physicist.

  5. Non-equilibrium blunt body flows in ionized gases

    International Nuclear Information System (INIS)

    Nishida, Michio

    1981-01-01

    The behaviors of electrons and electronically excited atoms in non-equilibrium and partially ionized blunt-body-flows are described. Formulation has been made separately in a shock layer and in a free stream, and then the free stream solution has been connected with the shock layer solution by matching the two solutions at the shock layer edge. The method of this matching is described here. The partially ionized gas is considered to be composed of neutral atoms, ions and electrons. Furthermore, the neutral atoms are divided into atoms in excited levels. Therefore, it is considered that electron energy released due to excitation, and that gained due to de-excitation, contribute to electron energy. Thus, the electron energy equation including these contributions is solved, coupled with the continuity equations of the excited atoms and the electrons. An electron temperature distribution from a free stream to a blunt body wall has been investigated for a case when the electrons are in thermal non-equilibrium with heavy particles in the free stream. In addition, the distributions of the excited atom density are discussed in the present analysis. (author)

  6. Amplitude oscillations in a non-equilibrium polariton condensate

    Science.gov (United States)

    Brierley, Richard; Littlewood, Peter; Eastham, Paul

    2011-03-01

    Like cold atomic gases, semiconductor nanostructures provide new opportunities for exploring non-equilibrium quantum dynamics. In semiconductor microcavities the strong coupling between trapped photons and excitons produces new quasiparticles, polaritons, which can undergo Bose-Einstein condensation. Quantum quenches can be realised by rapidly creating cold exciton populations with a laser [Eastham and Phillips, PRB 79 165303 (2009)]. The mean field theory of non-equilibrium polariton condensates predicts oscillations in the condensate amplitude due to the excitation of a Higgs mode. These oscillations are the analogs of those predicted in quenched cold atomic gases and may occur in the polariton system after performing a quench or by direct excitation of the amplitude mode. We have studied the stability of these oscillations beyond mean field theory. We show that homogeneous amplitude oscillations are unstable to decay into lower energy phase modes at finite wavevectors, suggesting the onset of chaotic behaviour. The resulting hierarchy of decay processes can be understood by analogy to optical parametric oscillators in microcavities. Polariton systems thus provide an interesting opportunity to study the dynamics of Higgs-like modes in a solid state system.

  7. The stationary non-equilibrium plasma of cosmic-ray electrons and positrons

    Science.gov (United States)

    Tomaschitz, Roman

    2016-06-01

    The statistical properties of the two-component plasma of cosmic-ray electrons and positrons measured by the AMS-02 experiment on the International Space Station and the HESS array of imaging atmospheric Cherenkov telescopes are analyzed. Stationary non-equilibrium distributions defining the relativistic electron-positron plasma are derived semi-empirically by performing spectral fits to the flux data and reconstructing the spectral number densities of the electronic and positronic components in phase space. These distributions are relativistic power-law densities with exponential cutoff, admitting an extensive entropy variable and converging to the Maxwell-Boltzmann or Fermi-Dirac distributions in the non-relativistic limit. Cosmic-ray electrons and positrons constitute a classical (low-density high-temperature) plasma due to the low fugacity in the quantized partition function. The positron fraction is assembled from the flux densities inferred from least-squares fits to the electron and positron spectra and is subjected to test by comparing with the AMS-02 flux ratio measured in the GeV interval. The calculated positron fraction extends to TeV energies, predicting a broad spectral peak at about 1 TeV followed by exponential decay.

  8. Stochastic simulations for the time evolution of systems which obey generalized statistics: fractional exclusion statistics and Gentile's statistics

    International Nuclear Information System (INIS)

    Nemnes, G A; Anghel, D V

    2010-01-01

    We present a stochastic method for the simulation of the time evolution in systems which obey generalized statistics, namely fractional exclusion statistics and Gentile's statistics. The transition rates are derived in the framework of canonical ensembles. This approach introduces a tool for describing interacting fermionic and bosonic systems in non-equilibrium as ideal FES systems, in a computationally efficient manner. The two types of statistics are analyzed comparatively, indicating their intrinsic thermodynamic differences and revealing key aspects related to the species size

  9. NON-EQUILIBRIUM IONIZATION MODELING OF THE CURRENT SHEET IN A SIMULATED SOLAR ERUPTION

    International Nuclear Information System (INIS)

    Shen Chengcai; Reeves, Katharine K.; Raymond, John C.; Murphy, Nicholas A.; Ko, Yuan-Kuen; Lin Jun; Mikić, Zoran; Linker, Jon A.

    2013-01-01

    The current sheet that extends from the top of flare loops and connects to an associated flux rope is a common structure in models of coronal mass ejections (CMEs). To understand the observational properties of CME current sheets, we generated predictions from a flare/CME model to be compared with observations. We use a simulation of a large-scale CME current sheet previously reported by Reeves et al. This simulation includes ohmic and coronal heating, thermal conduction, and radiative cooling in the energy equation. Using the results of this simulation, we perform time-dependent ionization calculations of the flow in a CME current sheet and construct two-dimensional spatial distributions of ionic charge states for multiple chemical elements. We use the filter responses from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory and the predicted intensities of emission lines to compute the count rates for each of the AIA bands. The results show differences in the emission line intensities between equilibrium and non-equilibrium ionization. The current sheet plasma is underionized at low heights and overionized at large heights. At low heights in the current sheet, the intensities of the AIA 94 Å and 131 Å channels are lower for non-equilibrium ionization than for equilibrium ionization. At large heights, these intensities are higher for non-equilibrium ionization than for equilibrium ionization inside the current sheet. The assumption of ionization equilibrium would lead to a significant underestimate of the temperature low in the current sheet and overestimate at larger heights. We also calculate the intensities of ultraviolet lines and predict emission features to be compared with events from the Ultraviolet Coronagraph Spectrometer on the Solar and Heliospheric Observatory, including a low-intensity region around the current sheet corresponding to this model

  10. Annotations to quantum statistical mechanics

    CERN Document Server

    Kim, In-Gee

    2018-01-01

    This book is a rewritten and annotated version of Leo P. Kadanoff and Gordon Baym’s lectures that were presented in the book Quantum Statistical Mechanics: Green’s Function Methods in Equilibrium and Nonequilibrium Problems. The lectures were devoted to a discussion on the use of thermodynamic Green’s functions in describing the properties of many-particle systems. The functions provided a method for discussing finite-temperature problems with no more conceptual difficulty than ground-state problems, and the method was equally applicable to boson and fermion systems and equilibrium and nonequilibrium problems. The lectures also explained nonequilibrium statistical physics in a systematic way and contained essential concepts on statistical physics in terms of Green’s functions with sufficient and rigorous details. In-Gee Kim thoroughly studied the lectures during one of his research projects but found that the unspecialized method used to present them in the form of a book reduced their readability. He st...

  11. Fast non-linear extraction of plasma equilibrium parameters using a neural network mapping

    International Nuclear Information System (INIS)

    Lister, J.B.; Schnurrenberger, H.

    1991-01-01

    The shaping of non-circular plasmas requires a non-linear mapping between the measured diagnostic signals and selected equilibrium parameters. The particular configuration of neural network known as the multilayer perceptron provides a powerful and general technique for formulating an arbitrary continuous non-linear multi-dimensional mapping. This technique has been successfully applied to the extraction of equilibrium parameters from measurements of single-null diverted plasmas in the DIII-D tokamak; the results are compared with a purely linear mapping. The method is promising, and hardware implementation is straightforward. (author). 17 refs, 8 figs, 2 tab

  12. Microscopic Simulation and Macroscopic Modeling for Thermal and Chemical Non-Equilibrium

    Science.gov (United States)

    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.

  13. Statistical physics of networks, information and complex systems

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory

    2009-01-01

    In this project we explore the mathematical methods and concepts of statistical physics that are fmding abundant applications across the scientific and technological spectrum from soft condensed matter systems and bio-infonnatics to economic and social systems. Our approach exploits the considerable similarity of concepts between statistical physics and computer science, allowing for a powerful multi-disciplinary approach that draws its strength from cross-fertilization and mUltiple interactions of researchers with different backgrounds. The work on this project takes advantage of the newly appreciated connection between computer science and statistics and addresses important problems in data storage, decoding, optimization, the infonnation processing properties of the brain, the interface between quantum and classical infonnation science, the verification of large software programs, modeling of complex systems including disease epidemiology, resource distribution issues, and the nature of highly fluctuating complex systems. Common themes that the project has been emphasizing are (i) neural computation, (ii) network theory and its applications, and (iii) a statistical physics approach to infonnation theory. The project's efforts focus on the general problem of optimization and variational techniques, algorithm development and infonnation theoretic approaches to quantum systems. These efforts are responsible for fruitful collaborations and the nucleation of science efforts that span multiple divisions such as EES, CCS, 0 , T, ISR and P. This project supports the DOE mission in Energy Security and Nuclear Non-Proliferation by developing novel infonnation science tools for communication, sensing, and interacting complex networks such as the internet or energy distribution system. The work also supports programs in Threat Reduction and Homeland Security.

  14. Statistical thermodynamics of association colloids : the equilibrium structure of micelles, vesicles, and bilayer membranes

    NARCIS (Netherlands)

    Leermakers, F.A.M.

    1988-01-01

    The aim of the present study was to unravel the general equilibrium physical properties of lipid bilayer membranes. We consider four major questions:
    1. What determines the morphology of the association colloids (micelles, membranes, vesicles) in general?
    2. Do the

  15. Non-equilibrium Green's functions method: Non-trivial and disordered leads

    Science.gov (United States)

    He, Yu; Wang, Yu; Klimeck, Gerhard; Kubis, Tillmann

    2014-11-01

    The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si0.5Ge0.5. It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si0.5Ge0.5 transistors by 45% compared to conventional lead methods.

  16. Non-equilibrium microwave plasma for efficient high temperature chemistry

    NARCIS (Netherlands)

    van den Bekerom, D.C.M.; den Harder, N.; Minea, T.; Palomares Linares, J.M.; Bongers, W.; van de Sanden, M.C.M.; van Rooij, G.J.

    2017-01-01

    This article describes a flowing microwave reactor that is used to drive efficient non-equilibrium chemistry for the application of conversion/activation of stable molecules such as CO2, N2 and CH4. The goal of the procedure described here is to measure the in situ gas temperature and gas

  17. Laser Thomson scattering diagnostics of non-equilibrium high pressure plasmas

    International Nuclear Information System (INIS)

    Muraoka, K.; Uchino, K.; Bowden, M.D.; Noguchi, Y.

    2001-01-01

    For various applications of non-equilibrium high pressure plasmas, knowledge of electron properties, such as electron density, electron temperature and/or electron energy distribution function (eedf), is prerequisite for any rational approach to understanding physical and chemical processes occurring in the plasmas. For this purpose, laser Thomson scattering has been successfully applied for the first time to measure the electron properties in plasmas for excimer laser pumping and in microdischarges. Although this diagnostic technique is well established for measurements in high temperature plasmas, its applications to these glow discharge plasmas have had various inherent difficulties, such as a presence of high density neutral particles (>10 21 m -3 ) in the excimer laser pumping discharges and an extremely small plasma size (<0.1 mm) and the presence of nearby walls for microdischarges. These difficulties have been overcome and clear signals have been obtained. The measured results are presented and their implications in the respective discharge phenomena are discussed

  18. HIGH METALLICITY AND NON-EQUILIBRIUM CHEMISTRY IN THE DAYSIDE ATMOSPHERE OF HOT-NEPTUNE GJ 436b

    International Nuclear Information System (INIS)

    Madhusudhan, N.; Seager, S.

    2011-01-01

    We present a detailed analysis of the dayside atmosphere of the hot-Neptune GJ 436b, based on recent Spitzer observations. We report statistical constraints on the thermal and chemical properties of the planetary atmosphere, study correlations between the various molecular species, and discuss scenarios of equilibrium and non-equilibrium chemistry in GJ 436b. We model the atmosphere with a one-dimensional line-by-line radiative transfer code with parameterized molecular abundances and temperature structure. We explore the model parameter space with 10 6 models, using a Markov chain Monte Carlo scheme. Our results encompass previous findings, indicating a paucity of methane, an overabundance of CO and CO 2 , and a slight underabundance of H 2 O, as compared to equilibrium chemistry with solar metallicity. The concentrations of the species are highly correlated. Our best-fit, and most plausible, constraints require a CH 4 mixing ratio of 10 -7 to10 -6 , with CO ≥10 -3 , CO 2 ∼10 -6 to10 -4 , and H 2 O ≤10 -4 ; higher CH 4 would require much higher CO and CO 2 . Based on calculations of equilibrium and non-equilibrium chemistry, we find that the observed abundances can potentially be explained by a combination of high metallicity (∼10x solar) and vertical mixing with K zz ∼ 10 6 -10 7 cm 2 s -1 . The inferred metallicity is enhanced over that of the host star which is known to be consistent with solar metallicity. Our constraints rule out a dayside thermal inversion in GJ 436b. We emphasize that the constraints reported in this work depend crucially on the observations in the two Spitzer channels at 3.6 μm and 4.5 μm. Future observations with warm Spitzer and with the James Webb Space Telescope will be extremely important to improve upon the present constraints on the abundances of carbon species in the dayside atmosphere of GJ 436b.

  19. Reconstructing Macroeconomics Based on Statistical Physics

    Science.gov (United States)

    Aoki, Masanao; Yoshikawa, Hiroshi

    We believe that time has come to integrate the new approach based on statistical physics or econophysics into macroeconomics. Toward this goal, there must be more dialogues between physicists and economists. In this paper, we argue that there is no reason why the methods of statistical physics so successful in many fields of natural sciences cannot be usefully applied to macroeconomics that is meant to analyze the macroeconomy comprising a large number of economic agents. It is, in fact, weird to regard the macroeconomy as a homothetic enlargement of the representative micro agent. We trust the bright future of the new approach to macroeconomies based on statistical physics.

