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....

An introduction to equilibrium thermodynamics

CERN Document Server

Morrill, Bernard; Hartnett, James P; Hughes, William F

1973-01-01

An Introduction to Equilibrium Thermodynamics discusses classical thermodynamics and irreversible thermodynamics. It introduces the laws of thermodynamics and the connection between statistical concepts and observable macroscopic properties of a thermodynamic system. Chapter 1 discusses the first law of thermodynamics while Chapters 2 through 4 deal with statistical concepts. The succeeding chapters describe the link between entropy and the reversible heat process concept of entropy; the second law of thermodynamics; Legendre transformations and Jacobian algebra. Finally, Chapter 10 provides a

Stochastic approach to equilibrium and nonequilibrium thermodynamics.

Science.gov (United States)

Tomé, Tânia; de Oliveira, Mário J

2015-04-01

We develop the stochastic approach to thermodynamics based on stochastic dynamics, which can be discrete (master equation) and continuous (Fokker-Planck equation), and on two assumptions concerning entropy. The first is the definition of entropy itself and the second the definition of entropy production rate, which is non-negative and vanishes in thermodynamic equilibrium. Based on these assumptions, we study interacting systems with many degrees of freedom in equilibrium or out of thermodynamic equilibrium and how the macroscopic laws are derived from the stochastic dynamics. These studies include the quasiequilibrium processes; the convexity of the equilibrium surface; the monotonic time behavior of thermodynamic potentials, including entropy; the bilinear form of the entropy production rate; the Onsager coefficients and reciprocal relations; and the nonequilibrium steady states of chemical reactions.

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.

Application of the ruthenium and technetium thermodynamic data bases used in the EQ3/6 geochemical codes

Energy Technology Data Exchange (ETDEWEB)

Isherwood, D.

1985-04-01

Based on a critical review of the available thermodynamic data, computerized data bases for technetium and ruthenium were created for use with the EQ3/6 geochemical computer codes. The technetium data base contains thermodynamic data for 8 aqueous species and 15 solids; 26 aqueous species and 9 solids were included in the ruthenium data base. The EQ3NR code was used to calculate solubility limits for ruthenium (8 x 10{sup -16} M) in ground water from Yucca Mountain, a potential nuclear waste repository site near the Nevada Test Site (NTS). The code confirmed the essentially unlimited solubility of technetium in oxidizing conditions, such as those that are believed to exist in the unsaturated zone at Yucca Mountain and the Cambric Nuclear event site at the NTS. Ruthenium migration observed from the Cambric site was evaluated. The solubility limit for ruthenium (as the aqueous species RuO{sub 4}{sup -}) when constrained by RuO{sub 2} is approximately equal to the concentration of ruthenium found in the cavity ground water (i.e., 2.1 x 10{sup -11} vs 4.5 x 10{sup -11} M). Differences in ruthenium solubility limits between Yucca Mountain and Cambric are primarily due to differences in ground-water pH. Technetium solubility (3 x 10{sup -8} M) for moderately reducing conditions (Eh = -0.1 V) using the metastable oxide, TcO{sub 2}.2H{sub 2}O, as the solubility constraint is within the range of experimental values recently published in a study of technetium sorption on basalt. Previously published technetium solubilities of 10{sup -12} to 10{sup -16} M were apparently based on a technetium data base that did not include aqueous species other than TcO{sub 4}{sup -}. When TcO(OH){sub 2}{sup 0} is included in the data base, the calculated values are much closer to the experimental results. Eh-pH diagrams were also generated for a variety of conditions using the SOLUPLOT code.

Application of the ruthenium and technetium thermodynamic data bases used in the EQ3/6 geochemical codes

International Nuclear Information System (INIS)

Isherwood, D.

1985-04-01

Based on a critical review of the available thermodynamic data, computerized data bases for technetium and ruthenium were created for use with the EQ3/6 geochemical computer codes. The technetium data base contains thermodynamic data for 8 aqueous species and 15 solids; 26 aqueous species and 9 solids were included in the ruthenium data base. The EQ3NR code was used to calculate solubility limits for ruthenium (8 x 10 -16 M) in ground water from Yucca Mountain, a potential nuclear waste repository site near the Nevada Test Site (NTS). The code confirmed the essentially unlimited solubility of technetium in oxidizing conditions, such as those that are believed to exist in the unsaturated zone at Yucca Mountain and the Cambric Nuclear event site at the NTS. Ruthenium migration observed from the Cambric site was evaluated. The solubility limit for ruthenium (as the aqueous species RuO 4 - ) when constrained by RuO 2 is approximately equal to the concentration of ruthenium found in the cavity ground water (i.e., 2.1 x 10 -11 vs 4.5 x 10 -11 M). Differences in ruthenium solubility limits between Yucca Mountain and Cambric are primarily due to differences in ground-water pH. Technetium solubility (3 x 10 -8 M) for moderately reducing conditions (Eh = -0.1 V) using the metastable oxide, TcO 2 .2H 2 O, as the solubility constraint is within the range of experimental values recently published in a study of technetium sorption on basalt. Previously published technetium solubilities of 10 -12 to 10 -16 M were apparently based on a technetium data base that did not include aqueous species other than TcO 4 - . When TcO(OH) 2 0 is included in the data base, the calculated values are much closer to the experimental results. Eh-pH diagrams were also generated for a variety of conditions using the SOLUPLOT code

Chemical Equilibrium as Balance of the Thermodynamic Forces

OpenAIRE

Zilbergleyt, B.

2004-01-01

The article sets forth comprehensive basics of thermodynamics of chemical equilibrium as balance of the thermodynamic forces. Based on the linear equations of irreversible thermodynamics, De Donder definition of the thermodynamic force, and Le Chatelier's principle, new thermodynamics of chemical equilibrium offers an explicit account for multiple chemical interactions within the system. Basic relations between energetic characteristics of chemical transformations and reaction extents are bas...

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...

Methane on Mars: Thermodynamic Equilibrium and Photochemical Calculations

Science.gov (United States)

Levine, J. S.; Summers, M. E.; Ewell, M.

2010-01-01

The detection of methane (CH4) in the atmosphere of Mars by Mars Express and Earth-based spectroscopy is very surprising, very puzzling, and very intriguing. On Earth, about 90% of atmospheric ozone is produced by living systems. A major question concerning methane on Mars is its origin - biological or geological. Thermodynamic equilibrium calculations indicated that methane cannot be produced by atmospheric chemical/photochemical reactions. Thermodynamic equilibrium calculations for three gases, methane, ammonia (NH3) and nitrous oxide (N2O) in the Earth s atmosphere are summarized in Table 1. The calculations indicate that these three gases should not exist in the Earth s atmosphere. Yet they do, with methane, ammonia and nitrous oxide enhanced 139, 50 and 12 orders of magnitude above their calculated thermodynamic equilibrium concentration due to the impact of life! Thermodynamic equilibrium calculations have been performed for the same three gases in the atmosphere of Mars based on the assumed composition of the Mars atmosphere shown in Table 2. The calculated thermodynamic equilibrium concentrations of the same three gases in the atmosphere of Mars is shown in Table 3. Clearly, based on thermodynamic equilibrium calculations, methane should not be present in the atmosphere of Mars, but it is in concentrations approaching 30 ppbv from three distinct regions on Mars.

Equilibrium thermodynamics in modified gravitational theories

International Nuclear Information System (INIS)

Bamba, Kazuharu; Geng, C.-Q.; Tsujikawa, Shinji

2010-01-01

We show that it is possible to obtain a picture of equilibrium thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density f(R,φ,X), where R is the Ricci scalar and X is the kinetic energy of a scalar field φ. This comes from a suitable definition of an energy-momentum tensor of the 'dark' component that respects to a local energy conservation in the Jordan frame. In this framework the horizon entropy S corresponding to equilibrium thermodynamics is equal to a quarter of the horizon area A in units of gravitational constant G, as in Einstein gravity. For a flat cosmological background with a decreasing Hubble parameter, S globally increases with time, as it happens for viable f(R) inflation and dark energy models. We also show that the equilibrium description in terms of the horizon entropy S is convenient because it takes into account the contribution of both the horizon entropy S in non-equilibrium thermodynamics and an entropy production term.

Equilibrium and out-of-equilibrium thermodynamics in supercooled liquids and glasses

International Nuclear Information System (INIS)

Mossa, S; Nave, E La; Tartaglia, P; Sciortino, F

2003-01-01

We review the inherent structure thermodynamical formalism and the formulation of an equation of state (EOS) for liquids in equilibrium based on the (volume) derivatives of the statistical properties of the potential energy surface. We also show that, under the hypothesis that during ageing the system explores states associated with equilibrium configurations, it is possible to generalize the proposed EOS to out-of-equilibrium (OOE) conditions. The proposed formulation is based on the introduction of one additional parameter which, in the chosen thermodynamic formalism, can be chosen as the local minimum where the slowly relaxing OOE liquid is trapped

Thermodynamics Far from Equilibrium: from Glasses to Black Holes

OpenAIRE

Nieuwenhuizen, Th. M.

2001-01-01

A framework for the non-equilibrium thermodynamics of glasses is discussed. It also explains the non-equilibrium thermodynamics of a black hole isolated from matter. The first and second laws of black dynamics and black hole thermodynamics are shown to coincide, while the third laws deal with different issues.

EQ3/6 data base - Ongoing development at Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

Delany, J.M.

1986-01-01

The EQ/6 Data Base has been revised and enhanced to meet the maintenance needs of a large continuously evolving data base. Within the last year a new data-base structure has been developed to manage the manipulation, basic data entry, import/export, retrieval and display features. The data management approach includes visual simplicity, on-line documentation, information management and controls to limit user error, ensure data protection and proper documentation of thermodynamic values and their sources

Local equilibrium and the second law of thermodynamics for irreversible systems with thermodynamic inertia.

Science.gov (United States)

Glavatskiy, K S

2015-10-28

Validity of local equilibrium has been questioned for non-equilibrium systems which are characterized by delayed response. In particular, for systems with non-zero thermodynamic inertia, the assumption of local equilibrium leads to negative values of the entropy production, which is in contradiction with the second law of thermodynamics. In this paper, we address this question by suggesting a variational formulation of irreversible evolution of a system with non-zero thermodynamic inertia. We introduce the Lagrangian, which depends on the properties of the normal and the so-called "mirror-image" systems. We show that the standard evolution equations, in particular, the Maxwell-Cattaneo-Vernotte equation, can be derived from the variational procedure without going beyond the assumption of local equilibrium. We also argue that the second law of thermodynamics in non-equilibrium should be understood as a consequence of the variational procedure and the property of local equilibrium. For systems with instantaneous response this leads to the standard requirement of the local instantaneous entropy production being always positive. However, if a system is characterized by delayed response, the formulation of the second law of thermodynamics should be altered. In particular, the quantity, which is always positive, is not the instantaneous entropy production, but the entropy production averaged over a proper time interval.

Local equilibrium and the second law of thermodynamics for irreversible systems with thermodynamic inertia

International Nuclear Information System (INIS)

Glavatskiy, K. S.

2015-01-01

Validity of local equilibrium has been questioned for non-equilibrium systems which are characterized by delayed response. In particular, for systems with non-zero thermodynamic inertia, the assumption of local equilibrium leads to negative values of the entropy production, which is in contradiction with the second law of thermodynamics. In this paper, we address this question by suggesting a variational formulation of irreversible evolution of a system with non-zero thermodynamic inertia. We introduce the Lagrangian, which depends on the properties of the normal and the so-called “mirror-image” systems. We show that the standard evolution equations, in particular, the Maxwell-Cattaneo-Vernotte equation, can be derived from the variational procedure without going beyond the assumption of local equilibrium. We also argue that the second law of thermodynamics in non-equilibrium should be understood as a consequence of the variational procedure and the property of local equilibrium. For systems with instantaneous response this leads to the standard requirement of the local instantaneous entropy production being always positive. However, if a system is characterized by delayed response, the formulation of the second law of thermodynamics should be altered. In particular, the quantity, which is always positive, is not the instantaneous entropy production, but the entropy production averaged over a proper time interval

EQ3NR, a computer program for geochemical aqueous speciation-solubility calculations: Theoretical manual, user's guide, and related documentation (Version 7.0)

International Nuclear Information System (INIS)

Wolery, T.J.

1992-01-01

EQ3NR is an aqueous solution speciation-solubility modeling code. It is part of the EQ3/6 software package for geochemical modeling. It computes the thermodynamic state of an aqueous solution by determining the distribution of chemical species, including simple ions, ion pairs, and complexes, using standard state thermodynamic data and various equations which describe the thermodynamic activity coefficients of these species. The input to the code describes the aqueous solution in terms of analytical data, including total (analytical) concentrations of dissolved components and such other parameters as the pH, pHCl, Eh, pe, and oxygen fugacity. The input may also include a desired electrical balancing adjustment and various constraints which impose equilibrium with special pure minerals, solid solution end-member components (of specified mole fractions), and gases (of specified fugacities). The code evaluates the degree of disequilibrium in terms of the saturation index (SI = 1og Q/K) and the thermodynamic affinity (A = -2.303 RT log Q/K) for various reactions, such as mineral dissolution or oxidation-reduction in the aqueous solution itself. Individual values of Eh, pe, oxygen fugacity, and Ah (redox affinity) are computed for aqueous redox couples. Equilibrium fugacities are computed for gas species. The code is highly flexible in dealing with various parameters as either model inputs or outputs. The user can specify modification or substitution of equilibrium constants at run time by using options on the input file

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

Thermodynamic and transport properties of gaseous tetrafluoromethane in chemical equilibrium

Science.gov (United States)

Hunt, J. L.; Boney, L. R.

1973-01-01

Equations and in computer code are presented for the thermodynamic and transport properties of gaseous, undissociated tetrafluoromethane (CF4) in chemical equilibrium. The computer code calculates the thermodynamic and transport properties of CF4 when given any two of five thermodynamic variables (entropy, temperature, volume, pressure, and enthalpy). Equilibrium thermodynamic and transport property data are tabulated and pressure-enthalpy diagrams are presented.

EQ3/6 software test and verification report 9/94

International Nuclear Information System (INIS)

Kishi, T.

1996-02-01

This document is the Software Test and Verification Report (STVR) for the EQ3/6 suite of codes as stipulated in the Individual Software Plan for Initial Qualification of EQ3/6 (ISP-NF-07, Revision 1, 11/25/92). The software codes, EQPT, EQ3NR, EQ6, and the software library EQLIB constitute the EQ3/6 software package. This software test and verification project for EQ3/6 was started under the requirements of the LLNL Yucca Mountain Project Software Quality Assurance Plan (SQAP), Revision 0, December 14, 1989, but QP 3.2, Revision 2, June 21, 1994 is now the operative controlling procedure. This is a ''V and V'' report in the language of QP 3.2, Revision 2. Because the author of this report does not have a background in geochemistry, other technical sources were consulted in order to acquire some familiarity with geochemisty, the terminology minology involved, and to review comparable computational methods especially, geochemical aqueous speciation-solubility calculations. The software for the EQ3/6 package consists of approximately 47,000 lines of FORTRAN77 source code and nine on platforms ranging from workstations to supercomputers. The physical control of EQ3/6 software package and documentation is on a SUN SPARC station. Walkthroughs of each principal software packages, EQPT, EQ3NR, and EQ6 were conducted in order to understand the computational procedures involved, to determine any commonality in procedures, and then to establish a plan for the test and verification of EQ3/6. It became evident that all three phases depended upon solving an n x n matrix by the Newton-Raphson Method. Thus, a great deal of emphasis on the test and verification of this procedure was carried out on the first code in the software package EQPT

EQ3/6 software test and verification report 9/94

Energy Technology Data Exchange (ETDEWEB)

Kishi, T.

1996-02-01

This document is the Software Test and Verification Report (STVR) for the EQ3/6 suite of codes as stipulated in the Individual Software Plan for Initial Qualification of EQ3/6 (ISP-NF-07, Revision 1, 11/25/92). The software codes, EQPT, EQ3NR, EQ6, and the software library EQLIB constitute the EQ3/6 software package. This software test and verification project for EQ3/6 was started under the requirements of the LLNL Yucca Mountain Project Software Quality Assurance Plan (SQAP), Revision 0, December 14, 1989, but QP 3.2, Revision 2, June 21, 1994 is now the operative controlling procedure. This is a ``V and V`` report in the language of QP 3.2, Revision 2. Because the author of this report does not have a background in geochemistry, other technical sources were consulted in order to acquire some familiarity with geochemisty, the terminology minology involved, and to review comparable computational methods especially, geochemical aqueous speciation-solubility calculations. The software for the EQ3/6 package consists of approximately 47,000 lines of FORTRAN77 source code and nine on platforms ranging from workstations to supercomputers. The physical control of EQ3/6 software package and documentation is on a SUN SPARC station. Walkthroughs of each principal software packages, EQPT, EQ3NR, and EQ6 were conducted in order to understand the computational procedures involved, to determine any commonality in procedures, and then to establish a plan for the test and verification of EQ3/6. It became evident that all three phases depended upon solving an n x n matrix by the Newton-Raphson Method. Thus, a great deal of emphasis on the test and verification of this procedure was carried out on the first code in the software package EQPT.

EQ3NR, a computer program for geochemical aqueous speciation-solubility calculations: Theoretical manual, user`s guide, and related documentation (Version 7.0); Part 3

Energy Technology Data Exchange (ETDEWEB)

Wolery, T.J.

1992-09-14

EQ3NR is an aqueous solution speciation-solubility modeling code. It is part of the EQ3/6 software package for geochemical modeling. It computes the thermodynamic state of an aqueous solution by determining the distribution of chemical species, including simple ions, ion pairs, and complexes, using standard state thermodynamic data and various equations which describe the thermodynamic activity coefficients of these species. The input to the code describes the aqueous solution in terms of analytical data, including total (analytical) concentrations of dissolved components and such other parameters as the pH, pHCl, Eh, pe, and oxygen fugacity. The input may also include a desired electrical balancing adjustment and various constraints which impose equilibrium with special pure minerals, solid solution end-member components (of specified mole fractions), and gases (of specified fugacities). The code evaluates the degree of disequilibrium in terms of the saturation index (SI = 1og Q/K) and the thermodynamic affinity (A = {minus}2.303 RT log Q/K) for various reactions, such as mineral dissolution or oxidation-reduction in the aqueous solution itself. Individual values of Eh, pe, oxygen fugacity, and Ah (redox affinity) are computed for aqueous redox couples. Equilibrium fugacities are computed for gas species. The code is highly flexible in dealing with various parameters as either model inputs or outputs. The user can specify modification or substitution of equilibrium constants at run time by using options on the input file.

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)

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.

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.

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...

Experimental determination of thermodynamic equilibrium in biocatalytic transamination.

Science.gov (United States)

Tufvesson, Pär; Jensen, Jacob S; Kroutil, Wolfgang; Woodley, John M

2012-08-01

The equilibrium constant is a critical parameter for making rational design choices in biocatalytic transamination for the synthesis of chiral amines. However, very few reports are available in the scientific literature determining the equilibrium constant (K) for the transamination of ketones. Various methods for determining (or estimating) equilibrium have previously been suggested, both experimental as well as computational (based on group contribution methods). However, none of these were found suitable for determining the equilibrium constant for the transamination of ketones. Therefore, in this communication we suggest a simple experimental methodology which we hope will stimulate more accurate determination of thermodynamic equilibria when reporting the results of transaminase-catalyzed reactions in order to increase understanding of the relationship between substrate and product molecular structure on reaction thermodynamics. Copyright © 2012 Wiley Periodicals, Inc.

Reaction of Topopah Spring tuff with J-13 water: a geochemical modeling approach using the EQ3/6 reaction path code

International Nuclear Information System (INIS)

Delany, J.M.

1985-01-01

EQ3/6 geochemical modeling code package was used to investigate the interaction of the Topopah Spring Tuff and J-13 water at high temperatures. EQ3/6 input parameters were obtained from the results of laboratory experiments using USW G-1 core and J-13 water. Laboratory experiments were run at 150 and 250 0 C for 66 days using both wafer-size and crushed tuff. EQ3/6 modeling reproduced results of the 150 0 C experiments except for a small increase in the concentration of potassium that occurs in the first few days of the experiments. At 250 0 C, the EQ3/6 modeling reproduced the major water/rock reactions except for a small increase in potassium, similar to that noted above, and an overall increase in aluminum. The increase in potassium concentration cannot be explained at this time, but the increase in A1 concentration is believed to be caused by the lack of thermodynamic data in the EQ3/6 data base for dachiardite, a zeolite observed as a run product at 250 0 C. The ability to reproduce the majority of the experimental rock/water interactions at 150 0 C validates the use of EQ3/6 as a geochemical modeling tool that can be used to theoretically investigate physical/chemical environments in support of the Waste Package Task of NNWSI

Thermodynamic equilibrium-air correlations for flowfield applications

Science.gov (United States)

Zoby, E. V.; Moss, J. N.

1981-01-01

Equilibrium-air thermodynamic correlations have been developed for flowfield calculation procedures. A comparison between the postshock results computed by the correlation equations and detailed chemistry calculations is very good. The thermodynamic correlations are incorporated in an approximate inviscid flowfield code with a convective heating capability for the purpose of defining the thermodynamic environment through the shock layer. Comparisons of heating rates computed by the approximate code and a viscous-shock-layer method are good. In addition to presenting the thermodynamic correlations, the impact of several viscosity models on the convective heat transfer is demonstrated.

EQPT, a data file preprocessor for the EQ3/6 software package: User's guide and related documentation (Version 7.0)

International Nuclear Information System (INIS)

Daveler, S.A.; Wolery, T.J.

1992-01-01

EQPT is a data file preprocessor for the EQ3/6 software package. EQ3/6 currently contains five primary data files, called datao files. These files comprise alternative data sets. These data files contain both standard state and activity coefficient-related data. Three (com, sup, and nea) support the use of the Davies or B equations for the activity coefficients; the other two (hmw and pit) support the use of Pitzer's (1973, 1975) equations. The temperature range of the thermodynamic data on these data files varies from 25 degrees C only to 0-300 degrees C. The principal modeling codes in EQ3/6, EQ3NR and EQ6, do not read a data0 file, however. Instead, these codes read an unformatted equivalent called a data1 file. EQPT writes a datal file, using the corresponding data0 file as input. In processing a data0 file, EQPT checks the data for common errors, such as unbalanced reactions. It also conducts two kinds of data transformation. Interpolating polynomials are fit to data which are input on temperature adds. The coefficients of these polynomials are then written on the datal file in place of the original temperature grids. A second transformation pertains only to data files tied to Pitzer's equations. The commonly reported observable Pitzer coefficient parameters are mapped into a set of primitive parameters by means of a set of conventional relations. These primitive form parameters are then written onto the datal file in place of their observable counterparts. Usage of the primitive form parameters makes it easier to evaluate Pitzer's equations in EQ3NR and EQ6. EQPT and the other codes in the EQ3/6 package are written in FORTRAN 77 and have been developed to run under the UNIX operating system on computers ranging from workstations to supercomputers

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.

Reaction of Topopah Spring tuff with J-13 water: a geochemical modeling approach using the EQ3/6 reaction path code

Energy Technology Data Exchange (ETDEWEB)

Delany, J.M.

1985-11-25

EQ3/6 geochemical modeling code package was used to investigate the interaction of the Topopah Spring Tuff and J-13 water at high temperatures. EQ3/6 input parameters were obtained from the results of laboratory experiments using USW G-1 core and J-13 water. Laboratory experiments were run at 150 and 250{sup 0}C for 66 days using both wafer-size and crushed tuff. EQ3/6 modeling reproduced results of the 150{sup 0}C experiments except for a small increase in the concentration of potassium that occurs in the first few days of the experiments. At 250{sup 0}C, the EQ3/6 modeling reproduced the major water/rock reactions except for a small increase in potassium, similar to that noted above, and an overall increase in aluminum. The increase in potassium concentration cannot be explained at this time, but the increase in A1 concentration is believed to be caused by the lack of thermodynamic data in the EQ3/6 data base for dachiardite, a zeolite observed as a run product at 250{sup 0}C. The ability to reproduce the majority of the experimental rock/water interactions at 150{sup 0}C validates the use of EQ3/6 as a geochemical modeling tool that can be used to theoretically investigate physical/chemical environments in support of the Waste Package Task of NNWSI.

A redefinition of Hawking temperature on the event horizon: Thermodynamical equilibrium

International Nuclear Information System (INIS)

Saha, Subhajit; Chakraborty, Subenoy

2012-01-01

In this Letter we have used the recently introduced redefined Hawking temperature on the event horizon and investigated whether the generalized second law of thermodynamics (GSLT) and thermodynamic equilibrium holds for both the event and the apparent horizons. Here we have considered FRW universe and examined the GSLT and thermodynamic equilibrium with three examples. Finally, we have concluded that from the thermodynamic viewpoint, the universe bounded by the event horizon is more realistic than that by the apparent horizon at least for some examples.

EQ3/6 geochemical modeling task plan for Nevada Nuclear Waste Storage Investigations (NNWSI)

Energy Technology Data Exchange (ETDEWEB)

Isherwood, D.; Wolery, T.

1984-04-10

This task plan outlines work needed to upgrade the EQ3/6 geochemical code and expand the supporting data bases to allow the Nevada Nuclear Waste Storage Investigations (NNWSI) to model chemical processes important to the storage of nuclear waste in a tuff repository in the unsaturated zone. The plan covers the fiscal years 1984 to 1988. The scope of work includes the development of sub-models in the EQ3/6 code package for studying the effects of sorption, precipitation kinetics, redox disequilibrium, and radiolysis on radionuclide speciation and solubility. The work also includes a glass/water interactions model and a geochemical flow model which will allow us to study waste form leaching and reactions involving the waste package. A special emphasis is placed on verification of new capabilities as they are developed and code documentation to meet NRC requirements. Data base expansion includes the addition of elements and associated aqueous species and solid phases that are specific to nuclear waste (e.g., actinides and fission products) and the upgrading and documentation of the thermodynamic data for other species of interest.

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

Are the Concepts of Dynamic Equilibrium and the Thermodynamic Criteria for Spontaneity, Nonspontaneity, and Equilibrium Compatible?

Science.gov (United States)

Silverberg, Lee J.; Raff, Lionel M.

2015-01-01

Thermodynamic spontaneity-equilibrium criteria require that in a single-reaction system, reactions in either the forward or reverse direction at equilibrium be nonspontaneous. Conversely, the concept of dynamic equilibrium holds that forward and reverse reactions both occur at equal rates at equilibrium to the extent allowed by kinetic…

EquilTheTA: Thermodynamic and transport properties of complex equilibrium plasmas

International Nuclear Information System (INIS)

Colonna, G.; D'Angola, A.

2012-01-01

EquilTheTA (EQUILibrium for plasma THErmodynamics and Transport Applications) is a web-based software which calculates chemical equilibrium product concentrations from any set of reactants and determines thermodynamic and transport properties for the product mixture in wide temperature and pressure ranges. The program calculates chemical equilibrium by using a hierarchical approach, thermodynamic properties and transport coefficients starting from recent and accurate databases of atomic and molecular energy levels and collision integrals. In the calculations, Debye length and cut-off are consistently updated and virial corrections (up to third order) can be considered. Transport coefficients are calculated by using high order approximations of the Chapman-Enskog method.

Stochastic thermodynamics of quantum maps with and without equilibrium.

Science.gov (United States)

Barra, Felipe; Lledó, Cristóbal

2017-11-01

We study stochastic thermodynamics for a quantum system of interest whose dynamics is described by a completely positive trace-preserving (CPTP) map as a result of its interaction with a thermal bath. We define CPTP maps with equilibrium as CPTP maps with an invariant state such that the entropy production due to the action of the map on the invariant state vanishes. Thermal maps are a subgroup of CPTP maps with equilibrium. In general, for CPTP maps, the thermodynamic quantities, such as the entropy production or work performed on the system, depend on the combined state of the system plus its environment. We show that these quantities can be written in terms of system properties for maps with equilibrium. The relations that we obtain are valid for arbitrary coupling strengths between the system and the thermal bath. The fluctuations of thermodynamic quantities are considered in the framework of a two-point measurement scheme. We derive the entropy production fluctuation theorem for general maps and a fluctuation relation for the stochastic work on a system that starts in the Gibbs state. Some simplifications for the probability distributions in the case of maps with equilibrium are presented. We illustrate our results by considering spin 1/2 systems under thermal maps, nonthermal maps with equilibrium, maps with nonequilibrium steady states, and concatenations of them. Finally, and as an important application, we consider a particular limit in which the concatenation of maps generates a continuous time evolution in Lindblad form for the system of interest, and we show that the concept of maps with and without equilibrium translates into Lindblad equations with and without quantum detailed balance, respectively. The consequences for the thermodynamic quantities in this limit are discussed.

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.

Two-temperature thermodynamic and transport properties of SF6–Cu plasmas

International Nuclear Information System (INIS)

Wu, Yi; Chen, Zhexin; Yang, Fei; Rong, Mingzhe; Sun, Hao; Cressault, Yann; Murphy, Anthony B; Guo, Anxiang; Liu, Zirui

2015-01-01

SF 6 and Cu are widely adopted in electrical equipment as a dielectric medium and for conductive components, respectively. SF 6 –Cu plasmas are frequently formed, particularly in high-voltage circuit breaker arcs and fault current arcs, due to erosion of the Cu components. In this paper, calculated values of the thermodynamic and transport properties of plasmas in SF 6 –Cu mixtures are presented for both thermal equilibrium and non-equilibrium conditions. The composition is determined by the two-temperature Saha equation and Guldberg–Waage equation in the form derived by van de Sanden. The composition and the thermodynamic properties are evaluated through a classical statistical mechanics approach. For the transport coefficients, the simplified Chapman–Enskog method developed by Devoto, which decouples the electrons and heavy species, has been applied using the most recent collision integrals. The thermodynamic and transport properties are calculated for different electron temperatures (300–40 000 K), ratios of electron to heavy-species temperature (1–10), pressures (0.1–10 atm) and copper molar proportions (0–50%). It is found that deviations from thermal equilibrium strongly affect the thermodynamic and transport properties of the SF 6 –Cu plasmas. Further, the presence of copper has different effects on some of the properties for plasmas in and out of thermal equilibrium. The main reason for these changes is that dissociation reactions are delayed for non-thermal equilibrium plasmas, which in turn influences the ionization reactions that occur. (paper)

Equilibrium thermodynamics

CERN Document Server

de Oliveira, Mário J

2017-01-01

This textbook provides an exposition of equilibrium thermodynamics and its applications to several areas of physics with particular attention to phase transitions and critical phenomena. The applications include several areas of condensed matter physics and include also a chapter on thermochemistry. Phase transitions and critical phenomena are treated according to the modern development of the field, based on the ideas of universality and on the Widom scaling theory. For each topic, a mean-field or Landau theory is presented to describe qualitatively the phase transitions. These theories include the van der Waals theory of the liquid-vapor transition, the Hildebrand-Heitler theory of regular mixtures, the Griffiths-Landau theory for multicritical points in multicomponent systems, the Bragg-Williams theory of order-disorder in alloys, the Weiss theory of ferromagnetism, the Néel theory of antiferromagnetism, the Devonshire theory for ferroelectrics and Landau-de Gennes theory of liquid crystals. This new edit...

Thermodynamics of ion exchange equilibrium for some uni ...

African Journals Online (AJOL)

The study on thermodynamics of ion exchange equilibrium for uni-univalent Cl-/I-, Cl-/Br-, and uni-divalent Cl-/SO42-, Cl-/C2O42- reaction systems was carried out using ion exchange resin Indion FF-IP. The equilibrium constant K was calculated by taking into account the activity coefficient of ions both in solution as well as ...

Thermodynamic equilibrium in relativistic rotating systems

International Nuclear Information System (INIS)

Suen, W.M.; Washington Univ., St. Louis, MO; Young, K.

1988-01-01

The thermodynamic equilibrium configurations of relativistic rotating stars are studied using the maximum entropy principle. It is shown that the heuristic arguments for the equilibrium conditions can be developed into a maximum entropy principle in which the variations are carried out in a fixed background spacetime. This maximum principle with the fixed background assumption is technically simpler than, but has to be justified by, a maximum entropy principle without the assumption. Such a maximum entropy principle is formulated in this paper, showing that the general relativistic system can be treated on the same footing as other long-range force systems. (author)

Thermodynamics of Growth, Non-Equilibrium Thermodynamics of Bacterial Growth : The Phenomenological and the Mosaic Approach

NARCIS (Netherlands)

Westerhoff, Hans V.; Lolkema, Juke S.; Otto, Roel; Hellingwerf, K

1982-01-01

Microbial growth is analyzed in terms of mosaic and phenomenological non-equilibrium thermodynamics. It turns out that already existing parameters devised to measure bacterial growth, such as YATP, µ, and Qsubstrate, have as thermodynamic equivalents flow ratio, output flow and input flow. With this

EQPT, a data file preprocessor for the EQ3/6 software package: User`s guide and related documentation (Version 7.0); Part 2

Energy Technology Data Exchange (ETDEWEB)

Daveler, S.A.; Wolery, T.J.

1992-12-17

EQPT is a data file preprocessor for the EQ3/6 software package. EQ3/6 currently contains five primary data files, called datao files. These files comprise alternative data sets. These data files contain both standard state and activity coefficient-related data. Three (com, sup, and nea) support the use of the Davies or B-dot equations for the activity coefficients; the other two (hmw and pit) support the use of Pitzer`s (1973, 1975) equations. The temperature range of the thermodynamic data on these data files varies from 25{degrees}C only to 0-300{degrees}C. The principal modeling codes in EQ3/6, EQ3NR and EQ6, do not read a data0 file, however. Instead, these codes read an unformatted equivalent called a data1 file. EQPT writes a datal file, using the corresponding data0 file as input. In processing a data0 file, EQPT checks the data for common errors, such as unbalanced reactions. It also conducts two kinds of data transformation. Interpolating polynomials are fit to data which are input on temperature adds. The coefficients of these polynomials are then written on the datal file in place of the original temperature grids. A second transformation pertains only to data files tied to Pitzer`s equations. The commonly reported observable Pitzer coefficient parameters are mapped into a set of primitive parameters by means of a set of conventional relations. These primitive form parameters are then written onto the datal file in place of their observable counterparts. Usage of the primitive form parameters makes it easier to evaluate Pitzer`s equations in EQ3NR and EQ6. EQPT and the other codes in the EQ3/6 package are written in FORTRAN 77 and have been developed to run under the UNIX operating system on computers ranging from workstations to supercomputers.