  20. Non-equilibrium hydrogen ionization in 2D simulations of the solar atmosphere

    NARCIS (Netherlands)

    Leenaarts, J.|info:eu-repo/dai/nl/304837946; Carlsson, M.; Hansteen, V.; Rutten, R.J.|info:eu-repo/dai/nl/074143662

    2007-01-01

    Context: The ionization of hydrogen in the solar chromosphere and transition region does not obey LTE or instantaneous statistical equilibrium because the timescale is long compared with important hydrodynamical timescales, especially of magneto-acoustic shocks. Since the pressure, temperature, and

  1. Non-equilibrium effects of core-cooling and time-dependent internal heating on mantle flush events

    Directory of Open Access Journals (Sweden)

    D. A. Yuen

    1995-01-01

    Full Text Available We have examined the non-equilibrium effects of core-cooling and time-dependent internal-heating on the thermal evolution of the Earth's mantle and on mantle flush events caused by the two major phase transitions. Both two- and three-dimensional models have been employed. The mantle viscosity responds to the secular cooling through changes in the averaged temperature field. A viscosity which decreases algebraically with the average temperature has been considered. The time-dependent internal-heating is prescribed to decrease exponentially with a single decay time. We have studied the thermal histories with initial Rayleigh numbers between 2 x 107 and 108 . Flush events, driven by the non-equilibrium forcings, are much more dramatic than those produced by the equilibrium boundary conditions and constant internal heating. Multiple flush events are found under non-equilibrium conditions in which there is very little internal heating or very fast decay rates of internal-heating. Otherwise, the flush events take place in a relatively continuous fashion. Prior to massive flush events small-scale percolative structures appear in the 3D temperature fields. Time-dependent signatures, such as the surface heat flux, also exhibits high frequency oscillatory patterns prior to massive flush events. These two observations suggest that the flush event may be a self-organized critical phenomenon. The Nusselt number as a function of the time-varying Ra does not follow the Nusselt vs. Rayleigh number power-law relationship based on equilibrium (constant temperature boundary conditions. Instead Nu(t may vary non-monotonically with time because of the mantle flush events. Convective processes in the mantle operate quite differently under non-equilibrium conditions from its behaviour under the usual equilibrium situations.

  2. Self-organization of grafted polyelectrolyte layers via the coupling of chemical equilibrium and physical interactions.

    Science.gov (United States)

    Tagliazucchi, Mario; de la Cruz, Mónica Olvera; Szleifer, Igal

    2010-03-23

    The competition between chemical equilibrium, for example protonation, and physical interactions determines the molecular organization and functionality of biological and synthetic systems. Charge regulation by displacement of acid-base equilibrium induced by changes in the local environment provides a feedback mechanism that controls the balance between electrostatic, van der Waals, steric interactions and molecular organization. Which strategies do responsive systems follow to globally optimize chemical equilibrium and physical interactions? We address this question by theoretically studying model layers of end-grafted polyacids. These layers spontaneously form self-assembled aggregates, presenting domains of controlled local pH and whose morphologies can be manipulated by the composition of the solution in contact with the film. Charge regulation stabilizes micellar domains over a wide range of pH by reducing the local charge in the aggregate at the cost of chemical free energy and gaining in hydrophobic interactions. This balance determines the boundaries between different aggregate morphologies. We show that a qualitatively new form of organization arises from the coupling between physical interactions and protonation equilibrium. This optimization strategy presents itself with polyelectrolytes coexisting in two different and well-defined protonation states. Our results underline the need of considering the coupling between chemical equilibrium and physical interactions due to their highly nonadditive behavior. The predictions provide guidelines for the creation of responsive polymer layers presenting self-organized patterns with functional properties and they give insights for the understanding of competing interactions in highly inhomogeneous and constrained environments such as those relevant in nanotechnology and those responsible for biological cells function.

  3. Instability Versus Equilibrium Propagation of Laser Beam in Plasma

    OpenAIRE

    Lushnikov, Pavel M.; Rose, Harvey A.

    2003-01-01

    We obtain, for the first time, an analytic theory of the forward stimulated Brillouin scattering instability of a spatially and temporally incoherent laser beam, that controls the transition between statistical equilibrium and non-equilibrium (unstable) self-focusing regimes of beam propagation. The stability boundary may be used as a comprehensive guide for inertial confinement fusion designs. Well into the stable regime, an analytic expression for the angular diffusion coefficient is obtain...

  4. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    International Nuclear Information System (INIS)

    Munafò, A.; Alfuhaid, S. A.; Panesi, M.; Cambier, J.-L.

    2015-01-01

    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

  5. Introduction to modern theoretical physics. Volume II. Quantum theory and statistical physics

    International Nuclear Information System (INIS)

    Harris, E.G.

    1975-01-01

    The topics discussed include the history and principles, some solvable problems, and symmetry in quantum mechanics, interference phenomena, approximation methods, some applications of nonrelativistic quantum mechanics, relativistic wave equations, quantum theory of radiation, second quantization, elementary particles and their interactions, thermodynamics, equilibrium statistical mechanics and its applications, the kinetic theory of gases, and collective phenomena

  6. Coupling of Higgs and Leggett modes in non-equilibrium superconductors.

    Science.gov (United States)

    Krull, H; Bittner, N; Uhrig, G S; Manske, D; Schnyder, A P

    2016-06-21

    In equilibrium systems amplitude and phase collective modes are decoupled, as they are mutually orthogonal excitations. The direct detection of these Higgs and Leggett collective modes by linear-response measurements is not possible, because they do not couple directly to the electromagnetic field. In this work, using numerical exact simulations we show for the case of two-gap superconductors, that optical pump-probe experiments excite both Higgs and Leggett modes out of equilibrium. We find that this non-adiabatic excitation process introduces a strong interaction between the collective modes, which is absent in equilibrium. Moreover, we propose a type of pump-probe experiment, which allows to probe and coherently control the Higgs and Leggett modes, and thus the order parameter directly. These findings go beyond two-band superconductors and apply to general collective modes in quantum materials.

  7. 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.

  8. Non-equilibrium Inertial Separation Array for High-throughput, Large-volume Blood Fractionation.

    Science.gov (United States)

    Mutlu, Baris R; Smith, Kyle C; Edd, Jon F; Nadar, Priyanka; Dlamini, Mcolisi; Kapur, Ravi; Toner, Mehmet

    2017-08-30

    Microfluidic blood processing is used in a range of applications from cancer therapeutics to infectious disease diagnostics. As these applications are being translated to clinical use, processing larger volumes of blood in shorter timescales with high-reliability and robustness is becoming a pressing need. In this work, we report a scaled, label-free cell separation mechanism called non-equilibrium inertial separation array (NISA). The NISA mechanism consists of an array of islands that exert a passive inertial lift force on proximate cells, thus enabling gentler manipulation of the cells without the need of physical contact. As the cells follow their size-based, deterministic path to their equilibrium positions, a preset fraction of the flow is siphoned to separate the smaller cells from the main flow. The NISA device was used to fractionate 400 mL of whole blood in less than 3 hours, and produce an ultrapure buffy coat (96.6% white blood cell yield, 0.0059% red blood cell carryover) by processing whole blood at 3 mL/min, or ∼300 million cells/second. This device presents a feasible alternative for fractionating blood for transfusion, cellular therapy and blood-based diagnostics, and could significantly improve the sensitivity of rare cell isolation devices by increasing the processed whole blood volume.

  9. Statistical methods for physical science

    CERN Document Server

    Stanford, John L

    1994-01-01

    This volume of Methods of Experimental Physics provides an extensive introduction to probability and statistics in many areas of the physical sciences, with an emphasis on the emerging area of spatial statistics. The scope of topics covered is wide-ranging-the text discusses a variety of the most commonly used classical methods and addresses newer methods that are applicable or potentially important. The chapter authors motivate readers with their insightful discussions, augmenting their material withKey Features* Examines basic probability, including coverage of standard distributions, time s

  10. Thermodynamic theory of equilibrium fluctuations

    International Nuclear Information System (INIS)

    Mishin, Y.

    2015-01-01

    The postulational basis of classical thermodynamics has been expanded to incorporate equilibrium fluctuations. The main additional elements of the proposed thermodynamic theory are the concept of quasi-equilibrium states, a definition of non-equilibrium entropy, a fundamental equation of state in the entropy representation, and a fluctuation postulate describing the probability distribution of macroscopic parameters of an isolated system. Although these elements introduce a statistical component that does not exist in classical thermodynamics, the logical structure of the theory is different from that of statistical mechanics and represents an expanded version of thermodynamics. Based on this theory, we present a regular procedure for calculations of equilibrium fluctuations of extensive parameters, intensive parameters and densities in systems with any number of fluctuating parameters. The proposed fluctuation formalism is demonstrated by four applications: (1) derivation of the complete set of fluctuation relations for a simple fluid in three different ensembles; (2) fluctuations in finite-reservoir systems interpolating between the canonical and micro-canonical ensembles; (3) derivation of fluctuation relations for excess properties of grain boundaries in binary solid solutions, and (4) derivation of the grain boundary width distribution for pre-melted grain boundaries in alloys. The last two applications offer an efficient fluctuation-based approach to calculations of interface excess properties and extraction of the disjoining potential in pre-melted grain boundaries. Possible future extensions of the theory are outlined.

  11. Statistical and thermal physics with computer applications

    CERN Document Server

    Gould, Harvey

    2010-01-01

    This textbook carefully develops the main ideas and techniques of statistical and thermal physics and is intended for upper-level undergraduate courses. The authors each have more than thirty years' experience in teaching, curriculum development, and research in statistical and computational physics. Statistical and Thermal Physics begins with a qualitative discussion of the relation between the macroscopic and microscopic worlds and incorporates computer simulations throughout the book to provide concrete examples of important conceptual ideas. Unlike many contemporary texts on the

  12. Non-equilibrium turbulence scalings in turbulent planar jets

    Science.gov (United States)

    Cafiero, Gioacchino; Vassilicos, John Christos; Turbulence, Mixing; Flow Control Group Team

    2017-11-01

    A revised version of the Townsend George theory, as proposed by Dairay et al. 2015, is applied to the study of turbulent planar jets (Cafiero and Vassilicos 2017). Requiring the self-similarity of only few quantities along with the non-equilibrium dissipation scaling law (Vassilicos 2015), it implies new mean flow and jet width scalings. In particular, the ratio of characteristic cross-stream to centreline streamwise velocities decays as the -1/3 power of streamwise distance in the region where the non-equilibrium dissipation scaling holds. In the definition of Cɛ both in Dairay et al. 2015 and in Cafiero and Vassilicos 2017 the local Reynolds number is based on the local flow width rather than on the integral lengthscale. We verify that the ratio of the integral lengthscale to the flow width is constant, thus enabling the use of the integral flow width in place of the integral lengthscale for defining Cɛ. The importance of this result is twofold: firstly it further strengthens the scalings obtained in the works of Dairay et al. 2015 and Cafiero and Vassilicos 2017; secondly the flow width is immediately accessible by any mean flow measurement, whereas the estimation of the integral lengthscale often requires an additional hypothesis. ERC Advanced Grant 320560.

  13. Self-organized crystallization mechanism of non-equilibrium 2:1 type phyllosilicate systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The crystallization mechanism of 2:1 type regular interstratified minerals is investigated in views of non-equilibrium thermodynamics. The structural chemistry of relative layers and their interstratified combinations is analyzed and six kinds of non-equilibrium chemical systems have been induced. The universal laws of chemical reactions which happened in the interface region of these non-equilibrium systems have been summarized. From these laws, two reaction systems crystallizing out Tosudite and Rectorite respectively have been recovered. The kinetic model of chemical reactions has been developed by means of the mass conservation law. The oscillatory solution showing regular interstratified features has also been obtained numerically. These results indicate that the difference in original chemical composition among systems can affect the chemical connotation of reactants, intermediate products and resultants, and the flow chart of chemical reaction, but cannot change their crystallization behavior of network-forming cations, bigger and smaller network-modifying cations during crystallization. Hence, their kinetic model reflecting the universal crystallization law of these cations is just the same. These systems will crystallize out regular interstratified minerals at suitable parameters, which always exist as domain with nanometer-sized in thickness and can be called the self-organized ordering structure.

  14. Validation of vibration-dissociation coupling models in hypersonic non-equilibrium separated flows

    Science.gov (United States)

    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.

  15. Non-axisymmetric equilibrium reconstruction and suppression of density limit disruptions in a current-carrying stellarator

    Science.gov (United States)

    Ma, Xinxing; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Knowlton, S. F.; Maurer, D. A.

    2017-10-01

    Non-axisymmetric equilibrium reconstructions have been routinely performed with the V3FIT code in the Compact Toroidal Hybrid (CTH), a stellarator/tokamak hybrid. In addition to 50 external magnetic measurements, 160 SXR emissivity measurements are incorporated into V3FIT to reconstruct the magnetic flux surface geometry and infer the current distribution within the plasma. Improved reconstructions of current and q profiles provide insight into understanding the physics of density limit disruptions observed in current-carrying discharges in CTH. It is confirmed that the final scenario of the density limit of CTH plasmas is consistent with classic observations in tokamaks: current profile shrinkage leads to growing MHD instabilities (tearing modes) followed by a loss of MHD equilibrium. It is also observed that the density limit at a given current linearly increases with increasing amounts of 3D shaping fields. Consequently, plasmas with densities up to two times the Greenwald limit are attained. Equilibrium reconstructions show that addition of 3D fields effectively moves resonance surfaces towards the edge of the plasma where the current profile gradient is less, providing a stabilizing effect. This work is supported by US Department of Energy Grant No. DE-FG02-00ER54610.

  16. Temperature in and out of equilibrium: A review of concepts, tools and attempts

    Science.gov (United States)

    Puglisi, A.; Sarracino, A.; Vulpiani, A.

    2017-11-01

    We review the general aspects of the concept of temperature in equilibrium and non-equilibrium statistical mechanics. Although temperature is an old and well-established notion, it still presents controversial facets. After a short historical survey of the key role of temperature in thermodynamics and statistical mechanics, we tackle a series of issues which have been recently reconsidered. In particular, we discuss different definitions and their relevance for energy fluctuations. The interest in such a topic has been triggered by the recent observation of negative temperatures in condensed matter experiments. Moreover, the ability to manipulate systems at the micro and nano-scale urges to understand and clarify some aspects related to the statistical properties of small systems (as the issue of temperature's ;fluctuations;). We also discuss the notion of temperature in a dynamical context, within the theory of linear response for Hamiltonian systems at equilibrium and stochastic models with detailed balance, and the generalized fluctuation-response relations, which provide a hint for an extension of the definition of temperature in far-from-equilibrium systems. To conclude we consider non-Hamiltonian systems, such as granular materials, turbulence and active matter, where a general theoretical framework is still lacking.

  17. Non-Equilibrium Thermodynamic Chemistry and the Composition of the Atmosphere of Mars

    Science.gov (United States)

    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.

  18. Optical orientation of the homogeneous non-equilibrium Bose-Einstein condensate of bright excitons (polaritons)

    OpenAIRE

    Korenev, V. L.

    2011-01-01

    A simple model, describing the dynamics of the non-equilibrium pseudospin of a homogeneous Bose-Einstein condensate of exciton polaritons, has been formulated. It explains the suppression of spin splitting of a non-equilibrium polariton condensate in an external magnetic field, the optical alignment, and the conversion of alignment into orientation of polaritons. It has been shown that inverse effects are possible, to wit, the spontaneous circular polarization and the enhancement of spin spli...

  19. Non-equilibrium quasiparticle processes in superconductor tunneling structures

    International Nuclear Information System (INIS)

    Perold, W.J.

    1990-01-01

    A broad overview is presented of the phenomenon of superconductivity. The tunneling of quasiparticles in superconducter-insulator structures is described. Related non-equilibrium processes, such as superconductor bandgap suppresion, quasiparticle diffusion and recombination, and excess quasiparticle collection are discussed. The processes are illustrated with numerical computer simulation data. The importance of the inter-relationship between these processes in practical multiple tunneling junction superconducting device structures is also emphasized. 14 refs., 8 figs

  20. Non-equilibrium dynamics of single polymer adsorption to solid surfaces

    NARCIS (Netherlands)

    Panja, D.; Barkema, G.T.; 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

  1. Basic researches on thermo-hydraulic non-equilibrium phenomena related to nuclear reactor safety

    International Nuclear Information System (INIS)

    Sakurai, Akira; Kataoka, Isao; Aritomi, Masanori.

    1989-01-01

    A review was made of recent developments of fundamental researches on thermo-hydraulic non-equilibrium phenomena related to light water reactor safety, in relation to problems to be solved for the improvement of safety analysis codes. As for the problems related to flow con ditions, fundamental researches on basic conservation equations and constitutive equations for transient two-phase flow were reviewed. Regarding to the problems related to thermal non-equilibrium phenomena, fundamental researches on film boiling in pool and forced convection, transient boiling heat transfer and flow behavior caused by pressure transients were reviewed. (author)

  2. Lectures on statistical mechanics

    CERN Document Server

    Bowler, M G

    1982-01-01

    Anyone dissatisfied with the almost ritual dullness of many 'standard' texts in statistical mechanics will be grateful for the lucid explanation and generally reassuring tone. Aimed at securing firm foundations for equilibrium statistical mechanics, topics of great subtlety are presented transparently and enthusiastically. Very little mathematical preparation is required beyond elementary calculus and prerequisites in physics are limited to some elementary classical thermodynamics. Suitable as a basis for a first course in statistical mechanics, the book is an ideal supplement to more convent

  3. Cumulants in perturbation expansions for non-equilibrium field theory

    International Nuclear Information System (INIS)

    Fauser, R.

    1995-11-01

    The formulation of perturbation expansions for a quantum field theory of strongly interacting systems in a general non-equilibrium state is discussed. Non-vanishing initial correlations are included in the formulation of the perturbation expansion in terms of cumulants. The cumulants are shown to be the suitable candidate for summing up the perturbation expansion. Also a linked-cluster theorem for the perturbation series with cumulants is presented. Finally a generating functional of the perturbation series with initial correlations is studied. We apply the methods to a simple model of a fermion-boson system. (orig.)

  4. Weighted Traffic Equilibrium Problem in Non Pivot Hilbert Spaces with Long Term Memory

    International Nuclear Information System (INIS)

    Giuffre, Sofia; Pia, Stephane

    2010-01-01

    In the paper we consider a weighted traffic equilibrium problem in a non-pivot Hilbert space and prove the equivalence between a weighted Wardrop condition and a variational inequality with long term memory. As an application we show, using recent results of the Senseable Laboratory at MIT, how wireless devices can be used to optimize the traffic equilibrium problem.

  5. Study of energy fluctuation effect on the statistical mechanics of equilibrium systems

    International Nuclear Information System (INIS)

    Lysogorskiy, Yu V; Wang, Q A; Tayurskii, D A

    2012-01-01

    This work is devoted to the modeling of energy fluctuation effect on the behavior of small classical thermodynamic systems. It is known that when an equilibrium system gets smaller and smaller, one of the major quantities that becomes more and more uncertain is its internal energy. These increasing fluctuations can considerably modify the original statistics. The present model considers the effect of such energy fluctuations and is based on an overlapping between the Boltzmann-Gibbs statistics and the statistics of the fluctuation. Within this o verlap statistics , we studied the effects of several types of energy fluctuations on the probability distribution, internal energy and heat capacity. It was shown that the fluctuations can considerably change the temperature dependence of internal energy and heat capacity in the low energy range and at low temperatures. Particularly, it was found that, due to the lower energy limit of the systems, the fluctuations reduce the probability for the low energy states close to the lowest energy and increase the total average energy. This energy increasing is larger for lower temperatures, making negative heat capacity possible for this case.

  6. Exciton correlations and input–output relations in non-equilibrium exciton superfluids

    International Nuclear Information System (INIS)

    Ye, Jinwu; Sun, Fadi; Yu, Yi-Xiang; Liu, Wuming

    2013-01-01

    The photoluminescence (PL) measurements on photons and the transport measurements on excitons are the two types of independent and complementary detection tools to search for possible exciton superfluids in electron–hole semi-conductor bilayer systems. In fact, it was believed that the transport measurements can provide more direct evidences on superfluids than the spectroscopic measurements. It is important to establish the relations between the two kinds of measurements. In this paper, using quantum Heisenberg–Langevin equations, we establish such a connection by calculating various exciton correlation functions in the putative exciton superfluids. These correlation functions include both normal and anomalous greater, lesser, advanced, retarded, and time-ordered exciton Green functions and also various two exciton correlation functions. We also evaluate the corresponding normal and anomalous spectral weights and the Keldysh distribution functions. We stress the violations of the fluctuation and dissipation theorem among these various exciton correlation functions in the non-equilibrium exciton superfluids. We also explore the input–output relations between various exciton correlation functions and those of emitted photons such as the angle resolved photon power spectrum, phase sensitive two mode squeezing spectrum and two photon correlations. Applications to possible superfluids in the exciton–polariton systems are also mentioned. For a comparison, using conventional imaginary time formalism, we also calculate all the exciton correlation functions in an equilibrium dissipative exciton superfluid in the electron–electron coupled semi-conductor bilayers at the quantum Hall regime at the total filling factor ν T =1. We stress the analogies and also important differences between the correlations functions in the two exciton superfluid systems. - Highlights: ► Establish the relations between photoluminescence and transport measurements. ► Stress the

  7. Non-equilibrium dynamics of single polymer adsorption to solid surfaces

    International Nuclear Information System (INIS)

    Panja, Debabrata; Barkema, Gerard T; Kolomeisky, Anatoly 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 in the absence of hydrodynamic interactions. We find that for weak adsorption energies the adsorption timescales ∼N (1+2ν)/(1+ν) , where ν is the Flory exponent for the polymer. We argue that in this regime the single chain adsorption is closely related to a field-driven polymer translocation through narrow pores. Surprisingly, for high adsorption energies the adsorption time becomes longer, as it scales as ∼N 1+ν , which is explained by strong stretching of the unadsorbed part of the polymer close to the adsorbing surface. These two dynamic regimes are separated by an energy scale that is characterized by non-equilibrium contributions during the adsorption process. (fast track communication)

  8. Time-dependent non-equilibrium dielectric response in QM/continuum approaches

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Feizhi; Lingerfelt, David B.; Li, Xiaosong, E-mail: benedetta.mennucci@unipi.it, E-mail: li@chem.washington.edu [Department of Chemistry, University of Washington, Seattle, Washington 98195 (United States); Mennucci, Benedetta, E-mail: benedetta.mennucci@unipi.it, E-mail: li@chem.washington.edu [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, 56126 Pisa (Italy)

    2015-01-21

    The Polarizable Continuum Models (PCMs) are some of the most inexpensive yet successful methods for including the effects of solvation in quantum-mechanical calculations of molecular systems. However, when applied to the electronic excitation process, these methods are restricted to dichotomously assuming either that the solvent has completely equilibrated with the excited solute charge density (infinite-time limit), or that it retains the configuration that was in equilibrium with the solute prior to excitation (zero-time limit). This renders the traditional PCMs inappropriate for resolving time-dependent solvent effects on non-equilibrium solute electron dynamics like those implicated in the instants following photoexcitation of a solvated molecular species. To extend the existing methods to this non-equilibrium regime, we herein derive and apply a new formalism for a general time-dependent continuum embedding method designed to be propagated alongside the solute’s electronic degrees of freedom in the time domain. Given the frequency-dependent dielectric constant of the solvent, an equation of motion for the dielectric polarization is derived within the PCM framework and numerically integrated simultaneously with the time-dependent Hartree fock/density functional theory equations. Results for small molecular systems show the anticipated dipole quenching and electronic state dephasing/relaxation resulting from out-of-phase charge fluctuations in the dielectric and embedded quantum system.

  9. Role of non-equilibrium conformations on driven polymer translocation.

    Science.gov (United States)

    Katkar, H H; Muthukumar, M

    2018-01-14

    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⟩/N K , is longer than the relaxation time τ 0 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⟩/N K 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 N K Kuhn segments, the condition ⟨τ⟩/N K polymers such as ssDNA, a crossover from quasi-equilibrium to non-equilibrium behavior would occur at N K ∼ O(1000).

  10. Non-equilibrium synthesis of alloys using lasers

    International Nuclear Information System (INIS)

    Mazumder, J.; Choi, J.; Ribaudo, C.; Wang, A.; Kar, A.

    1993-01-01

    This paper discusses microstructure and properties of alloys, produced by laser alloying and cladding technique, for various applications. These include Fe-Cr-W-C alloys for wear resistance, Ni-Cr-Al-Hf alloys for high temperature oxidation resistance and Mg-Al alloys for corrosion resistance. Also a mathematical model will be presented for the prediction of the composition of the metastable phases produced by laser synthesis. Microstructure was characterized using various electron optical techniques such as Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES) and Energy Dispersive X-Ray Analysis (EDAX). Wear properties were characterized by a line contact Block on Cylinder method. High temperature oxidation properties were characterized by using Perkin-Elmer Thermo-Gravimetric Analyzer (TGA) where dynamic weight change were monitored at 1,200 C. Corrosion properties were evaluated by a potentio-dynamic method using a computer controlled Potentiostat manufactured by EG ampersand G. A non-equilibrium M 6 C type carbide was found to be responsible for the improved wear resistance. Increased solid-solubility of Hf was found to be a major factor in improving the high temperature oxidation resistance of the Ni-Cr-Al-Hf alloys. Micro-Crystalline phases were observed in Mg-Al alloys. The rapid solidification was modeled using heat transfer in the liquid pool and the solid substrate and mass transfer in the liquid pool. Non-equilibrium partition coefficient was introduced through the boundary condition at the liquid-solid interface. A good correlation was observed between the prediction and the experimental data. 54 refs

  11. Non-Equilibrium Modeling of Inductively Coupled RF Plasmas

    Science.gov (United States)

    2015-01-01

    wall can be approximated with the expression for an infinite solenoid , B(r = R) = µ0NIc, where quan- tities N and Ic are the number of turns per unit...Modeling of non-equilibrium plasmas in an induc- tively coupled plasma facility. AIAA Paper 2014– 2235, 2014. 45th AIAA Plasmadynamics and Lasers ...1993. 24th Plas- madynamics and Laser Conference, Orlando, FL. [22] M. Capitelli, I. Armenise, D. Bruno, M. Caccia- tore, R. Celiberto, G. Colonna, O

  12. Non local-thermodynamical-equilibrium effects in the simulation of laser-produced plasmas

    International Nuclear Information System (INIS)

    Klapisch, M.; Bar-Shalom, A.; Oreg, J.; Colombant, D.