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

Equilibrium, kinetic and thermodynamic studies of uranium biosorption by calcium alginate beads

International Nuclear Information System (INIS)

Bai, Jing; Fan, Fangli; Wu, Xiaolei; Tian, Wei; Zhao, Liang; Yin, Xiaojie; Fan, Fuyou; Li, Zhan; Tian, Longlong; Wang, Yang; Qin, Zhi; Guo, Junsheng

2013-01-01

Calcium alginate beads are potential biosorbent for radionuclides removal as they contain carboxyl groups. However, until now limited information is available concerning the uptake behavior of uranium by this polymer gel, especially when sorption equilibrium, kinetics and thermodynamics are concerned. In present work, batch experiments were carried out to study the equilibrium, kinetics and thermodynamics of uranium sorption by calcium alginate beads. The effects of initial solution pH, sorbent amount, initial uranium concentration and temperature on uranium sorption were also investigated. The determined optimal conditions were: initial solution pH of 3.0, added sorbent amount of 40 mg, and uranium sorption capacity increased with increasing initial uranium concentration and temperature. Equilibrium data obtained under different temperatures were fitted better with Langmuir model than Freundlich model, uranium sorption was dominated by a monolayer way. The kinetic data can be well depicted by the pseudo-second-order kinetic model. The activation energy derived from Arrhenius equation was 30.0 kJ/mol and the sorption process had a chemical nature. Thermodynamic constants such as ΔH 0 , ΔS 0 and ΔG 0 were also evaluated, results of thermodynamic study showed that the sorption process was endothermic and spontaneous. -- Highlights: • Equilibrium, kinetics and thermodynamics of uranium sorption by CaAlg were studied. • Equilibrium studies show that Langmuir isotherm better fit with experimental data. • Pseudo-second-order kinetics model is found to be well depicting the kinetic data. • Thermodynamic study shows that the sorption process is endothermic and spontaneous

Thermodynamic and transport properties of two-temperature SF6 plasmas

International Nuclear Information System (INIS)

Wang Weizong; Rong Mingzhe; Wu Yi; Spencer, Joseph W.; Yan, Joseph D.; Mei, DanHua

2012-01-01

This paper deals with thermodynamic and transport properties of SF 6 plasmas in a two-temperature model for both thermal equilibrium and non-equilibrium conditions. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and Guldberg-Waage equation according to deviation of van de Sanden et al. Transport properties including diffusion coefficient, viscosity, thermal conductivity, and electrical conductivity are calculated with most recent collision interaction potentials by adopting Devoto’s electron and heavy particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of Chapman–Enskog method. The results are computed for various values of pressures from 0.1 atm to 10 atm and ratios of the electron temperature to the heavy particle temperature from 1 to 20 with electron temperature range from 300 to 40 000 K. In the local thermodynamic equilibrium regime, results are compared with available results of previously published studies.

Guide to data preparation for EQ3/6 (Wolery) modified for the IBM 3033

International Nuclear Information System (INIS)

Noy, D.J.

1981-11-01

The ability to predict mineral-fluid equilibria is an important aspect of geochemical research into radioactive waste disposal. The interaction of ground waters and waste leachates with the host rock of a disposal site, either at elevated or ambient temperatures, will influence the performance of the disposal system. The EQ3/6 package (Wolery, 1979) provides a technique for the prediction of such interactions using available thermodynamic data, and for extrapolating laboratory experimental data on rock-fluid equilibria. This report describes the modifications performed on this package to allow operation on an IBM machine, and is intended as a guide to data preparation for the programmes. (author)

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).

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

Thermodynamic quantities and defect equilibrium in La2-xSrxNiO4+δ

International Nuclear Information System (INIS)

Nakamura, Takashi; Yashiro, Keiji; Sato, Kazuhisa; Mizusaki, Junichiro

2009-01-01

In order to elucidate the relation between thermodynamic quantities, the defect structure, and the defect equilibrium in La 2-x Sr x NiO 4+δ , statistical thermodynamic calculation is carried out and calculated results are compared to those obtained from experimental data. Partial molar enthalpy of oxygen and partial molar entropy of oxygen are obtained from δ-P(O 2 )-T relation by using Gibbs-Helmholtz equation. Statistical thermodynamic model is derived from defect equilibrium models proposed before by authors, localized electron model and delocalized electron model which could well explain the variation of oxygen content of La 2-x Sr x NiO 4+δ . Although assumed defect species and their equilibrium are different, the results of thermodynamic calculation by localized electron model and delocalized electron model show minor difference. Calculated results by the both models agree with the thermodynamic quantities obtained from oxygen nonstoichiometry of La 2-x Sr x NiO 4+δ . - Graphical abstract: In order to elucidate the relation between thermodynamic quantities, the defect structure, and the defect equilibrium in La 2-x Sr x NiO 4+δ , statistics thermodynamic calculation is carried out and calculated results are compared to those obtained from experimental data.

Thermodynamics of the Rhodamine B Lactone--Zwitterion Equilibrium.

Science.gov (United States)

Hinckley, Daniel A.; Seybold, Paul G.

1987-01-01

Discusses the benefits of thermochromic transformations for studying thermodynamic properties. Describes an experiment that uses a commercially available dye, attains equilibrium rapidly, employs a simple, single-beam spectrophotometer, and is suitable for both physical chemistry and introductory chemistry laboratories. (TW)

Equilibrium sampling for a thermodynamic assessment of contaminated sediments

DEFF Research Database (Denmark)

) govern diffusive uptake and partitioning. Equilibrium sampling of sediment was introduced 15 years ago to measure Cfree, and it has since developed into a straightforward, precise and sensitive approach for determining Cfree and other exposure parameters that allow for thermodynamic assessment...... of polluted sediments. Glass jars with µm-thin silicone coatings on the inner walls can be used for ex situ equilibration while a device housing several silicone-coated fibers can be used for in situ equilibration. In both cases, parallel sampling with varying silicone thicknesses can be applied to confirm...... will focus at the latest developments in equilibrium sampling concepts and methods. Further, we will explain how these approaches can provide a new basis for a thermodynamic assessment of polluted sediments....

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

Is neoclassical microeconomics formally valid? An approach based on an analogy with equilibrium thermodynamics

Energy Technology Data Exchange (ETDEWEB)

Sousa, Tania; Domingos, Tiago [Environment and Energy Section, DEM, Instituto Superior Tecnico, Avenida Rovisco Pais, 1, 1049-001 Lisboa (Portugal)

2006-06-10

The relation between Thermodynamics and Economics is a paramount issue in Ecological Economics. Two different levels can be distinguished when discussing it: formal and substantive. At the formal level, a mathematical framework is used to describe both thermodynamic and economic systems. At the substantive level, thermodynamic laws are applied to economic processes. In Ecological Economics, there is a widespread claim that neoclassical economics has the same mathematical formulation as classical mechanics and is therefore fundamentally flawed because: (1) utility does not obey a conservation law as energy does; (2) an equilibrium theory cannot be used to study irreversible processes. Here, we show that neoclassical economics is based on a wrong formulation of classical mechanics, being in fact formally analogous to equilibrium thermodynamics. The similarity between both formalisms, namely that they are both cases of constrained optimisation, is easily perceived when thermodynamics is looked upon using the Tisza-Callen axiomatisation. In this paper, we take the formal analogy between equilibrium thermodynamics and economic systems far enough to answer the formal criticisms, proving that the formalism of neoclassical economics has irreversibility embedded in it. However, the formal similarity between equilibrium thermodynamics and neoclassical microeconomics does not mean that economic models are in accordance with mass, energy and entropy balance equations. In fact, neoclassical theory suffers from flaws in the substantive integration with thermodynamic laws as has already been fully demonstrated by valuable work done by ecological economists in this field. (author)

Entropy production in a fluid-solid system far from thermodynamic equilibrium.

Science.gov (United States)

Chung, Bong Jae; Ortega, Blas; Vaidya, Ashwin

2017-11-24

The terminal orientation of a rigid body in a moving fluid is an example of a dissipative system, out of thermodynamic equilibrium and therefore a perfect testing ground for the validity of the maximum entropy production principle (MaxEP). Thus far, dynamical equations alone have been employed in studying the equilibrium states in fluid-solid interactions, but these are far too complex and become analytically intractable when inertial effects come into play. At that stage, our only recourse is to rely on numerical techniques which can be computationally expensive. In our past work, we have shown that the MaxEP is a reliable tool to help predict orientational equilibrium states of highly symmetric bodies such as cylinders, spheroids and toroidal bodies. The MaxEP correctly helps choose the stable equilibrium in these cases when the system is slightly out of thermodynamic equilibrium. In the current paper, we expand our analysis to examine i) bodies with fewer symmetries than previously reported, for instance, a half-ellipse and ii) when the system is far from thermodynamic equilibrium. Using two-dimensional numerical studies at Reynolds numbers ranging between 0 and 14, we examine the validity of the MaxEP. Our analysis of flow past a half-ellipse shows that overall the MaxEP is a good predictor of the equilibrium states but, in the special case of the half-ellipse with aspect ratio much greater than unity, the MaxEP is replaced by the Min-MaxEP, at higher Reynolds numbers when inertial effects come into play. Experiments in sedimentation tanks and with hinged bodies in a flow tank confirm these calculations.

Thermodynamic properties and equilibrium constant of chemical reaction in nanosystem: An theoretical and experimental study

International Nuclear Information System (INIS)

Du, Jianping; Zhao, Ruihua; Xue, Yongqiang

2012-01-01

Highlights: ► There is an obvious influence of the size on thermodynamic properties for the reaction referring nano-reactants. ► Gibbs function, enthalpy, entropy and equilibrium constant are dependent on the reactant size. ► There is an approximate linear relation between them. - Abstract: The theoretical relations of thermodynamic properties, the equilibrium constant and reactant size in nanosystem are described. The effects of size on thermodynamic properties and the equilibrium constant were studied using nanosize zinc oxide and sodium bisulfate solution as a reaction system. The experimental results indicated that the molar Gibbs free energy, the molar enthalpy and the molar entropy of the reaction decrease, but the equilibrium constant increases with decreasing reactant size. Linear trends were observed between the reciprocal of size for nano-reactant and thermodynamic variable, which are consistent with the theoretical relations.

Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

Directory of Open Access Journals (Sweden)

G. L. Dotto

2013-03-01

Full Text Available The equilibrium and thermodynamics of azo dye (tartrazine and allura red biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0% and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

Kinetic, Equilibrium and thermodynamic studies on the biosorption ...

African Journals Online (AJOL)

The kinetics, equilibrium and thermodynamics of the biosorption of Cd (II) from aqueous solution by the leaf biomass of Calotropis procera popularly known in western Nigeria as 'bom bom'and genrally known as Sodom apple were investigated at different experimental conditions. Optimum conditions of pH, contact time, ...

Teaching Chemical Equilibrium and Thermodynamics in Undergraduate General Chemistry Classes.

Science.gov (United States)

Banerjee, Anil C.

1995-01-01

Discusses some of the conceptual difficulties encountered by undergraduate students in learning certain aspects of chemical equilibrium and thermodynamics. Discusses teaching strategies for dealing with these difficulties. (JRH)

Data Qualification Report For: Thermodynamic Data File, DATA0.YMP.R0 For Geochemical Code, EQ3/6?

International Nuclear Information System (INIS)

P.L. Cloke

2000-09-01

The objective of this work is to evaluate the adequacy of chemical thermodynamic data provided by Lawrence Livermore National Laboratory (LLNL) as DataO.ymp.ROA in response to an input request submitted under AP-3.14Q. This request specified that chemical thermodynamic data available in the file, Data0.com.R2, be updated, improved, and augmented for use in geochemical modeling used in Process Model Reports (PMRs) for Engineered Barrier Systems, Waste Form, Waste Package, Unsaturated Zone, and Near Field Environment, as well as for Performance Assessment. The data are qualified in the temperature range 0 to 100 C. Several Data Tracking Numbers (DTNs) associated with Analysis/Model Reports (AMR) addressing various aspects of the post-closure chemical behavior of the waste package and the Engineered Barrier System that rely on EQ316 outputs to which these data are used as input, are Principal Factor affecting. This qualification activity was accomplished in accordance with the AP-SIII.2Q using the Technical Assessment method. A development plan, TDP-EBS-MD-000044, was prepared in accordance with AP-2.13Q and approved by the Responsible Manager. In addition, a Process Control Evaluation was performed in accordance with AP-SV.1Q. The qualification method, selected in accordance with AP-SIII.2Q, was Technical Assessment. The rationale for this approach is that the data in File Data0.com.R2 are considered Handbook data and therefore do not themselves require qualification. Only changes to Data0.com.R2 required qualification. A new file has been produced which contains the database Data0.ymp.R0, which is recommended for qualification as a result of this action. Data0.ymp.R0 will supersede Data0.com.R2 for all Yucca Mountain Project (YMP) activities

Vapor-liquid equilibrium thermodynamics of N2 + CH4 - Model and Titan applications

Science.gov (United States)

Thompson, W. R.; Zollweg, John A.; Gabis, David H.

1992-01-01

A thermodynamic model is presented for vapor-liquid equilibrium in the N2 + CH4 system, which is implicated in calculations of the Titan tropospheric clouds' vapor-liquid equilibrium thermodynamics. This model imposes constraints on the consistency of experimental equilibrium data, and embodies temperature effects by encompassing enthalpy data; it readily calculates the saturation criteria, condensate composition, and latent heat for a given pressure-temperature profile of the Titan atmosphere. The N2 content of condensate is about half of that computed from Raoult's law, and about 30 percent greater than that computed from Henry's law.

Chemical equilibrium. [maximizing entropy of gas system to derive relations between thermodynamic variables

Science.gov (United States)

1976-01-01

The entropy of a gas system with the number of particles subject to external control is maximized to derive relations between the thermodynamic variables that obtain at equilibrium. These relations are described in terms of the chemical potential, defined as equivalent partial derivatives of entropy, energy, enthalpy, free energy, or free enthalpy. At equilibrium, the change in total chemical potential must vanish. This fact is used to derive the equilibrium constants for chemical reactions in terms of the partition functions of the species involved in the reaction. Thus the equilibrium constants can be determined accurately, just as other thermodynamic properties, from a knowledge of the energy levels and degeneracies for the gas species involved. These equilibrium constants permit one to calculate the equilibrium concentrations or partial pressures of chemically reacting species that occur in gas mixtures at any given condition of pressure and temperature or volume and temperature.

College Physical Chemistry Students' Conceptions of Equilibrium and Fundamental Thermodynamics.

Science.gov (United States)

Thomas, Peter L.; Schwenz, Richard W.

1998-01-01

Focuses on many alternative conceptions and nonconceptions about material related to equilibrium and thermodynamics. Uses interviews and compares the concepts from these with those expressed by experts in textbooks. (DDR)

Finite-size polyelectrolyte bundles at thermodynamic equilibrium

Science.gov (United States)

Sayar, M.; Holm, C.

2007-01-01

We present the results of extensive computer simulations performed on solutions of monodisperse charged rod-like polyelectrolytes in the presence of trivalent counterions. To overcome energy barriers we used a combination of parallel tempering and hybrid Monte Carlo techniques. Our results show that for small values of the electrostatic interaction the solution mostly consists of dispersed single rods. The potential of mean force between the polyelectrolyte monomers yields an attractive interaction at short distances. For a range of larger values of the Bjerrum length, we find finite-size polyelectrolyte bundles at thermodynamic equilibrium. Further increase of the Bjerrum length eventually leads to phase separation and precipitation. We discuss the origin of the observed thermodynamic stability of the finite-size aggregates.

Thermodynamic equilibrium and heavy particles near a black hole

Energy Technology Data Exchange (ETDEWEB)

Zeldovich, Ya B [AN SSSR, Moscow

1976-02-23

The purpose of this letter is to point out, that thermodynamic equilibrium in general relativity corresponds to T(r)=Tsub(infinity)g/sub 00/sup(-1/2)=Tsub(infinity)..sqrt..(r/(r-rsub(g))). The last expression is written for a static non-rotating (Schwarzschild) black hole.

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

Allowance for effects of thermodynamic nonideality in sedimentation equilibrium distributions reflecting protein dimerization.

Science.gov (United States)

Wills, Peter R; Scott, David J; Winzor, Donald J

2012-03-01

This reexamination of a high-speed sedimentation equilibrium distribution for α-chymotrypsin under slightly acidic conditions (pH 4.1, I(M) 0.05) has provided experimental support for the adequacy of nearest-neighbor considerations in the allowance for effects of thermodynamic nonideality in the characterization of protein self-association over a moderate concentration range (up to 8 mg/mL). A widely held but previously untested notion about allowance for thermodynamic nonideality effects is thereby verified experimentally. However, it has also been shown that a greater obstacle to better characterization of protein self-association is likely to be the lack of a reliable estimate of monomer net charge, a parameter that has a far more profound effect on the magnitude of the measured equilibrium constant than any deficiency in current procedures for incorporating the effects of thermodynamic nonideality into the analysis of sedimentation equilibrium distributions reflecting reversible protein self-association. Copyright © 2011 Elsevier Inc. All rights reserved.

Data Qualification Report For: Thermodynamic Data File, DATA0.YMP.R0 For Geochemical Code, EQ3/6 

Energy Technology Data Exchange (ETDEWEB)

P.L. Cloke

2001-10-16

The objective of this work is to evaluate the adequacy of chemical thermodynamic data provided by Lawrence Livermore National Laboratory (LLNL) as DataO.ymp.ROA in response to an input request submitted under AP-3.14Q. This request specified that chemical thermodynamic data available in the file, Data0.com.R2, be updated, improved, and augmented for use in geochemical modeling used in Process Model Reports (PMRs) for Engineered Barrier Systems, Waste Form, Waste Package, Unsaturated Zone, and Near Field Environment, as well as for Performance Assessment. The data are qualified in the temperature range 0 to 100 C. Several Data Tracking Numbers (DTNs) associated with Analysis/Model Reports (AMR) addressing various aspects of the post-closure chemical behavior of the waste package and the Engineered Barrier System that rely on EQ316 outputs to which these data are used as input, are Principal Factor affecting. This qualification activity was accomplished in accordance with the AP-SIII.2Q using the Technical Assessment method. A development plan, TDP-EBS-MD-000044, was prepared in accordance with AP-2.13Q and approved by the Responsible Manager. In addition, a Process Control Evaluation was performed in accordance with AP-SV.1Q. The qualification method, selected in accordance with AP-SIII.2Q, was Technical Assessment. The rationale for this approach is that the data in File Data0.com.R2 are considered Handbook data and therefore do not themselves require qualification. Only changes to Data0.com.R2 required qualification. A new file has been produced which contains the database Data0.ymp.R0, which is recommended for qualification as a result of this action. Data0.ymp.R0 will supersede Data0.com.R2 for all Yucca Mountain Project (YMP) activities.

Deviation from local thermodynamical equilibrium in the solar atmosphere. Metodology. The line source function

International Nuclear Information System (INIS)

Shchukina, N.G.

1980-01-01

The methodology of the problem of deviation from local thermodynamical equilibrium in the solar atmosphere is presented. The difficulties of solution and methods of realization are systematized. The processes of line formation are considered which take into account velocity fields, structural inhomogeneity, radiation non-coherence etc. as applied to a quiet solar atmosphere. The conclusion is made on the regularity of deviation of the local thermodynamic equilibrium in upper layers of the solar atmosphere

Equilibrium calculations, ch. 6

International Nuclear Information System (INIS)

Deursen, A.P.J. van

1976-01-01

A calculation is presented of dimer intensities obtained in supersonic expansions. There are two possible limiting considerations; the dimers observed are already present in the source, in thermodynamic equilibrium, and are accelerated in the expansion. Destruction during acceleration is neglected, as are processes leading to newly formed dimers. On the other hand one can apply a kinetic approach, where formation and destruction processes are followed throughout the expansion. The difficulty of this approach stems from the fact that the density, temperature and rate constants have to be known at all distances from the nozzle. The simple point of view has been adopted and the measured dimer intensities are compared with the equilibrium concentration in the source. The comparison is performed under the assumption that the detection efficiency for dimers is twice the detection efficiency for monomers. The experimental evidence against the simple point of view that the dimers of the onset region are formed in the source already, under equilibrium conditions, is discussed. (Auth.)

Classical or equilibrium thermodynamics: basic conceptual aspects

Directory of Open Access Journals (Sweden)

Luiz Augusto Calvo Tiritan

2008-08-01

Full Text Available The Classical or Equilibrium Thermodynamics is one of the most consolidated fields of Physics. It is synthesized by a well-known and self coherent knowledge structure. The essence of the Classical Thermodynamics theoretical structure consists of a set of natural laws that rule the macroscopic physical systems behavior. These laws were formulated based on observations generalizations and are mostly independent of any hypotheses concerning the microscopic nature of the matter. In general, the approaches established for the Classical Thermodynamics follow one of the following alternatives: the historical approach that describes chronologically the evolution of ideas, concepts and facts, and the postulational approach in which postulates are formulated but are not demonstrated a priori but can be confirmed a posteriori. In this work, a brief review of the pre-classical historical approach conceptual evolution is elaborated, from the beginning of the seventeenth century to the middle of the nineteenth century. As for this, the following themes are dealt with in an evolutionary and phenomenological way: heat nature, thermometry, calorimetry, Carnot’s heat engine, heat mechanical equivalent and the first and second laws. The Zeroth law that was formulated afterwards is included in the discussion.

Thermodynamic analysis of 6xxx series Al alloys: Phase fraction diagrams

OpenAIRE

Cui S.; Mishra R.; Jung I.-H.

2018-01-01

Microstructural evolution of 6xxx Al alloys during various metallurgical processes was analyzed using accurate thermodynamic database. Phase fractions of all the possible precipitate phases which can form in the as-cast and equilibrium states of the Al-Mg-Si-Cu-Fe-Mn-Cr alloys were calculated over the technically useful composition range. The influence of minor elements such as Cu, Fe, Mn, and Cr on the amount of each type of precipitate in the as-cast and equilibrium conditions were analyzed...

Thermodynamics of open, nonisothermal chemical systems far from equilibrium

International Nuclear Information System (INIS)

Yoshida, Nobuo

1992-01-01

The thermodynamic behavior of kinetic models based on a continuously stirred tank reactor (CSTR) is studied in an attempt to seek general trends in the thermodynamic properties of open nonlinear systems. The models consist of two reversible reactions, A + nB rightleftharpoons (n + 1) B (n = 0,1,or 2) and B rightleftharpoons C, taking place in an adiabatic CSTR. The heat of reaction is incorporated, and the rate constants are assumed to follow an Arrhenius temperature dependence. The models give rise to multiple stationary states and sustained oscillations (limit cycles). The entropy difference between stationary or oscillatory states and equilibrium and the rate of entropy production in the these states are calculated as a function of the residence time in the reactor. The entropy difference and entropy production may be taken, to some extent, as indicative of the influence of irreversible processes, which disappears at equilibrium. The results of the calculations reveal the following systematic trends: (I) The entropy difference or entropy production for stable states or both always increase as the residence time is shortened, namely, as the system is displaced further from equilibrium. (II) If stable and unstable states (stationary or oscillatory) coexist under identical conditions, then the stable state invariably has a smaller value of the entropy difference or entropy production or both than the corresponding unstable state. 26 refs., 3 figs

The Donnan equilibrium: I. On the thermodynamic foundation of the Donnan equation of state

International Nuclear Information System (INIS)

Philipse, A; Vrij, A

2011-01-01

The thermodynamic equilibrium between charged colloids and an electrolyte reservoir is named after Frederic Donnan who first published on it one century ago (Donnan 1911 Z. Electrochem. 17 572). One of the intriguing features of the Donnan equilibrium is the ensuing osmotic equation of state which is a nonlinear one, even when both colloids and ions obey Van 't Hoff's ideal osmotic pressure law. The Donnan equation of state, nevertheless, is internally consistent; we demonstrate it to be a rigorous consequence of the phenomenological thermodynamics of a neutral bulk suspension equilibrating with an infinite salt reservoir. Our proof is based on an exact thermodynamic relation between osmotic pressure and salt adsorption which, when applied to ideal ions, does indeed entail the Donnan equation of state. Our derivation also shows that, contrary to what is often assumed, the Donnan equilibrium does not require ideality of the colloids: the Donnan model merely evaluates the osmotic pressure of homogeneously distributed ions, in excess of the pressure exerted by an arbitrary reference fluid of uncharged colloids. We also conclude that results from the phenomenological Donnan model coincide with predictions from statistical thermodynamics in the limit of weakly charged, point-like colloids.

Letter Report: Progress in developing EQ3/6 for modeling boiling processes

Energy Technology Data Exchange (ETDEWEB)

Wolery, T. J., LLNL

1995-08-28

EQ3/6 is a software package for geochemical modeling of aqueous systems, such as water/rock or waste/water rock. It is being developed for a variety of applications in geochemical studies for the Yucca Mountain Site Characterization Project. The present focus is on development of capabilities to be used in studies of geochemical processes which will take place in the near-field environment and the altered zone of the potential repository. We have completed the first year of a planned two-year effort to develop capabilities for modeling boiling processes. These capabilities will interface with other existing and future modeling capabilities to provide a means of integrating the effects of various kinds of geochemical processes in complex systems. This year, the software has been modified to allow the formation of a generalized gas phase in a closed system for which the temperature and pressure are known (but not necessarily constant). The gas phase forms when its formation is thermodynamically favored; that is, when the system pressure is equal to the sum of the partial pressures of the gas species as computed from their equilibrium fugacities. It disappears when this sum falls below that pressure. `Boiling` is the special case in which the gas phase which forms consists mostly of water vapor. The reverse process is then `condensation.` To support calculations of boiling and condensation, we have added a capability to calculate the fugacity coefficients of gas species in the system H{sub 2}O-CO{sub 2}-CH{sub 4}-H{sub 2},-Awe{sub 2}-N{sub 2},-H{sub 2}S-NH3. This capability at present is accurate only at relatively low pressures, but is adequate for all likely repository boiling conditions. We have also modified the software to calculate changes in enthalpy (heat) and volume functions. Next year we will be extending the boiling capability to calculate the pressure or the temperature at known enthalpy. We will also add an option for open system boiling.

Diffusion approximations to the chemical master equation only have a consistent stochastic thermodynamics at chemical equilibrium.

Science.gov (United States)

Horowitz, Jordan M

2015-07-28

The stochastic thermodynamics of a dilute, well-stirred mixture of chemically reacting species is built on the stochastic trajectories of reaction events obtained from the chemical master equation. However, when the molecular populations are large, the discrete chemical master equation can be approximated with a continuous diffusion process, like the chemical Langevin equation or low noise approximation. In this paper, we investigate to what extent these diffusion approximations inherit the stochastic thermodynamics of the chemical master equation. We find that a stochastic-thermodynamic description is only valid at a detailed-balanced, equilibrium steady state. Away from equilibrium, where there is no consistent stochastic thermodynamics, we show that one can still use the diffusive solutions to approximate the underlying thermodynamics of the chemical master equation.

Hot nuclear matter and thermodynamical equilibrium

International Nuclear Information System (INIS)

Borderie, B.; Bacri, C.O.; Dore, D.; Frankland, J.D.; Plagnol, E.; Rivet, M.F.; Tassan-Got, L.

1999-01-01

Quasi-complete events from collisions between 36 Ar and 58 Ni corresponding to vaporized sources have been detected with the multidetector INDRA over the excitation energy range 10 - 28 AMeV. For the first time complete information concerning kinematical properties of emitted particles and chemical composition (mean values but also variances) are derived. Despite the very extreme conditions in which such sources are produced (binary collisions with short reaction times and source life-times), their properties are in agreement with the results of a statistical model including a final state excluded volume interaction and describing a gas of fermions and bosons in thermodynamical equilibrium. (authors)

A procedure to find thermodynamic equilibrium constants for CO2 and CH4 adsorption on activated carbon.

Science.gov (United States)

Trinh, T T; van Erp, T S; Bedeaux, D; Kjelstrup, S; Grande, C A

2015-03-28

Thermodynamic equilibrium for adsorption means that the chemical potential of gas and adsorbed phase are equal. A precise knowledge of the chemical potential is, however, often lacking, because the activity coefficient of the adsorbate is not known. Adsorption isotherms are therefore commonly fitted to ideal models such as the Langmuir, Sips or Henry models. We propose here a new procedure to find the activity coefficient and the equilibrium constant for adsorption which uses the thermodynamic factor. Instead of fitting the data to a model, we calculate the thermodynamic factor and use this to find first the activity coefficient. We show, using published molecular simulation data, how this procedure gives the thermodynamic equilibrium constant and enthalpies of adsorption for CO2(g) on graphite. We also use published experimental data to find similar thermodynamic properties of CO2(g) and of CH4(g) adsorbed on activated carbon. The procedure gives a higher accuracy in the determination of enthalpies of adsorption than ideal models do.

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.

Non-equilibrium Thermodynamics and the Production of Entropy Life, Earth, and Beyond

CERN Document Server

Kleidon, Axel

2005-01-01

The present volume studies the application of concepts from non-equilibrium thermodynamics to a variety of research topics. Emphasis is on the Maximum Entropy Production (MEP) principle and applications to Geosphere-Biosphere couplings. Written by leading researchers form a wide range of background, the book proposed to give a first coherent account of an emerging field at the interface of thermodynamics, geophysics and life sciences.

Dilepton production from quark gluon plasma using non-equilibrium thermodynamics

International Nuclear Information System (INIS)

Sinha, B.

1984-01-01

The importance of the approach phase to the thermodynamic equilibrium has been investigated for dilepton production from quark-gluon plasma - an effective temperature for the quarks as Brounian particle in a heat bath of gluons has been suggested. The spectrum for low invariant mass is, as a consequence, sharper

Computation of thermodynamic equilibrium in systems under stress

Science.gov (United States)

Vrijmoed, Johannes C.; Podladchikov, Yuri Y.

2016-04-01

Metamorphic reactions may be partly controlled by the local stress distribution as suggested by observations of phase assemblages around garnet inclusions related to an amphibolite shear zone in granulite of the Bergen Arcs in Norway. A particular example presented in fig. 14 of Mukai et al. [1] is discussed here. A garnet crystal embedded in a plagioclase matrix is replaced on the left side by a high pressure intergrowth of kyanite and quartz and on the right side by chlorite-amphibole. This texture apparently represents disequilibrium. In this case, the minerals adapt to the low pressure ambient conditions only where fluids were present. Alternatively, here we compute that this particular low pressure and high pressure assemblage around a stressed rigid inclusion such as garnet can coexist in equilibrium. To do the computations we developed the Thermolab software package. The core of the software package consists of Matlab functions that generate Gibbs energy of minerals and melts from the Holland and Powell database [2] and aqueous species from the SUPCRT92 database [3]. Most up to date solid solutions are included in a general formulation. The user provides a Matlab script to do the desired calculations using the core functions. Gibbs energy of all minerals, solutions and species are benchmarked versus THERMOCALC, PerpleX [4] and SUPCRT92 and are reproduced within round off computer error. Multi-component phase diagrams have been calculated using Gibbs minimization to benchmark with THERMOCALC and Perple_X. The Matlab script to compute equilibrium in a stressed system needs only two modifications of the standard phase diagram script. Firstly, Gibbs energy of phases considered in the calculation is generated for multiple values of thermodynamic pressure. Secondly, for the Gibbs minimization the proportion of the system at each particular thermodynamic pressure needs to be constrained. The user decides which part of the stress tensor is input as thermodynamic

Comparison of the applicability of commercial computer programs to study the thermodynamic stability of metal oxides

International Nuclear Information System (INIS)

Koukkari, P.; Olin, M.; Laitinen, T.; Sippola, H.

1999-04-01

The oxide films formed on primary circuit surfaces incorporate radioactive species from the coolant and influence different corrosion phenomena in nuclear power plants. One approach to improve the understanding on the formation and properties of these oxide films is to evaluate their thermodynamic stability. The aim of this work was to compare and demonstrate the applicability of different commercial thermodynamic computer programs to model the deposition of oxides containing iron, chromium and/or nickel in various nuclear power plant environments. The programs considered in this evaluation comprised the EQ3/6 program and a product group including such products as ChemSage, HSC (including SOLGASMIX and GIBBS), H+PLUS and ChemSheet. In the group the transfer of data between different products is relatively easy. The goal was to find out which programs can be applied to evaluate the stability of oxide films, but not to assess the absolute accuracy of the calculations. The evaluation was done by means of applying the programs to calculate the stability of pure and mixed oxides of iron, nickel and chromium on stainless steel both in WWER and BWR conditions at different temperatures and coolant compositions. The comparison showed that EQ3/6 is suitable for most thermodynamic calculations. EQ3/6 can be characterised as a professional tool, for which no commercial training is available. ChemSage is a versatile and reliable program, which can be well used together with HSC and H+PLUS. ChemSage is mainly a professional tool, while HSC is easier to operate by an occasional user. Commercial training and support is available for both ChemSage and HSC. ChemSheet has been designed to utilise the properties of ChemSage in a user-friendly spreadsheet environment. All the products tested calculate thermodynamic equilibrium. Thus they are suitable to characterise such conditions in which the formation of a certain phase is or becomes possible. On the other hand, the modelling of the

Nonequilibrium thermodynamic potentials for continuous-time Markov chains.

Science.gov (United States)

Verley, Gatien

2016-01-01

We connect the rare fluctuations of an equilibrium (EQ) process and the typical fluctuations of a nonequilibrium (NE) stationary process. In the framework of large deviation theory, this observation allows us to introduce NE thermodynamic potentials. For continuous-time Markov chains, we identify the relevant pairs of conjugated variables and propose two NE ensembles: one with fixed dynamics and fluctuating time-averaged variables, and another with fixed time-averaged variables, but a fluctuating dynamics. Accordingly, we show that NE processes are equivalent to conditioned EQ processes ensuring that NE potentials are Legendre dual. We find a variational principle satisfied by the NE potentials that reach their maximum in the NE stationary state and whose first derivatives produce the NE equations of state and second derivatives produce the NE Maxwell relations generalizing the Onsager reciprocity relations.