    1998-01-01

    Local thermodynamic equilibrium (LTE) breaks down in directly or indirectly driven laser plasmas because of sharp gradients, energy deposition, etc. For modeling non-LTE effects in hydrodynamical simulations, Busquet close-quote s model [Phys. Fluids B 5, 4191 (1993)] is very convenient and efficient. It uses off-line generated LTE opacities and equation of states via an effective, radiation-dependent ionization temperature T z . An overview of the model is given. The results are compared with an elaborate collisional radiative model based on superconfigurations. The agreements for average charge Z * and opacities are surprisingly good, even more so when the plasma is immersed in a radiation field. Some remaining discrepancy at low density is attributed to dielectronic recombination. Improvement appears possible, especially for emissivities, because the concept of ionization temperature seems to be validated. copyright 1998 American Institute of Physics

  13. A thermodynamic analysis of non-equilibrium heat conduction in a semi-infinite medium subjected to a step change in temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, A.K.; Hussain, T.A.; Shahad, Haroun A.K. [Babylon Univ., Dept. of Mechanical Engineering, Babylon (Iraq)

    2003-05-01

    The problem of non-equilibrium heat conduction in a semi-infinite medium subjected to a step change in temperature is analyzed thermodynamically using the extended irreversible thermodynamic approach. The results show clearly the wave nature of the dimensionless temperature distribution, Stanton number and the dimensionless entropy change profiles. The non-equilibrium profiles approach the equilibrium profiles as the speed of wave propagation is increased. The results also show that the non-equilibrium temperature is higher than the equilibrium temperature but the difference decreases as the wave propagation speed increases. (Author)

  14. Statistics for Physical Sciences An Introduction

    CERN Document Server

    Martin, Brian

    2012-01-01

    Statistical Methods for the Physical Sciences is an informal, relatively short, but systematic, guide to the more commonly used ideas and techniques in statistical analysis, as used in physical sciences, together with explanations of their origins. It steers a path between the extremes of a recipe of methods with a collection of useful formulas, and a full mathematical account of statistics, while at the same time developing the subject in a logical way. The book can be read in its entirety by anyone with a basic exposure to mathematics at the level of a first-year undergraduate student

  15. Introduction to mathematical statistical physics

    CERN Document Server

    Minlos, R A

    1999-01-01

    This book presents a mathematically rigorous approach to the main ideas and phenomena of statistical physics. The introduction addresses the physical motivation, focussing on the basic concept of modern statistical physics, that is the notion of Gibbsian random fields. Properties of Gibbsian fields are analyzed in two ranges of physical parameters: "regular" (corresponding to high-temperature and low-density regimes) where no phase transition is exhibited, and "singular" (low temperature regimes) where such transitions occur. Next, a detailed approach to the analysis of the phenomena of phase transitions of the first kind, the Pirogov-Sinai theory, is presented. The author discusses this theory in a general way and illustrates it with the example of a lattice gas with three types of particles. The conclusion gives a brief review of recent developments arising from this theory. The volume is written for the beginner, yet advanced students will benefit from it as well. The book will serve nicely as a supplement...

  16. The role of non-equilibrium fluxes in the relaxation processes of the linear chemical master equation.

    Science.gov (United States)

    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

  17. The role of non-equilibrium fluxes in the relaxation processes of the linear chemical master equation

    International Nuclear Information System (INIS)

    Oliveira, Luciana Renata de; Bazzani, Armando; Giampieri, Enrico; Castellani, Gastone C.

    2014-01-01

    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

  18. Neutron scattering on equilibrium and nonequilibrium phonons, excitons and polaritons

    International Nuclear Information System (INIS)

    Broude, V.L.; Sheka, E.F.

    1978-01-01

    A number of problems of solid-state physics representing interest for neutron spectroscopy of future is considered. The development of the neutron inelastic scattering spectroscopy (neutron spectroscopy of equilibrium phonons) is discussed with application to nuclear dynamics of crystals in the thermodynamic equilibrium. The results of high-flux neutron source experiments on molecular crystals are presented. The advantages of neutron inelastic scattering over optical spectroscopy are discussed. The spectroscopy of quasi-equilibrium and non-equilibrium quasi-particles is discussed. In particular, the neutron scattering on polaritons, excitons in thermal equilibrium and production of light-excitons are considered. The problem of the possibility of such experiments is elucidated

  19. Non-equilibrium physics of neural networks for leaning, memory and decision making: landscape and flux perspectives

    Science.gov (United States)

    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.

  20. Interface model conditions for a non-equilibrium heat transfer model for conjugate fluid/porous/solid domains

    International Nuclear Information System (INIS)

    Betchen, L.J.; Straatman, A.G.

    2005-01-01

    A mathematical and numerical model for the treatment of conjugate fluid flow and heat transfer problems in domains containing pure fluid, porous, and pure solid regions has been developed. The model is general and physically reasoned, and allows for local thermal non-equilibrium in the porous region. The model is developed for implementation on a simple collocated finite volume grid. Of particular novelty are the conditions implemented at the interfaces between porous regions, and those containing a pure solid or pure fluid. The model is validated by simulation of a three-dimensional porous plug problem for which experimental results are available. (author)

  1. Introduction to statistical physics and to computer simulations

    CERN Document Server

    Casquilho, João Paulo

    2015-01-01

    Rigorous and comprehensive, this textbook introduces undergraduate students to simulation methods in statistical physics. The book covers a number of topics, including the thermodynamics of magnetic and electric systems; the quantum-mechanical basis of magnetism; ferrimagnetism, antiferromagnetism, spin waves and magnons; liquid crystals as a non-ideal system of technological relevance; and diffusion in an external potential. It also covers hot topics such as cosmic microwave background, magnetic cooling and Bose-Einstein condensation. The book provides an elementary introduction to simulation methods through algorithms in pseudocode for random walks, the 2D Ising model, and a model liquid crystal. Any formalism is kept simple and derivations are worked out in detail to ensure the material is accessible to students from subjects other than physics.

  2. Non-equilibrium in flowing atmospheric plasmas

    International Nuclear Information System (INIS)

    Haas, J.C.M. de.

    1986-01-01

    This thesis deals with the fundamental aspects of two different plasmas applied in technological processes. The first one is the cesium seeded argon plasma in a closed cycle Magnetohydrodynamic (MHD) generator, the second is the thermal argon plasma in a cascade arc with an imposed flow. In Chapter 2 the influence of non-equilibrium on the mass and energy balances of a plasma is worked out. The general theory presented there can be applied to both the plasma in an MHD generator and to the cascade arc with imposed flow. Introductions to these plasmas are given in the Chapters 3 and 6 respectively. These chapters are both followed by two chapters which treat the theoretical and the experimental investigations. The results are summarized in Chapter 9. (Auth.)

  3. Seventeenth Workshop on Computer Simulation Studies in Condensed-Matter Physics

    CERN Document Server

    Landau, David P; Schütler, Heinz-Bernd; Computer Simulation Studies in Condensed-Matter Physics XVI

    2006-01-01

    This status report features the most recent developments in the field, spanning a wide range of topical areas in the computer simulation of condensed matter/materials physics. Both established and new topics are included, ranging from the statistical mechanics of classical magnetic spin models to electronic structure calculations, quantum simulations, and simulations of soft condensed matter. The book presents new physical results as well as novel methods of simulation and data analysis. Highlights of this volume include various aspects of non-equilibrium statistical mechanics, studies of properties of real materials using both classical model simulations and electronic structure calculations, and the use of computer simulations in teaching.

  4. Competitive agents in a market: Statistical physics of the minority game

    Science.gov (United States)

    Sherrington, David

    2007-10-01

    A brief review is presented of the minority game, a simple frustrated many-body system stimulated by considerations of a market of competitive speculative agents. Its cooperative behaviour exhibits phase transitions and both ergodic and non-ergodic regimes. It provides novel challenges to statistical physics, reminiscent of those of mean-field spin glasses.

  5. A Local Probe for Universal Non-equilibrium Dynamics

    Science.gov (United States)

    2015-06-01

    shown are polarizing beam splitters . About 700µW are superimposed with a reference laser on a glass plate and coupled into an optical fiber to detect...A Local Probe for Universal Non -equilibrium Dynamics We report on the results obtained across a nine-month ARO-sponsored project, whose purpose was...to implement a local probe for a gas of ultracold atoms. We used a phase plate with a spiral phase gradient to create a hollow-core laser beam . This

  6. Probing the conformational energetics of alkyl thiols on gold surfaces by means of a morphing/steering non-equilibrium tool.

    Science.gov (United States)

    Piserchia, Andrea; Zerbetto, Mirco; Frezzato, Diego

    2015-03-28

    In this work we show that a non-equilibrium statistical tool based on Jarzynski's equality (JE) can be applied to achieve a sufficiently accurate mapping of the torsion free energy, bond-by-bond, for an alkyl thiol ligand tethered to a gold surface and sensing the presence of the surrounding cluster of similar chains. The strength of our approach is the employment of a strategy to let grow the internal energetics of the whole system (namely, the "energy morphing" stage recently presented by us in J. Comput. Chem., 2014, 35, 1865-1881) before initiating the rotational steering, which yields accurate results in terms of statistical uncertainties and bias on the free energy profiles. The work is mainly methodological and illustrates the feasibility of this kind of inspection on nanoscale molecular clusters with conformational flexibility. The outcomes for the archetype of self-assembled-monolayers considered here, a regular pattern of 10-carbon alkyl thiols on an ideal gold surface, give information on the conformational mobility of the ligands. Notably, such information is unlikely to be obtained by means of standard equilibrium techniques or by conventional molecular dynamics simulations.

  7. Identifying apparent local stable isotope equilibrium in a complex non-equilibrium system.

    Science.gov (United States)

    He, Yuyang; Cao, Xiaobin; Wang, Jianwei; Bao, Huiming

    2018-02-28

    Although being out of equilibrium, biomolecules in organisms have the potential to approach isotope equilibrium locally because enzymatic reactions are intrinsically reversible. A rigorous approach that can describe isotope distribution among biomolecules and their apparent deviation from equilibrium state is lacking, however. Applying the concept of distance matrix in graph theory, we propose that apparent local isotope equilibrium among a subset of biomolecules can be assessed using an apparent fractionation difference (|Δα|) matrix, in which the differences between the observed isotope composition (δ') and the calculated equilibrium fractionation factor (1000lnβ) can be more rigorously evaluated than by using a previous approach for multiple biomolecules. We tested our |Δα| matrix approach by re-analyzing published data of different amino acids (AAs) in potato and in green alga. Our re-analysis shows that biosynthesis pathways could be the reason for an apparently close-to-equilibrium relationship inside AA families in potato leaves. Different biosynthesis/degradation pathways in tubers may have led to the observed isotope distribution difference between potato leaves and tubers. The analysis of data from green algae does not support the conclusion that AAs are further from equilibrium in glucose-cultured green algae than in the autotrophic ones. Application of the |Δα| matrix can help us to locate potential reversible reactions or reaction networks in a complex system such as a metabolic system. The same approach can be broadly applied to all complex systems that have multiple components, e.g. geochemical or atmospheric systems of early Earth or other planets. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Non-equilibrium between ions and electrons inside hot spots from National Ignition Facility experiments

    OpenAIRE

    Zhengfeng Fan; Yuanyuan Liu; Bin Liu; Chengxin Yu; Ke Lan; Jie Liu

    2017-01-01

    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...

  9. Equilibrium prices supported by dual price functions in markets with non-convexities

    International Nuclear Information System (INIS)

    Bjoerndal, Mette; Joernsten, Kurt

    2004-06-01

    The issue of finding market clearing prices in markets with non-convexities has had a renewed interest due to the deregulation of the electricity sector. In the day-ahead electricity market, equilibrium prices are calculated based on bids from generators and consumers. In most of the existing markets, several generation technologies are present, some of which have considerable non-convexities, such as capacity limitations and large start up costs. In this paper we present equilibrium prices composed of a commodity price and an uplift charge. The prices are based on the generation of a separating valid inequality that supports the optimal resource allocation. In the case when the sub-problem generated as the integer variables are held fixed to their optimal values possess the integrality property, the generated prices are also supported by non-linear price-functions that are the basis for integer programming duality. (Author)

  10. Modeling Inflation Using a Non-Equilibrium Equation of Exchange

    Science.gov (United States)

    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

  11. 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...

  12. Influence of Penning effect on the plasma features in a non-equilibrium atmospheric pressure plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Zhengshi; Zhang, Guanjun [School of Electrical Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Jiang, Nan; Cao, Zexian, E-mail: zxcao@iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-03-14

    Non-equilibrium atmospheric pressure plasma jet (APPJ) is a cold plasma source that promises various innovative applications. The influence of Penning effect on the formation, propagation, and other physical properties of the plasma bullets in APPJ remains a debatable topic. By using a 10 cm wide active electrode and a frequency of applied voltage down to 0.5 Hz, the Penning effect caused by preceding discharges can be excluded. It was found that the Penning effect originating in a preceding discharge helps build a conductive channel in the gas flow and provide seed electrons, thus the discharge can be maintained at a low voltage which in turn leads to a smaller propagation speed for the plasma bullet. Photographs from an intensified charge coupled device reveal that the annular structure of the plasma plume for He is irrelevant to the Penning ionization process arising from preceding discharges. By adding NH{sub 3} into Ar to introduce Penning effect, the originally filamentous discharge of Ar can display a rather extensive plasma plume in ambient as He. These results are helpful for the understanding of the behaviors of non-equilibrium APPJs generated under distinct conditions and for the design of plasma jet features, especially the spatial distribution and propagation speed, which are essential for application.

  13. Statistics a guide to the use of statistical methods in the physical sciences

    CERN Document Server

    Barlow, Roger J

    1989-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A.C. Phillips Computing for Scienti

  14. A numerical model for simulating electroosmotic micro- and nanochannel flows under non-Boltzmann equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoungjin; Kwak, Ho Sang [School of Mechanical Engineering, Kumoh National Institute of Technology, 1 Yangho, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Song, Tae-Ho, E-mail: kimkj@kumoh.ac.kr, E-mail: hskwak@kumoh.ac.kr, E-mail: thsong@kaist.ac.kr [Department of Mechanical, Aerospace and Systems Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong, Yuseong, Daejeon 305-701 (Korea, Republic of)

    2011-08-15

    This paper describes a numerical model for simulating electroosmotic flows (EOFs) under non-Boltzmann equilibrium in a micro- and nanochannel. The transport of ionic species is represented by employing the Nernst-Planck equation. Modeling issues related to numerical difficulties are discussed, which include the handling of boundary conditions based on surface charge density, the associated treatment of electric potential and the evasion of nonlinearity due to the electric body force. The EOF in the entrance region of a straight channel is examined. The numerical results show that the present model is useful for the prediction of the EOFs requiring a fine resolution of the electric double layer under either the Boltzmann equilibrium or non-equilibrium. Based on the numerical results, the correlation between the surface charge density and the zeta potential is investigated.

  15. Non-linear neutron star oscillations viewed as deviations from an equilibrium state

    International Nuclear Information System (INIS)

    Sperhake, U

    2002-01-01

    A numerical technique is presented which facilitates the evolution of non-linear neutron star oscillations with a high accuracy essentially independent of the oscillation amplitude. We apply this technique to radial neutron star oscillations in a Lagrangian formulation and demonstrate the superior performance of the new scheme compared with 'conventional' techniques. The key feature of our approach is to describe the evolution in terms of deviations from an equilibrium configuration. In contrast to standard perturbation analysis we keep all higher order terms in the evolution equations and thus obtain a fully non-linear description. The advantage of our scheme lies in the elimination of background terms from the equations and the associated numerical errors. The improvements thus achieved will be particularly significant in the study of mildly non-linear effects where the amplitude of the dynamic signal is small compared with the equilibrium values but large enough to warrant non-linear effects. We apply the new technique to the study of non-linear coupling of Eigenmodes and non-linear effects in the oscillations of marginally stable neutron stars. We find non-linear effects in low amplitude oscillations to be particularly pronounced in the range of modes with vanishing frequency which typically mark the onset of instability. (author)

  16. Statistical and physical evolution of QSO's

    International Nuclear Information System (INIS)

    Caditz, D.; Petrosian, V.

    1989-09-01

    The relationship between the physical evolution of discrete extragalactic sources, the statistical evolution of the observed population of sources, and the cosmological model is discussed. Three simple forms of statistical evolution: pure luminosity evolution (PLE), pure density evolution (PDE), and generalized luminosity evolution (GLE), are considered in detail together with what these forms imply about the physical evolution of individual sources. Two methods are used to analyze the statistical evolution of the observed distribution of QSO's (quasars) from combined flux limited samples. It is shown that both PLE and PDE are inconsistent with the data over the redshift range 0 less than z less than 2.2, and that a more complicated form of evolution such as GLE is required, independent of the cosmological model. This result is important for physical models of AGN, and in particular, for the accretion disk model which recent results show may be inconsistent with PLE

  17. 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...

  18. 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...

  19. The automated design of materials far from equilibrium

    Science.gov (United States)

    Miskin, Marc Z.

    Automated design is emerging as a powerful concept in materials science. By combining computer algorithms, simulations, and experimental data, new techniques are being developed that start with high level functional requirements and identify the ideal materials that achieve them. This represents a radically different picture of how materials become functional in which technological demand drives material discovery, rather than the other way around. At the frontiers of this field, materials systems previously considered too complicated can start to be controlled and understood. Particularly promising are materials far from equilibrium. Material robustness, high strength, self-healing and memory are properties displayed by several materials systems that are intrinsically out of equilibrium. These and other properties could be revolutionary, provided they can first be controlled. This thesis conceptualizes and implements a framework for designing materials that are far from equilibrium. We show how, even in the absence of a complete physical theory, design from the top down is possible and lends itself to producing physical insight. As a prototype system, we work with granular materials: collections of athermal, macroscopic identical objects, since these materials function both as an essential component of industrial processes as well as a model system for many non-equilibrium states of matter. We show that by placing granular materials in the context of design, benefits emerge simultaneously for fundamental and applied interests. As first steps, we use our framework to design granular aggregates with extreme properties like high stiffness, and softness. We demonstrate control over nonlinear effects by producing exotic aggregates that stiffen under compression. Expanding on our framework, we conceptualize new ways of thinking about material design when automatic discovery is possible. We show how to build rules that link particle shapes to arbitrary granular packing

  20. Statistics for non-statisticians

    CERN Document Server

    Madsen, Birger Stjernholm

    2016-01-01

    This book was written for those who need to know how to collect, analyze and present data. It is meant to be a first course for practitioners, a book for private study or brush-up on statistics, and supplementary reading for general statistics classes. The book is untraditional, both with respect to the choice of topics and the presentation: Topics were determined by what is most useful for practical statistical work, and the presentation is as non-mathematical as possible. The book contains many examples using statistical functions in spreadsheets. In this second edition, new topics have been included e.g. within the area of statistical quality control, in order to make the book even more useful for practitioners working in industry. .

  1. A non-equilibrium phase transition in a dissipative forest model

    International Nuclear Information System (INIS)

    Messer, Joachim A.

    2009-01-01

    The shape of the biostress force for a stressed Lotka-Volterra network is for the first time derived from Lindblad's dissipative dynamics. Numerical solutions for stressed prey-predator systems with limited resources show a threshold. A non-equilibrium phase transition to a phase with ecosystem dying after a few enforced oscillations (waldsterben phase) occurs.

  2. Speed of sound in hadronic matter using non-extensive statistics

    International Nuclear Information System (INIS)

    Khuntia, Arvind; Sahoo, Pragati; Garg, Prakhar; Sahoo, Raghunath; Jean Cleymans

    2015-01-01

    The evolution of the dense matter formed in high energy hadronic and nuclear collisions is controlled by the initial energy density and temperature. The expansion of the system is due to the very high initial pressure with lowering of temperature and energy density. The pressure (P) and energy density (ϵ) are related through speed of sound (c 2 s ) under the condition of local thermal equilibrium. The speed of sound plays a crucial role in hydrodynamical expansion of the dense matter created and the critical behaviour of the system evolving from deconfined Quark Gluon Phase (QGP) to confined hadronic phase. There have been several experimental and theoretical studies in this direction. The non-extensive Tsallis statistics gives better description of the transverse momentum spectra of the produced particles created in high energy p + p (p¯) and e + + e - collisions

  3. Non-linear quantum critical dynamics and fluctuation-dissipation ratios far from equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Farzaneh [Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden (Germany); Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden (Germany); Ribeiro, Pedro [CeFEMA, Instituto Superior Tcnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Russian Quantum Center, Novaya Street 100 A, Skolkovo, Moscow Area, 143025 (Russian Federation); Kirchner, Stefan, E-mail: stefan.kirchner@correlated-matter.com [Center for Correlated Matter, Zhejiang University, Hangzhou, Zhejiang 310058 (China)

    2016-02-15

    Non-thermal correlations of strongly correlated electron systems and the far-from-equilibrium properties of phases of condensed matter have become a topical research area. Here, an overview of the non-linear dynamics found near continuous zero-temperature phase transitions within the context of effective temperatures is presented. In particular, we focus on models of critical Kondo destruction. Such a quantum critical state, where Kondo screening is destroyed in a critical fashion, is realized in a number of rare earth intermetallics. This raises the possibility of experimentally testing for the existence of fluctuation-dissipation relations far from equilibrium in terms of effective temperatures. Finally, we present an analysis of a non-interacting, critical reference system, the pseudogap resonant level model, in terms of effective temperatures and contrast these results with those obtained near interacting quantum critical points. - Highlights: • Critical Kondo destruction explains the unusual properties of quantum critical heavy fermion compounds. • We review the concept of effective temperatures in models of critical Kondo destruction. • We compare effective temperatures found near non-interacting and fully interacting fixed points. • A comparison with non-interacting quantum impurity models is presented.

  4. Concept of probability in statistical physics

    CERN Document Server

    Guttmann, Y M

    1999-01-01

    Foundational issues in statistical mechanics and the more general question of how probability is to be understood in the context of physical theories are both areas that have been neglected by philosophers of physics. This book fills an important gap in the literature by providing a most systematic study of how to interpret probabilistic assertions in the context of statistical mechanics. The book explores both subjectivist and objectivist accounts of probability, and takes full measure of work in the foundations of probability theory, in statistical mechanics, and in mathematical theory. It will be of particular interest to philosophers of science, physicists and mathematicians interested in foundational issues, and also to historians of science.

  5. Symmetry, Invariance and Ontology in Physics and Statistics

    Directory of Open Access Journals (Sweden)

    Julio Michael Stern

    2011-09-01

    Full Text Available This paper has three main objectives: (a Discuss the formal analogy between some important symmetry-invariance arguments used in physics, probability and statistics. Specifically, we will focus on Noether’s theorem in physics, the maximum entropy principle in probability theory, and de Finetti-type theorems in Bayesian statistics; (b Discuss the epistemological and ontological implications of these theorems, as they are interpreted in physics and statistics. Specifically, we will focus on the positivist (in physics or subjective (in statistics interpretations vs. objective interpretations that are suggested by symmetry and invariance arguments; (c Introduce the cognitive constructivism epistemological framework as a solution that overcomes the realism-subjectivism dilemma and its pitfalls. The work of the physicist and philosopher Max Born will be particularly important in our discussion.

  6. Phenomenological model for non-equilibrium deuteron emission in nucleon induced reactions

    International Nuclear Information System (INIS)

    Broeders, C.H.M.; Konobeyev, A.Yu.

    2005-01-01

    A new approach is proposed for the calculation of non-equilibrium deuteron energy distributions in nuclear reactions induced by nucleons of intermediate energies. It combines the model of the nucleon pick-up, the coalescence and the deuteron knock-out. Emission and absorption rates for excited particles are described by the pre-equilibrium hybrid model. The model of Sato, Iwamoto, Harada is used to describe the nucleon pick-up and the coalescence of nucleons from the exciton configurations starting from (2p, 1h). The model of deuteron knock-out is formulated taking into account the Pauli principle for the nucleon-deuteron interaction inside a nucleus. The contribution of the direct nucleon pick-up is described phenomenologically. The multiple pre-equilibrium emission of particles is taken into account. The calculated deuteron energy distributions are compared with experimental data from 12 C to 209 Bi. (orig.)

  7. Instability of quantum equilibrium in Bohm's dynamics.

    Science.gov (United States)

    Colin, Samuel; Valentini, Antony

    2014-11-08

    We consider Bohm's second-order dynamics for arbitrary initial conditions in phase space. In principle, Bohm's dynamics allows for 'extended' non-equilibrium, with initial momenta not equal to the gradient of phase of the wave function (as well as initial positions whose distribution departs from the Born rule). We show that extended non-equilibrium does not relax in general and is in fact unstable. This is in sharp contrast with de Broglie's first-order dynamics, for which non-standard momenta are not allowed and which shows an efficient relaxation to the Born rule for positions. On this basis, we argue that, while de Broglie's dynamics is a tenable physical theory, Bohm's dynamics is not. In a world governed by Bohm's dynamics, there would be no reason to expect to see an effective quantum theory today (even approximately), in contradiction with observation.

  8. Non-equilibrium phenomena near vapor-liquid interfaces

    CERN Document Server

    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...

  9. Measurement and Prediction of Radiative Non-Equilibrium for Air Shocks Between 7-9 km/s

    Science.gov (United States)

    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.

  10. The quasi-equilibrium response of MOS structures: Quasi-static factor

    Science.gov (United States)

    Okeke, M.; Balland, B.

    1984-07-01

    The dynamic response of a MOS structure driven into a non-equilibrium behaviour by a voltage ramp is presented. In contrast to Khun's quasi-static technique it is shown that any ramp-driven MOS structure has some degree of non-equilibrium. A quasi staticity factor μAK which serves as a measure of the degree of quasi-equilibrium, has been introduced for the first time. The mathematical model presented in the paper allows a better explanation of the experimental recordings. It is shown that this model could be used to analyse the various features of the response of the structure and that such physical parameters as the generation-rate, trap activation energy, and the effective capture constants could be obtained.

  11. Statistical mechanics

    CERN Document Server

    Davidson, Norman

    2003-01-01

    Clear and readable, this fine text assists students in achieving a grasp of the techniques and limitations of statistical mechanics. The treatment follows a logical progression from elementary to advanced theories, with careful attention to detail and mathematical development, and is sufficiently rigorous for introductory or intermediate graduate courses.Beginning with a study of the statistical mechanics of ideal gases and other systems of non-interacting particles, the text develops the theory in detail and applies it to the study of chemical equilibrium and the calculation of the thermody

  12. Equilibrium Transitions from Non Renewable Energy to Renewable Energy under Capacity Constraints

    OpenAIRE

    Amigues, Jean-Pierre; Ayong Le Kama, Alain; Moreaux, Michel

    2013-01-01

    We study the transition between non-renewable and renewable energy sources with adjustment costs over the production capacity of renewable energy. Assuming constant variable marginal costs for both energy sources, convex adjustment costs and a more expensive renewable energy, we show the following. With sufficiently abundant non-renewable energy endowments, the dynamic equilibrium path is composed of a first time phase of only non-renewable energy use followed by a transition phase substituti...

  13. On radial stationary solutions to a model of non-equilibrium growth

    Czech Academy of Sciences Publication Activity Database

    Escudero, C.; Hakl, Robert; Peral, I.; Torres, P.J.