Bifurcation and Stability Analysis of the Equilibrium States in Thermodynamic Systems in a Small Vicinity of the Equilibrium Values of Parameters

Science.gov (United States)

Barsuk, Alexandr A.; Paladi, Florentin

2018-04-01

The dynamic behavior of thermodynamic system, described by one order parameter and one control parameter, in a small neighborhood of ordinary and bifurcation equilibrium values of the system parameters is studied. Using the general methods of investigating the branching (bifurcations) of solutions for nonlinear equations, we performed an exhaustive analysis of the order parameter dependences on the control parameter in a small vicinity of the equilibrium values of parameters, including the stability analysis of the equilibrium states, and the asymptotic behavior of the order parameter dependences on the control parameter (bifurcation diagrams). The peculiarities of the transition to an unstable state of the system are discussed, and the estimates of the transition time to the unstable state in the neighborhood of ordinary and bifurcation equilibrium values of parameters are given. The influence of an external field on the dynamic behavior of thermodynamic system is analyzed, and the peculiarities of the system dynamic behavior are discussed near the ordinary and bifurcation equilibrium values of parameters in the presence of external field. The dynamic process of magnetization of a ferromagnet is discussed by using the general methods of bifurcation and stability analysis presented in the paper.

Disposal of high level nuclear wastes: Thermodynamic equilibrium and environment ethics

Institute of Scientific and Technical Information of China (English)

RANA Mukhtar Ahmed

2009-01-01

Contamination of soil, water or air, due to a failure of containment or disposal of high level nuclear wastes, can potentially cause serious hazards to the environment or human health. Essential elements of the environment and radioactivity dangers to it are illustrated. Issues of high level nuclear waste disposal are discussed with a focus on thermodynamic equilibrium and environment ethics. Major aspects of the issues are analyzed and described briefly to build a perception of risks involved and ethical implications. Nuclear waste containment repository should be as close as possible to thermodynamic equilibrium. A clear demonstration about safety aspects of nuclear waste management is required in gaining public and political confidence in any possible scheme of permanent disposal. Disposal of high level nuclear waste offers a spectrum of environment connected challenges and a long term future of nuclear power depends on the environment friendly solution of the problem of nuclear wastes.

Atomistic-level non-equilibrium model for chemically reactive systems based on steepest-entropy-ascent quantum thermodynamics

International Nuclear Information System (INIS)

Li, Guanchen; Al-Abbasi, Omar; Von Spakovsky, Michael R

2014-01-01

This paper outlines an atomistic-level framework for modeling the non-equilibrium behavior of chemically reactive systems. The framework called steepest- entropy-ascent quantum thermodynamics (SEA-QT) is based on the paradigm of intrinsic quantum thermodynamic (IQT), which is a theory that unifies quantum mechanics and thermodynamics into a single discipline with wide applications to the study of non-equilibrium phenomena at the atomistic level. SEA-QT is a novel approach for describing the state of chemically reactive systems as well as the kinetic and dynamic features of the reaction process without any assumptions of near-equilibrium states or weak-interactions with a reservoir or bath. Entropy generation is the basis of the dissipation which takes place internal to the system and is, thus, the driving force of the chemical reaction(s). The SEA-QT non-equilibrium model is able to provide detailed information during the reaction process, providing a picture of the changes occurring in key thermodynamic properties (e.g., the instantaneous species concentrations, entropy and entropy generation, reaction coordinate, chemical affinities, reaction rate, etc). As an illustration, the SEA-QT framework is applied to an atomistic-level chemically reactive system governed by the reaction mechanism F + H 2 ↔ FH + H

The Donnan equilibrium: I. On the thermodynamic foundation of the Donnan equation of state

NARCIS (Netherlands)

Philipse, A.P.; Vrij, A.

2011-01-01

The thermodynamic equilibrium between charged colloids and an electrolyte reservoir is named after Frederic Donnan who first published on it one century ago (Donnan 1911 Z. Electrochem. 17 572). One of the intriguing features of the Donnan equilibrium is the ensuing osmotic equation of state which

The energy balance of a plasma in partial local thermodynamic equilibrium

NARCIS (Netherlands)

Kroesen, G.M.W.; Schram, D.C.; Timmermans, C.J.; de Haas, J.C.M.

1990-01-01

The energy balance for electrons and heavy particles constituting a plasma in partial local thermodynamic equilibrium is derived. The formulation of the energy balance used allows for evaluation of the source terms without knowledge of the particle and radiation transport situation, since most of

Plan for integrated testing for NNWSI [Nevada Nuclear Waste Storage Investigations] non EQ3/6 data base portion

International Nuclear Information System (INIS)

Oversby, V.M.

1987-01-01

The purposes of the Integrated Testing Task are to develop laboratory data on thermodynamic properties for actinide and fission product elements for use in the EQ3/6 geochemical modelling code; to determine the transport properties of radionuclides in the near-field environment; and develop and validate a model to describe the rate of release of radionuclides from the near-field environment. Activities to achieve the firs item have been described in the Scientific Investigation Plan for EQ3/6, where quality assurance levels were assigned to the acitivities. This Scientific Investigation Plan describes activities to achieve the second and third purposes. The information gathered in these activities will be used to assess compliance with the performance objective for the Engineered Barrier System (EBS) to control the rate of release of radionuclides if the repository license application includes part of the host rock; to provide a source term for release of radionuclides from the waste package near-field environment to the system performance assessment task for use in showing compliance with the Environmental Protection Agency requirements; and to provide a source term for release of radionculides from the waste package near-field environment to the system performance assessment task for use in doing calculations of cumulative releases of radionuclides from the repository over 100,000 years as required by the site evaluation process. 5 refs

Thermodynamics of the multicomponent vapor-liquid equilibrium under capillary pressure difference

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

2001-01-01

We discuss the two-phase multicomponent equilibrium, provided that the phase pressures are different due to the action of capillary forces. We prove the two general properties of such an equilibrium, which have previously been known for a single-component case, however, to the best of our knowledge......, not for the multicomponent mixtures. The importance is emphasized on the space of the intensive variables P, T and mu (i), where the laws of capillary equilibrium have a simple geometrical interpretation. We formulate thermodynamic problems specific to such an equilibrium, and outline changes to be introduced to common...... algorithms of flash calculations in order to solve these problems. Sample calculations show large variation of the capillary properties of the mixture in the very neighborhood of the phase envelope and the restrictive role of the spinodal surface as a boundary for possible equilibrium states with different...

Extension of the EQ3/6 computer codes to geochemical modeling of brines

Energy Technology Data Exchange (ETDEWEB)

Jackson, K.J.; Wolery, T.J.

1984-10-23

Recent modifications to the EQ3/6 geochemical modeling software package provide for the use of Pitzer's equations to calculate the activity coefficients of aqueous species and the activity of water. These changes extend the range of solute concentrations over which the codes can be used to dependably calculate equilibria in geochemical systems, and permit the inclusion of ion pairs, complexes, and undissociated acids and bases as explicit component species in the Pitzer model. Comparisons of calculations made by the EQ3NR and EQ6 compuer codes with experimental data confirm that the modifications not only allow the codes to accurately evaluate activity coefficients in concentrated solutions, but also permit prediction of solubility limits of evaporite minerals in brines at 25/sup 0/C and elevated temperatures. Calculations for a few salts can be made at temperatures up to approx. 300/sup 0/C, but the temperature range for most electrolytes is constrained by the availability of requisite data to values less than or equal to 100/sup 0/C. The implementation of Pitzer's equations in EQ3/6 allows application of these codes to problems involving calculation of geochemical equilibria in brines; such as evaluation of the chemical environment which might be anticipated for nuclear waste canisters located in a salt repository. 26 references, 3 figures, 1 table.

Disposal of high level nuclear wastes: thermodynamic equilibrium and environment ethics

International Nuclear Information System (INIS)

Rana, M.A.

2009-01-01

Contamination of soil, water or air, due to a failure of containment or disposal of high level nuclear wastes, can potentially cause serious hazards to the environment or human health. Essential elements of the environment and radioactivity dangers to it are illustrated. Issues of high level nuclear waste disposal are discussed with a focus on thermodynamic equilibrium and environment ethics. Major aspects of the issues are analyzed and described briefly to build a perception of risks involved and ethical implications. Nuclear waste containment repository should be as close as possible to thermodynamic equilibrium. A clear demonstration about safety aspects of nuclear waste management is required in gaining public and political confidence in any possible scheme of permanent disposal. Disposal of high level nuclear waste offers a spectrum of environment connected challenges and a long term future of nuclear power depends on the environment friendly solution of the problem of nuclear wastes. (authors)

A development of multi-Species mass transport model considering thermodynamic phase equilibrium

DEFF Research Database (Denmark)

Hosokawa, Yoshifumi; Yamada, Kazuo; Johannesson, Björn

2008-01-01

) variation in solid-phase composition when using different types of cement, (ii) physicochemical evaluation of steel corrosion initiation behaviour by calculating the molar ratio of chloride ion to hydroxide ion [Cl]/[OH] in pore solution, (iii) complicated changes of solid-phase composition caused......In this paper, a multi-species mass transport model, which can predict time dependent variation of pore solution and solid-phase composition due to the mass transport into the hardened cement paste, has been developed. Since most of the multi-species models established previously, based...... on the Poisson-Nernst-Planck theory, did not involve the modeling of chemical process, it has been coupled to thermodynamic equilibrium model in this study. By the coupling of thermodynamic equilibrium model, the multi-species model could simulate many different behaviours in hardened cement paste such as: (i...

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.

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)

A facilitated diffusion model constrained by the probability isotherm: a pedagogical exercise in intuitive non-equilibrium thermodynamics.

Science.gov (United States)

Chapman, Brian

2017-06-01

This paper seeks to develop a more thermodynamically sound pedagogy for students of biological transport than is currently available from either of the competing schools of linear non-equilibrium thermodynamics (LNET) or Michaelis-Menten kinetics (MMK). To this end, a minimal model of facilitated diffusion was constructed comprising four reversible steps: cis- substrate binding, cis → trans bound enzyme shuttling, trans -substrate dissociation and trans → cis free enzyme shuttling. All model parameters were subject to the second law constraint of the probability isotherm, which determined the unidirectional and net rates for each step and for the overall reaction through the law of mass action. Rapid equilibration scenarios require sensitive 'tuning' of the thermodynamic binding parameters to the equilibrium substrate concentration. All non-equilibrium scenarios show sigmoidal force-flux relations, with only a minority of cases having their quasi -linear portions close to equilibrium. Few cases fulfil the expectations of MMK relating reaction rates to enzyme saturation. This new approach illuminates and extends the concept of rate-limiting steps by focusing on the free energy dissipation associated with each reaction step and thereby deducing its respective relative chemical impedance. The crucial importance of an enzyme's being thermodynamically 'tuned' to its particular task, dependent on the cis- and trans- substrate concentrations with which it deals, is consistent with the occurrence of numerous isoforms for enzymes that transport a given substrate in physiologically different circumstances. This approach to kinetic modelling, being aligned with neither MMK nor LNET, is best described as intuitive non-equilibrium thermodynamics, and is recommended as a useful adjunct to the design and interpretation of experiments in biotransport.

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)

Departure from Local Thermodynamic Equilibrium in argon plasmas sustained in a Torche à Injection Axiale sur Guide d'Ondes

International Nuclear Information System (INIS)

Rincón, R.; Muñoz, J.; Calzada, M.D.

2015-01-01

Plasma torches are suitable plasma sources for a wide range of applications. The capability of these discharges to produce processes like sample excitation or decomposition of molecules inside them depends on the density of the plasma species and their energies (temperatures). The relation between these parameters determines the specific state of thermodynamic equilibrium in the discharge. Thus, the understanding of plasma possibilities for application purposes is related to the knowledge of the plasma thermodynamic equilibrium degree. In this paper a discussion about the equilibrium state for Ar plasmas generated by using a Torche à Injection Axiale sur Guide d'Ondes, TIAGO device, is presented. Emission spectroscopy techniques were used to measure gas temperature and electron density at the exit of the nozzle torch and along the dart. Boltzmann-plots as well as b p parameters were calculated to characterize the type and degree of departure from partial Local Saha Equilibrium (pLSE). This study indicates that the closer situation to Local Thermodynamic Equilibrium (LTE) of the plasma corresponds to larger Ar flows which highlights the importance of the nitrogen (atmosphere surrounding the plasma) in the kinetics of Ar-TIAGO discharges. - Highlights: • Discharges sustained in Ar using a TIAGO Torch show a significant departure from Local Thermodynamic Equilibrium. • Nitrogen entrance from surrounding air highly influences Thermodynamic Equilibrium. • Departure from LTE has been studied by means of Boltzmann plots and b p parameters. • The discharge is ionizing at the nozzle exit plasma, while along the dart it becomes recombining

An Easy and Effective Demonstration of Enzyme Stereospecificity and Equilibrium Thermodynamics

Science.gov (United States)

Herdman, Chelsea; Dickman, Michael

2011-01-01

Enzyme stereospecificity and equilibrium thermodynamics can be demonstrated using the coupling of two amino acid derivatives by Thermoase C160. This protease will catalyze peptide bond formation between Z-L-AspOH and L-PheOMe to form the Aspartame precursor Z-L-Asp-L-PheOMe. Reaction completion manifests itself by precipitation of the product. As…

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

Understanding the relationship between the EQ-5D, SF-6D, HAQ and disease activity in inflammatory arthritis.

LENUS (Irish Health Repository)

Adams, Roisin

2012-02-01

BACKGROUND: The growth of economic analyses and in particular cost-utility analyses (CUA), which use the QALY as a measure of outcome, has heightened the interest in the methodologies used to calculate the QALY. The EQ-5D has produced quite different utility values from that of the SF-6D. This article seeks to understand these differences using a cohort of patients with inflammatory arthritis. OBJECTIVE: To examine the relationship between the disease-specific measure, Health Assessment Questionnaire (HAQ) disability index (DI) and the preference-based measures, SF-6D, EQ-5D and European League Against Arthritis (EULAR) Disease Activity Score (DAS) in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA). METHODS: Patients with RA and PsA (n = 504) attending a tertiary rheumatology referral centre completed the HAQ, SF-6D and the EQ-5D before starting biological therapy and again 12 months later. The SF-36 was converted into a utility using the preference-based SF-6D. Clinical outcomes such as the DAS, joint counts and laboratory measures were also recorded. We calculated single index utility scores from the preference-based instruments using UK population norms. We used regression analysis to derive a mapping function and calculated utility scores from the HAQDI and the DAS 28. RESULTS: The mean utility observed at baseline for RA was 0.43 for the EQ-5D and 0.54 for the SF-6D and for PsA was 0.49 for the EQ-5D and 0.57 for the SF-6D. The utility gain demonstrated by the EQ-5D was over twice that of the SF-6D. The EQ-5D scored 17% of the RA group as less than 0 (state defined as worse than death); 7% of this group remained less than 0 at follow-up. The distribution of the utility estimates was similar for both RA and PsA. CONCLUSIONS: Our findings draw attention to the impact of states worse than death on the overall distribution for the EQ-5D derived utilities and how these impact on its use in practice. EQ-5D-derived QALY changes are over twice

Statistical thermodynamics

International Nuclear Information System (INIS)

Hwang, Jeong Ui; Jang, Jong Jae; Jee, Jong Gi

1987-01-01

The contents of this book are thermodynamics on the law of thermodynamics, classical thermodynamics and molecule thermodynamics, basics of molecule thermodynamics, molecule and assembly partition function, molecule partition function, classical molecule partition function, thermodynamics function for ideal assembly in fixed system, thermodynamics function for ideal assembly in running system, Maxwell-Boltzmann's law of distribution, chemical equilibrium like calculation of equilibrium constant and theory of absolute reaction rate.

A survey of upwind methods for flows with equilibrium and non-equilibrium chemistry and thermodynamics

Science.gov (United States)

Grossman, B.; Garrett, J.; Cinnella, P.

1989-01-01

Several versions of flux-vector split and flux-difference split algorithms were compared with regard to general applicability and complexity. Test computations were performed using curve-fit equilibrium air chemistry for an M = 5 high-temperature inviscid flow over a wedge, and an M = 24.5 inviscid flow over a blunt cylinder for test computations; for these cases, little difference in accuracy was found among the versions of the same flux-split algorithm. For flows with nonequilibrium chemistry, the effects of the thermodynamic model on the development of flux-vector split and flux-difference split algorithms were investigated using an equilibrium model, a general nonequilibrium model, and a simplified model based on vibrational relaxation. Several numerical examples are presented, including nonequilibrium air chemistry in a high-temperature shock tube and nonequilibrium hydrogen-air chemistry in a supersonic diffuser.

Studies on the formulation of thermodynamics and stochastic theory for systems far from equilibrium

Energy Technology Data Exchange (ETDEWEB)

Ross, J. [Stanford Univ., CA (United States)

1995-12-31

We have been working for some time on the formulation of thermodynamics and the theory of fluctuations in systems far from equilibrium and progress in several aspects of that development are reported here.

Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters.

Science.gov (United States)

Liu, Xiang; Lee, Duu-Jong

2014-05-01

This meta-analysis evaluates adsorption studies that report thermodynamic parameters for heavy metals and dyes from wastewaters. The adsorbents were derived from agricultural waste, industrial wastes, inorganic particulates, or some natural products. The adsorption mechanisms, derivation of thermodynamic relationships, and possible flaws made in such evaluation are discussed. This analysis shows that conclusions from the examined standard enthalpy and entropy changes are highly contestable. The reason for this flaw may be the poor physical structure of adsorbents tested, such that pore transport controlled the solute flux, leaving a surface reaction process near equilibrium. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of the applicability of commercial computer programs to study the thermodynamic stability of metal oxides; Vertailu kaupallisten laskentaohjelmien soveltuvuudesta metallioksidien termodynaamiseen stabiilisuustarkasteluun

Energy Technology Data Exchange (ETDEWEB)

Koukkari, P.; Olin, M. [VTT Chemical Technology, Espoo (Finland); Laitinen, T. [VTT Manufacturing Technology, Espoo (Finland); Sippola, H. [GEM Systems Oy (Finland)

1999-04-01

The oxide films formed on primary circuit surfaces incorporate radioactive species from the coolant and influence different corrosion phenomena in nuclear power plants. One approach to improve the understanding on the formation and properties of these oxide films is to evaluate their thermodynamic stability. The aim of this work was to compare and demonstrate the applicability of different commercial thermodynamic computer programs to model the deposition of oxides containing iron, chromium and/or nickel in various nuclear power plant environments. The programs considered in this evaluation comprised the EQ3/6 program and a product group including such products as ChemSage, HSC (including SOLGASMIX and GIBBS), H+PLUS and ChemSheet. In the group the transfer of data between different products is relatively easy. The goal was to find out which programs can be applied to evaluate the stability of oxide films, but not to assess the absolute accuracy of the calculations. The evaluation was done by means of applying the programs to calculate the stability of pure and mixed oxides of iron, nickel and chromium on stainless steel both in WWER and BWR conditions at different temperatures and coolant compositions. The comparison showed that EQ3/6 is suitable for most thermodynamic calculations. EQ3/6 can be characterised as a professional tool, for which no commercial training is available. ChemSage is a versatile and reliable program, which can be well used together with HSC and H+PLUS. ChemSage is mainly a professional tool, while HSC is easier to operate by an occasional user. Commercial training and support is available for both ChemSage and HSC. ChemSheet has been designed to utilise the properties of ChemSage in a user-friendly spreadsheet environment. All the products tested calculate thermodynamic equilibrium. Thus they are suitable to characterise such conditions in which the formation of a certain phase is or becomes possible. On the other hand, the modelling of the

Validation and comparison of EuroQoL-5 dimension (EQ-5D) and Short Form-6 dimension (SF-6D) among stable angina patients.

Science.gov (United States)

Wu, Jing; Han, Yuerong; Zhao, Fei-Li; Zhou, Jin; Chen, Zhijun; Sun, He

2014-10-25

Several preference-based health-related quality of life (HRQoL) instruments have been published and widely used in different populations. However no consensus has emerged regarding the most appropriate instrument in therapeutic area of stable angina. This study compared and validated the psychometric properties of two generic preference-based instruments, the EQ-5D and SF-6D, among Chinese stable angina patients. Convergent validity of the EQ-5D and SF-6D was examined with eight a priori hypotheses from stable angina patients in conjunction with Seattle Angina Questionnaire (SAQ). Responsiveness was compared using the effect size (ES), relative efficiency (RE) and receiver operating characteristic (ROC) curves. Agreement between the EQ-5D and SF-6D was tested using intra-class correlation coefficient (ICC) and Bland-Altman plot. Factors affecting utility difference were explored with multiple linear regression analysis. In 411 patients (mean age 68.08 ± 11.35), mean utility scores (SD) were 0.78 (0.15) for the EQ-5D and 0.68 (0.12) for the SF-6D. Validity was demonstrated by the moderate to strong correlation coefficients (Range: 0.368-0.594, Pstable-angina-specific health status than the EQ-5D (ES: 0.426 to 1.126). RE suggested that the SF-6D (RE: 44.8 to 177.8%) was more efficient than the EQ-5D except for physical function. Poor agreement between them was observed with ICC (0.448, Pstable angina patients. The SF-6D may be a more effective tool with lower ceiling effect and greater sensitivity. Further study is needed to compare other properties, such as reliability and longitudinal response.

Thermodynamic analysis of 6xxx series Al alloys: Phase fraction diagrams

Directory of Open Access Journals (Sweden)

Cui S.

2018-01-01

Full Text Available Microstructural evolution of 6xxx Al alloys during various metallurgical processes was analyzed using accurate thermodynamic database. Phase fractions of all the possible precipitate phases which can form in the as-cast and equilibrium states of the Al-Mg-Si-Cu-Fe-Mn-Cr alloys were calculated over the technically useful composition range. The influence of minor elements such as Cu, Fe, Mn, and Cr on the amount of each type of precipitate in the as-cast and equilibrium conditions were analyzed. Phase fraction diagrams at 500 °C were mapped in the composition range of 0-1.1 wt.% Mg and 0-0.7 wt.% Si to investigate the as-homogenized microstructure. In addition, phase fraction diagram of Mg2Si at 177 °C was mapped to understand the microstructure after final annealing of 6xxx Al alloy. Based on the calculated diagrams, the design strategy of 6xxx Al alloy to produce highest strength due to Mg2Si is discussed.

A basic introduction to the thermodynamics of the Earth system far from equilibrium and maximum entropy production

Science.gov (United States)

Kleidon, A.

2010-01-01

The Earth system is remarkably different from its planetary neighbours in that it shows pronounced, strong global cycling of matter. These global cycles result in the maintenance of a unique thermodynamic state of the Earth's atmosphere which is far from thermodynamic equilibrium (TE). Here, I provide a simple introduction of the thermodynamic basis to understand why Earth system processes operate so far away from TE. I use a simple toy model to illustrate the application of non-equilibrium thermodynamics and to classify applications of the proposed principle of maximum entropy production (MEP) to such processes into three different cases of contrasting flexibility in the boundary conditions. I then provide a brief overview of the different processes within the Earth system that produce entropy, review actual examples of MEP in environmental and ecological systems, and discuss the role of interactions among dissipative processes in making boundary conditions more flexible. I close with a brief summary and conclusion. PMID:20368248

A basic introduction to the thermodynamics of the Earth system far from equilibrium and maximum entropy production.

Science.gov (United States)

Kleidon, A

2010-05-12

The Earth system is remarkably different from its planetary neighbours in that it shows pronounced, strong global cycling of matter. These global cycles result in the maintenance of a unique thermodynamic state of the Earth's atmosphere which is far from thermodynamic equilibrium (TE). Here, I provide a simple introduction of the thermodynamic basis to understand why Earth system processes operate so far away from TE. I use a simple toy model to illustrate the application of non-equilibrium thermodynamics and to classify applications of the proposed principle of maximum entropy production (MEP) to such processes into three different cases of contrasting flexibility in the boundary conditions. I then provide a brief overview of the different processes within the Earth system that produce entropy, review actual examples of MEP in environmental and ecological systems, and discuss the role of interactions among dissipative processes in making boundary conditions more flexible. I close with a brief summary and conclusion.

Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defect conducting ceramics.

Science.gov (United States)

Zhu, Huayang; Ricote, Sandrine; Coors, W Grover; Kee, Robert J

2015-01-01

A model-based interpretation of measured equilibrium conductivity and conductivity relaxation is developed to establish thermodynamic, transport, and kinetics parameters for multiple charged defect conducting (MCDC) ceramic materials. The present study focuses on 10% yttrium-doped barium zirconate (BZY10). In principle, using the Nernst-Einstein relationship, equilibrium conductivity measurements are sufficient to establish thermodynamic and transport properties. However, in practice it is difficult to establish unique sets of properties using equilibrium conductivity alone. Combining equilibrium and conductivity-relaxation measurements serves to significantly improve the quantitative fidelity of the derived material properties. The models are developed using a Nernst-Planck-Poisson (NPP) formulation, which enables the quantitative representation of conductivity relaxations caused by very large changes in oxygen partial pressure.

Modeling the nonequilibrium effects in a nonquasi-equilibrium thermodynamic cycle based on steepest entropy ascent and an isothermal-isobaric ensemble

International Nuclear Information System (INIS)

Li, Guanchen; Spakovsky, Michael R. von

2016-01-01

Conventional first principle approaches for studying nonequilibrium or far-from-equilibrium processes depend on the mechanics of individual particles or quantum states. They also require many details of the mechanical features of a system to arrive at a macroscopic property. In contrast, thermodynamics provides an approach for determining macroscopic property values without going into these details, because the overall effect of particle dynamics results, for example, at stable equilibrium in an invariant pattern of the “Maxwellian distribution”, which in turn leads to macroscopic properties. However, such an approach is not generally applicable to a nonequilibrium process except in the near-equilibrium realm. To adequately address these drawbacks, steepest-entropy-ascent quantum thermodynamics (SEAQT) provides a first principle, thermodynamic-ensemble approach applicable to the entire nonequilibrium realm. Based on prior developments by the authors, this paper applies the SEAQT framework to modeling the nonquasi-equilibrium cycle, which a system with variable volume undergoes. Using the concept of hypoequilibrium state and nonequilibrium intensive properties, this framework provides a complete description of the nonequilibrium evolution in state of the system. Results presented here reveal how nonequilibrium effects influence the performance of the cycle. - Highlights: • First-principles nonequilibrium model of thermodynamic cycles. • Study of thermal efficiency losses due to nonequilibrium effects. • Study of systems undergoing nonquasi-equilibrium processes. • Study of the coupling of system relaxation and interaction with a reservoir.

Combined steam and carbon dioxide reforming of methane and side reactions: Thermodynamic equilibrium analysis and experimental application

International Nuclear Information System (INIS)

Jang, Won-Jun; Jeong, Dae-Woon; Shim, Jae-Oh; Kim, Hak-Min; Roh, Hyun-Seog; Son, In Hyuk; Lee, Seung Jae

2016-01-01

Highlights: • Selected variables have a significant influence on yields of synthesis gas. • (CO_2 + H_2O)/CH_4 affects the temperature which can achieve the maximum conversion. • Coke is formed at low temperatures even with excess oxidizing agent. • The occurrence of RWGS becomes critical in real chemical reactions. • Equilibrium conversions are maintained for 500 h without detectable deactivation. - Abstract: Thermodynamic equilibrium analysis of the combined steam and carbon dioxide reforming of methane (CSCRM) and side reactions was performed using total Gibbs free energy minimization. The effects of (CO_2 + H_2O)/CH_4 ratio (0.9–2.9), CO_2:H_2O ratio (3:1–1:3), and temperature (500–1000 °C) on the equilibrium conversions, yields, coke yield, and H_2/CO ratio were investigated. A (CO_2 + H_2O)/CH_4 ratio greater than 1.2, a CO_2:H_2O ratio of 1:2.1, and a temperature of at least 850 °C are preferable reaction conditions for the synthesis gas preparation in the gas to liquid process. Simulated conditions were applied to the CSCRM reaction and the experimental data were compared with the thermodynamic equilibrium results. The thermodynamic equilibrium results were mostly consistent with the experimental data, but the reverse water gas shift reaction rapidly occurred in the real chemical reaction and under excess oxidizing agent conditions. In addition, a long-term stability test (under simulated conditions) showed that the equilibrium conversion was maintained for 500 h and that the coke formation on the used catalyst was not observed.

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.

Phase equilibrium engineering

CERN Document Server

Brignole, Esteban Alberto

2013-01-01

Traditionally, the teaching of phase equilibria emphasizes the relationships between the thermodynamic variables of each phase in equilibrium rather than its engineering applications. This book changes the focus from the use of thermodynamics relationships to compute phase equilibria to the design and control of the phase conditions that a process needs. Phase Equilibrium Engineering presents a systematic study and application of phase equilibrium tools to the development of chemical processes. The thermodynamic modeling of mixtures for process development, synthesis, simulation, design and

Thermodynamics for scientists and engineers

International Nuclear Information System (INIS)

Lim, Gyeong Hui

2011-02-01

This book deals with thermodynamics for scientists and engineers. It consists of 11 chapters, which are concept and background of thermodynamics, the first law of thermodynamics, the second law of thermodynamics and entropy, mathematics related thermodynamics, properties of thermodynamics on pure material, equilibrium, stability of thermodynamics, the basic of compound, phase equilibrium of compound, excess gibbs energy model of compound and activity coefficient model and chemical equilibrium. It has four appendixes on properties of pure materials and thermal mass.

Quantum corrections to the stress-energy tensor in thermodynamic equilibrium with acceleration

Science.gov (United States)

Becattini, F.; Grossi, E.

2015-08-01

We show that the stress-energy tensor has additional terms with respect to the ideal form in states of global thermodynamic equilibrium in flat spacetime with nonvanishing acceleration and vorticity. These corrections are of quantum origin and their leading terms are second order in the gradients of the thermodynamic fields. Their relevant coefficients can be expressed in terms of correlators of the stress-energy tensor operator and the generators of the Lorentz group. With respect to previous assessments, we find that there are more second-order coefficients and that all thermodynamic functions including energy density receive acceleration and vorticity dependent corrections. Notably, also the relation between ρ and p , that is, the equation of state, is affected by acceleration and vorticity. We have calculated the corrections for a free real scalar field—both massive and massless—and we have found that they increase, particularly for a massive field, at very high acceleration and vorticity and very low temperature. Finally, these nonideal terms depend on the explicit form of the stress-energy operator, implying that different stress-energy tensors of the scalar field—canonical or improved—are thermodynamically inequivalent.

Stochastic thermodynamics

Science.gov (United States)

Eichhorn, Ralf; Aurell, Erik

2014-04-01

'Stochastic thermodynamics as a conceptual framework combines the stochastic energetics approach introduced a decade ago by Sekimoto [1] with the idea that entropy can consistently be assigned to a single fluctuating trajectory [2]'. This quote, taken from Udo Seifert's [3] 2008 review, nicely summarizes the basic ideas behind stochastic thermodynamics: for small systems, driven by external forces and in contact with a heat bath at a well-defined temperature, stochastic energetics [4] defines the exchanged work and heat along a single fluctuating trajectory and connects them to changes in the internal (system) energy by an energy balance analogous to the first law of thermodynamics. Additionally, providing a consistent definition of trajectory-wise entropy production gives rise to second-law-like relations and forms the basis for a 'stochastic thermodynamics' along individual fluctuating trajectories. In order to construct meaningful concepts of work, heat and entropy production for single trajectories, their definitions are based on the stochastic equations of motion modeling the physical system of interest. Because of this, they are valid even for systems that are prevented from equilibrating with the thermal environment by external driving forces (or other sources of non-equilibrium). In that way, the central notions of equilibrium thermodynamics, such as heat, work and entropy, are consistently extended to the non-equilibrium realm. In the (non-equilibrium) ensemble, the trajectory-wise quantities acquire distributions. General statements derived within stochastic thermodynamics typically refer to properties of these distributions, and are valid in the non-equilibrium regime even beyond the linear response. The extension of statistical mechanics and of exact thermodynamic statements to the non-equilibrium realm has been discussed from the early days of statistical mechanics more than 100 years ago. This debate culminated in the development of linear response

Equilibrium and Thermodynamic Studies of Anionic Dyes Removal by an Anionic Clay-Layered Double Hydroxide

International Nuclear Information System (INIS)

Kantasamy, N.; Siti Mariam Sumari

2016-01-01

Adsorption isotherm describes the interaction of adsorbates with adsorbent in equilibrium. Equilibrium data was examined using Langmuir and Freundlich isotherm models. Thermodynamic studies were used to evaluate the thermodynamic parameters; heat of enthalpy change (ΔH degree), Gibbs free energy change (ΔG degree) and heat of entropy change (ΔSdegree) in order to gain information regarding the nature of adsorption (exothermic or endothermic). Four reactive dyes of anionic type, Acid Blue 29 (AB29), Reactive Black 5 (RB5), Reactive Orange 16 (RO16) and Reactive Red 120 (RR120) were used to obtain equilibrium isotherms at 25, 35, 45 and 55 degree Celsius. Based on Giles' classification, the isotherm produced were of L2-type, indicating strong dye affinity towards the adsorbent, and with weak competition with the solvent molecules for active adsorption sites. Equilibrium data fitted both Langmuir and Freundlich isotherm models with high correlation coefficient (R"2 > 0.91) indicating the possibility of both homogeneity and heterogeneous nature of adsorption. The negative values of ΔGdegree indicate the adsorption processes were spontaneous and feasible. The negative values of ΔHdegree lie between -20 to -75 kJ/ mol, suggesting these processes were exothermic and physical in nature. The negative values of ΔSdegree are indication of decreased disorder and randomness of spontaneous adsorption of reactive dyes on layered double hydroxide as adsorbent. (author)

Comparison of analytical charge-form and equilibrium thermodynamic speciation of certain radionuclides

International Nuclear Information System (INIS)

Jenne, E.A.; Cowan, C.E.; Robertson, D.E.