    2013-01-01

    Roč. 24, č. 3 (2013), s. 437-453 ISSN 0956-7925 Institutional support: RVO:67985840 Keywords : non-equilibrium growth * radial solutions * variational methods Subject RIV: BA - General Mathematics Impact factor: 1.081, year: 2013 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8897362

  14. Shot noise enhancement from non-equilibrium plasmons in Luttinger liquid junctions

    International Nuclear Information System (INIS)

    Kim, Jaeuk U; Kinaret, Jari M; Choi, Mahn-Soo

    2005-01-01

    We consider a quantum wire double junction system with each wire segment described by a spinless Luttinger model, and study theoretically shot noise in this system in the sequential tunnelling regime. We find that the non-equilibrium plasmonic excitations in the central wire segment give rise to qualitatively different behaviour compared to the case with equilibrium plasmons. In particular, shot noise is greatly enhanced by them, and exceeds the Poisson limit. We show that the enhancement can be explained by the emergence of several current-carrying processes, and that the effect disappears if the channels effectively collapse to one because of fast plasmon relaxation processes, for example

  15. Nonequilibrium statistical mechanics ensemble method

    CERN Document Server

    Eu, Byung Chan

    1998-01-01

    In this monograph, nonequilibrium statistical mechanics is developed by means of ensemble methods on the basis of the Boltzmann equation, the generic Boltzmann equations for classical and quantum dilute gases, and a generalised Boltzmann equation for dense simple fluids The theories are developed in forms parallel with the equilibrium Gibbs ensemble theory in a way fully consistent with the laws of thermodynamics The generalised hydrodynamics equations are the integral part of the theory and describe the evolution of macroscopic processes in accordance with the laws of thermodynamics of systems far removed from equilibrium Audience This book will be of interest to researchers in the fields of statistical mechanics, condensed matter physics, gas dynamics, fluid dynamics, rheology, irreversible thermodynamics and nonequilibrium phenomena

  16. Non-equilibrium Green's functions method: Non-trivial and disordered leads

    International Nuclear Information System (INIS)

    He, Yu; Wang, Yu; Klimeck, Gerhard; Kubis, Tillmann

    2014-01-01

    The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si 0.5 Ge 0.5 . It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si 0.5 Ge 0.5 transistors by 45% compared to conventional lead methods

  17. Statistical and particle physics: Common problems and techniques

    International Nuclear Information System (INIS)

    Bowler, K.C.; Mc Kane, A.J.

    1984-01-01

    These proceedings contain statistical mechanical studies in condensed matter physics; interfacial problems in statistical physics; string theory; general monte carlo methods and their application to Lattice gauge theories; topological excitations in field theory; phase transformation kinetics; and studies of chaotic systems

  18. GPU-computing in econophysics and statistical physics

    Science.gov (United States)

    Preis, T.

    2011-03-01

    A recent trend in computer science and related fields is general purpose computing on graphics processing units (GPUs), which can yield impressive performance. With multiple cores connected by high memory bandwidth, today's GPUs offer resources for non-graphics parallel processing. This article provides a brief introduction into the field of GPU computing and includes examples. In particular computationally expensive analyses employed in financial market context are coded on a graphics card architecture which leads to a significant reduction of computing time. In order to demonstrate the wide range of possible applications, a standard model in statistical physics - the Ising model - is ported to a graphics card architecture as well, resulting in large speedup values.

  19. Para-equilibrium phase diagrams

    International Nuclear Information System (INIS)

    Pelton, Arthur D.; Koukkari, Pertti; Pajarre, Risto; Eriksson, Gunnar

    2014-01-01

    Highlights: • A rapidly cooled system may attain a state of para-equilibrium. • In this state rapidly diffusing elements reach equilibrium but others are immobile. • Application of the Phase Rule to para-equilibrium phase diagrams is discussed. • A general algorithm to calculate para-equilibrium phase diagrams is described. - Abstract: If an initially homogeneous system at high temperature is rapidly cooled, a temporary para-equilibrium state may result in which rapidly diffusing elements have reached equilibrium but more slowly diffusing elements have remained essentially immobile. The best known example occurs when homogeneous austenite is quenched. A para-equilibrium phase assemblage may be calculated thermodynamically by Gibbs free energy minimization under the constraint that the ratios of the slowly diffusing elements are the same in all phases. Several examples of calculated para-equilibrium phase diagram sections are presented and the application of the Phase Rule is discussed. Although the rules governing the geometry of these diagrams may appear at first to be somewhat different from those for full equilibrium phase diagrams, it is shown that in fact they obey exactly the same rules with the following provision. Since the molar ratios of non-diffusing elements are the same in all phases at para-equilibrium, these ratios act, as far as the geometry of the diagram is concerned, like “potential” variables (such as T, pressure or chemical potentials) rather than like “normal” composition variables which need not be the same in all phases. A general algorithm to calculate para-equilibrium phase diagrams is presented. In the limit, if a para-equilibrium calculation is performed under the constraint that no elements diffuse, then the resultant phase diagram shows the single phase with the minimum Gibbs free energy at any point on the diagram; such calculations are of interest in physical vapor deposition when deposition is so rapid that phase

  20. A statistical investigation of the effects of edge localized modes on the equilibrium reconstruction in JET

    International Nuclear Information System (INIS)

    Murari, A; Peluso, E; Gaudio, P; Gelfusa, M; Maviglia, F; Hawkes, N

    2012-01-01

    The configuration of magnetic fields is an essential ingredient of tokamak physics. In modern day devices, the magnetic topology is normally derived from equilibrium codes, which solve the Grad–Shafranov equation with constraints imposed by the available measurements. On JET, the main code used for this purpose is EFIT and the more commonly used diagnostics are external pick-up coils. Both the code and the measurements present worse performance during edge localized modes (ELMs). To quantify this aspect, various statistical indicators, based on the values of the residuals and their probability distribution, are defined and calculated. They all show that the quality of EFIT reconstructions is clearly better in the absence of ELMs. To investigate the possible causes of the detrimental effects of ELMs on the reconstruction, the pick-up coils are characterized individually and both the spatial distribution and time behaviour of their residuals are analysed in detail. The coils with a faster time response are the ones reproduced less well by EFIT. The constraints of current and pressure at the separatrix are also varied but the effects of such modifications do not result in decisive improvements in the quality of the reconstructions. The interpretation of this experimental evidence is not absolutely compelling but strongly indicative of deficiencies in the physics model on which the JET reconstruction code is based. (paper)

  1. Local equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    From 3-6 September the First International Workshop on Local Equilibrium in Strong Interaction Physics took place in Bad-Honnef at the Physics Centre of the German Physical Society. A number of talks covered the experimental and theoretical investigation of the 'hotspots' effect, both in high energy particle physics and in intermediate energy nuclear physics.

  2. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

    International Nuclear Information System (INIS)

    Ma, Wen; Yildiz, Bilge; Herbert, F. William; Senanayake, Sanjaya D.

    2015-01-01

    The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr 1+ , Zr 2+ , and Zr 3+ as non-equilibrium oxidation states, in addition to Zr 4+ in the stoichiometric ZrO 2 . This finding resolves the long-debated question of whether it is possible to form any valence states between Zr 0 and Zr 4+ at the metal-oxide interface. The presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr

  3. A class of almost equilibrium states in Robertson-Walker spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Kueskue, Muharrem

    2008-11-06

    In quantum field theory in curved spacetimes the construction of the algebra of observables of linear fields is today well understood. However, it remains a non-trivial task to construct physically meaningful states on the algebra. For instance, we are in the unsatisfactory situation that there exist no examples of states suited to describe local thermal equilibrium in a non-stationary spacetime. In this thesis, we construct a class of states for the Klein-Gordon field in Robertson-Walker spacetimes, which seem to provide the first example of thermal states in a spacetime without time translation symmetry. More precisely, in the setting of real, linear, scalar fields in Robertson-Walker spacetimes we define on the set of homogeneous, isotropic, quasi-free states a free energy functional that is based on the averaged energy density measured by an isotropic observer along his worldline. This functional is well defined and lower bounded by a suitable quantum energy inequality. Subsequently, we minimize this functional and obtain states that we interpret as 'almost equilibrium states'. It turns out that the states of low energy are the ground states of the almost equilibrium states. Finally, we prove that the almost equilibrium states satisfy the Hadamard condition, which qualifies them as physically meaningful states. (orig.)

  4. A class of almost equilibrium states in Robertson-Walker spacetimes

    International Nuclear Information System (INIS)

    Kueskue, Muharrem

    2008-01-01

    In quantum field theory in curved spacetimes the construction of the algebra of observables of linear fields is today well understood. However, it remains a non-trivial task to construct physically meaningful states on the algebra. For instance, we are in the unsatisfactory situation that there exist no examples of states suited to describe local thermal equilibrium in a non-stationary spacetime. In this thesis, we construct a class of states for the Klein-Gordon field in Robertson-Walker spacetimes, which seem to provide the first example of thermal states in a spacetime without time translation symmetry. More precisely, in the setting of real, linear, scalar fields in Robertson-Walker spacetimes we define on the set of homogeneous, isotropic, quasi-free states a free energy functional that is based on the averaged energy density measured by an isotropic observer along his worldline. This functional is well defined and lower bounded by a suitable quantum energy inequality. Subsequently, we minimize this functional and obtain states that we interpret as 'almost equilibrium states'. It turns out that the states of low energy are the ground states of the almost equilibrium states. Finally, we prove that the almost equilibrium states satisfy the Hadamard condition, which qualifies them as physically meaningful states. (orig.)

  5. Global regionalized seismicity in view of Non-Extensive Statistical Physics

    Science.gov (United States)

    Chochlaki, Kalliopi; Vallianatos, Filippos; Michas, Georgios

    2018-03-01

    In the present work we study the distribution of Earth's shallow seismicity on different seismic zones, as occurred from 1981 to 2011 and extracted from the Centroid Moment Tensor (CMT) catalog. Our analysis is based on the subdivision of the Earth's surface into seismic zones that are homogeneous with regards to seismic activity and orientation of the predominant stress field. For this, we use the Flinn-Engdahl regionalization (FE) (Flinn and Engdahl, 1965), which consists of fifty seismic zones as modified by Lombardi and Marzocchi (2007). The latter authors grouped the 50 FE zones into larger tectonically homogeneous ones, utilizing the cumulative moment tensor method, resulting into thirty-nine seismic zones. In each one of these seismic zones we study the distribution of seismicity in terms of the frequency-magnitude distribution and the inter-event time distribution between successive earthquakes, a task that is essential for hazard assessments and to better understand the global and regional geodynamics. In our analysis we use non-extensive statistical physics (NESP), which seems to be one of the most adequate and promising methodological tools for analyzing complex systems, such as the Earth's seismicity, introducing the q-exponential formulation as the expression of probability distribution function that maximizes the Sq entropy as defined by Tsallis, (1988). The qE parameter is significantly greater than one for all the seismic regions analyzed with value range from 1.294 to 1.504, indicating that magnitude correlations are particularly strong. Furthermore, the qT parameter shows some temporal correlations but variations with cut-off magnitude show greater temporal correlations when the smaller magnitude earthquakes are included. The qT for earthquakes with magnitude greater than 5 takes values from 1.043 to 1.353 and as we increase the cut-off magnitude to 5.5 and 6 the qT value ranges from 1.001 to 1.242 and from 1.001 to 1.181 respectively, presenting

  6. Nonequilibrium statistical mechanics of systems with long-range interactions

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Yan, E-mail: levin@if.ufrgs.br; Pakter, Renato, E-mail: pakter@if.ufrgs.br; Rizzato, Felipe B., E-mail: rizzato@if.ufrgs.br; Teles, Tarcísio N., E-mail: tarcisio.teles@fi.infn.it; Benetti, Fernanda P.C., E-mail: fbenetti@if.ufrgs.br

    2014-02-01

    Systems with long-range (LR) forces, for which the interaction potential decays with the interparticle distance with an exponent smaller than the dimensionality of the embedding space, remain an outstanding challenge to statistical physics. The internal energy of such systems lacks extensivity and additivity. Although the extensivity can be restored by scaling the interaction potential with the number of particles, the non-additivity still remains. Lack of additivity leads to inequivalence of statistical ensembles. Before relaxing to thermodynamic equilibrium, isolated systems with LR forces become trapped in out-of-equilibrium quasi-stationary states (qSSs), the lifetime of which diverges with the number of particles. Therefore, in the thermodynamic limit LR systems will not relax to equilibrium. The qSSs are attained through the process of collisionless relaxation. Density oscillations lead to particle–wave interactions and excitation of parametric resonances. The resonant particles escape from the main cluster to form a tenuous halo. Simultaneously, this cools down the core of the distribution and dampens out the oscillations. When all the oscillations die out the ergodicity is broken and a qSS is born. In this report, we will review a theory which allows us to quantitatively predict the particle distribution in the qSS. The theory is applied to various LR interacting systems, ranging from plasmas to self-gravitating clusters and kinetic spin models.

  7. Statistical mechanics and the foundations of thermodynamics

    International Nuclear Information System (INIS)

    Martin-Loef, A.

    1979-01-01

    These lectures are designed as an introduction to classical statistical mechanics and its relation to thermodynamics. They are intended to bridge the gap between the treatment of the subject in physics text books and the modern presentations of mathematically rigorous results. We shall first introduce the probability distributions, ensembles, appropriate for describing systems in equilibrium and consider some of their basic physical applications. We also discuss the problem of approach to equilibrium and how irreversibility comes into the dynamics. We then give a detailed description of how the law of large numbers for macrovariables in equilibrium is derived from the fact that entropy is an extensive quantity in the thermodynamic limit. We show in a natural way how to split the energy changes in an thermodynamical process into work and heat leading to a derivation of the first and second laws of thermodynamics from the rules of thermodynamical equilibrium. We have elaborated this part in detail because we feel it is quite satisfactory, that the establishment of the limit of thermodynamic functions as achieved in the modern development of the mathematical aspects of statistical mechanics allows a more general and logically clearer presentation of the bases of thermodynamics. We close these lectures by presenting the basic facts about fluctuation theory. The treatment aims to be reasonably self-contained both concerning the physics and mathematics needed. No knowledge of quantum mechanics is presupposed. Since we spent a large part on mathematical proofs and give many technical facts these lectures are probably most digestive for the mathematically inclined reader who wants to understand the physics of the subject. (HJ)

  8. Non-equilibrium reacting gas flows kinetic theory of transport and relaxation processes

    CERN Document Server

    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.

  9. Effect of magnetic field on charge imbalance relaxation of non-equilibrium superconductivity

    International Nuclear Information System (INIS)

    Tsuboi, Kazuki; Yagi, Ryuta

    2010-01-01

    We have studied relaxation of charge imbalance of non-equilibrium superconductivity in magnetic field. We found that excess current due to charge imbalance showed striking dependence on magnitude of magnetic field and its orientation. We discussed origin of the relaxation.

  10. A corrected NEGF + DFT approach for calculating electronic transport through molecular devices: Filling bound states and patching the non-equilibrium integration

    International Nuclear Information System (INIS)

    Li Rui; Zhang Jiaxing; Hou Shimin; Qian Zekan; Shen Ziyong; Zhao Xingyu; Xue Zengquan

    2007-01-01

    We discuss two problems in the conventional approach for studying charge transport in molecular electronic devices that is based on the non-equilibrium Green's function formalism and density functional theory, i.e., the bound states and the numerical integration of the non-equilibrium density matrix. A scheme of filling the bound states in the bias window and a method of patching the non-equilibrium integration are proposed, both of which are referred to as the non-equilibrium correction. The discussion is illustrated by means of calculations on a model system consisting of a 4,4 bipyridine molecule connected to two semi-infinite gold monatomic chains

  11. Statistical Survey of Non-Formal Education

    Directory of Open Access Journals (Sweden)

    Ondřej Nývlt

    2012-12-01

    Full Text Available focused on a programme within a regular education system. Labour market flexibility and new requirements on employees create a new domain of education called non-formal education. Is there a reliable statistical source with a good methodological definition for the Czech Republic? Labour Force Survey (LFS has been the basic statistical source for time comparison of non-formal education for the last ten years. Furthermore, a special Adult Education Survey (AES in 2011 was focused on individual components of non-formal education in a detailed way. In general, the goal of the EU is to use data from both internationally comparable surveys for analyses of the particular fields of lifelong learning in the way, that annual LFS data could be enlarged by detailed information from AES in five years periods. This article describes reliability of statistical data aboutnon-formal education. This analysis is usually connected with sampling and non-sampling errors.

  12. Non-relativistic and relativistic quantum kinetic equations in nuclear physics

    International Nuclear Information System (INIS)

    Botermans, W.M.M.

    1989-01-01

    In this thesis an attempt is made to draw up a quantummechanical tranport equation for the explicit calculation oof collision processes between two (heavy) ions, by making proper approaches of the exact equations (non-rel.: N-particles Schroedinger equation; rel.: Euler-Lagrange field equations.). An important starting point in the drag-up of the theory is the behaviour of nuclear matter in equilibrium which is determined by individual as well as collective effects. The central point in this theory is the effective interaction between two nucleons both surrounded by other nucleons. In the derivation of the tranport equations use is made of the green's function formalism as developed by Schwinger and Keldys. For the Green's function kinematic equations are drawn up and are solved by choosing a proper factorization of three- and four-particle Green's functions in terms of one- and two-particle Green's functions. The necessary boundary condition is obtained by explicitly making use of Boltzmann's assumption that colliding particles are statistically uncorrelated. Finally a transport equation is obtained in which the mean field as well as the nucleon-nucleon collisions are given by the same (medium dependent) interaction. This interaction is the non-equilibrium extension of the interaction as given in the Brueckner theory of nuclear matter. Together, kinetic equation and interaction, form a self-consistent set of equations for the case of a non-relativistic as well as for the case of a relativistic starting point. (H.W.) 148 refs.; 6 figs.; 411 schemes

  13. Non-equilibrium Green's functions method: Non-trivial and disordered leads

    Energy Technology Data Exchange (ETDEWEB)

    He, Yu, E-mail: heyuyhe@gmail.com; Wang, Yu; Klimeck, Gerhard; Kubis, Tillmann [Network for Computational Nanotechnology, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-11-24

    The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si{sub 0.5}Ge{sub 0.5}. It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si{sub 0.5}Ge{sub 0.5} transistors by 45% compared to conventional lead methods.

  14. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1962-01-01

    Semiconductor Statistics presents statistics aimed at complementing existing books on the relationships between carrier densities and transport effects. The book is divided into two parts. Part I provides introductory material on the electron theory of solids, and then discusses carrier statistics for semiconductors in thermal equilibrium. Of course a solid cannot be in true thermodynamic equilibrium if any electrical current is passed; but when currents are reasonably small the distribution function is but little perturbed, and the carrier distribution for such a """"quasi-equilibrium"""" co

  15. Noise-Induced Modulation of the Relaxation Kinetics around a Non-Equilibrium Steady State of Non-Linear Chemical Reaction Networks

    OpenAIRE

    Ramaswamy, Rajesh; Sbalzarini, Ivo F; González-Segredo, Nélido

    2011-01-01

    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. Confi...

  16. Thermal Non-equilibrium Consistent with Widespread Cooling

    Science.gov (United States)

    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.

  17. Vol. 3: Statistical Physics and Phase Transitions

    International Nuclear Information System (INIS)

    Sitenko, A.

    1993-01-01

    Problems of modern physics and the situation with physical research in Ukraine are considered. Programme of the conference includes scientific and general problems. Its proceedings are published in 6 volumes. The papers presented in this volume refer to statistical physics and phase transition theory

  18. Behavior of Triple Langmuir Probes in Non-Equilibrium Plasmas

    Science.gov (United States)

    Polzin, Kurt A.; Ratcliffe, Alicia C.

    2018-01-01

    The triple Langmuir probe is an electrostatic probe in which three probe tips collect current when inserted into a plasma. The triple probe differs from a simple single Langmuir probe in the nature of the voltage applied to the probe tips. In the single probe, a swept voltage is applied to the probe tip to acquire a waveform showing the collected current as a function of applied voltage (I-V curve). In a triple probe three probe tips are electrically coupled to each other with constant voltages applied between each of the tips. The voltages are selected such that they would represent three points on the single Langmuir probe I-V curve. Elimination of the voltage sweep makes it possible to measure time-varying plasma properties in transient plasmas. Under the assumption of a Maxwellian plasma, one can determine the time-varying plasma temperature T(sub e)(t) and number density n(sub e)(t) from the applied voltage levels and the time-histories of the collected currents. In the present paper we examine the theory of triple probe operation, specifically focusing on the assumption of a Maxwellian plasma. Triple probe measurements have been widely employed for a number of pulsed and timevarying plasmas, including pulsed plasma thrusters (PPTs), dense plasma focus devices, plasma flows, and fusion experiments. While the equilibrium assumption may be justified for some applications, it is unlikely that it is fully justifiable for all pulsed and time-varying plasmas or for all times during the pulse of a plasma device. To examine a simple non-equilibrium plasma case, we return to basic governing equations of probe current collection and compute the current to the probes for a distribution function consisting of two Maxwellian distributions with different temperatures (the two-temperature Maxwellian). A variation of this method is also employed, where one of the Maxwellians is offset from zero (in velocity space) to add a suprathermal beam of electrons to the tail of the

  19. Modeling and numerical analysis of non-equilibrium two-phase flows

    International Nuclear Information System (INIS)

    Rascle, P.; El Amine, K.

    1997-01-01

    We are interested in the numerical approximation of two-fluid models of nonequilibrium two-phase flows described by six balance equations. We introduce an original splitting technique of the system of equations. This technique is derived in a way such that single phase Riemann solvers may be used: moreover, it allows a straightforward extension to various and detailed exchange source terms. The properties of the fluids are first approached by state equations of ideal gas type and then extended to real fluids. For the construction of numerical schemes , the hyperbolicity of the full system is not necessary. When based on suitable kinetic unwind schemes, the algorithm can compute flow regimes evolving from mixture to single phase flows and vice versa. The whole scheme preserves the physical features of all the variables which remain in the set of physical states. Several stiff numerical tests, such as phase separation and phase transition are displayed in order to highlight the efficiency of the proposed method. The document is a PhD thesis divided in 6 chapters and two annexes. They are entitled: 1. - Introduction (in French), 2. - Two-phase flow, modelling and hyperbolicity (in French), 3. - A numerical method using upwind schemes for the resolution of two-phase flows without exchange terms (in English), 4. - A numerical scheme for one-phase flow of real fluids (in English), 5. - An upwind numerical for non-equilibrium two-phase flows (in English), 6. - The treatment of boundary conditions (in English), A.1. The Perthame scheme (in English) and A.2. The Roe scheme (in English)

  20. Influence of pre-strain on thermal stability of non-equilibrium microstructures in a low alloy steel

    International Nuclear Information System (INIS)

    Sun, Chao; Yang, Shanwu; Wang, Xian; Zhang, Rui; He, Xinlai

    2013-01-01

    Highlights: ► High pre-strain and low pre-strain influence differently on thermal stability of non-equilibrium microstructures. ► High pre-strain, in which dislocation sources can be actuated and dislocation density is increased excessively, will markedly promote recrystallization. ► Low pre-strain, in which dislocations are induced to redistribute into a low-energy structure, can slow down microstructure evolution. -- Abstract: Non-equilibrium microstructures in steels including martensite and bainite, which are main phases in current high strength steels, possess high strength and hardness. However, these microstructures are metastable due to their high density of crystal defects. In the present investigation, hardness test, optical microscopy and electron microscopy have been carried out to detect microstructure evolution in a low alloy steel, which was reheated and held isothermally at 550 °C. Special emphasis was put on influence of pre-strain on thermal stability of non-equilibrium microstructures. It is found that high pre-strain, in which dislocation sources can be actuated and dislocation density is increased excessively, will markedly promote recrystallization of non-equilibrium microstructures at 550 °C, while low pre-strain, in which only can mono-glide of dislocations can be operated in each grain and dislocations are induced to redistribute into a low-energy structure, can slow down microstructure evolution

  1. A framework for modelling gene regulation which accommodates non-equilibrium mechanisms.

    Science.gov (United States)

    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

  2. First principles modeling of hydrocarbons conversion in non-equilibrium plasma

    Energy Technology Data Exchange (ETDEWEB)

    Deminsky, M.A.; Strelkova, M.I.; Durov, S.G.; Jivotov, V.K.; Rusanov, V.D.; Potapkin, B.V. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

    2001-07-01

    Theoretical justification of catalytic activity of non-equilibrium plasma in hydrocarbons conversion process is presented in this paper. The detailed model of highest hydrocarbons conversion includes the gas-phase reactions, chemistry of the growth of polycyclic aromatic hydrocarbons (PAHs), precursor of soot particles formation, neutral, charged clusters and soot particle formation, ion-molecular gas-phase and heterogeneous chemistry. The results of theoretical analysis are compared with experimental results. (authors)

  3. A Study of the Polycondensation of (Tetrahydroxy(TetraarylCyclotetrasiloxanes under Equilibrium and Non-Equilibrium Conditions in the Presence and Absence of Montmorillonite

    Directory of Open Access Journals (Sweden)

    Nataliya N. Makarova

    2018-04-01

    Full Text Available Oligo- and polycyclosiloxanes were obtained by the polycondensation of (tetrahydroxy(tetraarylcyclotetrasiloxanes in equilibrium and non-equilibrium conditions in the presence and absence of montmorillonite (MMT. Their composition and the structures of their components were investigated by infrared (IR spectroscopy, 29Si nuclear magnetic resonance (NMR spectroscopy, atmospheric pressure chemical ionization (APCI mass spectrometry, powder X-ray diffraction (XRD, and gel-penetrating chromatography (GPC. Also, a comparison of polymers formed in the presence of MMT and via anionic polymerization was performed showing differences in their structures.

  4. Mechanical measurement of hydrogen bonded host-guest systems under non-equilibrium, near-physiological conditions.

    Science.gov (United States)

    Naranjo, Teresa; Cerrón, Fernando; Nieto-Ortega, Belén; Latorre, Alfonso; Somoza, Álvaro; Ibarra, Borja; Pérez, Emilio M

    2017-09-01

    Decades after the birth of supramolecular chemistry, there are many techniques to measure noncovalent interactions, such as hydrogen bonding, under equilibrium conditions. As ensembles of molecules rapidly lose coherence, we cannot extrapolate bulk data to single-molecule events under non-equilibrium conditions, more relevant to the dynamics of biological systems. We present a new method that exploits the high force resolution of optical tweezers to measure at the single molecule level the mechanical strength of a hydrogen bonded host-guest pair out of equilibrium and under near-physiological conditions. We utilize a DNA reporter to unambiguously isolate single binding events. The Hamilton receptor-cyanuric acid host-guest system is used as a test bed. The force required to dissociate the host-guest system is ∼17 pN and increases with the pulling rate as expected for a system under non-equilibrium conditions. Blocking one of the hydrogen bonding sites results in a significant decrease of the force-to-break by 1-2 pN, pointing out the ability of the method to resolve subtle changes in the mechanical strength of the binding due to the individual H-bonding components. We believe the method will prove to be a versatile tool to address important questions in supramolecular chemistry.

  5. Statistical physics including applications to condensed matter

    CERN Document Server

    Hermann, Claudine

    2005-01-01

    Statistical Physics bridges the properties of a macroscopic system and the microscopic behavior of its constituting particles, otherwise impossible due to the giant magnitude of Avogadro's number. Numerous systems of today's key technologies -- as e.g. semiconductors or lasers -- are macroscopic quantum objects; only statistical physics allows for understanding their fundamentals. Therefore, this graduate text also focuses on particular applications such as the properties of electrons in solids with applications, and radiation thermodynamics and the greenhouse effect.

  6. Safety bey statistics? A critical view on statistical methods applied in health physics

    International Nuclear Information System (INIS)

    Kraut, W.

    2016-01-01

    The only proper way to describe uncertainties in health physics is by statistical means. But statistics never can replace Your personal evaluation of effect, nor can statistics transmute randomness into certainty like an ''uncertainty laundry''. The paper discusses these problems in routine practical work.