1984-01-01

Calculating trace element speciation with a thermodynamic model is often challenged on the basis that the existing thermodynamic data are not sufficiently reliable. Water quality data and corresponding analytical charge-form speciation analysis were available for radionuclides occurring in a low-level radioactive groundwater. This offered an opportunity for comparing the results of an equilibrium thermodynamic model with the results of analytical charge-form speciation. The charge-form speciation was determined using the Battelle Large Volume Water Sampler, which contains consecutive layers of cation resin, anion resin and activated aluminum oxide for retention of cationic, anionic and non-ionic dissolved chemical species, respectively. The thermodynamic speciation of Cs, Cr, Fe, I, Mn, Mo, Na, and Zn was calculated using the MINTEQ geochemical model. Ce, Co, Tc, Np, Pm, and Sb were speciated by hand calculation. Excellent agreement between the analytically determined charge-form and the thermodynamic speciation was observed for 54 Mn, 144 Ce, 131 I, 24 Na, 137 Cs, 99 Mo, 99 Tc, 151 Pm, 239 Np. Organic complexation by natural and/or synthetic organics in the waters may be important in the speciation of 65 An, 60 Co, 131 I, 59 Fe and possibly 51 Cr. Both 124 Sb and 125 Sb appeared to be in redox disequilibria with the groundwater. 29 references, 2 tables

Thermodynamic parameters for mixtures of quartz under shock wave loading in views of the equilibrium model

International Nuclear Information System (INIS)

Maevskii, K. K.; Kinelovskii, S. A.

2015-01-01

The numerical results of modeling of shock wave loading of mixtures with the SiO 2 component are presented. The TEC (thermodynamic equilibrium component) model is employed to describe the behavior of solid and porous multicomponent mixtures and alloys under shock wave loading. State equations of a Mie–Grüneisen type are used to describe the behavior of condensed phases, taking into account the temperature dependence of the Grüneisen coefficient, gas in pores is one of the components of the environment. The model is based on the assumption that all components of the mixture under shock-wave loading are in thermodynamic equilibrium. The calculation results are compared with the experimental data derived by various authors. The behavior of the mixture containing components with a phase transition under high dynamic loads is described

SOLGAS refined: A computerized thermodynamic equilibrium calculation tool

International Nuclear Information System (INIS)

Trowbridge, L.D.; Leitnaker, J.M.

1993-11-01

SOLGAS, an early computer program for calculating equilibrium in a chemical system, has been made more user-friendly, and several open-quote bells and whistlesclose quotes have been added. The necessity to include elemental species has been eliminated. The input of large numbers of starting conditions has been automated. A revised format for entering data simplifies and reduces chances for error. Calculated errors by SOLGAS are flagged, and several programming errors are corrected. Auxiliary programs are available to assemble and partially automate plotting of large amounts of data. Thermodynamic input data can be changed open-quotes on line.close-quote The program can be operated with or without a co-processor. Copies of the program, suitable for the IBM-PC or compatible with at least 384 bytes of low RAM, are available from the authors

Elemental transport coefficients in viscous plasma flows near local thermodynamic equilibrium

International Nuclear Information System (INIS)

Orsini, Alessio; Kustova, Elena V.

2009-01-01

We propose a convenient formulation of elemental transport coefficients in chemically reacting and plasma flows locally approaching thermodynamic equilibrium. A set of transport coefficients for elemental diffusion velocities, heat flux, and electric current is introduced. These coefficients relate the transport fluxes with the electric field and with the spatial gradients of elemental fractions, pressure, and temperature. The proposed formalism based on chemical elements and fully symmetric with the classical transport theory based on chemical species, is particularly suitable to model mixing and demixing phenomena due to diffusion of chemical elements. The aim of this work is threefold: to define a simple and rigorous framework suitable for numerical implementation, to allow order of magnitude estimations and qualitative predictions of elemental transport phenomena, and to gain a deeper insight into the physics of chemically reacting flows near local equilibrium.

Validation and comparison of EuroQoL-5 dimension (EQ-5D) and Short Form-6 dimension (SF-6D) among stable angina patients

OpenAIRE

Wu, Jing; Han, Yuerong; Zhao, Fei-Li; Zhou, Jin; Chen, Zhijun; Sun, He

2014-01-01

Objectives Several preference-based health-related quality of life (HRQoL) instruments have been published and widely used in different populations. However no consensus has emerged regarding the most appropriate instrument in therapeutic area of stable angina. This study compared and validated the psychometric properties of two generic preference-based instruments, the EQ-5D and SF-6D, among Chinese stable angina patients. Methods Convergent validity of the EQ-5D and SF-6D was examined with ...

Local thermodynamic equilibrium in a laser-induced plasma evidenced by blackbody radiation

Science.gov (United States)

Hermann, Jörg; Grojo, David; Axente, Emanuel; Craciun, Valentin

2018-06-01

We show that the plasma produced by laser ablation of solid materials in specific conditions has an emission spectrum that is characterized by the saturation of the most intense spectral lines at the blackbody radiance. The blackbody temperature equals the excitation temperature of atoms and ions, proving directly and unambiguously a plasma in local thermodynamic equilibrium. The present investigations take benefit from the very rich and intense emission spectrum generated by ablation of a nickel-chromium-molybdenum alloy. This alternative and direct proof of the plasma equilibrium state re-opens the perspectives of quantitative material analyses via calibration-free laser-induced breakdown spectroscopy. Moreover, the unique properties of this laser-produced plasma promote its use as radiation standard for intensity calibration of spectroscopic instruments.

Modeling ion exchange in clinoptilolite using the EQ3/6 geochemical modeling code

International Nuclear Information System (INIS)

Viani, B.E.; Bruton, C.J.

1992-06-01

Assessing the suitability of Yucca Mtn., NV as a potential repository for high-level nuclear waste requires the means to simulate ion-exchange behavior of zeolites. Vanselow and Gapon convention cation-exchange models have been added to geochemical modeling codes EQ3NR/EQ6, allowing exchange to be modeled for up to three exchangers or a single exchanger with three independent sites. Solid-solution models that are numerically equivalent to the ion-exchange models were derived and also implemented in the code. The Gapon model is inconsistent with experimental adsorption isotherms of trace components in clinoptilolite. A one-site Vanselow model can describe adsorption of Cs or Sr on clinoptilolite, but a two-site Vanselow exchange model is necessary to describe K contents of natural clinoptilolites

Non-equilibrium Thermodynamic Dissolution Theory for Multi-Component Solid/Liquid Surfaces Involving Surface Adsorption and Radiolysis Kinetics

International Nuclear Information System (INIS)

Stout, R B

2001-01-01

A theoretical expression is developed for the dissolution rate response for multi-component radioactive materials that have surface adsorption kinetics and radiolysis kinetics when wetted by a multi-component aqueous solution. An application for this type of dissolution response is the performance evaluation of multi-component spent nuclear fuels (SNFs) for long term interim storage and for geological disposition. Typically, SNF compositions depend on initial composition, uranium oxide and metal alloys being most common, and on reactor burnup which results in a wide range of fission product and actinide concentrations that decay by alpha, beta, and gamma radiation. These compositional/burnup ranges of SNFs, whether placed in interim storage or emplaced in a geologic repository, will potentially be wetted by multi-component aqueous solutions, and these solutions may be further altered by radiolytic aqueous species due to three radiation fields. The solid states of the SNFs are not thermodynamically stable when wetted and will dissolve, with or without radiolysis. The following development of a dissolution theory is based on a non-equilibrium thermodynamic analysis of energy reactions and energy transport across a solid-liquid phase change discontinuity that propagates at a quasi-steady, dissolution velocity. The integral form of the energy balance equation is used for this spatial surface discontinuity analysis. The integral formulation contains internal energy functional of classical thermodynamics for both the SNFs' solid state and surface adsorption species, and the adjacent liquid state, which includes radiolytic chemical species. The steady-state concentrations of radiolytic chemical species are expressed by an approximate analysis of the decay radiation transport equation. For purposes of illustration a modified Temkin adsorption isotherm was assumed for the surface adsorption kinetics on an arbitrary, finite area of the solid-liquid dissolution interface. For

Deviation from local thermodynamic equilibrium in a cesium-seeded argon plasma

International Nuclear Information System (INIS)

Stefanov, B.; Zarkova, L.

1985-11-01

The possibility of deviations from local thermodynamic equilibrium of a cesium seeded argon plasma has been analyzed. A four level model of cesium has been employed. Overpopulations of the ground state and the first excited state as well as the corresponding reduction of the electron density are calculated for cylindrical discharge structures by solving stationary rate equations. Numerical results are presented. These results indicate that in a large regime of plasma conditions the LTE assumption is valid for electron temperatures larger than 3000 K. (orig.)

Absolute determination of the gelling point of gelatin under quasi-thermodynamic equilibrium.

Science.gov (United States)

Bellini, Franco; Alberini, Ivana; Ferreyra, María G; Rintoul, Ignacio

2015-05-01

Thermodynamic studies on phase transformation of biopolymers in solution are useful to understand their nature and to evaluate their technological potentials. Thermodynamic studies should be conducted avoiding time-related phenomena. This condition is not easily achieved in hydrophilic biopolymers. In this contribution, the simultaneous effects of pH, salt concentration, and cooling rate (Cr) on the folding from random coil to triple helical collagen-like structures of gelatin were systematically studied. The phase transformation temperature at the absolute invariant condition of Cr = 0 °C/min (T(T)Cr=0) ) is introduced as a conceptual parameter to study phase transformations in biopolymers under quasi-thermodynamic equilibrium and avoiding interferences coming from time-related phenomena. Experimental phase diagrams obtained at different Cr are presented. The T(T)(Cr=0) compared with pH and TT(Cr=0) compared with [NaCl] diagram allowed to explore the transformation process at Cr = 0 °C/min. The results were explained by electrostatic interactions between the biopolymers and its solvation milieu. © 2015 Institute of Food Technologists®

Monte Carlo simulations for thermodynamical properties calculations of plasmas at thermodynamical equilibrium. Applications to opacity and equation of state calculations

International Nuclear Information System (INIS)

Gilles, D.

2005-01-01

This report is devoted to illustrate the power of a Monte Carlo (MC) simulation code to study the thermodynamical properties of a plasma, composed of classical point particles at thermodynamical equilibrium. Such simulations can help us to manage successfully the challenge of taking into account 'exactly' all classical correlations between particles due to density effects, unlike analytical or semi-analytical approaches, often restricted to low dense plasmas. MC simulations results allow to cover, for laser or astrophysical applications, a wide range of thermodynamical conditions from more dense (and correlated) to less dense ones (where potentials are long ranged type). Therefore Yukawa potentials, with a Thomas-Fermi temperature- and density-dependent screening length, are used to describe the effective ion-ion potentials. In this report we present two MC codes ('PDE' and 'PUCE') and applications performed with these codes in different fields (spectroscopy, opacity, equation of state). Some examples of them are discussed and illustrated at the end of the report. (author)

A spreadsheet-coupled SOLGAS: A computerized thermodynamic equilibrium calculation tool. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Trowbridge, L.D.; Leitnaker, J.M. [Oak Ridge K-25 Site, TN (United States). Technical Analysis and Operations Div.

1995-07-01

SOLGAS, an early computer program for calculating equilibrium in a chemical system, has been made more user-friendly, and several ``bells and whistles`` have been added. The necessity to include elemental species has been eliminated. The input of large numbers of starting conditions has been automated. A revised spreadsheet-based format for entering data, including non-ideal binary and ternary mixtures, simplifies and reduces chances for error. Calculational errors by SOLGAS are flagged, and several programming errors are corrected. Auxiliary programs are available to assemble and partially automate plotting of large amounts of data. Thermodynamic input data can be changed on line. The program can be operated with or without a co-processor. Copies of the program, suitable for the IBM-PC or compatibles with at least 384 bytes of low RAM, are available from the authors. This user manual contains appendices with examples of the use of SOLGAS. These range from elementary examples, such as, the relationships among water, ice, and water vapor, to more complex systems: phase diagram calculation of UF{sub 4} and UF{sub 6} system; burning UF{sub 4} in fluorine; thermodynamic calculation of the Cl-F-O-H system; equilibria calculations in the CCl{sub 4}--CH{sub 3}OH system; and limitations applicable to aqueous solutions. An appendix also contains the source code.

SOLGAS refined: A computerized thermodynamic equilibrium calculation tool

Energy Technology Data Exchange (ETDEWEB)

Trowbridge, L.D.; Leitnaker, J.M.

1993-11-01

SOLGAS, an early computer program for calculating equilibrium in a chemical system, has been made more user-friendly, and several{open_quote} bells and whistles{close_quotes} have been added. The necessity to include elemental species has been eliminated. The input of large numbers of starting conditions has been automated. A revised format for entering data simplifies and reduces chances for error. Calculated errors by SOLGAS are flagged, and several programming errors are corrected. Auxiliary programs are available to assemble and partially automate plotting of large amounts of data. Thermodynamic input data can be changed {open_quotes}on line.{close_quote} The program can be operated with or without a co-processor. Copies of the program, suitable for the IBM-PC or compatible with at least 384 bytes of low RAM, are available from the authors.

Generalization of Gibbs Entropy and Thermodynamic Relation

OpenAIRE

Park, Jun Chul

2010-01-01

In this paper, we extend Gibbs's approach of quasi-equilibrium thermodynamic processes, and calculate the microscopic expression of entropy for general non-equilibrium thermodynamic processes. Also, we analyze the formal structure of thermodynamic relation in non-equilibrium thermodynamic processes.

GEODAT. Development of thermodynamic data for the thermodynamic equilibrium modeling of processes in deep geothermal formations. Combined report

International Nuclear Information System (INIS)

Moog, Helge C.; Regenspurg, Simona; Voigt, Wolfgang

2015-02-01

The concept for geothermal energy application for electricity generation can be differentiated into three compartments: In the geologic compartment cooled fluid is pressed into a porous or fractured rock formation, in the borehole compartment a hot fluid is pumped to the surface and back into the geothermal reservoir, in the aboveground facility the energy is extracted from the geothermal fluid by heat exchangers. Pressure and temperature changes influence the thermodynamic equilibrium of a system. The modeling of a geothermal system has therefore to consider besides the mass transport the heat transport and consequently changing solution compositions and the pressure/temperature effected chemical equilibrium. The GEODAT project is aimed to simulate the reactive mass transport in a geothermal reservoir in the North German basin (Gross Schoenebeck). The project was performed by the cooperation of three partners: Geoforschungsinstitut Potsdam, Bergakademie Freiberg and GRS.

Classical relativistic ideal gas in thermodynamic equilibrium in a uniformly accelerated reference frame

International Nuclear Information System (INIS)

Louis-Martinez, Domingo J

2011-01-01

A classical (non-quantum-mechanical) relativistic ideal gas in thermodynamic equilibrium in a uniformly accelerated frame of reference is studied using Gibbs's microcanonical and grand canonical formulations of statistical mechanics. Using these methods explicit expressions for the particle, energy and entropy density distributions are obtained, which are found to be in agreement with the well-known results of the relativistic formulation of Boltzmann's kinetic theory. Explicit expressions for the total entropy, total energy and rest mass of the gas are obtained. The position of the center of mass of the gas in equilibrium is found. The non-relativistic and ultrarelativistic approximations are also considered. The phase space volume of the system is calculated explicitly in the ultrarelativistic approximation.

Effect of configuration widths on the spectra of local thermodynamic equilibrium plasmas

International Nuclear Information System (INIS)

Bar-Shalom, A.; Oreg, J.; Goldstein, W.H.

1995-01-01

We present the extension of the supertransition-array (STA) theory to include configuration widths in the spectra of local thermodynamic equilibrium (LTE) plasmas. Exact analytic expressions for the moments of a STA are given, accounting for the detailed contributions of individual levels within the configurations that belong to a STA. The STA average energy is shifted and an additional term appears in its variance. Various cases are presented, demonstrating the effect of these corrections on the LTE spectrum

Equilibrium sampling for a thermodynamic assessment of contaminated sediments

DEFF Research Database (Denmark)

Mayer, Philipp; Nørgaard Schmidt, Stine; Mäenpää, Kimmo

Hydrophobic organic contaminants (HOCs) reaching the aquatic environment are largely stored in sediments. The risk of contaminated sediments is challenging to assess since traditional exhaustive extraction methods yield total HOC concentrations, whereas freely dissolved concentrations (Cfree......) govern diffusive uptake and partitioning. Equilibrium sampling of sediment was introduced 15 years ago to measure Cfree, and it has since developed into a straightforward, precise and sensitive approach for determining Cfree and other exposure parameters that allow for thermodynamic assessment...... of polluted sediments. Glass jars with µm-thin silicone coatings on the inner walls can be used for ex situ equilibration while a device housing several silicone-coated fibers can be used for in situ equilibration. In both cases, parallel sampling with varying silicone thicknesses can be applied to confirm...

Qualification of Thermodynamic Data for Geochemical Modeling of Mineral-Water Interactions in Dilute Systems

International Nuclear Information System (INIS)

T. J. Wolery; C.F. Jove-Colon

2004-01-01

The purpose of this analysis report is to qualify the thermochemical database data0.ymp.R2 (DTN: MO0302SPATHDYN.000 [DIRS 161756], qualified by this report) and supporting calculations (DTNs: MO0302SPATHDYN.001 [DIRS 161886], and MO0303SPASPEQ2.000 [DIRS 162278]), which were originally documented in ''Data Qualification: Update and Revision of the Geochemical Thermodynamic Database, Data0.ymp'' (Steinborn et al. 2003 [DIRS 161956]). This original document still serves as the record of development of the data0.ymp.R2 database (DTN: MO0302SPATHDYN.000 [DIRS 161756]). The data0.ymp.R2 thermodynamic database (DTN: MO0302SPATHDYN.000 [DIRS 161756]) was developed for use with software code EQ3/6 (EQ3/6 V8.0, STN: 10813-8.0-00) (BSC 2003 [DIRS 162228]) and software code EQ6 (EQ6 V7.2bLV, STN: 10075-7.2bLV-02) (BSC 2002 [DIRS 159731]) to conduct geochemical modeling of mineral-fluid interactions involving aqueous solutions (ionic strengths of up to one molal; see Section 6.5) and temperatures of up to 300 C along the liquid-vapor saturation curve of pure water. The data0.ymp.R2 database (DTN: MO0302SPATHDYN.000 [DIRS 161756]) is an update of the previously qualified predecessor database data0.ymp.R0 (DTN: MO0009THRMODYN.001 [DIRS 152576]). The scope of this report is limited to qualification of the updates, as well as identification and evaluation of certain errors and discrepancies as discussed

A Head-to-Head Comparison of UK SF-6D and Thai and UK EQ-5D-5L Value Sets in Thai Patients with Chronic Diseases.

Science.gov (United States)

Sakthong, Phantipa; Munpan, Wipaporn

2017-10-01

Little was known about the head-to-head comparison of psychometric properties between SF-6D and EQ-5D-5L or the different value sets of EQ-5D-5L. Therefore, this study set out to compare the psychometric properties including agreement, convergent, and known-group validity between the SF-6D and the EQ-5D-5L using the real value sets from Thailand and the UK in patients with chronic diseases. 356 adults taking a medication for at least 3 months were identified from a university hospital in Bangkok, Thailand, between July 2014 and March 2015. Agreement was assessed by intraclass correlation coefficients (ICCs) and Bland-Altman plots. Convergent validity was evaluated using Spearman's rank correlation coefficients between SF-6D and EQ-5D-5L and EQ-VAS and SF-12v2. For known-groups validity, the Mann-Whitney U test and Kruskal-Wallis test were used to examine the associations between SF-6D and EQ-5D-5L and patient characteristics. Agreements between the SF-6D and the EQ-5D-5L using Thai and UK value sets were fair, with ICCs of 0.45 and 0.49, respectively. Bland-Altman plots showed that the majority of the SF-6D index scores were lower than the EQ-5D-5L index scores. Both the EQ-5D-5L value sets were more related to the EQ-VAS and physical health, while the SF-6D was more associated with mental health. Both EQ-5D-5L value sets were more sensitive than the SF-6D in discriminating patients with different levels of more known groups except for adverse drug reactions. The SF-6D and both EQ-5D-5L value sets appeared to be valid but sensitive to different outcomes in Thai patients with chronic diseases.

Non-equilibrium thermodynamics in cells.

Science.gov (United States)

Jülicher, Frank; Grill, Stephan W; Salbreux, Guillaume

2018-03-15

We review the general hydrodynamic theory of active soft materials that is motivated in partic- ular by biological matter. We present basic concepts of irreversible thermodynamics of spatially extended multicomponent active systems. Starting from the rate of entropy production, we iden- tify conjugate thermodynamic fluxes and forces and present generic constitutive equations of polar active fluids and active gels. We also discuss angular momentum conservation which plays a role in the the physics of active chiral gels. The irreversible thermodynamics of active gels provides a general framework to discuss the physics that underlies a wide variety of biological processes in cells and in multicellular tissues. © 2018 IOP Publishing Ltd.

Stability of the thermodynamic equilibrium - A test of the validity of dynamic models as applied to gyroviscous perpendicular magnetohydrodynamics

Science.gov (United States)

Faghihi, Mustafa; Scheffel, Jan; Spies, Guenther O.

1988-05-01

Stability of the thermodynamic equilibrium is put forward as a simple test of the validity of dynamic equations, and is applied to perpendicular gyroviscous magnetohydrodynamics (i.e., perpendicular magnetohydrodynamics with gyroviscosity added). This model turns out to be invalid because it predicts exponentially growing Alfven waves in a spatially homogeneous static equilibrium with scalar pressure.

Stability of the thermodynamic equilibrium: A test of the validity of dynamic models as applied to gyroviscous perpendicular magnetohydrodynamics

International Nuclear Information System (INIS)

Faghihi, M.; Scheffel, J.; Spies, G.O.

1988-01-01

Stability of the thermodynamic equilibrium is put forward as a simple test of the validity of dynamic equations, and is applied to perpendicular gyroviscous magnetohydrodynamics (i.e., perpendicular magnetohydrodynamics with gyroviscosity added). This model turns out to be invalid because it predicts exponentially growing Alfven waves in a spatially homogeneous static equilibrium with scalar pressure

A consistent set of thermodynamic constants for americium (III) species with hydroxyl and carbonate

International Nuclear Information System (INIS)

Kerrisk, J.F.; Silva, R.J.

1986-01-01

A consistent set of thermodynamic constants for aqueous species, and compounds of Am(III) with hydroxyl and carbonate ligands has been developed. The procedure used to develop these constants involved establishing a value for one formation constant at a time in a sequential order, starting with the hydrolysis products and hydroxide solids, and then proceeding to carbonate species. The EQ3NR chemical-equilibrium model was used to test the constants developed. These constants are consistent with most of the experimental data that form their basis; however, considerable uncertainty still exists in some aspects of the Am(III) data

Thermodynamic and Quantum Thermodynamic Analyses of Brownian Movement

OpenAIRE

Gyftopoulos, Elias P.

2006-01-01

Thermodynamic and quantum thermodynamic analyses of Brownian movement of a solvent and a colloid passing through neutral thermodynamic equilibrium states only. It is shown that Brownian motors and E. coli do not represent Brownian movement.

The zeroth law of thermodynamics and volume-preserving conservative system in equilibrium with stochastic damping

International Nuclear Information System (INIS)

Qian, Hong

2014-01-01

We propose a mathematical formulation of the zeroth law of thermodynamics and develop a stochastic dynamical theory, with a consistent irreversible thermodynamics, for systems possessing sustained conservative stationary current in phase space while in equilibrium with a heat bath. The theory generalizes underdamped mechanical equilibrium: dx=gdt+{−D∇ϕdt+√(2D)dB(t)}, with ∇⋅g=0 and {⋯} respectively representing phase-volume preserving dynamics and stochastic damping. The zeroth law implies stationary distribution u ss (x)=e −ϕ(x) . We find an orthogonality ∇ϕ⋅g=0 as a hallmark of the system. Stochastic thermodynamics based on time reversal (t,ϕ,g)→(−t,ϕ,−g) is formulated: entropy production e p # (t)=−dF(t)/dt; generalized “heat” h d # (t)=−dU(t)/dt, U(t)=∫ R n ϕ(x)u(x,t)dx being “internal energy”, and “free energy” F(t)=U(t)+∫ R n u(x,t)lnu(x,t)dx never increases. Entropy follows (dS)/(dt) =e p # −h d # . Our formulation is shown to be consistent with an earlier theory of P. Ao. Its contradistinctions to other theories, potential-flux decomposition, stochastic Hamiltonian system with even and odd variables, Klein–Kramers equation, Freidlin–Wentzell's theory, and GENERIC, are discussed.

Catalytic supercritical water gasification of primary paper sludge using a homogeneous and heterogeneous catalyst: Experimental vs thermodynamic equilibrium results.

Science.gov (United States)

Louw, Jeanne; Schwarz, Cara E; Burger, Andries J

2016-02-01

H2, CH4, CO and CO2 yields were measured during supercritical water gasification (SCWG) of primary paper waste sludge (PWS) at 450°C. Comparing these yields with calculated thermodynamic equilibrium values offer an improved understanding of conditions required to produce near-equilibrium yields. Experiments were conducted at different catalyst loads (0-1g/gPWS) and different reaction times (15-120min) in a batch reactor, using either K2CO3 or Ni/Al2O3-SiO2 as catalyst. K2CO3 up to 1g/gPWS increased the H2 yield significantly to 7.5mol/kgPWS. However, these yields and composition were far from equilibrium values, with carbon efficiency (CE) and energy recovery (ER) of only 29% and 20%, respectively. Addition of 0.5-1g/gPWS Ni/Al2O3-SiO2 resulted in high H2 and CH4 yields (6.8 and 14.8mol/kgPWS), CE of 84-90%, ER of 83% and a gas composition relatively close to the equilibrium values (at hold times of 60-120min). Copyright © 2015 Elsevier Ltd. All rights reserved.

Some consideration on the thermodynamics of the universe

International Nuclear Information System (INIS)

Hoenl, H.

1977-01-01

It is shown that the thermodynamics of the universe display certain features that are foreign to classical thermodynamics, the discrepancy having its origin in the cosmic expansion of the universe. This is apparent, for example, in the outstanding fact that in the early stages of the universe (some 10 5 or 10 6 years after the Big Bang) the distribution of matter was essentially homogeneous and, owing to the extremely high density and temperature, was in thermodynamic equilibrium. However, in its present state, after the formation of the celestial bodies, (the inhomogeneous phase of the universe), it has moved far away from thermodynamic equilibrium. It is stated that to prove entropy conservation during the homogeneous phase of the universe, one only needs the most general thermodynamical-statistical principles. (U,K)

Braun-Le Chatelier principle in dissipative thermodynamics

OpenAIRE

Pavelka, Michal; Grmela, Miroslav

2016-01-01

Braun-Le Chatelier principle is a fundamental result of equilibrium thermodynamics, showing how stable equilibrium states shift when external conditions are varied. The principle follows from convexity of thermodynamic potential. Analogously, from convexity of dissipation potential it follows how steady non-equilibrium states shift when thermodynamic forces are varied, which is the extension of the principle to dissipative thermodynamics.

Coronal and local thermodynamic equilibriums in a hollow cathode discharge

International Nuclear Information System (INIS)

Zheng Xutao

2005-01-01

A characteristic two-section profile of excited-state populations is observed in a hollow cathode discharge and is explained by coexistence of the coronal equilibrium (CE) and the local thermodynamic equilibrium (LTE). At helium pressure 0.1 Torr and cathode current 200-300 mA, vacuum ultraviolet radiations from He I 1snp 1 P (n=2-16) and He II np 2 P (n=2-14) are resolved with a 2.2-M McPherson spectrometer. Relative populations of these states are deduced from the discrete line intensities and are plotted against energy levels. For both the He I and He II series, as energy level increases, populations of high-n (n>10) states are found to decrease much more quickly than low-n (n<7) populations. While low-n populations are described with the CE dominated by direct electron-impact excitations, high-n populations are fitted with the LTE to calculate the population temperatures of gas atoms and ions. Validities of the CE and LTE in different n-ranges are considered on the competition between radiative decays of the excited states and their collisions with gas atoms. (author)

Application of constrained equilibrium thermodynamics to irradiated alloy systems

Science.gov (United States)

Holloway, James Paul; Stubbins, James F.

1984-05-01

Equilibrium thermodynamics are applied to systems with an excess of point defects to calculate the relative stability of phases. It is possible to model systems with supersaturation levels of vacancies and interstitials, such as those found under irradiation. The calculations reveal the extent to which phase compositional boundaries could shift when one phase or both in a two phase system contain an excess of point defects. Phase boundary shifts in the Ni-Si, Fe-Ni, Ni-Cr, and Fe-Cr systems are examined as a function of the number of excess defects in each phase. It is also found that the critical temperature of the sigma phase in the Fe-Cr system and the fcc-bcc transition in the Fe-Ni are sensitive to excess defect concentrations. These results may apply to local irradiation-induced phase transformations in the presence of solute segregation.

Equilibrium, kinetics and thermodynamics studies of textile dyes adsorption on modified Tunisian clay

Directory of Open Access Journals (Sweden)

naghmouchi nahed

2016-04-01

Full Text Available The adsorption capacity of two anionic textile dyes (RR120 and BB150 on DMSO intercalated Tunisian raw clay was investigated with respect to contact time, initial dye concentration, pH and Temperature. The equilibrium data were fitted into Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. The kinetic parameters were calculated using pseudo-first order, pseudo second-order, intra-particle diffusion and Elovich kinetic models. The thermodynamic parameters (DH°, DS° and DG° of the adsorption process were also evaluated.

Continuous equilibrium scores: factoring in the time before a fall.

Science.gov (United States)

Wood, Scott J; Reschke, Millard F; Owen Black, F

2012-07-01

The equilibrium (EQ) score commonly used in computerized dynamic posturography is normalized between 0 and 100, with falls assigned a score of 0. The resulting mixed discrete-continuous distribution limits certain statistical analyses and treats all trials with falls equally. We propose a simple modification of the formula in which peak-to-peak sway data from trials with falls is scaled according the percent of the trial completed to derive a continuous equilibrium (cEQ) score. The cEQ scores for trials without falls remain unchanged from the original methodology. The cEQ factors in the time before a fall and results in a continuous variable retaining the central tendencies of the original EQ distribution. A random set of 5315 Sensory Organization Test trials were pooled that included 81 falls. A comparison of the original and cEQ distributions and their rank ordering demonstrated that trials with falls continue to constitute the lower range of scores with the cEQ methodology. The area under the receiver operating characteristic curve (0.997) demonstrates that the cEQ retained near-perfect discrimination between trials with and without falls. We conclude that the cEQ score provides the ability to discriminate between ballistic falls from falls that occur later in the trial. This approach of incorporating time and sway magnitude can be easily extended to enhance other balance tests that include fall data or incomplete trials. Copyright © 2012 Elsevier B.V. All rights reserved.

Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

International Nuclear Information System (INIS)

Martin del Campo, Julia S.; Patino, Rodrigo

2011-01-01

Research highlights: → The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. → A spectrophotometric method is proposed for kinetic and thermodynamic analysis. → The pH and the temperature influences are reported on physical chemical properties. → Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD ox ) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD ox as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, Δ f G o = -1784 ± 5 kJ mol -1 .

Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

Energy Technology Data Exchange (ETDEWEB)

Martin del Campo, Julia S. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico); Patino, Rodrigo, E-mail: rtarkus@mda.cinvestav.mx [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico)

2011-04-20

Research highlights: {yields} The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. {yields} A spectrophotometric method is proposed for kinetic and thermodynamic analysis. {yields} The pH and the temperature influences are reported on physical chemical properties. {yields} Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD{sub ox}) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD{sub ox} as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, {Delta}{sub f}G{sup o} = -1784 {+-} 5 kJ mol{sup -1}.

Thermodynamic properties of the Pd77.5Cu6Si16.5 undercooled liquid

International Nuclear Information System (INIS)

Fiore, Gianluca; Battezzati, Livio

2009-01-01

Proper understanding of glass formation implies the knowledge of the thermodynamics of the undercooled melts. Specifically, high values of the excess specific heat of the liquid are expected for good glass-formers. Extending the work of Gillessen and Herlach [F. Gillessen, D.M. Herlach, J. Non-Cryst. Solids 117-118 (1990) 555-558], we re-propose a calculation of the temperature dependence of entropy difference between amorphous-liquid and crystal states. An amorphous Pd 77.5 Cu 6 Si 16.5 alloy has been produced by injection casting in a cylindrical copper mould. DSC measurements in the liquid, amorphous and crystalline states were performed with samples sliced from the cylinder to determine the heat of fusion, of crystallization and the difference in specific heat capacity between amorphous-liquid and crystal phases. These thermodynamic quantities are used to calculate the thermodynamic functions of the liquid-glass with reference to the equilibrium crystal mixture. The data are compared to those of other bulk glass-formers in terms of fragility plots.

Viscous behavior of (Sn61.9Pb38.1)100-xREx (x=0, 0.1, 0.3, 1 wt%) solder alloys

International Nuclear Information System (INIS)

Wu Yuqin; Bian Xiufang; Zhao Yan; Li Xuelian; Zhang Yanning; Tian Yongsheng; Lv Xiaoqian

2008-01-01

The viscous behavior of (Sn 61.9 Pb 38.1 ) 100-x RE x (x=0, 0.1, 0.3, 1 wt%) solder alloys has been investigated by a torsional oscillation viscometer. The structural transition temperature T ' increases with increasing addition of RE elements. Above T ' , the viscosities of melts increase with increasing addition of RE, and are fitted well with the Arrhenius equation. The time dependence of viscosity at the measured temperature below T ' follows the exponential relaxation function and reflects the process of the structural transition in the melt, which can be considered as the thermodynamic equilibrium process. The thermodynamic equilibrium relaxation time τ eq increases with both the equilibrium viscosity η eq and the discrepancy in viscosity (Δη), between the initial state and the equilibrium state. However, it decreases with the measured temperature T. The size of clusters in the melts increases with increasing of viscosity and is restricted by the thermodynamic equilibrium conditions

Non-equilibrium thermodynamics of highly rarefied neutron gas under creative and destructive reactions

International Nuclear Information System (INIS)

Hayasaka, Hideo

1978-01-01

The thermodynamic structures of non-equilibrium steady states of a highly rarefied neutron gas in various media are considered in terms of the irreversible processes due to creative and destructive reactions of neutrons with nuclei of these media and to neutrons supplied from external sources. The respective subsystems of the stationary neutron gas are regarded as imperfect equilibrium systems in the presence of the medium and the external neutron sources, and are treated like different species in a mixture. The entropy production due to neutron-nuclear reactions has a minimum value at the steady state. The distribution function of such a neutron gas is determined from the extremum condition in which entropy does not change, and is expressed as a shifted Boltzmann distribution specified by the respective values of the generalized chemical potential for each energy level. (author)

Thermodynamics of calcium-isotope-exchange reactions. 1. Exchange between isotopic calcium carbonates and aqueous calcium ions

International Nuclear Information System (INIS)

Zhang, R.S.; Nash, C.P.; Rock, P.A.

1988-01-01

This paper reports the authors results for the direct experimental determination of the equilibrium constant for the calcium-isotope-exchange reaction 40 CaCO 3 (s) + 44 CaCl 2 (aq) reversible 44 CaCO 2 (s) + 40 CaCl 2 (aq). The reaction was studied in electrochemical double cells without liquid junction of the type shown in eq 2. The experimental value of the equilibrium constant at 295 +/- 2 K is K = 1.08 +/- 0.02. The experimental value for K is compared with the values of K calculated for various model reactions according to the statistical thermodynamic theory of isotope effects. The isotopic solid carbonates were modeled according to both the Debye and Kieffer theories. No structured models of solvated isotopic aqueous calcium ions yield calculated equilibrium constants in agreement with their experimental results. This conclusion is in agreement with published molecular dynamics calculations which show that the aqueous solvation of Ca 2 =(aq) is essentially unstructured

Basic Thermodynamics

International Nuclear Information System (INIS)

Duthil, P

2014-01-01

The goal of this paper is to present a general thermodynamic basis that is useable in the context of superconductivity and particle accelerators. The first part recalls the purpose of thermodynamics and summarizes its important concepts. Some applications, from cryogenics to magnetic systems, are covered. In the context of basic thermodynamics, only thermodynamic equilibrium is considered

Basic Thermodynamics

Energy Technology Data Exchange (ETDEWEB)

Duthil, P [Orsay, IPN (France)

2014-07-01

The goal of this paper is to present a general thermodynamic basis that is useable in the context of superconductivity and particle accelerators. The first part recalls the purpose of thermodynamics and summarizes its important concepts. Some applications, from cryogenics to magnetic systems, are covered. In the context of basic thermodynamics, only thermodynamic equilibrium is considered.

Choice of the thermodynamic variables

International Nuclear Information System (INIS)

Balian, R.

1985-09-01

Some basic ideas of thermodynamics and statistical mechanics, both at equilibrium and off equilibrium, are recalled. In particular, the selection of relevant variables which underlies any macroscopic description is discussed, together with the meaning of the various thermodynamic quantities, in order to set the thermodynamic approaches used in nuclear physics in a general prospect [fr

Equilibrium, kinetic and thermodynamic studies of adsorption of Th(IV) from aqueous solution onto kaolin

International Nuclear Information System (INIS)

Hongxia Zhang; Zhiwei Niu; Zhi Liu; Zhaodong Wen; Weiping Li; Xiaoyun Wang; Wangsuo Wu

2015-01-01

The kinetics and thermodynamics of the adsorption of Th(IV) on the kaolin were studied by using batch method. In addition, the experimental data were studied by dynamic and thermodynamic models. The results showed that the adsorption capacity of the adsorbent increased with increasing temperature and solid liquid ratio, but decreased with increasing initial Th(IV) ion concentration, and the best fit was obtained for the pseudo-second-order kinetics model. The calculated activation energy for adsorption was about 45 kJ/mol, which indicated the adsorption process to be chemisorption. The adsorption isotherm data could be well described by the Langmuir as well as Dubinin-Radushkevich model. The mean free energy (E) of adsorption was calculated to be about 15 kJ/mol. The thermodynamic data calculated showed that the adsorption was spontaneous and enhanced at higher temperature. Considering kinetics and equilibrium studies, the adsorption on the sites was the rate-limiting step and that adsorption was mainly a chemisorption process through cation exchange. (author)

Equilibrium, kinetic and thermodynamic studies of the biosorption of textile dye (Reactive Red 195) onto Pinus sylvestris L

International Nuclear Information System (INIS)

Aksakal, Ozkan; Ucun, Handan

2010-01-01

This study investigated the biosorption of Reactive Red 195 (RR 195), an azo dye, from aqueous solution by using cone biomass of Pinus sylvestris Linneo. To this end, pH, initial dye concentration, biomass dosage and contact time were studied in a batch biosorption system. Maximum pH for efficient RR 195 biosorption was found to be 1.0 and the initial RR 195 concentration increased with decreasing percentage removal. Biosorption capacity increased from 6.69 mg/g at 20 deg. C to 7.38 mg/g at 50 deg. C for 200 mg/L dye concentration. Kinetics of the interactions was tested by pseudo-first-order and pseudo-second-order kinetics, the Elovich equation and intraparticle diffusion mechanism. Pseudo-second-order kinetic model provided a better correlation for the experimental data studied in comparison to the pseudo-first-order kinetic model and intraparticle diffusion mechanism. Moreover, the Elovich equation also showed a good fit to the experimental data. Freundlich and Langmuir adsorption isotherms were used for the mathematical description of the biosorption equilibrium data. The activation energy of biosorption (Ea) was found to be 8.904 kJ/mol by using the Arrhenius equation. Using the thermodynamic equilibrium coefficients obtained at different temperatures, the study also evaluated the thermodynamic constants of biosorption (ΔG o , ΔH o and ΔS). The results indicate that cone biomass can be used as an effective and low-cost biosorbent to remove reactive dyes from aqueous solution.

Thermodynamic modelling and Gulliver-Scheil simulation of multi-component Al alloys

International Nuclear Information System (INIS)

Du Yong; Liu Shuhong; Chang, Keke; Hu Biao; Bu Mengjie; Jie Wanqi; Huang Weidong; Wang Jincheng

2012-01-01

Based on critical review for the available experimental phase diagram data of the Al-Cu-Fe-Mn, Al-Cu-Fe-Ni, Al-Cu-Fe-Si, Al-Fe-Mg-Si, Al-Fe-Mn-Si, and Al-Mg-Mn-Zn systems, a set of self-consistent thermodynamic parameters for these systems has been established using CALPHAD approach. In combination with the constituent binary, ternary, and quaternary systems, a thermodynamic database for the Al-Cu-Fe-Mg-Mn-Ni-Si-Zn system is developed. The calculated phase diagrams and invariant reactions agree well with the experimental data. The obtained database has been used to describe the solidification behaviour of Al alloys: Al365.1(91.95Al-0.46Fe-0.3Mg-0.32Mn-6.97Si, in wt.%) and Al365.2 (92.77Al-0.08Fe-0.35Mg-6.8Si, in wt.%) under both equilibrium and Gulliver-Scheil non-equilibrium conditions. The reliability of the present thermodynamic database is verified by the good agreement between calculation and measurement for both equilibrium and Gulliver–Scheil non-equilibrium solidification.

Advanced thermodynamics engineering

CERN Document Server

Annamalai, Kalyan; Jog, Milind A

2011-01-01

Thermolab Excel-Based Software for Thermodynamic Properties and Flame Temperatures of Fuels IntroductionImportance, Significance and LimitationsReview of ThermodynamicsMathematical BackgroundOverview of Microscopic/NanothermodynamicsSummaryAppendix: Stokes and Gauss Theorems First Law of ThermodynamicsZeroth LawFirst Law for a Closed SystemQuasi Equilibrium (QE) and Nonquasi-equilibrium (NQE) ProcessesEnthalpy and First LawAdiabatic Reversible Process for Ideal Gas with Constant Specific HeatsFirst Law for an Open SystemApplications of First Law for an Open SystemIntegral and Differential Form

Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters: Research updated.

Science.gov (United States)

Chang, Yingju; Lai, Juin-Yih; Lee, Duu-Jong

2016-12-01

The standard Gibbs free energy, enthalpy and entropy change data for adsorption equilibrium reported in biosorption literature during January 2013-May2016 were listed. Since the studied biosorption systems are all near-equilibrium processes, the enthalpy and entropy change data evaluated by fitting temperature-dependent free energy data using van Hoff's equation reveal a compensation artifact. Additional confusion is introduced with arbitrarily chosen adsorbate concentration unit in bulk solution that added free energy change of mixing into the reported free energy and enthalpy change data. Different standard states may be chosen for properly describing biosorption processes; however, this makes the general comparison between data from different systems inappropriate. No conclusion should be drawn based on unjustified thermodynamic parameters reported in biosorption studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermodynamics and proton activities of protic ionic liquids with quantum cluster equilibrium theory

Science.gov (United States)

Ingenmey, Johannes; von Domaros, Michael; Perlt, Eva; Verevkin, Sergey P.; Kirchner, Barbara

2018-05-01

We applied the binary Quantum Cluster Equilibrium (bQCE) method to a number of alkylammonium-based protic ionic liquids in order to predict boiling points, vaporization enthalpies, and proton activities. The theory combines statistical thermodynamics of van-der-Waals-type clusters with ab initio quantum chemistry and yields the partition functions (and associated thermodynamic potentials) of binary mixtures over a wide range of thermodynamic phase points. Unlike conventional cluster approaches that are limited to the prediction of thermodynamic properties, dissociation reactions can be effortlessly included into the bQCE formalism, giving access to ionicities, as well. The method is open to quantum chemical methods at any level of theory, but combination with low-cost composite density functional theory methods and the proposed systematic approach to generate cluster sets provides a computationally inexpensive and mostly parameter-free way to predict such properties at good-to-excellent accuracy. Boiling points can be predicted within an accuracy of 50 K, reaching excellent accuracy for ethylammonium nitrate. Vaporization enthalpies are predicted within an accuracy of 20 kJ mol-1 and can be systematically interpreted on a molecular level. We present the first theoretical approach to predict proton activities in protic ionic liquids, with results fitting well into the experimentally observed correlation. Furthermore, enthalpies of vaporization were measured experimentally for some alkylammonium nitrates and an excellent linear correlation with vaporization enthalpies of their respective parent amines is observed.

Modeling the Non-Equilibrium Process of the Chemical Adsorption of Ammonia on GaN(0001) Reconstructed Surfaces Based on Steepest-Entropy-Ascent Quantum Thermodynamics.

Science.gov (United States)

Kusaba, Akira; Li, Guanchen; von Spakovsky, Michael R; Kangawa, Yoshihiro; Kakimoto, Koichi

2017-08-15

Clearly understanding elementary growth processes that depend on surface reconstruction is essential to controlling vapor-phase epitaxy more precisely. In this study, ammonia chemical adsorption on GaN(0001) reconstructed surfaces under metalorganic vapor phase epitaxy (MOVPE) conditions (3Ga-H and N ad -H + Ga-H on a 2 × 2 unit cell) is investigated using steepest-entropy-ascent quantum thermodynamics (SEAQT). SEAQT is a thermodynamic-ensemble based, first-principles framework that can predict the behavior of non-equilibrium processes, even those far from equilibrium where the state evolution is a combination of reversible and irreversible dynamics. SEAQT is an ideal choice to handle this problem on a first-principles basis since the chemical adsorption process starts from a highly non-equilibrium state. A result of the analysis shows that the probability of adsorption on 3Ga-H is significantly higher than that on N ad -H + Ga-H. Additionally, the growth temperature dependence of these adsorption probabilities and the temperature increase due to the heat of reaction is determined. The non-equilibrium thermodynamic modeling applied can lead to better control of the MOVPE process through the selection of preferable reconstructed surfaces. The modeling also demonstrates the efficacy of DFT-SEAQT coupling for determining detailed non-equilibrium process characteristics with a much smaller computational burden than would be entailed with mechanics-based, microscopic-mesoscopic approaches.

Direct evidence of departure from local thermodynamic equilibrium in a free-burning arc-discharge plasma

International Nuclear Information System (INIS)

Snyder, S.C.; Lassahn, G.D.; Reynolds, L.D.

1993-01-01

Radial profiles of gas temperature, electron temperature, and electron density were measured in a free-burning atmospheric-pressure argon arc-discharge plasma using line-shape analysis of scattered laser light. This method yields gas temperature, electron temperature, and electron density directly, with no reliance on the assumption of local thermodynamic equilibrium (LTE). Our results show a significant departure from LTE in the center of the discharge, contrary to expectations

Quantum thermodynamics. Emergence of thermodynamic behavior within composite quantum systems. 2. ed.

International Nuclear Information System (INIS)

Gemmer, Jochen; Michel, M.; Mahler, Guenter

2009-01-01

This introductory text treats thermodynamics as an incomplete description of quantum systems with many degrees of freedom. Its main goal is to show that the approach to equilibrium -with equilibrium characterized by maximum ignorance about the open system of interest- neither requires that many particles nor is the precise way of partitioning, relevant for the salient features of equilibrium and equilibration. Furthermore, the text depicts that it is indeed quantum effects that are at work in bringing about thermodynamic behavior of modest-sized open systems, thus making Von Neumann's concept of entropy appear much more widely useful than sometimes feared, far beyond truly macroscopic systems in equilibrium. This significantly revised and expanded second edition pays more attention to the growing number of applications, especially non-equilibrium phenomena and thermodynamic processes of the nano-domain. In addition, to improve readability and reduce unneeded technical details, a large portion of this book has been thoroughly rewritten. (orig.)

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.)

Thermodynamic versus non-equilibrium stability of palmitic acid monolayers in calcium-enriched sea spray aerosol proxy systems.

Science.gov (United States)

Wellen Rudd, Bethany A; Vidalis, Andrew S; Allen, Heather C

2018-04-16

Of the major cations in seawater (Na+, Mg2+, Ca2+, K+), Ca2+ is found to be the most enriched in fine sea spray aerosols (SSA). In this work, we investigate the binding of Ca2+ to the carboxylic acid headgroup of palmitic acid (PA), a marine-abundant fatty acid, and the impact such binding has on the stability of PA monolayers in both equilibrium and non-equilibrium systems. A range of Ca2+ conditions from 10 μM to 300 mM was utilized to represent the relative concentration of Ca2+ in high and low relative humidity aerosol environments. The CO2- stretching modes of PA detected by surface-sensitive infrared reflection-absorption spectroscopy (IRRAS) reveal ionic binding motifs of the Ca2+ ion to the carboxylate group with varying degrees of hydration. Surface tensiometry was used to determine the thermodynamic equilibrium spreading pressure (ESP) of PA on the various aqueous CaCl2 subphases. Up to concentrations of 1 mM Ca2+, each system reached equilibrium, and Ca2+:PA surface complexation gave rise to a lower energy state revealed by elevated surface pressures relative to water. We show that PA films are not thermodynamically stable at marine aerosol-relevant Ca2+ concentrations ([Ca2+] ≥ 10 mM). IRRAS and vibrational sum frequency generation (VSFG) spectroscopy were used to investigate the surface presence of PA on high concentration Ca2+ aqueous subphases. Non-equilibrium relaxation (NER) experiments were also conducted and monitored by Brewster angle microscopy (BAM) to determine the effect of the Ca2+ ions on PA stability. At high surface pressures, the relaxation mechanisms of PA varied among the systems and were dependent on Ca2+ concentration.

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.

Thermodynamic and structure-property study of liquid-vapor equilibrium for aroma compounds.

Science.gov (United States)

Tromelin, Anne; Andriot, Isabelle; Kopjar, Mirela; Guichard, Elisabeth

2010-04-14

Thermodynamic parameters (T, DeltaH degrees , DeltaS degrees , K) were collected from the literature and/or calculated for five esters, four ketones, two aldehydes, and three alcohols, pure compounds and compounds in aqueous solution. Examination of correlations between these parameters and the range values of DeltaH degrees and DeltaS degrees puts forward the key roles of enthalpy for vaporization of pure compounds and of entropy in liquid-vapor equilibrium of compounds in aqueous solution. A structure-property relationship (SPR) study was performed using molecular descriptors on aroma compounds to better understand their vaporization behavior. In addition to the role of polarity for vapor-liquid equilibrium of compounds in aqueous solution, the structure-property study points out the role of chain length and branching, illustrated by the correlation between the connectivity index CHI-V-1 and the difference between T and log K for vaporization of pure compounds and compounds in aqueous solution. Moreover, examination of the esters' enthalpy values allowed a probable conformation adopted by ethyl octanoate in aqueous solution to be proposed.

Statistical thermodynamics

International Nuclear Information System (INIS)

Lim, Gyeong Hui

2008-03-01

This book consists of 15 chapters, which are basic conception and meaning of statistical thermodynamics, Maxwell-Boltzmann's statistics, ensemble, thermodynamics function and fluctuation, statistical dynamics with independent particle system, ideal molecular system, chemical equilibrium and chemical reaction rate in ideal gas mixture, classical statistical thermodynamics, ideal lattice model, lattice statistics and nonideal lattice model, imperfect gas theory on liquid, theory on solution, statistical thermodynamics of interface, statistical thermodynamics of a high molecule system and quantum statistics

Early history of extended irreversible thermodynamics (1953-1983): An exploration beyond local equilibrium and classical transport theory

Science.gov (United States)

Lebon, G.; Jou, D.

2015-06-01

This paper gives a historical account of the early years (1953-1983) of extended irreversible thermodynamics (EIT). The salient features of this formalism are to upgrade the thermodynamic fluxes of mass, momentum, energy, and others, to the status of independent variables, and to explore the consistency between generalized transport equations and a generalized version of the second law of thermodynamics. This requires going beyond classical irreversible thermodynamics by redefining entropy and entropy flux. EIT provides deeper foundations, closer relations with microscopic formalisms, a wider spectrum of applications, and a more exciting conceptual appeal to non-equilibrium thermodynamics. We first recall the historical contributions by Maxwell, Cattaneo, and Grad on generalized transport equations. A thermodynamic theory wide enough to cope with such transport equations was independently proposed between 1953 and 1983 by several authors, each emphasizing different kinds of problems. In 1983, the first international meeting on this theory took place in Bellaterra (Barcelona). It provided the opportunity for the various authors to meet together for the first time and to discuss the common points and the specific differences of their previous formulations. From then on, a large amount of applications and theoretical confirmations have emerged. From the historical point of view, the emergence of EIT has been an opportunity to revisit the foundations and to open new avenues in thermodynamics, one of the most classical and well consolidated physical theories.

A conservative multicomponent diffusion algorithm for ambipolar plasma flows in local thermodynamic equilibrium

International Nuclear Information System (INIS)

Peerenboom, Kim; Van Boxtel, Jochem; Janssen, Jesper; Van Dijk, Jan

2014-01-01

The usage of the local thermodynamic equilibrium (LTE) approximation can be a very powerful assumption for simulations of plasmas in or close to equilibrium. In general, the elemental composition in LTE is not constant in space and effects of mixing and demixing have to be taken into account using the Stefan–Maxwell diffusion description. In this paper, we will introduce a method to discretize the resulting coupled set of elemental continuity equations. The coupling between the equations is taken into account by the introduction of the concept of a Péclet matrix. It will be shown analytically and numerically that the mass and charge conservation constraints can be fulfilled exactly. Furthermore, a case study is presented to demonstrate the applicability of the method to a simulation of a mercury-free metal-halide lamp. The source code for the simulations presented in this paper is provided as supplementary material (stacks.iop.org/JPhysD/47/425202/mmedia). (paper)

Use of the SSF equations in the Kojima-Moon-Ochi thermodynamic consistency test of isothermal vapour-liquid equilibrium data

Directory of Open Access Journals (Sweden)

SLOBODAN P. SERBANOVIC

2000-12-01

Full Text Available The Kojima-Moon-Ochi (KMO thermodynamic consistency test of vapour–liquid equilibrium (VLE measurements for 32 isothermal data sets of binary systems of various complexity was applied using two fitting equations: the Redlich-Kister equation and the Sum of Symmetrical Functions. It was shown that the enhanced reliability of the fitting of the experimental data can change the conclusions drawn on their thermodynamic consistency in those cases of VLE data sets that are estimated to be near the border of consistency.

Thermodynamic approach to biomass gasification

International Nuclear Information System (INIS)

Boissonnet, G.; Seiler, J.M.

2003-01-01

The document presents an approach of biomass transformation in presence of steam, hydrogen or oxygen. Calculation results based on thermodynamic equilibrium are discussed. The objective of gasification techniques is to increase the gas content in CO and H 2 . The maximum content in these gases is obtained when thermodynamic equilibrium is approached. Any optimisation action of a process. will, thus, tend to approach thermodynamic equilibrium conditions. On the other hand, such calculations can be used to determine the conditions which lead to an increase in the production of CO and H 2 . An objective is also to determine transformation enthalpies that are an important input for process calculations. Various existing processes are assessed, and associated thermodynamic limitations are evidenced. (author)

Friction-induced vibrations and self-organization mechanics and non-equilibrium thermodynamics of sliding contact

CERN Document Server

Nosonovsky, Michael

2013-01-01

Many scientists and engineers do not realize that, under certain conditions, friction can lead to the formation of new structures at the interface, including in situ tribofilms and various patterns. In turn, these structures-usually formed by destabilization of the stationary sliding regime-can lead to the reduction of friction and wear. Friction-Induced Vibrations and Self-Organization: Mechanics and Non-Equilibrium Thermodynamics of Sliding Contact combines the mechanical and thermodynamic methods in tribology, thus extending the field of mechanical friction-induced vibrations to non-mechanical instabilities and self-organization processes at the frictional interface. The book also relates friction-induced self-organization to novel biomimetic materials, such as self-lubricating, self-cleaning, and self-healing materials. Explore Friction from a Different Angle-as a Fundamental Force of Nature The book begins with an exploration of friction as a fundamental force of nature throughout the history of science....

Correspondence between EQ-5D health state classifications and EQ VAS scores

Directory of Open Access Journals (Sweden)

Whynes David K

2008-11-01

Full Text Available Abstract Background The EQ-5D health-related quality of life instrument comprises a health state classification followed by a health evaluation using a visual analogue scale (VAS. The EQ-5D has been employed frequently in economic evaluations, yet the relationship between the two parts of the instrument remains ill-understood. In this paper, we examine the correspondence between VAS scores and health state classifications for a large sample, and identify variables which contribute to determining the VAS scores independently of the health states as classified. Methods A UK trial of management of low-grade abnormalities detected on screening for cervical pre-cancer (TOMBOLA provided EQ-5D data for over 3,000 women. Information on distress and multi-dimensional health locus of control had been collected using other instruments. A linear regression model was fitted, with VAS score as the dependent variable. Independent variables comprised EQ-5D health state classifications, distress, locus of control, and socio-demographic characteristics. Equivalent EQ-5D and distress data, collected at twelve months, were available for over 2,000 of the women, enabling us to predict changes in VAS score over time from changes in EQ-5D classification and distress. Results In addition to EQ-5D health state classification, VAS score was influenced by the subject's perceived locus of control, and by her age, educational attainment, ethnic origin and smoking behaviour. Although the EQ-5D classification includes a distress dimension, the independent measure of distress was an additional determinant of VAS score. Changes in VAS score over time were explained by changes in both EQ-5D severities and distress. Women allocated to the experimental management arm of the trial reported an increase in VAS score, independently of any changes in health state and distress. Conclusion In this sample, EQ VAS scores were predictable from the EQ-5D health state classification, although

Complexation (cucurbit[6]uril-pyrene): Thermodynamic and spectroscopic properties

Energy Technology Data Exchange (ETDEWEB)

Sueldo Occello, Valeria N.; Rossi, Rita H. de; Veglia, Alicia V., E-mail: aveglia@fcq.unc.edu.ar

2015-02-15

The influence of the macrocyclic compound cucurbit[6]uril (CB6) on the photophysical properties of the fluorophore pyrene (PYR) has been studied. Guest–host interaction was observed by UV–visible spectroscopy and spectrofluorimetry. The fluorescence of PYR was significantly increased in the presence of CB6. The binding equilibrium constants for the complex with 1:1 stoichiometry were determined in HCOOH 55% w/v. The values of the association constants, K{sub A}, and the fluorescence quantum yield ratios between complexed and free substrate, ϕ{sup PYR–CB6}/ϕ{sup PYR}, at different temperatures were (3.1±0.9)×10{sup 2} M{sup −1} and (5.1±0.2), (3.6±0.5)×10{sup 2} M{sup −1} and (5.9±0.1), (4.8±0.7)×10{sup 2} M{sup −1} and (5.5±0.1) at 15.0 °C, 25.0 °C and 40.0 °C, respectively. The enthalpic and entropic contributions to the complexation process were determined, yielding ΔS=(92±3) J mol{sup −1} K{sup −1} and ΔH=(13±1) kJ mol{sup −1}. From these results it can be concluded that the complex formation is mainly driven by the entropic term. The forces involved in the complexation are interpreted from the sign and magnitude of the thermodynamic parameters obtained. The partial inclusion of PYR or the formation of a suspended complex is proposed in base of all the data. The interaction is also demonstrated in the solid state by differential scanning calorimetric (DSC) measurements. - Highlights: • The cucurbit[6]uril (CB6) effects on the absorption and fluorescence of pyrene (PYR) were analyzed. • The association constant (K{sub A}) and the stoichiometry of the complex were determined. • The complex formation was confirmed by differential scanning calorimetry (DSC). • The thermodynamic parameters were determined. • The hydrophobic entropic contribution is the main driving force for the PYR–CB6 complex formation.

Geochemical modeling (EQ3/6) plan: Office of Civilian Radioactive Waste Management Program

International Nuclear Information System (INIS)

McKenzie, W.F.; Wolery, T.J.; Delany, J.M.; Silva, R.J.; Jackson, K.J.; Bourcier, W.L.; Emerson, D.O.

1986-01-01

This plan replaces an earlier plan for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. It includes activities for all repository projects in the Office of Geologic Repositories: NNWSI, the Basalt Waste Isolation Project, the Salt Repository Project, and the Crystalline Project. Each of these projects is part of the Office of Civilian Radioactive Waste Management (OCRWM) Program. The scope of work for fiscal years 1986 to 1992 includes the work required to upgrade the geochemical codes and supporting data bases, to permit modeling of chemical processes associated with nuclear waste repositories in four geological environments: tuff, salt, basalt, and crystalline rock. Planned tasks include theoretical studies and code development to take account of the effects of precipitation kinetics, sorption, solid solutions, glass/water interactions, variable gas fugacities, and simple mass transport. Recent progress has been made in the ability of the codes to account for precipitation kinetics, highly-saline solutions, and solid solutions. Transition state theory was re-examined resulting in new insights that will provide the foundation for further improvements necessary to model chemical kinetics. Currently there is an increased effort that is concentrated on the supporting data base. For aqueous species and solid phases, specific to nuclear waste, requisite thermodynamic values reported in the literature are being evaluated and for cases where essential data is lacking, laboratory measurements will be carried out. Significant modifications and expansions have been made to the data base. During FY86, the total number of species in the data base has almost doubled and many improvements have been made with regard to consistency, organization, user applications, and documentation. Two Ridge computers using a RISC implementation of UNIX were installed; they are completely dedicated EQ3/6 machines

Geochemical modeling (EQ3/6) plan: Office of Civilian Radioactive Waste Management Program

Energy Technology Data Exchange (ETDEWEB)

McKenzie, W.F.; Wolery, T.J.; Delany, J.M.; Silva, R.J.; Jackson, K.J.; Bourcier, W.L.; Emerson, D.O.

1986-08-28

This plan replaces an earlier plan for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. It includes activities for all repository projects in the Office of Geologic Repositories: NNWSI, the Basalt Waste Isolation Project, the Salt Repository Project, and the Crystalline Project. Each of these projects is part of the Office of Civilian Radioactive Waste Management (OCRWM) Program. The scope of work for fiscal years 1986 to 1992 includes the work required to upgrade the geochemical codes and supporting data bases, to permit modeling of chemical processes associated with nuclear waste repositories in four geological environments: tuff, salt, basalt, and crystalline rock. Planned tasks include theoretical studies and code development to take account of the effects of precipitation kinetics, sorption, solid solutions, glass/water interactions, variable gas fugacities, and simple mass transport. Recent progress has been made in the ability of the codes to account for precipitation kinetics, highly-saline solutions, and solid solutions. Transition state theory was re-examined resulting in new insights that will provide the foundation for further improvements necessary to model chemical kinetics. Currently there is an increased effort that is concentrated on the supporting data base. For aqueous species and solid phases, specific to nuclear waste, requisite thermodynamic values reported in the literature are being evaluated and for cases where essential data is lacking, laboratory measurements will be carried out. Significant modifications and expansions have been made to the data base. During FY86, the total number of species in the data base has almost doubled and many improvements have been made with regard to consistency, organization, user applications, and documentation. Two Ridge computers using a RISC implementation of UNIX were installed; they are completely dedicated EQ3/6 machines.

Viscous behavior of (Sn{sub 61.9}Pb{sub 38.1}){sub 100-x}RE{sub x} (x=0, 0.1, 0.3, 1 wt%) solder alloys

Energy Technology Data Exchange (ETDEWEB)

Wu Yuqin [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University (Southern Campus), 73 Jingshi Road, Jinan 250061 (China); Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University (Southern Campus), 73 Jingshi Road, Jinan 250061 (China)], E-mail: xfbian@sdu.edu.cn; Zhao Yan; Li Xuelian; Zhang Yanning; Tian Yongsheng; Lv Xiaoqian [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University (Southern Campus), 73 Jingshi Road, Jinan 250061 (China)

2008-05-19

The viscous behavior of (Sn{sub 61.9}Pb{sub 38.1}){sub 100-x}RE{sub x} (x=0, 0.1, 0.3, 1 wt%) solder alloys has been investigated by a torsional oscillation viscometer. The structural transition temperature T{sup '} increases with increasing addition of RE elements. Above T{sup '}, the viscosities of melts increase with increasing addition of RE, and are fitted well with the Arrhenius equation. The time dependence of viscosity at the measured temperature below T{sup '} follows the exponential relaxation function and reflects the process of the structural transition in the melt, which can be considered as the thermodynamic equilibrium process. The thermodynamic equilibrium relaxation time {tau}{sub eq} increases with both the equilibrium viscosity {eta}{sub eq} and the discrepancy in viscosity ({delta}{eta}), between the initial state and the equilibrium state. However, it decreases with the measured temperature T. The size of clusters in the melts increases with increasing of viscosity and is restricted by the thermodynamic equilibrium conditions.

The Use of VMD Data/Model to Test Different Thermodynamic Models for Vapour-Liquid Equilibrium

DEFF Research Database (Denmark)

Abildskov, Jens; Azquierdo-Gil, M.A.; Jonsson, Gunnar Eigil

2004-01-01

Vacuum membrane distillation (VMD) has been studied as a separation process to remove volatile organic compounds from aqueous streams. A vapour pressure difference across a microporous hydrophobic membrane is the driving force for the mass transport through the membrane pores (this transport take...... place in vapour phase). The vapour pressure difference is obtained in VMD processes by applying a vacuum on one side of the membrane. The membrane acts as a mere support for the liquid-vapour equilibrium. The evaporation of the liquid stream takes place on the feed side of the membrane...... values; membrane type: PTFE/PP/PVDF; feed flow rate; feed temperature. A comparison is made between different thermodynamic models for calculating the vapour-liquid equilibrium at the membrane/pore interface. (C) 2004 Elsevier B.V. All rights reserved....

Distance-dependent diffusion-controlled reaction of •NO and O2•- at chemical equilibrium with ONOO-.

Science.gov (United States)

Botti, Horacio; Möller, Matías N; Steinmann, Daniel; Nauser, Thomas; Koppenol, Willem H; Denicola, Ana; Radi, Rafael

2010-12-16

The fast reaction of (•)NO and O(2)(•-) to give ONOO(-) has been extensively studied at irreversible conditions, but the reasons for the wide variations in observed forward rate constants (3.8 ≤ k(f) ≤ 20 × 10(9) M(-1) s(-1)) remain unexplained. We characterized the diffusion-dependent aqueous (pH > 12) chemical equilibrium of the form (•)NO + O(2)(•-) = ONOO(-) with respect to its dependence on temperature, viscosity, and [ONOO(-)](eq) by determining [ONOO(-)](eq) and [(•)NO](eq). The equilibrium forward reaction rate constant (k(f)(eq)) has negative activation energy, in contrast to that found under irreversible conditions. In contradiction to the law of mass action, we demonstrate that the equilibrium constant depends on ONOO(-) concentration. Therefore, a wide range of k(f)(eq) values could be derived (7.5-21 × 10(9) M(-1) s(-1)). Of general interest, the variations in k(f) can thus be explained by its dependence on the distance between ONOO(-) particles (sites of generation of (•)NO and O(2)(•-)).

Adsorption of cadmium from aqueous solution onto untreated coffee grounds: Equilibrium, kinetics and thermodynamics

Energy Technology Data Exchange (ETDEWEB)

Azouaou, N., E-mail: azouaou20@yahoo.fr [Laboratory of Reaction Genius, Faculty of Mechanical and Processes Genius, University of Sciences and Technology Houari - Boumediene, USTHB, BP no 32 El Alia bab ezzouar, 16111 Algiers (Algeria); Sadaoui, Z. [Laboratory of Reaction Genius, Faculty of Mechanical and Processes Genius, University of Sciences and Technology Houari - Boumediene, USTHB, BP no 32 El Alia bab ezzouar, 16111 Algiers (Algeria); Djaafri, A. [Central laboratory, SEAAL, 97 Parc ben omar, Kouba, Algiers (Algeria); Mokaddem, H. [Laboratory of Reaction Genius, Faculty of Mechanical and Processes Genius, University of Sciences and Technology Houari - Boumediene, USTHB, BP no 32 El Alia bab ezzouar, 16111 Algiers (Algeria)

2010-12-15

Adsorption can be used as a cost effective and efficient technique for the removal of toxic heavy metals from wastewater. Waste materials with no further treatment such as coffee grounds from cafeterias may act as adsorbents for the removal of cadmium. Batch kinetic and equilibrium experiments were conducted to study the effects of contact time, adsorbent dose, initial pH, particle size, initial concentration of cadmium and temperature. Three adsorption isotherm models namely, Langmuir, Freundlich and Dubinin-Radushkevich were used to analyse the equilibrium data. The Langmuir isotherm which provided the best correlation for Cd{sup 2+} adsorption onto coffee grounds, shows that the adsorption was favourable and the adsorption capacity found was equal to 15.65 mg g{sup -1}. Thermodynamic parameters were evaluated and the adsorption was exothermic. The equilibrium was achieved less than 120 min. The adsorption kinetic data was fitted with first and second order kinetic models. Finally it was concluded that the cadmium adsorption kinetic onto coffee grounds was well fitted by second order kinetic model rather than first order model. The results suggest that coffee grounds have high possibility to be used as effective and economical adsorbent for Cd{sup 2+} removal.