  7. Statistical analysis of the equilibrium configurations of the W7-X stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, A [Max-Planck-Institut fuer Plasmaphysik, Euratom Association, Greifswald (Germany); Geiger, J [Max-Planck-Institut fuer Plasmaphysik, Euratom Association, Greifswald (Germany); Mc Carthy, P J [Department of Physics, University College Cork, Association EURATOM-DCU, Cork (Ireland)

    2007-05-15

    Equilibrium magnetic configurations of W7-X stellarator plasma were analysed in this study. The statistical method of function parametrization was used to recover the physical properties of the magnetic configurations, such as the flux surface geometry, the magnetic field and the iota profile from simulated experimental data. The study was carried out with a net toroidal current. Idealized 'measurements' were first used to recover the configuration. These ' measurements' were then perturbed with noise and the effect of this perturbation on the recovered configuration parameters was estimated. The noise was scanned over a range large enough to encompass that expected in the actual experiment. In the process, it was possible to ascertain the limit of tolerable noise that can be allowed in the inputs so as not to significantly perturb the outputs recovered with noiseless 'measurements'. Generally, a cubic polynomial model was found to be necessary for noise levels below 10%. For higher noise levels, a quadratic polynomial performed as well as the cubic. The noise level of 10% was also the approximate limit up to which the recovery with ideal measurements was generally reproduced. For the flux geometry recovery, however, the quadratic model performed similarly to the cubic for any value of noise, with the latter model proving to be significantly better only for the noiseless case. Also, with noisy predictors the recovery error for the flux surfaces increases linearly with effective radius from the plasma core up to the edge.

  8. Measurement of use value and non-use value of environmental quality consistent with general equilibrium approach

    OpenAIRE

    Naoki Sakamoto; Kazunori Nakajima

    2014-01-01

    This paper proposes the consistent method with general equilibrium models to measure use value and non-use value of large-scale change in environmental quality. First, we develop a general equilibrium model that parameters of the utility function with environmental quality as a dependent variable can be estimated on the basis of the travel cost method and the contingent variation method. Second, we examine to identify the general equilibrium impact of environmental quality by a comparative st...

  9. Heuristic versus statistical physics approach to optimization problems

    International Nuclear Information System (INIS)

    Jedrzejek, C.; Cieplinski, L.

    1995-01-01

    Optimization is a crucial ingredient of many calculation schemes in science and engineering. In this paper we assess several classes of methods: heuristic algorithms, methods directly relying on statistical physics such as the mean-field method and simulated annealing; and Hopfield-type neural networks and genetic algorithms partly related to statistical physics. We perform the analysis for three types of problems: (1) the Travelling Salesman Problem, (2) vector quantization, and (3) traffic control problem in multistage interconnection network. In general, heuristic algorithms perform better (except for genetic algorithms) and much faster but have to be specific for every problem. The key to improving the performance could be to include heuristic features into general purpose statistical physics methods. (author)

  10. The Matrix model, a driven state variables approach to non-equilibrium thermodynamics

    NARCIS (Netherlands)

    Jongschaap, R.J.J.

    2001-01-01

    One of the new approaches in non-equilibrium thermodynamics is the so-called matrix model of Jongschaap. In this paper some features of this model are discussed. We indicate the differences with the more common approach based upon internal variables and the more sophisticated Hamiltonian and GENERIC

  11. Controlling competing electronic orders via non-equilibrium acoustic phonons

    Science.gov (United States)

    Schuett, Michael; Orth, Peter; Levchenko, Alex; Fernandes, Rafael

    The interplay between multiple electronic orders is a hallmark of strongly correlated systems displaying unconventional superconductivity. While doping, pressure, and magnetic field are the standard knobs employed to assess these different phases, ultrafast pump-and-probe techniques opened a new window to probe these systems. Recent examples include the ultrafast excitation of coherent optical phonons coupling to electronic states in cuprates and iron pnictides. In this work, we demonstrate theoretically that non-equilibrium acoustic phonons provide a promising framework to manipulate competing electronic phases and favor unconventional superconductivity over other states. In particular, we show that electrons coupled to out-of-equilibrium anisotropic acoustic phonons enter a steady state in which the effective electronic temperature varies around the Fermi surface. Such a momentum-dependent temperature can then be used to selectively heat electronic states that contribute primarily to density-wave instabilities, reducing their competition with superconductivity. We illustrate this phenomenon by computing the microscopic steady-state phase diagram of the iron pnictides, showing that superconductivity is enhanced with respect to the competing antiferromagnetic phase.

  12. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity.

    Science.gov (United States)

    Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto

    2015-09-30

    Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer.

  13. Precipitation in as-solidified undercooled Ni-Si hypoeutectic alloy: Effect of non-equilibrium solidification

    Energy Technology Data Exchange (ETDEWEB)

    Fan Kai [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Liu Feng, E-mail: liufeng@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Yang Gencang; Zhou Yaohe [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China)

    2011-08-25

    Highlights: {yields} The solid solubility of Si atom in {alpha}-Ni matrix increased with undercooling in the as-solidified sample. {yields} The effect of non-equilibrium solidification on precipitation has been theoretically described. {yields} The nucleation density, the real-time particle size and the precipitation rate are all increased upon annealing. {yields} The precipitate process can be artificially controlled by modifying the initial melt undercooling and the annealing time. - Abstract: Applying glass fluxing and cyclic superheating, high undercooling up to {approx}350 K was achieved for Ni-Si hypoeutectic alloy melt. By isothermally annealing the as-solidified alloy subjected to different undercoolings, precipitation behavior of Ni{sub 3}Si particle, at 973 K, was systematically studied. It was found that, the nucleation density and the real-time particle size, as well as the precipitation rate, were all increased, provided the sample was solidified subjected to higher undercooling. This was ascribed mainly to the increased solid solubility of Si atom in {alpha}-Ni matrix upon non-equilibrium solidification. On this basis, the non-equilibrium dendrite growth upon solidification and the soft impingement prevailing upon solid-state precipitation have been quantitatively connected. As such, the effect of liquid/solid transformation on subsequent precipitation was described.

  14. Precipitation in as-solidified undercooled Ni-Si hypoeutectic alloy: Effect of non-equilibrium solidification

    International Nuclear Information System (INIS)

    Fan Kai; Liu Feng; Yang Gencang; Zhou Yaohe

    2011-01-01

    Highlights: → The solid solubility of Si atom in α-Ni matrix increased with undercooling in the as-solidified sample. → The effect of non-equilibrium solidification on precipitation has been theoretically described. → The nucleation density, the real-time particle size and the precipitation rate are all increased upon annealing. → The precipitate process can be artificially controlled by modifying the initial melt undercooling and the annealing time. - Abstract: Applying glass fluxing and cyclic superheating, high undercooling up to ∼350 K was achieved for Ni-Si hypoeutectic alloy melt. By isothermally annealing the as-solidified alloy subjected to different undercoolings, precipitation behavior of Ni 3 Si particle, at 973 K, was systematically studied. It was found that, the nucleation density and the real-time particle size, as well as the precipitation rate, were all increased, provided the sample was solidified subjected to higher undercooling. This was ascribed mainly to the increased solid solubility of Si atom in α-Ni matrix upon non-equilibrium solidification. On this basis, the non-equilibrium dendrite growth upon solidification and the soft impingement prevailing upon solid-state precipitation have been quantitatively connected. As such, the effect of liquid/solid transformation on subsequent precipitation was described.

  15. Non-equilibrium current via geometric scatterers

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Neidhardt, H.; Tater, Miloš; Zagrebnov, V. A.

    2014-01-01

    Roč. 47, č. 39 (2014), s. 395301 ISSN 1751-8113 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : non-equilibrioum steady states * geometric scatterer * Landauer-Buttiker formula Subject RIV: BE - Theoretical Physics Impact factor: 1.583, year: 2014

  16. Electron density measurement of non-equilibrium atmospheric pressure plasma using dispersion interferometer

    Science.gov (United States)

    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).

  17. Non-equilibrium relaxation and near-arrest dynamics in colloidal suspensions

    International Nuclear Information System (INIS)

    Medina-Noyola, M; RamIrez-Gonzalez, Pedro

    2009-01-01

    In this work we propose a theory to describe the irreversible diffusive relaxation of the local concentration of a colloidal dispersion that proceeds toward its stable thermodynamic equilibrium state, but which may in the process be trapped in metastable or dynamically arrested states. The central assumption of this theory is that the irreversible relaxation of the macroscopically observed mean value n-bar(r,t) of the local concentration of colloidal particles is described by a diffusion equation involving a local mobility b*(r,t) that depends not only on the mean value n-bar(r,t) but also on the covariance σ(r,r';t)≡δn(r,t)δn(r',t)-bar of the fluctuations δn(r,t)≡n(r,t)-n-bar(r,t). This diffusion equation must hence be solved simultaneously with the relaxation equation for the covariance σ(r,r';t), and here we also derive the corresponding relaxation equation. The dependence of the local mobility b*(r,t) on the mean value and the covariance is determined by a self-consistent set of equations involving now the spatially and temporally non-local time-dependent correlation functions, which in a uniform system in equilibrium reduces to the self-consistent generalized Langevin equation (SCGLE) theory of colloid dynamics. The resulting general theory considers the possibility that these relaxation processes occur under the influence of external fields, such as gravitational forces acting in the process of sedimentation. In this paper, however, we describe a simpler application, in which the system remains spatially uniform during the irreversible relaxation process, and discuss the general features of the glass transition scenario predicted by this non-equilibrium theory.

  18. Optimization of two-phase R600a ejector geometries using a non-equilibrium CFD model

    International Nuclear Information System (INIS)

    Lee, Moon Soo; Lee, Hoseong; Hwang, Yunho; Radermacher, Reinhard; Jeong, Hee-Moon

    2016-01-01

    Highlights: • Empirical mass transfer coefficient correlation is built based on Weber number. • Developed model is validated in terms of the e and DP. • A set of Pareto solutions is obtained from MOGA based OAAO method. • DP is improved up to 10,379 Pa with the same e of the baseline. • e is enhanced up to 0.782 with the same DP of the baseline case. - Abstract: A vapor compression cycle, which is typically utilized for the heat pump, air conditioning and refrigeration systems, has inherent thermodynamic losses associated with expansion and compression processes. To minimize these losses and improve the energy efficiency of the vapor compression cycle, an ejector can be applied. However, due to the occurrence of complex physics i.e., non-equilibrium flashing compressible flow in the nozzle with possible shock interactions, it has not been feasible to model or optimize the design of a two-phase ejector. In this study, a homogeneous, non-equilibrium, two-phase flow computational fluid dynamics (CFD) model in a commercial code is used with an in-house empirical correlation for the mass transfer coefficient and real gas properties to perform a geometric optimization of a two-phase ejector. The model is first validated with experimental data of an ejector with R600a as the working fluid. After that, the design parameters of the ejector are optimized using multi-objective genetic algorithm (MOGA) based online approximation-assisted optimization (OAAO) approaches to find the maximum performance.

  19. Statistical physics and condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document is divided into 4 sections: 1) General aspects of statistical physics. The themes include: possible geometrical structures of thermodynamics, the thermodynamical foundation of quantum measurement, transport phenomena (kinetic theory, hydrodynamics and turbulence) and out of equilibrium systems (stochastic dynamics and turbulence). The techniques involved here are typical of applied analysis: stability criteria, mode decomposition, shocks and stochastic equations. 2) Disordered, glassy and granular systems: statics and dynamics. The complexity of the systems can be studied through the structure of their phase space. The geometry of this phase space is studied in several works: the overlap distribution can now be computed with a very high precision; the boundary energy between low lying states does not behave like in ordinary systems; and the Edward's hypothesis of equi-probability of low lying metastable states is invalidated. The phenomenon of aging, characteristic of glassy dynamics, is studied in several models. Dynamics of biological systems or of fracture is shown to bear some resemblance with that of disordered systems. 3) Quantum systems. The themes include: mesoscopic superconductors, supersymmetric approach to strongly correlated electrons, quantum criticality and heavy fermion compounds, optical sum rule violation in the cuprates, heat capacity of lattice spin models from high-temperature series expansion, Lieb-Schultz-Mattis theorem in dimension larger than one, quantum Hall effect, Bose-Einstein condensation and multiple-spin exchange model on the triangular lattice. 4) Soft condensed matter and biological systems. Path integral representations are invaluable to describe polymers, proteins and self-avoiding membranes. Using these methods, problems as diverse as the titration of a weak poly-acid by a strong base, the denaturation transition of DNA or bridge-hopping in conducting polymers have been addressed. The problems of RNA folding

  20. Statistical physics and condensed matter

    International Nuclear Information System (INIS)

    2003-01-01

    This document is divided into 4 sections: 1) General aspects of statistical physics. The themes include: possible geometrical structures of thermodynamics, the thermodynamical foundation of quantum measurement, transport phenomena (kinetic theory, hydrodynamics and turbulence) and out of equilibrium systems (stochastic dynamics and turbulence). The techniques involved here are typical of applied analysis: stability criteria, mode decomposition, shocks and stochastic equations. 2) Disordered, glassy and granular systems: statics and dynamics. The complexity of the systems can be studied through the structure of their phase space. The geometry of this phase space is studied in several works: the overlap distribution can now be computed with a very high precision; the boundary energy between low lying states does not behave like in ordinary systems; and the Edward's hypothesis of equi-probability of low lying metastable states is invalidated. The phenomenon of aging, characteristic of glassy dynamics, is studied in several models. Dynamics of biological systems or of fracture is shown to bear some resemblance with that of disordered systems. 3) Quantum systems. The themes include: mesoscopic superconductors, supersymmetric approach to strongly correlated electrons, quantum criticality and heavy fermion compounds, optical sum rule violation in the cuprates, heat capacity of lattice spin models from high-temperature series expansion, Lieb-Schultz-Mattis theorem in dimension larger than one, quantum Hall effect, Bose-Einstein condensation and multiple-spin exchange model on the triangular lattice. 4) Soft condensed matter and biological systems. Path integral representations are invaluable to describe polymers, proteins and self-avoiding membranes. Using these methods, problems as diverse as the titration of a weak poly-acid by a strong base, the denaturation transition of DNA or bridge-hopping in conducting polymers have been addressed. The problems of RNA folding has