Adsorption of cadmium from aqueous solution onto untreated coffee grounds: Equilibrium, kinetics and thermodynamics

International Nuclear Information System (INIS)

Azouaou, N.; Sadaoui, Z.; Djaafri, A.; Mokaddem, H.

2010-01-01

Adsorption can be used as a cost effective and efficient technique for the removal of toxic heavy metals from wastewater. Waste materials with no further treatment such as coffee grounds from cafeterias may act as adsorbents for the removal of cadmium. Batch kinetic and equilibrium experiments were conducted to study the effects of contact time, adsorbent dose, initial pH, particle size, initial concentration of cadmium and temperature. Three adsorption isotherm models namely, Langmuir, Freundlich and Dubinin-Radushkevich were used to analyse the equilibrium data. The Langmuir isotherm which provided the best correlation for Cd 2+ adsorption onto coffee grounds, shows that the adsorption was favourable and the adsorption capacity found was equal to 15.65 mg g -1 . Thermodynamic parameters were evaluated and the adsorption was exothermic. The equilibrium was achieved less than 120 min. The adsorption kinetic data was fitted with first and second order kinetic models. Finally it was concluded that the cadmium adsorption kinetic onto coffee grounds was well fitted by second order kinetic model rather than first order model. The results suggest that coffee grounds have high possibility to be used as effective and economical adsorbent for Cd 2+ removal.

Considerations on non equilibrium thermodynamics of interactions

Science.gov (United States)

Lucia, Umberto

2016-04-01

Nature can be considered the ;first; engineer! For scientists and engineers, dynamics and evolution of complex systems are not easy to predict. A fundamental approach to study complex system is thermodynamics. But, the result is the origin of too many schools of thermodynamics with a consequent difficulty in communication between thermodynamicists and other scientists and, also, among themselves. The solution is to obtain a unified approach based on the fundamentals of physics. Here we suggest a possible unification of the schools of thermodynamics starting from two fundamental concepts of physics, interaction and flows.

Analysis of radioactive-matter interaction near thermodynamical equilibrium states

International Nuclear Information System (INIS)

Damamme, G.

1993-01-01

We study the absorption/emission process of photon by matter in the framework of a radiativo-collisionnal model of atom, a thermodynamical approach being used. The considered matter description is the atomic sphere one. First we give the expression of the balance equation around an equilibrium state. Then we express the atomic populations in function of the characteristics of the radiation and of the free electrons and of their time history. This permit us to interpret the photon balance as being due to true emission/absorption process of photons as well as fluorescence terms, all these processes being affected by relaxation effects. The total energy balance between matter and radiation can also be analyzed in the same way and conduct to introduce one photon effective interactions terms for each radiative proper mode, terms also affected by retardation effects. Such a taking into account of atom populations has no consequence on the radiative flux equation (i.e. the transfer opacity) but can considerably modify the energy balance between matter and radiation. (author). 11 refs., 3 figs

Application of the thermodynamic extremal principle to phase-field modeling of non-equilibrium solidification in multi-component alloys

International Nuclear Information System (INIS)

Zhang, Xiao; Wang, Haifeng; Kuang, Wangwang; Zhang, Jianbao

2017-01-01

Modeling of non-equilibrium solidification in multi-component alloys is of singular importance in microstructure control, which however owing to the complex systems with complex additional constraints is still an open problem. In this work, the thermodynamic extremal principle was applied to solve the complex additional constraints self-consistently in thermodynamics. Consequently, short-range solute redistribution and long-range solute diffusion that share the same mobility are integrated naturally into the solute diffusion equations, thus avoiding the introduction of additional kinetic coefficients (e.g. interface permeability) to describe solute redistribution. Application to the non-equilibrium solidification of Al-Si-Cu alloys shows that anomalous solute trapping and anomalous solute profiles within the diffuse interface could occur, thus highlighting the important effect of the interaction among the component elements on the interface kinetics. The current phase-field model might be preferred for simulations not only because of its simplest form of evolution equations but also its feasibility to increase the simulation efficiency by the “thin interface limit” analysis.

Thermodynamic equilibrium solubility measurements in simulated fluids by 96-well plate method in early drug discovery.

Science.gov (United States)

Bharate, Sonali S; Vishwakarma, Ram A

2015-04-01

An early prediction of solubility in physiological media (PBS, SGF and SIF) is useful to predict qualitatively bioavailability and absorption of lead candidates. Despite of the availability of multiple solubility estimation methods, none of the reported method involves simplified fixed protocol for diverse set of compounds. Therefore, a simple and medium-throughput solubility estimation protocol is highly desirable during lead optimization stage. The present work introduces a rapid method for assessment of thermodynamic equilibrium solubility of compounds in aqueous media using 96-well microplate. The developed protocol is straightforward to set up and takes advantage of the sensitivity of UV spectroscopy. The compound, in stock solution in methanol, is introduced in microgram quantities into microplate wells followed by drying at an ambient temperature. Microplates were shaken upon addition of test media and the supernatant was analyzed by UV method. A plot of absorbance versus concentration of a sample provides saturation point, which is thermodynamic equilibrium solubility of a sample. The established protocol was validated using a large panel of commercially available drugs and with conventional miniaturized shake flask method (r(2)>0.84). Additionally, the statistically significant QSPR models were established using experimental solubility values of 52 compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermodynamic models for determination of solid–liquid equilibrium of the 6-benzyladenine in pure and binary organic solvents

International Nuclear Information System (INIS)

Li, Tao; Deng, Renlun; Wu, Gang; Gu, Pengfei; Hu, Yonghong; Yang, Wenge; Yu, Yemin; Zhang, Yuhao; Yang, Chen

2017-01-01

Highlights: • The solubility increased with increasing temperature. • Data were fitted using the modified Apelblat equation and other models in pure solvents. • Data were fitted using the modified Apelblat equation and other models in binary solvent mixture. - Abstract: Data on corresponding solid–liquid equilibrium of 6-benzyladenine in different solvents are essential for a preliminary study of industrial applications. In this paper, the solid–liquid equilibrium of 6-benzyladenine in methanol, ethanol, 1-butanol, acetone, acetonitrile, ethyl acetate, dimethyl formamide and tetrahydrofuran pure solvents and (dimethyl formamide + actone) mixture solvents was explored within the temperature range from (278.15 to 333.15) K under 0.1 MPa. For the temperature range investigated, the solubility of 6-benzyladenine in the solvents increased with increasing temperature. The solubility of 6-benzyladenine in dimethyl formamide is superior to other selected pure solvents. The modified Apelblat model, the Buchowski-Ksiazaczak λh model, and the ideal model were adopted to describe and predict the change tendency of solubility. Computational results showed that the modified Apelblat model has more advantages than the other two models. The solubility results were fitted using a modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redich-Kister (CNIBS/R-K) model, Jouyban-Acree model and Ma model in (dimethyl formamide + acetone) binary solvent mixture. Computational results showed that the modified Apelblat model is superior to the other equations.

Local Thermodynamic Equilibrium in Laser-Induced Breakdown Spectroscopy: Beyond the McWhirter criterion

International Nuclear Information System (INIS)

Cristoforetti, G.; De Giacomo, A.; Dell'Aglio, M.; Legnaioli, S.; Tognoni, E.; Palleschi, V.; Omenetto, N.

2010-01-01

In the Laser-Induced Breakdown Spectroscopy (LIBS) technique, the existence of Local Thermodynamic Equilibrium (LTE) is the essential requisite for meaningful application of theoretical Boltzmann-Maxwell and Saha-Eggert expressions that relate fundamental plasma parameters and concentration of analyte species. The most popular criterion reported in the literature dealing with plasma diagnostics, and usually invoked as a proof of the existence of LTE in the plasma, is the McWhirter criterion [R.W.P. McWhirter, in: Eds. R.H. Huddlestone, S.L. Leonard, Plasma Diagnostic Techniques, Academic Press, New York, 1965, pp. 201-264]. However, as pointed out in several papers, this criterion is known to be a necessary but not a sufficient condition to insure LTE. The considerations reported here are meant to briefly review the theoretical analysis underlying the concept of thermodynamic equilibrium and the derivation of the McWhirter criterion, and to critically discuss its application to a transient and non-homogeneous plasma, like that created by a laser pulse on solid targets. Specific examples are given of theoretical expressions involving relaxation times and diffusion coefficients, as well as a discussion of different experimental approaches involving space and time-resolved measurements that could be used to complement a positive result of the calculation of the minimum electron number density required for LTE using the McWhirter formula. It is argued that these approaches will allow a more complete assessment of the existence of LTE and therefore permit a better quantitative result. It is suggested that the mere use of the McWhirter criterion to assess the existence of LTE in laser-induced plasmas should be discontinued.

A Laser Induced Breakdown Spectroscopy application based on Local Thermodynamic Equilibrium assumption for the elemental analysis of alexandrite gemstone and copper-based alloys

Energy Technology Data Exchange (ETDEWEB)

De Giacomo, A. [Department of Chemistry, University of Bari, Via Orabona 4, 70126 Bari (Italy); Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Dell' Aglio, M. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Gaudiuso, R., E-mail: rosalba.gaudiuso@ba.imip.cnr.it [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Santagata, A. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Potenza, Via S. Loja, Zona Ind., 85050 Tito Scalo (PZ) (Italy); Senesi, G.S. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Rossi, M.; Ghiara, M.R. [Department of Earth Sciences, University of Naples ' Federico II' , Via Mezzocannone 8, 80134 Naples (Italy); Capitelli, F. [Institute of Crystallography - CNR, Via Salaria Km 29.300, 00015 Monterotondo (Roma) (Italy); De Pascale, O. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy)

2012-04-04

Graphical abstract: Self-calibrated analytical techniques based on the approximation of Local Thermodynamic Equilibrium (LTE) have been employed for the analysis of gemstones and copper-based alloys by LIBS (Laser Induced Breakdown Spectroscopy), with a special focus on LTE conditions in laser induced plasmas. Highlights: Black-Right-Pointing-Pointer Discussion of Local Thermodynamic Equilibrium (LTE) condition in laser-induced plasmas. Black-Right-Pointing-Pointer LIBS enables elemental analysis with self-calibrated LTE-based methods. Black-Right-Pointing-Pointer Be detection in alexandrite gemstone is made possible by LIBS. - Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is an appealing technique to study laser-induced plasmas (LIPs), both from the basic diagnostics point of view and for analytical applications. LIPs are complex dynamic systems, expanding at supersonic velocities and undergoing a transition between different plasma regimes. If the Local Thermodynamic Equilibrium (LTE) condition is valid for such plasmas, several analytical methods can be employed and fast quantitative analyses can be performed on a variety of samples. In the present paper, a discussion about LTE is carried out and an innovative application to the analysis of the alexandrite gemstone is presented. In addition, a study about the influence of plasma parameters on the performance of LTE-based methods is reported for bronze and brass targets.

Local thermodynamic equilibrium in rapidly heated high energy density plasmas

International Nuclear Information System (INIS)

Aslanyan, V.; Tallents, G. J.

2014-01-01

Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance

Thermodynamic Equilibrium Calculations on Cd Transformation during Sewage Sludge Incineration.

Science.gov (United States)

Liu, Jing-yong; Huang, Limao; Sun, Shuiyu; Ning, Xun'an; Kuo, Jiahong; Sun, Jian; Wang, Yujie; Xie, Wuming

2016-06-01

Thermodynamic equilibrium calculations were performed to reveal the distribution of cadmium during the sewage sludge incineration process. During sludge incineration in the presence of major minerals, such as SiO2, Al2O3 and CaO, the strongest effect was exerted by SiO2 on the Cd transformation compared with the effect of others. The stable solid product of CdSiO3 was formed easily with the reaction between Cd and SiO2, which can restrain the emissions of gaseous Cd pollutants. CdCl2 was formed more easily in the presence of chloride during incineration, thus, the volatilization of Cd was advanced by increasing chlorine content. At low temperatures, the volatilization of Cd was restrained due to the formation of the refractory solid metal sulfate. At high temperatures, the speciation of Cd was not affected by the presence of sulfur, but sulfur could affect the formation temperature of gaseous metals.

Thermodynamics of Radiation Modes

Science.gov (United States)

Pina, Eduardo; de la Selva, Sara Maria Teresa

2010-01-01

We study the equilibrium thermodynamics of the electromagnetic radiation in a cavity of a given volume and temperature. We found three levels of description, the thermodynamics of one mode, the thermodynamics of the distribution of frequencies in a band by summing over the frequencies in it and the global thermodynamics by summing over all the…

Contact Geometry of Mesoscopic Thermodynamics and Dynamics

Directory of Open Access Journals (Sweden)

Miroslav Grmela

2014-03-01

Full Text Available The time evolution during which macroscopic systems reach thermodynamic equilibrium states proceeds as a continuous sequence of contact structure preserving transformations maximizing the entropy. This viewpoint of mesoscopic thermodynamics and dynamics provides a unified setting for the classical equilibrium and nonequilibrium thermodynamics, kinetic theory, and statistical mechanics. One of the illustrations presented in the paper is a new version of extended nonequilibrium thermodynamics with fluxes as extra state variables.

A consistent model for the equilibrium thermodynamic functions of partially ionized flibe plasma with Coulomb corrections

International Nuclear Information System (INIS)

Zaghloul, Mofreh R.

2003-01-01

Flibe (2LiF-BeF2) is a molten salt that has been chosen as the coolant and breeding material in many design studies of the inertial confinement fusion (ICF) chamber. Flibe plasmas are to be generated in the ICF chamber in a wide range of temperatures and densities. These plasmas are more complex than the plasma of any single chemical species. Nevertheless, the composition and thermodynamic properties of the resulting flibe plasmas are needed for the gas dynamics calculations and the determination of other design parameters in the ICF chamber. In this paper, a simple consistent model for determining the detailed plasma composition and thermodynamic functions of high-temperature, fully dissociated and partially ionized flibe gas is presented and used to calculate different thermodynamic properties of interest to fusion applications. The computed properties include the average ionization state; kinetic pressure; internal energy; specific heats; adiabatic exponent, as well as the sound speed. The presented results are computed under the assumptions of local thermodynamic equilibrium (LTE) and electro-neutrality. A criterion for the validity of the LTE assumption is presented and applied to the computed results. Other attempts in the literature are assessed with their implied inaccuracies pointed out and discussed

Thermodynamic Study of Tl6SBr4 Compound and Some Regularities in Thermodynamic Properties of Thallium Chalcohalides

Directory of Open Access Journals (Sweden)

Dunya Mahammad Babanly

2017-01-01

Full Text Available The solid-phase diagram of the Tl-TlBr-S system was clarified and the fundamental thermodynamic properties of Tl6SBr4 compound were studied on the basis of electromotive force (EMF measurements of concentration cells relative to a thallium electrode. The EMF results were used to calculate the relative partial thermodynamic functions of thallium in alloys and the standard integral thermodynamic functions (-ΔfG0, -ΔfH0, and S0298 of Tl6SBr4 compound. All data regarding thermodynamic properties of thallium chalcogen-halides are generalized and comparatively analyzed. Consequently, certain regularities between thermodynamic functions of thallium chalcogen-halides and their binary constituents as well as degree of ionization (DI of chemical bonding were revealed.

Comparison of the SF6D, the EQ5D, and the oswestry disability index in patients with chronic low back pain and degenerative disc disease.

Science.gov (United States)

Johnsen, Lars G; Hellum, Christian; Nygaard, Oystein P; Storheim, Kjersti; Brox, Jens I; Rossvoll, Ivar; Leivseth, Gunnar; Grotle, Margreth

2013-04-26

The need for cost effectiveness analyses in randomized controlled trials that compare treatment options is increasing. The selection of the optimal utility measure is important, and a central question is whether the two most commonly used indexes - the EuroQuol 5D (EQ5D) and the Short Form 6D (SF6D) - can be used interchangeably. The aim of the present study was to compare change scores of the EQ5D and SF6D utility indexes in terms of some important measurement properties. The psychometric properties of the two utility indexes were compared to a disease-specific instrument, the Oswestry Disability Index (ODI), in the setting of a randomized controlled trial for degenerative disc disease. In a randomized controlled multicentre trial, 172 patients who had experienced low back pain for an average of 6 years were randomized to either treatment with an intensive back rehabilitation program or surgery to insert disc prostheses. Patients filled out the ODI, EQ5D, and SF-36 at baseline and two-year follow up. The utility indexes was compared with respect to measurement error, structural validity, criterion validity, responsiveness, and interpretability according to the COSMIN taxonomy. At follow up, 113 patients had change score values for all three instruments. The SF6D had better similarity with the disease-specific instrument (ODI) regarding sensitivity, specificity, and responsiveness. Measurement error was lower for the SF6D (0.056) compared to the EQ5D (0.155). The minimal important change score value was 0.031 for SF6D and 0.173 for EQ5D. The minimal detectable change score value at a 95% confidence level were 0.157 for SF6D and 0.429 for EQ5D, and the difference in mean change score values (SD) between them was 0.23 (0.29) and so exceeded the clinical significant change score value for both instruments. Analysis of psychometric properties indicated that the indexes are unidimensional when considered separately, but that they do not exactly measure the same

Thermodynamic equilibrium model to predict the cobalt distribution coefficient in the CoCl2--HCl--H2O--TBP liquid--liquid extraction system

International Nuclear Information System (INIS)

Nevarez, M.; Bautista, R.G.

1976-01-01

The development of a thermodynamic equilibrium model to predict the cobalt distribution coefficient in the CoCl 2 -HCl-H 2 O-TBP system is described. The model makes use of the various aqueous phase cobaltous chloride complexes stoichiometric stability constants expressed as their degree of formation, their mechanism of extraction into the organic phase, and the equilibrium constant for the extraction reaction. The model was verified by the good agreement between the calculated cobalt distribution coefficients and those obtained experimentally both in the present study and published by other investigators. The optimum extraction of cobalt by the TBP occurred at an HCl equilibrium aqueous place concentration between 8.5 and 9.5M. The development of efficient procedures for the separation and concentration of important industrial metals from their aqueous solutions by liquid-liquid extraction has recently been given impetus by the realization of an impending shortage of energy and mineral resources. Liquid-liquid extraction is one of the few methods by which it is possible to quantitatively separate elements which are similar in properties. The use of liquid-liquid extraction to separate cobalt and nickel, which very frequently occur in nature together, is an important separation problem in nonferrous metallurgy. There is some fundamental information available in the chemical literature regarding the mechanism and equilibrium thermodynamic properties of selected liquid-liquid extraction systems. This research effort shows how this available information can be utilized to improve existing separation and concentration theory and technique. The development and application of a thermodynamic equilibrium model for describing the liquid-liquid extraction of cobaltous chloride from aqueous HCl solutions by tributyl phosphate (TBP) using experimental data obtained in this investigation and from the literature are presented

Chemical equilibrium of glycerol carbonate synthesis from glycerol

International Nuclear Information System (INIS)

Li Jiabo; Wang Tao

2011-01-01

Research highlights: → Transesterification of glycerol with cyclic carbonates or alkyl carbonates is thermodynamically favourable for the preparation of glycerol carbonate from glycerol. → The reaction of glycerol and carbon dioxide is thermodynamically limited. → High temperature and low pressure is favourable to the reaction of glycerol and urea. → Increasing temperature can increase the chemical equilibrium constant for the reaction of glycerol and dimethyl carbonate. → For the reaction of glycerol and ethylene carbonate, increasing temperature can decrease the chemical equilibrium constant. - Abstract: In this paper, the chemical equilibrium for the glycerol carbonate preparation from glycerol was investigated. The chemical equilibrium constants were calculated for the reactions to produce glycerol carbonate from glycerol. The theoretical calculation was compared with the experimental results for the transesterification of glycerol with dimethyl carbonate. Transesterification of glycerol with cyclic carbonates or alkyl carbonates is thermodynamically favourable for producing glycerol carbonate from glycerol according to the equilibrium constant. Increasing temperature can increase the chemical equilibrium constant for the reaction of glycerol with dimethyl carbonate. For the reaction of glycerol with ethylene carbonate, increasing temperature can decrease the chemical equilibrium constant. The reaction of glycerol with carbon dioxide is thermodynamically limited. High temperature and low pressure are favourable to the reaction of glycerol and urea.

Formation of super disperse phase and its influence on equilibrium and thermodynamics of thermal dehydration

Energy Technology Data Exchange (ETDEWEB)

Polyachenok, O.G. [Department of Chemistry, Mogilev State University of Foodstuffs, 212027 (Belarus)], E-mail: polyachenok@mogilev.by; Dudkina, E.N.; Branovitskaya, N.V. [Department of Chemistry, Mogilev State University of Foodstuffs, 212027 (Belarus); Polyachenok, L.D. [Department of Chemistry, Mogilev State University of A.A. Kuleshov, 212022 (Belarus)

2008-01-30

New data on the dehydration and rehydration processes of calcium, manganese and copper dichlorides are presented that reveal surprising, in a certain sense, behaviour difficult to be explained for the last two chlorides in terms of the usual conception of thermodynamic equilibrium. A substantial role of a super disperse phase at studying the equilibrium of the thermal decomposition of a hydrate is postulated to explain the experimental results for manganese and copper dichlorides. It is shown that the formation of such a phase of the hydrate is able to change appreciably the experimental results, causing the increase of water vapour pressure and the decrease of the derived enthalpy of a reaction. The results obtained allow to understand the reasons for considerable differences of some literature data. They enable to receive more precise and reliable data for thermal dehydration and probably for some other decomposition processes.

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.)

Measurement properties of the EQ-5D-5L compared to the EQ-5D-3L in psoriasis patients.

Science.gov (United States)

Poór, Adrienn Katalin; Rencz, Fanni; Brodszky, Valentin; Gulácsi, László; Beretzky, Zsuzsanna; Hidvégi, Bernadett; Holló, Péter; Kárpáti, Sarolta; Péntek, Márta

2017-12-01

The purpose of this study is to assess the measurement properties of EQ-5D-5L compared to EQ-5D-3L in psoriasis patients. A cross-sectional survey was carried out at an academic dermatology clinic in Hungary. Psoriasis patients completed the EQ-5D-3L, EQ-5D-5L and Dermatology Life Quality Index (DLQI) questionnaires, and Psoriasis Area and Severity Index (PASI) was assessed. The UK value sets were used to calculate the 3L and 5L index scores. We tested the feasibility, ceiling effect, redistribution properties, the level of inconsistency and informativity (Shannon and Shannon Evenness indices). Spearman's rank-order correlations were performed between EQ-5D, EQ VAS, DLQI and PASI scores. Known-groups validity was evaluated by comparing age groups, clinical subtypes and treatment groups. Mean age of the 238 patients was 47 years, and 36.6% of them received biological therapy. Mean EQ-5D index score was 0.77 (SD: 0.26) with the 3L and 0.84 (SD: 0.19) with the 5L. The overall ceiling effect decreased from 37.1 (3L) to 32.9% (5L). Shannon index improved significantly for most dimensions, but Shannon Evenness index improved only in three dimensions. Compared to the 3L, the 5L version confirmed a better convergent validity with PASI, but not with the DLQI. Known-groups validity was equally demonstrated both for the 5L and 3L. The EQ-5D-5L seems to improve measurement properties by reducing ceiling effects, strengthening correlations with PASI and improving informativity. Follow-up studies are needed to test responsiveness and reliability in psoriasis.

Implementing an Equilibrium Law Teaching Sequence for Secondary School Students to Learn Chemical Equilibrium

Science.gov (United States)

Ghirardi, Marco; Marchetti, Fabio; Pettinari, Claudio; Regis, Alberto; Roletto, Ezio

2015-01-01

A didactic sequence is proposed for the teaching of chemical equilibrium law. In this approach, we have avoided the kinetic derivation and the thermodynamic justification of the equilibrium constant. The equilibrium constant expression is established empirically by a trial-and-error approach. Additionally, students learn to use the criterion of…

Advanced classical thermodynamics

International Nuclear Information System (INIS)

Emanuel, G.

1987-01-01

The theoretical and mathematical foundations of thermodynamics are presented in an advanced text intended for graduate engineering students. Chapters are devoted to definitions and postulates, the fundamental equation, equilibrium, the application of Jacobian theory to thermodynamics, the Maxwell equations, stability, the theory of real gases, critical-point theory, and chemical thermodynamics. Diagrams, graphs, tables, and sample problems are provided. 38 references

Sensitivity analysis of EQ3

International Nuclear Information System (INIS)

Horwedel, J.E.; Wright, R.Q.; Maerker, R.E.

1990-01-01

A sensitivity analysis of EQ3, a computer code which has been proposed to be used as one link in the overall performance assessment of a national high-level waste repository, has been performed. EQ3 is a geochemical modeling code used to calculate the speciation of a water and its saturation state with respect to mineral phases. The model chosen for the sensitivity analysis is one which is used as a test problem in the documentation of the EQ3 code. Sensitivities are calculated using both the CHAIN and ADGEN options of the GRESS code compiled under G-float FORTRAN on the VAX/VMS and verified by perturbation runs. The analyses were performed with a preliminary Version 1.0 of GRESS which contains several new algorithms that significantly improve the application of ADGEN. Use of ADGEN automates the implementation of the well-known adjoint technique for the efficient calculation of sensitivities of a given response to all the input data. Application of ADGEN to EQ3 results in the calculation of sensitivities of a particular response to 31,000 input parameters in a run time of only 27 times that of the original model. Moreover, calculation of the sensitivities for each additional response increases this factor by only 2.5 percent. This compares very favorably with a running-time factor of 31,000 if direct perturbation runs were used instead. 6 refs., 8 tabs

Comparative evaluation of kinetic, equilibrium and semi-equilibrium models for biomass gasification

Energy Technology Data Exchange (ETDEWEB)

Buragohain, Buljit [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Chakma, Sankar; Kumar, Peeush [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Mahanta, Pinakeswar [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Moholkar, Vijayanand S. [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India)

2013-07-01

Modeling of biomass gasification has been an active area of research for past two decades. In the published literature, three approaches have been adopted for the modeling of this process, viz. thermodynamic equilibrium, semi-equilibrium and kinetic. In this paper, we have attempted to present a comparative assessment of these three types of models for predicting outcome of the gasification process in a circulating fluidized bed gasifier. Two model biomass, viz. rice husk and wood particles, have been chosen for analysis, with gasification medium being air. Although the trends in molar composition, net yield and LHV of the producer gas predicted by three models are in concurrence, significant quantitative difference is seen in the results. Due to rather slow kinetics of char gasification and tar oxidation, carbon conversion achieved in single pass of biomass through the gasifier, calculated using kinetic model, is quite low, which adversely affects the yield and LHV of the producer gas. Although equilibrium and semi-equilibrium models reveal relative insensitivity of producer gas characteristics towards temperature, the kinetic model shows significant effect of temperature on LHV of the gas at low air ratios. Kinetic models also reveal volume of the gasifier to be an insignificant parameter, as the net yield and LHV of the gas resulting from 6 m and 10 m riser is same. On a whole, the analysis presented in this paper indicates that thermodynamic models are useful tools for quantitative assessment of the gasification process, while kinetic models provide physically more realistic picture.

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...

Quantum thermodynamics of nanoscale steady states far from equilibrium

Science.gov (United States)

Taniguchi, Nobuhiko

2018-04-01

We develop an exact quantum thermodynamic description for a noninteracting nanoscale steady state that couples strongly with multiple reservoirs. We demonstrate that there exists a steady-state extension of the thermodynamic function that correctly accounts for the multiterminal Landauer-Büttiker formula of quantum transport of charge, energy, or heat via the nonequilibrium thermodynamic relations. Its explicit form is obtained for a single bosonic or fermionic level in the wide-band limit, and corresponding thermodynamic forces (affinities) are identified. Nonlinear generalization of the Onsager reciprocity relations are derived. We suggest that the steady-state thermodynamic function is also capable of characterizing the heat current fluctuations of the critical transport where the thermal fluctuations dominate. Also, the suggested nonequilibrium steady-state thermodynamic relations seemingly persist for a spin-degenerate single level with local interaction.

Equilibrium Constant as Solution to the Open Chemical Systems

OpenAIRE

Zilbergleyt, B.

2008-01-01

According to contemporary views, equilibrium constant is relevant only to true thermodynamic equilibria in isolated systems with one chemical reaction. The paper presents a novel formula that ties-up equilibrium constant and chemical system composition at any state, isolated or open as well. Extending the logarithmic logistic map of the Discrete Thermodynamics of Chemical Equilibria, this formula maps the system population at isolated equilibrium into the population at any open equilibrium at...

Microcanonical ensemble extensive thermodynamics of Tsallis statistics

International Nuclear Information System (INIS)

Parvan, A.S.

2005-01-01

The microscopic foundation of the generalized equilibrium statistical mechanics based on the Tsallis entropy is given by using the Gibbs idea of statistical ensembles of the classical and quantum mechanics.The equilibrium distribution functions are derived by the thermodynamic method based upon the use of the fundamental equation of thermodynamics and the statistical definition of the functions of the state of the system. It is shown that if the entropic index ξ = 1/q - 1 in the microcanonical ensemble is an extensive variable of the state of the system, then in the thermodynamic limit z bar = 1/(q - 1)N = const the principle of additivity and the zero law of thermodynamics are satisfied. In particular, the Tsallis entropy of the system is extensive and the temperature is intensive. Thus, the Tsallis statistics completely satisfies all the postulates of the equilibrium thermodynamics. Moreover, evaluation of the thermodynamic identities in the microcanonical ensemble is provided by the Euler theorem. The principle of additivity and the Euler theorem are explicitly proved by using the illustration of the classical microcanonical ideal gas in the thermodynamic limit

Microcanonical ensemble extensive thermodynamics of Tsallis statistics

International Nuclear Information System (INIS)

Parvan, A.S.

2006-01-01

The microscopic foundation of the generalized equilibrium statistical mechanics based on the Tsallis entropy is given by using the Gibbs idea of statistical ensembles of the classical and quantum mechanics. The equilibrium distribution functions are derived by the thermodynamic method based upon the use of the fundamental equation of thermodynamics and the statistical definition of the functions of the state of the system. It is shown that if the entropic index ξ=1/(q-1) in the microcanonical ensemble is an extensive variable of the state of the system, then in the thermodynamic limit z-bar =1/(q-1)N=const the principle of additivity and the zero law of thermodynamics are satisfied. In particular, the Tsallis entropy of the system is extensive and the temperature is intensive. Thus, the Tsallis statistics completely satisfies all the postulates of the equilibrium thermodynamics. Moreover, evaluation of the thermodynamic identities in the microcanonical ensemble is provided by the Euler theorem. The principle of additivity and the Euler theorem are explicitly proved by using the illustration of the classical microcanonical ideal gas in the thermodynamic limit

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

Science.gov (United States)

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

1998-05-01

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'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 Tz. 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.

Thermodynamics of nanoadsorption from solution: Theoretical and experimental research

International Nuclear Information System (INIS)

Wen, Yan-Zhen; Xue, Yong-Qiang; Cui, Zi-Xiang; Wang, Yan

2015-01-01

Highlights: • The thermodynamic theory of nanoadsorption was proposed. • The thermodynamic relations of nanoadsorption were derived. • The results of the experiments are accord with the theory. - Abstract: In this study, the effect of nanoparticle size on adsorption thermodynamics was investigated. The results of theoretical and experimental studies show that particle size significantly affects the equilibrium constant and thermodynamic properties of nanoadsorption. Relationships between the equilibrium constant, thermodynamic properties and particle size were derived using the thermodynamic theory of nanoadsorption. The equilibrium constant and thermodynamic properties were obtained by investigating the adsorption of Cu 2+ onto different sizes of nano-ZnO and the adsorption of Ag + onto different sizes of nano-TiO 2 . Good agreement was achieved between results obtained by experiments and predicted by theoretical analyses. The equilibrium constant and the molar Gibbs free energy of nanoadsorption were found to increase with smaller nanoparticle size. However, the effects of particle size on the molar enthalpy and the molar entropy are uncertain. In addition, the molar Gibbs free energy, the molar enthalpy, the molar entropy and the logarithm of the equilibrium constant are linearly related to the reciprocal of the diameter of the nanoparticle. The thermodynamic properties revealed in this study may provide important guidelines for research and application in the field of nanoadsorption

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.

Thermodynamics of Micellar Systems : Comparison of Mass Action and Phase Equilibrium Models for the Calculation of Standard Gibbs Energies of Micelle Formation

NARCIS (Netherlands)

Blandamer, Michael J.; Cullis, Paul M.; Soldi, L. Giorgio; Engberts, Jan B.F.N.; Kacperska, Anna; Os, Nico M. van

1995-01-01

Micellar colloids are distinguished from other colloids by their association-dissociation equilibrium in solution between monomers, counter-ions and micelles. According to classical thermodynamics, the standard Gibbs energy of formation of micelles at fixed temperature and pressure can be related to

Establishment of data base files of thermodynamic data developed by OECD/NEA. Pt. 1. Thermodynamic data of Np and Pu

International Nuclear Information System (INIS)

Yoshida, Yasushi; Sasamoto, Hiroshi

2004-01-01

Thermodynamic data base for compounds and complexes of actinides and fission products specialized in modeling requirements for safety assessments of radioactive waste disposal systems are being developed by NEA TDB project of OECD/NEA. In this project, relevant data bases for compounds and complexes of Np and Pu were published in 2001. JNC established the data base files available for geochemical calculation codes using these Np and Pu published data. And this procedure for establishment and contents of data base files are described in this report. These data base files were prepared as the formats of major geochemical codes PHREEQE, PHREEQC, EQ3/6 and Geochemist's workbench. Additionally modification for data in the thermodynamic data base files which had been already published by JNC was also done. This procedure and revised data bases are shown in the appendix of this report. (author)

Interfaces at equilibrium: A guide to fundamentals.

Science.gov (United States)

Marmur, Abraham

2017-06-01

The fundamentals of the thermodynamics of interfaces are reviewed and concisely presented. The discussion starts with a short review of the elements of bulk thermodynamics that are also relevant to interfaces. It continues with the interfacial thermodynamics of two-phase systems, including the definition of interfacial tension and adsorption. Finally, the interfacial thermodynamics of three-phase (wetting) systems is discussed, including the topic of non-wettable surfaces. A clear distinction is made between equilibrium conditions, in terms of minimizing energies (internal, Gibbs or Helmholtz), and equilibrium indicators, in terms of measurable, intrinsic properties (temperature, chemical potential, pressure). It is emphasized that the equilibrium indicators are the same whatever energy is minimized, if the boundary conditions are properly chosen. Also, to avoid a common confusion, a distinction is made between systems of constant volume and systems with drops of constant volume. Copyright © 2016 Elsevier B.V. All rights reserved.

Computing Properties Of Chemical Mixtures At Equilibrium

Science.gov (United States)

Mcbride, B. J.; Gordon, S.

1995-01-01

Scientists and engineers need data on chemical equilibrium compositions to calculate theoretical thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93 is general program that calculates chemical equilibrium compositions and properties of mixtures for any chemical system for which thermodynamic data are available. Includes thermodynamic data for more than 1,300 gaseous and condensed species and thermal-transport data for 151 gases. Written in FORTRAN 77.

A study in cosmology and causal thermodynamics

International Nuclear Information System (INIS)

Oliveira, H.P. de.

1986-01-01

The especial relativity of thermodynamic theories for reversible and irreversible processes in continuous medium is studied. The formalism referring to equilibrium and non-equilibrium configurations, and theories which includes the presence of gravitational fields are discussed. The nebular model in contraction with dissipative processes identified by heat flux and volumetric viscosity is thermodymically analysed. This model is presented by a plane conformal metric. The temperature, pressure, entropy and entropy production within thermodynamic formalism which adopts the hypothesis of local equilibrium, is calculated. The same analysis is carried out considering a causal thermodynamics, which establishes a local entropy of non-equilibrium. Possible homogeneous and isotropic cosmological models, considering the new phenomenological equation for volumetric viscosity deriving from cause thermodynamics are investigated. The found out models have plane spatial section (K=0) and some ones do not have singularities. The energy conditions are verified and the entropy production for physically reasobable models are calculated. (M.C.K.) [pt

Geometric description of BTZ black hole thermodynamics

International Nuclear Information System (INIS)

Quevedo, Hernando; Sanchez, Alberto

2009-01-01

We study the properties of the space of thermodynamic equilibrium states of the Banados-Teitelboim-Zanelli (BTZ) black hole in (2+1) gravity. We use the formalism of geometrothermodynamics to introduce in the space of equilibrium states a two-dimensional thermodynamic metric whose curvature is nonvanishing, indicating the presence of thermodynamic interaction, and free of singularities, indicating the absence of phase transitions. Similar results are obtained for generalizations of the BTZ black hole which include a Chern-Simons term and a dilatonic field. Small logarithmic corrections of the entropy turn out to be represented by small corrections of the thermodynamic curvature, reinforcing the idea that thermodynamic curvature is a measure of thermodynamic interaction.

Thermodynamic investigation of the MOCVD of copper films from bis ...

Indian Academy of Sciences (India)

Equilibrium concentrations of various condensed and gaseous phases have been thermodynamically calculated, using the free energy minimization criterion, for the metalorganic chemical vapour deposition (MOCVD) of copper films using bis(2,2,6,6-tetramethyl-3,5-heptadionato)copper(II) as the precursor material.

Kinetics, Equilibrium, and Thermodynamic Studies on Adsorption of Methylene Blue by Carbonized Plant Leaf Powder

Directory of Open Access Journals (Sweden)

V. Gunasekar

2013-01-01

Full Text Available Carbon synthesized from plant leaf powder was employed for the adsorption of methylene blue from aqueous effluent. Effects of pH (2, 4, 6, 8, and 9, dye concentration (50, 100, 150, and 200 mg/dm3, adsorbent dosage (0.5, 1.0, 1.5, and 2.0 g/dm3, and temperature (303, 313, and 323 K were studied. The process followed pseudo-second-order kinetics. Equilibrium data was examined with Langmuir and Freundlich isotherm models and Langmuir model was found to be the best fitting model with high R2 and low chi2 values. Langmuir monolayer adsorption capacity of the adsorbent was found to be 61.22 mg/g. From the thermodynamic analysis, ΔH, ΔG, and ΔS values for the adsorption of MB onto the plant leaf carbon were found out. From the values of free energy change, the process was found out to be feasible process. From the magnitude of ΔH, the process was found to be endothermic physisorption.

Effect of heavy ion irradiation on thermodynamically equilibrium Zr-Excel alloy

Science.gov (United States)

Yu, Hongbing; Liang, Jianlie; Yao, Zhongwen; Kirk, Mark A.; Daymond, Mark R.

2017-05-01

The thermodynamically equilibrium state was achieved in a Zr-Sn-Nb-Mo alloy by long-term annealing at an intermediate temperature. The fcc intermetallic Zr(Mo, Nb)2 enriched with Fe was observed at the equilibrium state. In-situ 1 MeV Kr2+ heavy ion irradiation was performed in a TEM to study the stability of the intermetallic particles under irradiation and the effects of the intermetallic particle on the evolution of type dislocation loops at different temperatures from 80 to 550 °C. Chemi-STEM elemental maps were made at the same particles before and after irradiation up to 10 dpa. It was found that no elemental redistribution occurs at 200 °C and below. Selective depletion of Fe was observed from some precipitates under irradiation at higher temperatures. No change in the morphology of particles and no evidence showing a crystalline to amorphous transformation were observed at all irradiation temperatures. The formation of type dislocation loops was observed under irradiation at 80 and 200 °C, but not at 450 and 550 °C. The loops were non-uniformly distributed; a localized high density of type dislocation loops were observed near the second phase particles; we suggest that loop nucleation is favored as a result of the stress induced by the particles, rather than by elemental redistribution. The stability of the second phase particles and the formation of the type loops under heavy ion irradiation are discussed.

Preserving EQ as per CSA N290.13: EQ of equipment for CANDU NPP

International Nuclear Information System (INIS)

Bordeleau, H.

2006-01-01

EQ is basically a Quality Assurance process that ensures that required safety related equipment will performed their safety functions during accident generating harsh environmental condition. As any good Quality Assurance Program, EQ activities have to be imbedded in the normal tasks of the people at the plant in such a way that it is not an extra concern but part of the things to be assessed and done on a regular basis so that the EQ Status of the equipment will not be compromised. The experience shows us that even with brand new plants there are discrepancies between equipment designed to be installed and that installed (wrong model or wrong instrument). Improper installation was also found. To eliminate these mistakes it is recommended to have a thorough initial inspection during construction or commissioning and later at regular intervals during operation. To avoid new mistakes during maintenance, crews have to be properly qualified and trained on completed procedure with appropriate work report that will required to be scrutinized for possible common cause failure and OPEX report. Procurement and handling of equipment and spare parts require a thorough revision of procurement and storage practices to guarantee proper storage, availability and identification of equipment for EQ replacement. A shelf life program for degradable material shall be implemented. Condition monitoring program could be use to extend life of equipment or as a qualification methods, caution should be use to look very precisely to the critical parameters that need to be monitored and to carefully tailor the monitoring program. EQ program should also consider barriers, they are not EQ equipment; it is usually made out of non-ageing material like metal or concrete. But there could be sealing material used in conjunction with the barriers and these may need special care. The impact of EQ parameters changes related to services conditions, new technical data or condition monitoring has to be

Structural equation modeling with EQS basic concepts, applications, and programming

CERN Document Server

Byrne, Barbara M

2013-01-01

Readers who want a less mathematical alternative to the EQS manual will find exactly what they're looking for in this practical text. Written specifically for those with little to no knowledge of structural equation modeling (SEM) or EQS, the author's goal is to provide a non-mathematical introduction to the basic concepts of SEM by applying these principles to EQS, Version 6.1. The book clearly demonstrates a wide variety of SEM/EQS applications that include confirmatory factor analytic and full latent variable models. Written in a "user-friendly" style, the author "walks" the reader through the varied steps involved in the process of testing SEM models: model specification and estimation, assessment of model fit, EQS output, and interpretation of findings. Each of the book's applications is accompanied by: a statement of the hypothesis being tested, a schematic representation of the model, explanations of the EQS input and output files, tips on how to use the pull-down menus, and the data file upon which ...

Equilibrium, kinetic and thermodynamic studies on the adsorption of phenol onto graphene

Energy Technology Data Exchange (ETDEWEB)

Li, Yanhui, E-mail: liyanhui@tsinghua.org.cn [Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Du, Qiuju; Liu, Tonghao; Sun, Jiankun; Jiao, Yuqin [Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Xia, Yanzhi, E-mail: xiayzh@qdu.edu.cn [Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Xia, Linhua; Wang, Zonghua [Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Zhang, Wei; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai [Key Laboratory for Advanced Manufacturing by Material Processing Technology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

2012-08-15

Graphical abstract: The effect of temperature on phenol adsorbed by graphene shows that the equilibrium adsorption capacity of phenol increases with the increase in temperature from 285 to 333 K. Increasing adsorption capacities with temperature indicates that the adsorption of phenol is controlled by an endothermic reaction. Highlights: ► The graphene has high phenol adsorption capacity. ► The graphene has a high specific surface area of 305 m{sup 2}/g. ► The adsorption capacity is high at acidic pH range. ► The graphene has rapid phenol adsorption rate. ► Phenol adsorption is a spontaneous and endothermic process. -- Abstract: Graphene, a new member of carbon family, has been prepared, characterized and used as adsorbent to remove phenol from aqueous solution. The effect parameters including pH, dosage, contact time, and temperature on the adsorption properties of phenol onto graphene were investigated. The results showed that the maximum adsorption capacity can reach 28.26 mg/g at the conditions of initial phenol concentration of 50 mg/L, pH 6.3 and 285 K. Adsorption data were well described by both Freundlich and Langmuir models. The kinetic study illustrated that the adsorption of phenol onto graphene fit the pseudo second-order model. The thermodynamic parameters indicated that the adsorption of phenol onto graphene was endothermic and spontaneous.

Equilibrium, kinetic and thermodynamic studies on the adsorption of phenol onto graphene

International Nuclear Information System (INIS)

Li, Yanhui; Du, Qiuju; Liu, Tonghao; Sun, Jiankun; Jiao, Yuqin; Xia, Yanzhi; Xia, Linhua; Wang, Zonghua; Zhang, Wei; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai

2012-01-01

Graphical abstract: The effect of temperature on phenol adsorbed by graphene shows that the equilibrium adsorption capacity of phenol increases with the increase in temperature from 285 to 333 K. Increasing adsorption capacities with temperature indicates that the adsorption of phenol is controlled by an endothermic reaction. Highlights: ► The graphene has high phenol adsorption capacity. ► The graphene has a high specific surface area of 305 m 2 /g. ► The adsorption capacity is high at acidic pH range. ► The graphene has rapid phenol adsorption rate. ► Phenol adsorption is a spontaneous and endothermic process. -- Abstract: Graphene, a new member of carbon family, has been prepared, characterized and used as adsorbent to remove phenol from aqueous solution. The effect parameters including pH, dosage, contact time, and temperature on the adsorption properties of phenol onto graphene were investigated. The results showed that the maximum adsorption capacity can reach 28.26 mg/g at the conditions of initial phenol concentration of 50 mg/L, pH 6.3 and 285 K. Adsorption data were well described by both Freundlich and Langmuir models. The kinetic study illustrated that the adsorption of phenol onto graphene fit the pseudo second-order model. The thermodynamic parameters indicated that the adsorption of phenol onto graphene was endothermic and spontaneous.

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.

Particle creation and non-equilibrium thermodynamical prescription of dark fluids for universe bounded by an event horizon

OpenAIRE

Saha, Subhajit; Biswas, Atreyee; Chakraborty, Subenoy

2015-01-01

In the present work, flat FRW model of the universe is considered to be an isolated open thermodynamical system where non-equilibrium prescription has been studied using the mechanism of particle creation. In the perspective of recent observational evidences, the matter distribution in the universe is assumed to be dominated by dark matter and dark energy. The dark matter is chosen as dust while for dark energy, the following choices are considered: (i) Perfect fluid with constant equation of...

Entropy equilibrium equation and dynamic entropy production in environment liquid

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

The entropy equilibrium equation is the basis of the nonequilibrium state thermodynamics. But the internal energy implies the kinetic energy of the fluid micelle relative to mass center in the classical entropy equilibrium equation at present. This internal energy is not the mean kinetic energy of molecular movement in thermodynamics. Here a modified entropy equilibrium equation is deduced, based on the concept that the internal energy is just the mean kinetic energy of the molecular movement. A dynamic entropy production is introduced into the entropy equilibrium equation to describe the dynamic process distinctly. This modified entropy equilibrium equation can describe not only the entropy variation of the irreversible processes but also the reversible processes in a thermodynamic system. It is more reasonable and suitable for wider applications.

Correlations in plasma in thermodynamic equilibrium; Les correlations dans un plasma en equilibre

Energy Technology Data Exchange (ETDEWEB)

Yvon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper treats of a fully, ionized plasma in thermodynamic equilibrium. An attempt is made at reviewing the calculation of spatial correlations in such a plasma. The equation of recurrence and the principle of superposition are used. The linear approximation is first treated. The next higher approximation is studied in the case of a neutral homogeneous and isotropic plasma. (author) [French] Un plasma completement ionise est en equilibre thermodynamique. On tente une mise au point du calcul des correlations de position dans ce plasma. On utilise les equations de recurrence et le principe de superposition. On expose d'abord l'approximation lineaire. Dans le cas d'un plasma neutre homogene et isotrope l'etude est poursuivie a l'approximation suivante. (auteur)

Performance of the EQ-5D and the EQ-5D+C in elderly patients with cognitive impairments

Directory of Open Access Journals (Sweden)

Verhey Frans RJ

2007-06-01

Full Text Available Abstract Background The EQ-5D is a reliable tool for measuring Health-Related Quality of Life (HRQoL. However, concern has been expressed that it may ignore elements of HRQoL, particularly cognition. In response to this concern, the EQ-5D has been extended with a cognitive dimension (EQ-5D+C. The aim of this study was to compare the performance of the EQ-5D and the EQ-5D+C in elderly patients with cognitive impairments by assessing their construct validity and responsiveness. Methods Data from the MEDICIE study (n = 196 were used, in which all questionnaires were rated by proxies. Results Regarding construct validity, we found similar correlations between the EQ-5D and the Mini Mental State Examination (MMSE and between the EQ-5D+C and the MMSE. Furthermore, both the EQ-5D and the EQ-5D+C were responsive to changes in the MMSE, with the EQ-5D performing slightly better. Conclusion We conclude that the EQ-5D performs well for evaluating HRQoL in a population with cognitive impairments. Based on the results of this explorative study, it does not seem necessary to adjust the current classification system by adding a cognitive dimension. However, in order to compare both instruments regarding utility values, it is necessary to develop a new scoring algorithm for the EQ-5D+C by conducting a general population study. Considering the explorative nature of this study, it is recommended that more aspects of the validity of both the EQ-5D and the EQ-5D+C are explored in patients with cognitive impairments using a more tailored study design.

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

Modern thermodynamics from heat engines to dissipative structures

CERN Document Server

Kondepudi, Dilip

2014-01-01

Modern Thermodynamics: From Heat Engines to Dissipative Structures, Second Edition presents a comprehensive introduction to 20th century thermodynamics that can be applied to both equilibrium and non-equilibrium systems, unifying what was traditionally divided into 'thermodynamics' and 'kinetics' into one theory of irreversible processes. This comprehensive text, suitable for introductory as well as advanced courses on thermodynamics, has been widely used by chemists, physicists, engineers and geologists.  Fully revised and expanded, this new edition includes the following updates and featur

Mathematical foundations of thermodynamics

CERN Document Server

Giles, R; Stark, M; Ulam, S

2013-01-01

Mathematical Foundations of Thermodynamics details the core concepts of the mathematical principles employed in thermodynamics. The book discusses the topics in a way that physical meanings are assigned to the theoretical terms. The coverage of the text includes the mechanical systems and adiabatic processes; topological considerations; and equilibrium states and potentials. The book also covers Galilean thermodynamics; symmetry in thermodynamics; and special relativistic thermodynamics. The book will be of great interest to practitioners and researchers of disciplines that deal with thermodyn

Partition functions. I. Improved partition functions and thermodynamic quantities for normal, equilibrium, and ortho and para molecular hydrogen

Science.gov (United States)

Popovas, A.; Jørgensen, U. G.

2016-11-01

Context. Hydrogen is the most abundant molecule in the Universe. Its thermodynamic quantities dominate the physical conditions in molecular clouds, protoplanetary disks, etc. It is also of high interest in plasma physics. Therefore thermodynamic data for molecular hydrogen have to be as accurate as possible in a wide temperature range. Aims: We here rigorously show the shortcomings of various simplifications that are used to calculate the total internal partition function. These shortcomings can lead to errors of up to 40 percent or more in the estimated partition function. These errors carry on to calculations of thermodynamic quantities. Therefore a more complicated approach has to be taken. Methods: Seven possible simplifications of various complexity are described, together with advantages and disadvantages of direct summation of experimental values. These were compared to what we consider the most accurate and most complete treatment (case 8). Dunham coefficients were determined from experimental and theoretical energy levels of a number of electronically excited states of H2. Both equilibrium and normal hydrogen was taken into consideration. Results: Various shortcomings in existing calculations are demonstrated, and the reasons for them are explained. New partition functions for equilibrium, normal, and ortho and para hydrogen are calculated and thermodynamic quantities are reported for the temperature range 1-20 000 K. Our results are compared to previous estimates in the literature. The calculations are not limited to the ground electronic state, but include all bound and quasi-bound levels of excited electronic states. Dunham coefficients of these states of H2 are also reported. Conclusions: For most of the relevant astrophysical cases it is strongly advised to avoid using simplifications, such as a harmonic oscillator and rigid rotor or ad hoc summation limits of the eigenstates to estimate accurate partition functions and to be particularly careful when

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

Experimental determination of thermodynamic equilibrium in biocatalytic transamination

DEFF Research Database (Denmark)

Tufvesson, Pär; Jensen, Jacob Skibsted; Kroutil, Wolfgang

2012-01-01

The equilibrium constant is a critical parameter for making rational design choices in biocatalytic transamination for the synthesis of chiral amines. However, very few reports are available in the scientific literature determining the equilibrium constant (K) for the transamination of ketones....... Various methods for determining (or estimating) equilibrium have previously been suggested, both experimental as well as computational (based on group contribution methods). However, none of these were found suitable for determining the equilibrium constant for the transamination of ketones. Therefore...

Thermodynamics of Fluids Under Flow Second Edition

CERN Document Server

Jou, David; Criado-Sancho, Manuel

2011-01-01

This is the second edition of the book “Thermodynamics of Fluids under Flow,” which was published in 2000 and has now been corrected, expanded and updated. This is a companion book to our other title Extended irreversible thermodynamics (D. Jou, J. Casas-Vázquez and G. Lebon, Springer, 4th edition 2010), and of the textbook Understanding non-equilibrium thermodynamics (G. Lebon, D. Jou and J. Casas-Vázquez, Springer, 2008. The present book is more specialized than its counterpart, as it focuses its attention on the non-equilibrium thermodynamics of flowing fluids, incorporating non-trivial thermodynamic contributions of the flow, going beyond local equilibrium theories, i.e., including the effects of internal variables and of external forcing due to the flow. Whereas the book's first edition was much more focused on polymer solutions, with brief glimpses into ideal and real gases, the present edition covers a much wider variety of systems, such as: diluted and concentrated polymer solutions, polymer ble...

New insights for mesospheric OH: multi-quantum vibrational relaxation as a driver for non-local thermodynamic equilibrium

Directory of Open Access Journals (Sweden)

K. S. Kalogerakis

2018-01-01

Full Text Available The question of whether mesospheric OH(v rotational population distributions are in equilibrium with the local kinetic temperature has been debated over several decades. Despite several indications for the existence of non-equilibrium effects, the general consensus has been that emissions originating from low rotational levels are thermalized. Sky spectra simultaneously observing several vibrational levels demonstrated reproducible trends in the extracted OH(v rotational temperatures as a function of vibrational excitation. Laboratory experiments provided information on rotational energy transfer and direct evidence for fast multi-quantum OH(high-v vibrational relaxation by O atoms. We examine the relationship of the new relaxation pathways with the behavior exhibited by OH(v rotational population distributions. Rapid OH(high-v + O multi-quantum vibrational relaxation connects high and low vibrational levels and enhances the hot tail of the OH(low-v rotational distributions. The effective rotational temperatures of mesospheric OH(v are found to deviate from local thermodynamic equilibrium for all observed vibrational levels. Dedicated to Tom G. Slanger in celebration of his 5 decades of research in aeronomy.

Modern thermodynamics

CERN Document Server

Ben-Naim, Arieh

2017-01-01

This textbook introduces thermodynamics with a modern approach, starting from four fundamental physical facts (the atomic nature of matter, the indistinguishability of atoms and molecules of the same species, the uncertainty principle, and the existence of equilibrium states) and analyzing the behavior of complex systems with the tools of information theory, in particular with Shannon's measure of information (or SMI), which can be defined on any probability distribution. SMI is defined and its properties and time evolution are illustrated, and it is shown that the entropy is a particular type of SMI, i.e. the SMI related to the phase-space distribution for a macroscopic system at equilibrium. The connection to SMI allows the reader to understand what entropy is and why isolated systems follow the Second Law of Thermodynamics. The Second Llaw is also formulated for other systems, not thermally isolated and even open with respect to the transfer of particles. All the fundamental aspects of thermodynamics are d...

Deducting the temperature dependence of the structural relaxation time in equilibrium far below the nominal Tg by aging the decoupled conductivity relaxation to equilibrium.

Science.gov (United States)

Wojnarowska, Z; Ngai, K L; Paluch, M

2014-05-07

Using broadband dielectric spectroscopy we investigate the changes in the conductivity relaxation times τσ observed during the physical aging of the protic ionic conductor carvedilol dihydrogen phosphate (CP). Due to the large decoupling of ion diffusion from host molecule reorientation, the ion conductivity relaxation time τσ(Tage,tage) can be directly measured at temperatures Tage below Tg for exceedingly long aging times tage till τσ(Tage,tage) has reached the equilibrium value τσ(eq)(Tage). The dependence of τσ(Tage,tage) on tage is well described by the stretched exponential function, τσ(Tage, tage) = Aexp[-((tage)/(τage(Tage)))(β)] + τσ(eq)(Tage), where β is a constant and τage(Tage) can be taken as the structural α-relaxation time of the equilibrium liquid at T = Tage. The value of τσ(eq)(Tage) obtained after 63 days long annealing of CP, deviates from the Vogel-Fulcher-Tammann-Hesse (VFTHσ) dependence of τσ(T) determined from data taken above Tg and extrapolated down to Tage. Concurrently, τage(Tage) also deviates from the Vogel-Fulcher-Tammann-Hesse (VFTHα) dependence. The results help to answer the longstanding question of whether the VFTH dependence of τσ(T) as well as the structural α-relaxation time τα(T) holds or not in the equilibrium liquid state far below Tg.

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

Local thermodynamic equilibrium considerations in powerchip laser-induced plasmas

Energy Technology Data Exchange (ETDEWEB)

Merten, Jonathan A., E-mail: jmerten@astate.edu; Smith, Benjamin W., E-mail: bwsmith@chem.ufl.edu; Omenetto, Nicoló, E-mail: omenetto@chem.ufl.edu

2013-05-01

Time-resolved emission experiments are reported in the fast-decaying transient plasma induced by a microchip laser on an aluminum target in three different cover gases, i.e., air, argon and helium. The laser operates at 532 nm, with a repetition frequency of 1 kHz and a pulse width of less than 0.5 ns. The overall persistence of plasma emission is of the order of 100 ns. We examine the existence of local thermodynamic equilibrium (LTE) by evaluating the temporal criteria required (in addition to the McWhirter criterion), as recommended by Cristoforetti et al. (Spectrochim. Acta Part B 65, 2010, 86–95). The temporal criteria examine the evolution of temperature and electron number density and compare their rate of change to the rate at which electron collisions can thermalize the change. These considerations are used to determine time windows in which LTE may be present. Our results suggest that calibration-free LIBS measurements with these lasers may be possible for some elements at early times, especially under argon. - Highlights: ► Powerchip laser-induced plasma evolution is affected by cover gas. ► Plasma often out of LTE, despite fulfilling the McWhirter criterion ► Calibration-free LIBS may be possible with powerchip laser plasmas.

Model uncertainties of local-thermodynamic-equilibrium K-shell spectroscopy

Science.gov (United States)

Nagayama, T.; Bailey, J. E.; Mancini, R. C.; Iglesias, C. A.; Hansen, S. B.; Blancard, C.; Chung, H. K.; Colgan, J.; Cosse, Ph.; Faussurier, G.; Florido, R.; Fontes, C. J.; Gilleron, F.; Golovkin, I. E.; Kilcrease, D. P.; Loisel, G.; MacFarlane, J. J.; Pain, J.-C.; Rochau, G. A.; Sherrill, M. E.; Lee, R. W.

2016-09-01

Local-thermodynamic-equilibrium (LTE) K-shell spectroscopy is a common tool to diagnose electron density, ne, and electron temperature, Te, of high-energy-density (HED) plasmas. Knowing the accuracy of such diagnostics is important to provide quantitative conclusions of many HED-plasma research efforts. For example, Fe opacities were recently measured at multiple conditions at the Sandia National Laboratories Z machine (Bailey et al., 2015), showing significant disagreement with modeled opacities. Since the plasma conditions were measured using K-shell spectroscopy of tracer Mg (Nagayama et al., 2014), one concern is the accuracy of the inferred Fe conditions. In this article, we investigate the K-shell spectroscopy model uncertainties by analyzing the Mg spectra computed with 11 different models at the same conditions. We find that the inferred conditions differ by ±20-30% in ne and ±2-4% in Te depending on the choice of spectral model. Also, we find that half of the Te uncertainty comes from ne uncertainty. To refine the accuracy of the K-shell spectroscopy, it is important to scrutinize and experimentally validate line-shape theory. We investigate the impact of the inferred ne and Te model uncertainty on the Fe opacity measurements. Its impact is small and does not explain the reported discrepancies.

Local thermodynamic equilibrium considerations in powerchip laser-induced plasmas

International Nuclear Information System (INIS)

Merten, Jonathan A.; Smith, Benjamin W.; Omenetto, Nicoló

2013-01-01

Time-resolved emission experiments are reported in the fast-decaying transient plasma induced by a microchip laser on an aluminum target in three different cover gases, i.e., air, argon and helium. The laser operates at 532 nm, with a repetition frequency of 1 kHz and a pulse width of less than 0.5 ns. The overall persistence of plasma emission is of the order of 100 ns. We examine the existence of local thermodynamic equilibrium (LTE) by evaluating the temporal criteria required (in addition to the McWhirter criterion), as recommended by Cristoforetti et al. (Spectrochim. Acta Part B 65, 2010, 86–95). The temporal criteria examine the evolution of temperature and electron number density and compare their rate of change to the rate at which electron collisions can thermalize the change. These considerations are used to determine time windows in which LTE may be present. Our results suggest that calibration-free LIBS measurements with these lasers may be possible for some elements at early times, especially under argon. - Highlights: ► Powerchip laser-induced plasma evolution is affected by cover gas. ► Plasma often out of LTE, despite fulfilling the McWhirter criterion ► Calibration-free LIBS may be possible with powerchip laser plasmas

Application of non-equilibrium thermodynamics to two-phase flows with a change of phase

International Nuclear Information System (INIS)

Delhaye, J.M.

1969-01-01

In this report we use the methods of non-equilibrium thermodynamics in two-phase flows. This paper follows a prior one in which we have studied the conservation laws and derived the general equations of two-phase flow. In the first part the basic ideas of thermodynamics of irreversible systems are given. We follow the classical point of view. The second part is concerned with the derivation of a closed set of equations for the two phase elementary volume model. In this model we assume that the elementary volume contains two phases and that it is possible to define a volumetric local concentration. To obtain the entropy balance we can choose either the reversibility of the barycentric motion or the reversibility of each phase. We adopt the last assumption and our derivation is the same as this of I.Prigogine and P. Mazur about the hydrodynamics of liquid helium. The scope of this work is not to find a general solution to the problems of two phase flows but to obtain a new set of equations which may be used to explain some characteristic phenomena of two-phase flow such as wave propagation or critical states. (author) [fr

Some aspects of plasma thermodynamics

International Nuclear Information System (INIS)

Gorgoraki, V.I.

1986-01-01

The objective reasons which have inhibited the development of a plasma-thermodynamics theory are discussed and the authors formulate the fundamental principles which can be the basis of a common plasma-thermodynamics theory. Two kinds of thermodynamic equilibrium plasmas are discussed, an isothermal plasma and a nonisothermal plasma. An isothermal plasma is a high-temperature plasma; the Saha-Eggert equation describes its behavior. A nonisothermal plasma is a low-temperature plasma, and the reactions taking place therein are purely plasma-chemical. The ionization equilibrium and the composition of such a plasma can be found with the aid of the equations presented in this paper

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

EQ-5D Portuguese population norms.

Science.gov (United States)

Ferreira, Lara Noronha; Ferreira, Pedro L; Pereira, Luis N; Oppe, Mark

2014-03-01

The EQ-5D is a widely used preference-based measure. Normative data can be used as references to analyze the effects of healthcare, determine the burden of disease and enable regional or country comparisons. Population norms for the EQ-5D exist for other countries but have not been previously published for Portugal. The purpose of this study was to derive EQ-5D Portuguese population norms. The EQ-5D was applied by phone interview to a random sample of the Portuguese general population (n = 1,500) stratified by age, gender and region. The Portuguese value set was used to derive the EQ-5D index. Mean values were computed by gender and age groups, marital status, educational attainment, region and other variables to obtain the EQ-5D Portuguese norms. Health status declines with advancing age, and women reported worse health status than men. These results are similar to other EQ-5D population health studies. This study provides Portuguese population health-related quality of life data measured by the EQ-5D that can be used as population norms. These norms can be used to inform Portuguese policy makers, health care professionals and researchers in issues related to health care policy and planning and quantification of treatment effects on health status.

Hydroxylamine and methoxyamine mutagenesis: displacement of the tautomeric equilibrium of the promutagen N6-methoxyadenosine by complementary base pairing.

Science.gov (United States)

Stolarski, R; Kierdaszuk, B; Hagberg, C E; Shugar, D

1984-06-19

The imino-amino tautomeric equilibrium of the promutagenic adenosine analogue N6-methoxy-2',3',5'-tri-O-methyladenosine [OMe6A(Me)3], in solvents of various polarities, has been studied with the aid of 1H and 13C NMR spectroscopy. The high energy barrier (free enthalpy delta G = 80 +/- 5 kJ X mol-1) between the two tautomeric species renders possible direct observation of the independent sets of all 1H and 13C signals from each of them. The equilibrium ranges from 10% imino in CCl4 to 90% in aqueous medium. Thermodynamic parameters, including energy barriers and lifetimes, were calculated from the temperature dependence of the equilibrium. Essentially similar results prevail for the promutagenic N6-hydroxy analogue. The conformations of the sugar moieties, and of the base about the glycosidic bond, for both tautomers are similar to those for adenosine. The conformation of the exocyclic N6-OCH3 group, which determines the ability of each species to form planar associates (hydrogen-bonded base pairs), has also been evaluated. Formation of autoassociates of OMe6A(Me)3 and of heteroassociates with the potentially complementary 2',3',5'-tri-O-methyluridine and -cytidine, in chloroform solution, was also investigated. The amino form base pairs with uridine and the imino form with cytidine. Formation of a complementary base pair by a given tautomeric species was accompanied by an increase of up to 10% in the population of this species and a concomitant decrease in population of the other species.(ABSTRACT TRUNCATED AT 250 WORDS)

Covariant Thermodynamics of Quantum Systems: Passivity, Semipassivity, and the Unruh Effect

NARCIS (Netherlands)

Kuckert, Bernd

2001-01-01

According to the Second Law of Thermodynamics, cycles applied to thermodynamic equilibrium states cannot perform any work (passivity property of thermodynamic equilibrium states). In the presence of matter this can hold only in the rest frame of the matter, as moving matter makes windmills and

Effect of heavy ion irradiation on thermodynamically equilibrium Zr-Excel alloy

Energy Technology Data Exchange (ETDEWEB)

Yu, Hongbing [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, K7L 3N6 (Canada); Liang, Jianlie [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, K7L 3N6 (Canada); College of Science, Guangxi University for Nationalities, 188, East Da Xue Rd., Nanning, Guangxi, 530006 P.R.C (China); Yao, Zhongwen, E-mail: yaoz@queensu.ca [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, K7L 3N6 (Canada); Kirk, Mark A. [Material Science Division Argonne National Laboratory, Argonne, IL 60439 (United States); Daymond, Mark R., E-mail: mark.daymond@queensu.ca [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, K7L 3N6 (Canada)

2017-05-15

The thermodynamically equilibrium state was achieved in a Zr-Sn-Nb-Mo alloy by long-term annealing at an intermediate temperature. The fcc intermetallic Zr(Mo, Nb){sub 2} enriched with Fe was observed at the equilibrium state. In-situ 1 MeV Kr{sup 2+} heavy ion irradiation was performed in a TEM to study the stability of the intermetallic particles under irradiation and the effects of the intermetallic particle on the evolution of type dislocation loops at different temperatures from 80 to 550 °C. Chemi-STEM elemental maps were made at the same particles before and after irradiation up to 10 dpa. It was found that no elemental redistribution occurs at 200 °C and below. Selective depletion of Fe was observed from some precipitates under irradiation at higher temperatures. No change in the morphology of particles and no evidence showing a crystalline to amorphous transformation were observed at all irradiation temperatures. The formation of type dislocation loops was observed under irradiation at 80 and 200 °C, but not at 450 and 550 °C. The loops were non-uniformly distributed; a localized high density of type dislocation loops were observed near the second phase particles; we suggest that loop nucleation is favored as a result of the stress induced by the particles, rather than by elemental redistribution. The stability of the second phase particles and the formation of the type loops under heavy ion irradiation are discussed.

Lagrangian formulation of irreversible thermodynamics and the second law of thermodynamics.

Science.gov (United States)

Glavatskiy, K S

2015-05-28

We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a Lagrangian, which depends on the properties of the normal and the so-called "mirror-image" system. The Lagrangian is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the Lagrangian. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an "integral of evolution" which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium.

A non-equilibrium thermodynamics model of reconstituted Ca(2+)-ATPase.

Science.gov (United States)

Waldeck, A R; van Dam, K; Berden, J; Kuchel, P W

1998-01-01

A non-equilibrium thermodynamics (NET) model describing the action of completely coupled or 'slipping' reconstituted Ca(2+)-ATPase is presented. Variation of the coupling stoichiometries with the magnitude of the electrochemical gradients, as the ATPase hydrolyzes ATP, is an indication of molecular slip. However, the Ca2+ and H+ membrane-leak conductances may also be a function of their respective gradients. Such non-ohmic leak typically yields 'flow-force' relationships that are similar to those that are obtained when the pump slips; hence, caution needs to be exercised when interpreting data of Ca(2+)-ATPase-mediated fluxes that display a non-linear dependence on the electrochemical proton (delta mu H) and/or calcium gradients (delta mu Ca). To address this issue, three experimentally verifiable relationships differentiating between membrane leak and enzymic slip were derived. First, by measuring delta mu H as a function of the rate of ATP hydrolysis by the enzyme. Second, by measuring the overall 'efficiency' of the pump as a function of delta mu H. Third, by measuring the proton ejection rate by the pump as a function of its ATP hydrolysis rate.

Research Article

African Journals Online (AJOL)

2016-06-18

Jun 18, 2016 ... High-pressure technologies create processes that produce new products ... modeling and simulation of thermodynamic systems. .... Phase equilibrium calculations has been conducted based on the Eq. (2) and using MATLAB.

Comparing the UK EQ-5D-3L and English EQ-5D-5L Value Sets.

Science.gov (United States)

Mulhern, Brendan; Feng, Yan; Shah, Koonal; Janssen, Mathieu F; Herdman, Michael; van Hout, Ben; Devlin, Nancy

2018-06-01

Three EQ-5D value sets (EQ-5D-3L, crosswalk, and EQ-5D-5L) are now available for cost-utility analysis in the UK and/or England. The value sets' characteristics differ, and it is important to assess the implications of these differences. The aim of this paper is to compare the three value sets. We carried out analysis comparing the predicted values from each value set, and investigated how differences in health on the descriptive system is reflected in the utility score by assessing the value of adjacent states. We also assessed differences in values using data from patients who completed both EQ-5D-3L and EQ-5D-5L. The distribution of the value sets systematically differed. EQ-5D-5L values were higher than EQ-5D-3L/crosswalk values. The overall range and difference between adjacent states was smaller. In the patient data, the EQ-5D-5L produced higher values across all conditions and there was some evidence that the value sets rank different health conditions in a similar severity order. There are important differences between the value sets. Due to the smaller range of EQ-5D-5L values, the possible change in quality-adjusted life years (QALYs) might be reduced, but they will apply to both control and intervention groups, and will depend on whether the gain is in quality of life, survival, or both. The increased sensitivity of EQ-5D-5L may also favour QALY gains even if the changes in utility are smaller. Further work should assess the impact of the different value sets on cost effectiveness by repeating the analysis on clinical trial data.

Extended Irreversible Thermodynamics

CERN Document Server

Jou, David

2010-01-01

This is the 4th edition of the highly acclaimed monograph on Extended Irreversible Thermodynamics, a theory that goes beyond the classical theory of irreversible processes. In contrast to the classical approach, the basic variables describing the system are complemented by non-equilibrium quantities. The claims made for extended thermodynamics are confirmed by the kinetic theory of gases and statistical mechanics. The book covers a wide spectrum of applications, and also contains a thorough discussion of the foundations and the scope of the current theories on non-equilibrium thermodynamics. For this new edition, the authors critically revised existing material while taking into account the most recent developments in fast moving fields such as heat transport in micro- and nanosystems or fast solidification fronts in materials sciences. Several fundamental chapters have been revisited emphasizing physics and applications over mathematical derivations. Also, fundamental questions on the definition of non-equil...

Thermodynamic DFT analysis of natural gas.

Science.gov (United States)

Neto, Abel F G; Huda, Muhammad N; Marques, Francisco C; Borges, Rosivaldo S; Neto, Antonio M J C

2017-08-01

Density functional theory was performed for thermodynamic predictions on natural gas, whose B3LYP/6-311++G(d,p), B3LYP/6-31+G(d), CBS-QB3, G3, and G4 methods were applied. Additionally, we carried out thermodynamic predictions using G3/G4 averaged. The calculations were performed for each major component of seven kinds of natural gas and to their respective air + natural gas mixtures at a thermal equilibrium between room temperature and the initial temperature of a combustion chamber during the injection stage. The following thermodynamic properties were obtained: internal energy, enthalpy, Gibbs free energy and entropy, which enabled us to investigate the thermal resistance of fuels. Also, we estimated an important parameter, namely, the specific heat ratio of each natural gas; this allowed us to compare the results with the empirical functions of these parameters, where the B3LYP/6-311++G(d,p) and G3/G4 methods showed better agreements. In addition, relevant information on the thermal and mechanic resistance of natural gases were investigated, as well as the standard thermodynamic properties for the combustion of natural gas. Thus, we show that density functional theory can be useful for predicting the thermodynamic properties of natural gas, enabling the production of more efficient compositions for the investigated fuels. Graphical abstract Investigation of the thermodynamic properties of natural gas through the canonical ensemble model and the density functional theory.

The equilibrium of neural firing: A mathematical theory

Energy Technology Data Exchange (ETDEWEB)

Lan, Sizhong, E-mail: lsz@fuyunresearch.org [Fuyun Research, Beijing, 100055 (China)

2014-12-15

Inspired by statistical thermodynamics, we presume that neuron system has equilibrium condition with respect to neural firing. We show that, even with dynamically changeable neural connections, it is inevitable for neural firing to evolve to equilibrium. To study the dynamics between neural firing and neural connections, we propose an extended communication system where noisy channel has the tendency towards fixed point, implying that neural connections are always attracted into fixed points such that equilibrium can be reached. The extended communication system and its mathematics could be useful back in thermodynamics.

Uniform topology on EQ-algebras

Directory of Open Access Journals (Sweden)

Yang Jiang

2017-04-01

Full Text Available In this paper, we use filters of an EQ-algebra E to induce a uniform structure (E, , and then the part induce a uniform topology in E. We prove that the pair (E, is a topological EQ-algebra, and some properties of (E, are investigated. In particular, we show that (E, is a first-countable, zero-dimensional, disconnected and completely regular space. Finally, by using convergence of nets, the convergence of topological EQ-algebras is obtained.

Equilibrium Partitioning Sediment Benchmarks (ESBs) for the ...

Science.gov (United States)

This document describes procedures to determine the concentrations of nonionic organic chemicals in sediment interstitial waters. In previous ESB documents, the general equilibrium partitioning (EqP) approach was chosen for the derivation of sediment benchmarks because it accounts for the varying bioavailability of chemicals in different sediments and allows for the incorporation of the appropriate biological effects concentration. This provides for the derivation of benchmarks that are causally linked to the specific chemical, applicable across sediments, and appropriately protective of benthic organisms.  This equilibrium partitioning sediment benchmark (ESB) document was prepared by scientists from the Atlantic Ecology Division, Mid-Continent Ecology Division, and Western Ecology Division, the Office of Water, and private consultants. The document describes procedures to determine the interstitial water concentrations of nonionic organic chemicals in contaminated sediments. Based on these concentrations, guidance is provided on the derivation of toxic units to assess whether the sediments are likely to cause adverse effects to benthic organisms. The equilibrium partitioning (EqP) approach was chosen because it is based on the concentrations of chemical(s) that are known to be harmful and bioavailable in the environment.  This document, and five others published over the last nine years, will be useful for the Program Offices, including Superfund, a

Letter report: status on code maintenance (EQ3/6)

International Nuclear Information System (INIS)

Wolery, T.J.

1995-01-01

EQ3/6 is a software package for geochemical modeling of aqueous systems, such as water/rock or waste/water rock. It is being developed for a variety of applications in geochemical studies for the Yucca Mountain Site Characterization Project. Version 7.2a was the first version of this software to be certified for use in quality- affecting work (originally issued for use in non-quality-affecting work only on 12/28/93; certified on S/17/94). In the past year, the Version 7 line software has been maintained while the new Version 8 line has been developed. In this period, sixteen defect reports have been logged and resolved. Corrected software is being released as Version 7.2b. Defect reporting and resolution for the Version 7 line will continue until all released versions in this line are retired, perhaps six months to a year after Version 8.0 is released later this year. The Version 7 software is written in Fortran 77, technically speaking, but incorporates many aspects of older Fortran. The Version 8 software is written in a much more modern Fortran, technically somewhere between Fortran 77 and Fortran 90. Future code maintenance activities will include a more complete move to Fortran 90, as well as continued maintaining of defect reporting and resolution

Dissipation and the relaxation to equilibrium

International Nuclear Information System (INIS)

Evans, Denis J; Williams, Stephen R; Searles, Debra J

2009-01-01

Using the recently derived dissipation theorem and a corollary of the transient fluctuation theorem (TFT), namely the second-law inequality, we derive the unique time independent, equilibrium phase space distribution function for an ergodic Hamiltonian system in contact with a remote heat bath. We prove under very general conditions that any deviation from this equilibrium distribution breaks the time independence of the distribution. Provided temporal correlations decay, we show that any nonequilibrium distribution that is an even function of the momenta eventually relaxes (not necessarily monotonically) to the equilibrium distribution. Finally we prove that the negative logarithm of the microscopic partition function is equal to the thermodynamic Helmholtz free energy divided by the thermodynamic temperature and Boltzmann's constant. Our results complement and extend the findings of modern ergodic theory and show the importance of dissipation in the process of relaxation towards equilibrium

Experimental determination and thermodynamic modeling of phase equilibrium and protein partitioning in aqueous two-phase systems containing biodegradable salts

International Nuclear Information System (INIS)

Perez, Brenda; Malpiedi, Luciana Pellegrini; Tubío, Gisela; Nerli, Bibiana; Alcântara Pessôa Filho, Pedro de

2013-01-01

Highlights: ► Binodal data of systems (water + polyethyleneglycol + sodium) succinate are reported. ► Pitzer model describes the phase equilibrium of systems formed by polyethyleneglycol and biodegradable salts satisfactorily. ► This simple thermodynamic framework was able to predict the partitioning behaviour of model proteins acceptably well. - Abstract: Phase diagrams of sustainable aqueous two-phase systems (ATPSs) formed by polyethyleneglycols (PEGs) of different average molar masses (4000, 6000, and 8000) and sodium succinate are reported in this work. Partition coefficients (Kps) of seven model proteins: bovine serum albumin, catalase, beta-lactoglobulin, alpha-amylase, lysozyme, pepsin, urease and trypsin were experimentally determined in these systems and in ATPSs formed by the former PEGs and other biodegradable sodium salts: citrate and tartrate. An extension of Pitzer model comprising long and short-range term contributions to the excess Gibbs free energy was used to describe the (liquid + liquid) equilibrium. Comparison between experimental and calculated tie line data showed mean deviations always lower than 3%, thus indicating a good correlation. The partition coefficients were modeled by using the same thermodynamic approach. Predicted and experimental partition coefficients correlated quite successfully. Mean deviations were found to be lower than the experimental uncertainty for most of the assayed proteins.

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)

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)

Alkylation of isobutane by ethylene: A thermodynamic study

Energy Technology Data Exchange (ETDEWEB)

Goupil, J.M.; Poirier, J.L.; Cornet, D. (Univ. of Caen (France). Lab. Catalyse et Spectrochimie)

1994-03-01

Alkylation of isobutane by ethylene produces mainly hexanes, but a variety of other compounds, alkanes or alkenes, may be formed by secondary reactions such as successive alkylations, isomerization, and ethylene polymerization. The equilibrium distribution of products is evaluated in the temperature range 280--680 K and at various initial compositions and pressures. Isomer groups are treated using Alberty's formulation. Calculations show that alkenes are thermodynamically unstable under usual reaction conditions. The equilibrium amounts of alkanes are such that C[sub 6] [much gt] C[sub 8] [much gt] C[sub 10] and heavy alkanes also appear unstable. The selective formation of particular isomers (dimethylbutanes, trimethylpentanes) is also integrated in the equilibrium equations. The calculated compositions (C[sub 6]:C[sub 8]:C[sub 10]) are compared with experimental data.

CET89 - CHEMICAL EQUILIBRIUM WITH TRANSPORT PROPERTIES, 1989

Science.gov (United States)

Mcbride, B.

1994-01-01

Scientists and engineers need chemical equilibrium composition data to calculate the theoretical thermodynamic properties of a chemical system. This information is essential in the design and analysis of equipment such as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical processing equipment. The substantial amount of numerical computation required to obtain equilibrium compositions and transport properties for complex chemical systems led scientists at NASA's Lewis Research Center to develop CET89, a program designed to calculate the thermodynamic and transport properties of these systems. CET89 is a general program which will calculate chemical equilibrium compositions and mixture properties for any chemical system with available thermodynamic data. Generally, mixtures may include condensed and gaseous products. CET89 performs the following operations: it 1) obtains chemical equilibrium compositions for assigned thermodynamic states, 2) calculates dilute-gas transport properties of complex chemical mixtures, 3) obtains Chapman-Jouguet detonation properties for gaseous species, 4) calculates incident and reflected shock properties in terms of assigned velocities, and 5) calculates theoretical rocket performance for both equilibrium and frozen compositions during expansion. The rocket performance function allows the option of assuming either a finite area or an infinite area combustor. CET89 accommodates problems involving up to 24 reactants, 20 elements, and 600 products (400 of which may be condensed). The program includes a library of thermodynamic and transport properties in the form of least squares coefficients for possible reaction products. It includes thermodynamic data for over 1300 gaseous and condensed species and transport data for 151 gases. The subroutines UTHERM and UTRAN convert thermodynamic and transport data to unformatted form for faster processing. The program conforms to the FORTRAN 77 standard, except for

A non-equilibrium thermodynamic model for tumor extracellular matrix with enzymatic degradation

Science.gov (United States)

Xue, Shi-Lei; Li, Bo; Feng, Xi-Qiao; Gao, Huajian

2017-07-01

The extracellular matrix (ECM) of a solid tumor not only affords scaffolding to support tumor architecture and integrity but also plays an essential role in tumor growth, invasion, metastasis, and therapeutics. In this paper, a non-equilibrium thermodynamic theory is established to study the chemo-mechanical behaviors of tumor ECM, which is modeled as a poroelastic polyelectrolyte consisting of a collagen network and proteoglycans. By using the principle of maximum energy dissipation rate, we deduce a set of governing equations for drug transport and mechanosensitive enzymatic degradation in ECM. The results reveal that osmosis is primarily responsible for the compression resistance of ECM. It is suggested that a well-designed ECM degradation can effectively modify the tumor microenvironment for improved efficiency of cancer therapy. The theoretical predictions show a good agreement with relevant experimental observations. This study aimed to deepen our understanding of tumor ECM may be conducive to novel anticancer strategies.

Particle creation and non-equilibrium thermodynamical prescription of dark fluids for universe bounded by an event horizon

Science.gov (United States)

Saha, Subhajit; Biswas, Atreyee; Chakraborty, Subenoy

2015-03-01

In the present work, flat FRW model of the universe is considered to be an isolated open thermodynamical system where non-equilibrium prescription has been studied using the mechanism of particle creation. In the perspective of recent observational evidences, the matter distribution in the universe is assumed to be dominated by dark matter and dark energy. The dark matter is chosen as dust while for dark energy, the following choices are considered: (i) Perfect fluid with constant equation of state and (ii) Holographic dark energy. In both the cases, the validity of generalized second law of thermodynamics (GSLT) which states that the total entropy of the fluid as well as that of the horizon should not decrease with the evolution of the universe, has been examined graphically for universe bounded by the event horizon. It is found that GSLT holds in both the cases with some restrictions on the interacting coupling parameter.

A statistical model for instable thermodynamical systems

International Nuclear Information System (INIS)

Sommer, Jens-Uwe

2003-01-01

A generic model is presented for statistical systems which display thermodynamic features in contrast to our everyday experience, such as infinite and negative heat capacities. Such system are instable in terms of classical equilibrium thermodynamics. Using our statistical model, we are able to investigate states of instable systems which are undefined in the framework of equilibrium thermodynamics. We show that a region of negative heat capacity in the adiabatic environment, leads to a first order like phase transition when the system is coupled to a heat reservoir. This phase transition takes place without a phase coexistence. Nevertheless, all intermediate states are stable due to fluctuations. When two instable system are brought in thermal contact, the temperature of the composed system is lower than the minimum temperature of the individual systems. Generally, the equilibrium states of instable system cannot be simply decomposed into equilibrium states of the individual systems. The properties of instable system depend on the environment, ensemble equivalence is broken

Thermodynamic behaviour of ruthenium at high temperatures

International Nuclear Information System (INIS)

Garisto, F.

1988-01-01

Thermodynamic equilibrium calculations are used to determine the chemical speciation of ruthenium under postulated reactor accident conditions. The speciation of ruthenium is determined for various values of temperature, pressure, oxygen partial pressure and ruthenium concentration. The importance of these variables, in particular the oxygen partial pressure, in determining the volatility of ruthenium is clearly demonstrated in this report. Reliable thermodynamic data are required to determine the behaviour of ruthenium using equilibrium calculations. Therefore, it was necessary to compile a thermodynamic database for the ruthenium species that can be formed under reactor accident conditions. The origin of the thermodynamic data for the ruthenium species included in our calculations is discussed in detail in Appendix A. 23 refs

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)

A new perspective on the electron transfer: recovering the Butler-Volmer equation in non-equilibrium thermodynamics.

Science.gov (United States)

Dreyer, Wolfgang; Guhlke, Clemens; Müller, Rüdiger

2016-09-28

Electron transfer reactions are commonly described by the phenomenological Butler-Volmer equation which has its origin in kinetic theories. The Butler-Volmer equation relates interfacial reaction rates to bulk quantities like the electrostatic potential and electrolyte concentrations. Although the general structure of the equation is well accepted, for modern electrochemical systems like batteries and fuel cells there is still intensive discussion about the specific dependencies of the coefficients. A general guideline for the derivation of Butler-Volmer type equations is missing in the literature. We derive very general relations of Butler-Volmer structure which are based on a rigorous non-equilibrium thermodynamic model and allow for adaption to a wide variety of electrochemical systems. We discuss the application of the new thermodynamic approach to different scenarios like the classical electron transfer reactions at metal electrodes and the intercalation process in lithium-iron-phosphate electrodes. Furthermore we show that under appropriate conditions also adsorption processes can lead to Butler-Volmer equations. We illustrate the application of our theory by a strongly simplified example of electroplating.

Thermodynamics for the practicing engineer

CERN Document Server

Theodore, Louis; Vanvliet, Timothy

2009-01-01

This book concentrates specifically on the applications of thermodynamics, rather than the theory. It addresses both technical and pragmatic problems in the field, and covers such topics as enthalpy effects, equilibrium thermodynamics, non-ideal thermodynamics and energy conversion applications. Providing the reader with a working knowledge of the principles of thermodynamics, as well as experience in their application, it stands alone as an easy-to-follow self-teaching aid to practical applications and contains worked examples.

Non-local thermodynamic equilibrium stellar spectroscopy with 1D and 3D models - II. Chemical properties of the Galactic metal-poor disk and the halo

DEFF Research Database (Denmark)

Bergemann, Maria; Collet, Remo; Schönrich, Ralph

2016-01-01

We have analysed high-resolution spectra of 328 stars and derived Mg abundances using non-local thermodynamic equilibrium (NLTE) spectral line formation calculations and plane-parallel model stellar atmospheres derived from the mean stratification of 3D hydrodynamical surface convection simulations...

Nonequilibrium thermodynamics of dilute polymer solutions in flow.

Science.gov (United States)

Latinwo, Folarin; Hsiao, Kai-Wen; Schroeder, Charles M

2014-11-07

Modern materials processing applications and technologies often occur far from equilibrium. To this end, the processing of complex materials such as polymer melts and nanocomposites generally occurs under strong deformations and flows, conditions under which equilibrium thermodynamics does not apply. As a result, the ability to determine the nonequilibrium thermodynamic properties of polymeric materials from measurable quantities such as heat and work is a major challenge in the field. Here, we use work relations to show that nonequilibrium thermodynamic quantities such as free energy and entropy can be determined for dilute polymer solutions in flow. In this way, we determine the thermodynamic properties of DNA molecules in strong flows using a combination of simulations, kinetic theory, and single molecule experiments. We show that it is possible to calculate polymer relaxation timescales purely from polymer stretching dynamics in flow. We further observe a thermodynamic equivalence between nonequilibrium and equilibrium steady-states for polymeric systems. In this way, our results provide an improved understanding of the energetics of flowing polymer solutions.

A NON-LOCAL THERMODYNAMIC EQUILIBRIUM ANALYSIS OF BORON ABUNDANCES IN METAL-POOR STARS

International Nuclear Information System (INIS)

Tan Kefeng; Shi Jianrong; Zhao Gang

2010-01-01

The non-local thermodynamic equilibrium (NLTE) line formation of neutral boron in the atmospheres of cool stars are investigated. Our results confirm that NLTE effects for the B I resonance lines, which are due to a combination of overionization and optical pumping effects, are most important for hot, metal-poor, and low-gravity stars; however, the amplitude of departures from local thermodynamic equilibrium (LTE) found by this work is smaller than that of previous studies. In addition, our calculation shows that the line formation of B I will get closer to LTE if the strength of collisions with neutral hydrogen increases, which is contrary to the result of previous studies. The NLTE line formation results are applied to the determination of boron abundances for a sample of 16 metal-poor stars with the method of spectrum synthesis of the B I 2497 A resonance lines using the archived HST/GHRS spectra. Beryllium and oxygen abundances are also determined for these stars with the published equivalent widths of the Be II 3131 A resonance and O I 7774 A triplet lines, respectively. The abundances of the nine stars which are not depleted in Be or B show that, no matter what the strength of collisions with neutral hydrogen may be, both Be and B increase with O quasilinearly in the logarithmic plane, which confirms the conclusions that Be and B are mainly produced by the primary process in the early Galaxy. The most noteworthy result of this work is that B increases with Fe or O at a very similar speed as, or a bit faster than, Be does, which is in accord with the theoretical models. The B/Be ratios remain almost constant over the metallicity range investigated here. Our average B/Be ratio falls in the interval [13 ± 4, 17 ± 4], which is consistent with the predictions of the spallation process. The contribution of B from the ν-process may be required if the 11 B/ 10 B isotopic ratios in metal-poor stars are the same as the meteoric value. An accurate measurement of the

Generic Natural Systems Evaluation - Thermodynamic Database Development and Data Management

Energy Technology Data Exchange (ETDEWEB)

Wolery, T W; Sutton, M

2011-09-19

Thermodynamic data are essential for understanding and evaluating geochemical processes, as by speciation-solubility calculations, reaction-path modeling, or reactive transport simulation. These data are required to evaluate both equilibrium states and the kinetic approach to such states (via the affinity term or its equivalent in commonly used rate laws). These types of calculations and the data needed to carry them out are a central feature of geochemistry in many applications, including water-rock interactions in natural systems at low and high temperatures. Such calculations are also made in engineering studies, for example studies of interactions involving man-made materials such as metal alloys and concrete. They are used in a fairly broad spectrum of repository studies where interactions take place among water, rock, and man-made materials (e.g., usage on YMP and WIPP). Waste form degradation, engineered barrier system performance, and near-field and far-field transport typically incorporate some level of thermodynamic modeling, requiring the relevant supporting data. Typical applications of thermodynamic modeling involve calculations of aqueous speciation (which is of great importance in the case of most radionuclides), solubilities of minerals and related solids, solubilities of gases, and stability relations among the various possible phases that might be present in a chemical system at a given temperature and pressure. If a phase can have a variable chemical composition, then a common calculational task is to determine that composition. Thermodynamic modeling also encompasses ion exchange and surface complexation processes. Any and all of these processes may be important in a geochemical process or reactive transport calculation. Such calculations are generally carried out using computer codes. For geochemical modeling calculations, codes such as EQ3/6 and PHREEQC, are commonly used. These codes typically provide 'full service' geochemistry

Generic Natural Systems Evaluation - Thermodynamic Database Development and Data Management

International Nuclear Information System (INIS)

Wolery, T.W.; Sutton, M.

2011-01-01

Thermodynamic data are essential for understanding and evaluating geochemical processes, as by speciation-solubility calculations, reaction-path modeling, or reactive transport simulation. These data are required to evaluate both equilibrium states and the kinetic approach to such states (via the affinity term or its equivalent in commonly used rate laws). These types of calculations and the data needed to carry them out are a central feature of geochemistry in many applications, including water-rock interactions in natural systems at low and high temperatures. Such calculations are also made in engineering studies, for example studies of interactions involving man-made materials such as metal alloys and concrete. They are used in a fairly broad spectrum of repository studies where interactions take place among water, rock, and man-made materials (e.g., usage on YMP and WIPP). Waste form degradation, engineered barrier system performance, and near-field and far-field transport typically incorporate some level of thermodynamic modeling, requiring the relevant supporting data. Typical applications of thermodynamic modeling involve calculations of aqueous speciation (which is of great importance in the case of most radionuclides), solubilities of minerals and related solids, solubilities of gases, and stability relations among the various possible phases that might be present in a chemical system at a given temperature and pressure. If a phase can have a variable chemical composition, then a common calculational task is to determine that composition. Thermodynamic modeling also encompasses ion exchange and surface complexation processes. Any and all of these processes may be important in a geochemical process or reactive transport calculation. Such calculations are generally carried out using computer codes. For geochemical modeling calculations, codes such as EQ3/6 and PHREEQC, are commonly used. These codes typically provide 'full service' geochemistry, meaning that

GENERIC Integrators: Structure Preserving Time Integration for Thermodynamic Systems

Science.gov (United States)

Öttinger, Hans Christian

2018-04-01

Thermodynamically admissible evolution equations for non-equilibrium systems are known to possess a distinct mathematical structure. Within the GENERIC (general equation for the non-equilibrium reversible-irreversible coupling) framework of non-equilibrium thermodynamics, which is based on continuous time evolution, we investigate the possibility of preserving all the structural elements in time-discretized equations. Our approach, which follows Moser's [1] construction of symplectic integrators for Hamiltonian systems, is illustrated for the damped harmonic oscillator. Alternative approaches are sketched.

Thermodynamic analysis of chemical heat pumps

International Nuclear Information System (INIS)

Obermeier, Jonas; Müller, Karsten; Arlt, Wolfgang

2015-01-01

Thermal energy storages and heat pump units represent an important part of high efficient renewable energy systems. By using thermally driven, reversible chemical reactions a combination of thermal energy storage and heat pump can be realized. The influences of thermophysical properties of the involved components on the efficiency of a heat pump cycle is analysed and the relevance of the thermodynamic driving force is worked out. In general, the behaviour of energetic and exergetic efficiency is contrary. In a real cycle, higher enthalpies of reaction decrease the energetic efficiency but increase the exergetic efficiency. Higher enthalpies of reaction allow for lower offsets from equilibrium state for a default thermodynamic driving force of the reaction. - Highlights: • A comprehensive efficiency analysis of gas-solid heat pumps is proposed. • Link between thermodynamic driving force and equilibrium drop is shown. • Calculation of the equilibrium drop based on thermochemical properties. • Reaction equilibria of the decomposition reaction of salt hydrates. • Contrary behavior of energetic and exergetic efficiency

Thermodynamic Simulation of Equilibrium Composition of Reaction Products at Dehydration of a Technological Channel in a Uranium-Graphite Reactor

Science.gov (United States)

Pavliuk, A. O.; Zagumennov, V. S.; Kotlyarevskiy, S. G.; Bespala, E. V.

2018-01-01

The problems of accumulation of nuclear fuel spills in the graphite stack in the course of operation of uranium-graphite nuclear reactors are considered. The results of thermodynamic analysis of the processes in the graphite stack at dehydration of a technological channel, fuel element shell unsealing and migration of fission products, and activation of stable nuclides in structural elements of the reactor and actinides inside the graphite moderator are given. The main chemical reactions and compounds that are produced in these modes in the reactor channel during its operation and that may be hazardous after its shutdown and decommissioning are presented. Thermodynamic simulation of the equilibrium composition is performed using the specialized code TERRA. The results of thermodynamic simulation of the equilibrium composition in different cases of technological channel dehydration in the course of the reactor operation show that, if the temperature inside the active core of the nuclear reactor increases to the melting temperature of the fuel element, oxides and carbides of nuclear fuel are produced. The mathematical model of the nonstationary heat transfer in a graphite stack of a uranium-graphite reactor in the case of the technological channel dehydration is presented. The results of calculated temperature evolution at the center of the fuel element, the replaceable graphite element, the air gap, and in the surface layer of the block graphite are given. The numerical results show that, in the case of dehydration of the technological channel in the uranium-graphite reactor with metallic uranium, the main reaction product is uranium dioxide UO2 in the condensed phase. Low probability of production of pyrophoric uranium compounds (UH3) in the graphite stack is proven, which allows one to disassemble the graphite stack without the risk of spontaneous graphite ignition in the course of decommissioning of the uranium-graphite nuclear reactor.

A Unified Graphical Representation of Chemical Thermodynamics and Equilibrium

Science.gov (United States)

Hanson, Robert M.

2012-01-01

During the years 1873-1879, J. Willard Gibbs published his now-famous set of articles that form the basis of the current perspective on chemical thermodynamics. The second article of this series, "A Method of Geometrical Representation of the Thermodynamic Properties of Substances by Means of Surfaces," published in 1873, is particularly notable…

Native characterization of nucleic acid motif thermodynamics via non-covalent catalysis

Science.gov (United States)

Wang, Chunyan; Bae, Jin H.; Zhang, David Yu

2016-01-01

DNA hybridization thermodynamics is critical for accurate design of oligonucleotides for biotechnology and nanotechnology applications, but parameters currently in use are inaccurately extrapolated based on limited quantitative understanding of thermal behaviours. Here, we present a method to measure the ΔG° of DNA motifs at temperatures and buffer conditions of interest, with significantly better accuracy (6- to 14-fold lower s.e.) than prior methods. The equilibrium constant of a reaction with thermodynamics closely approximating that of a desired motif is numerically calculated from directly observed reactant and product equilibrium concentrations; a DNA catalyst is designed to accelerate equilibration. We measured the ΔG° of terminal fluorophores, single-nucleotide dangles and multinucleotide dangles, in temperatures ranging from 10 to 45 °C. PMID:26782977

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.

Understanding of surface pit formation mechanism of GaN grown in MOCVD based on local thermodynamic equilibrium assumption

International Nuclear Information System (INIS)

Gao Zhi-Yuan; Xue Xiao-Wei; Li Jiang-Jiang; Wang Xun; Xing Yan-Hui; Cui Bi-Feng; Zou De-Shu

2016-01-01

Frank’s theory describes that a screw dislocation will produce a pit on the surface, and has been evidenced in many material systems including GaN. However, the size of the pit calculated from the theory deviates significantly from experimental result. Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c -plane GaN, we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same. If the kinetic process is too vigorous or too slow to reach a balance, the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state. When the curvature at the center of the dislocation core reaches the critical value 1/ r 0 , at the edge of the spiral, the accelerating rate of the curvature may not fall to zero, so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit. (paper)

Integration of the metal ion charge neutralization model for humic acid complexation into the geochemical speciation code EQ3/6

International Nuclear Information System (INIS)

Brendler, V.

2002-01-01

Geochemical modeling often requires the consideration of humics as major complexing agent and colloid. The metal ion charge neutralization model can handle respective interactions and has therefore been integrated into the speciation software EQ3/6. An application showing the influence of the pH-dependence of the loading capacity on actinide speciation is given. (orig.)

Thermodynamic, kinetic and mechanistic investigations of ...

Indian Academy of Sciences (India)

with respect to the rate determining step and the thermodynamic quantities with respect to the equilibrium steps were evaluated and ... are, (1) to establish a rate law through kinetic measure- ments, (2) to ..... second and third equilibrium steps.

Thermodynamic extremal principles for irreversible processes in materials science

Czech Academy of Sciences Publication Activity Database

Fischer, F. D.; Svoboda, Jiří; Petryk, H.

2014-01-01

Roč. 67, APR (2014), s. 1-20 ISSN 1359-6454 Institutional support: RVO:68081723 Keywords : Non- equilibrium * Thermodynamics * Entropy * Onsager's principle * Thermodynamic extremal principles Subject RIV: BJ - Thermodynamics Impact factor: 4.465, year: 2014

Primed infusion with delayed equilibrium of Gd.DTPA for enhanced imaging of small pulmonary metastases.

Science.gov (United States)

Kalber, Tammy L; Campbell-Washburn, Adrienne E; Siow, Bernard M; Sage, Elizabeth; Price, Anthony N; Ordidge, Katherine L; Walker-Samuel, Simon; Janes, Sam M; Lythgoe, Mark F

2013-01-01

To use primed infusions of the magnetic resonance imaging (MRI) contrast agent Gd.DTPA (Magnevist), to achieve an equilibrium between blood and tissue (eqMRI). This may increase tumor Gd concentrations as a novel cancer imaging methodology for the enhancement of small tumor nodules within the low signal-to-noise background of the lung. A primed infusion with a delay before equilibrium (eqMRI) of the Gd(III) chelator Gd.DTPA, via the intraperitoneal route, was used to evaluate gadolinium tumor enhancement as a function of a bolus injection, which is applied routinely in the clinic, compared to gadolinium maintained at equilibrium. A double gated (respiration and cardiac) spin-echo sequence at 9.4T was used to evaluate whole lungs pre contrast and then at 15 (representative of bolus enhancement), 25 and 35 minutes (representative of eqMRI). This was carried out in two lung metastasis models representative of high and low tumor cell seeding. Lungs containing discrete tumor nodes where inflation fixed and taken for haematoxylin and eosin staining as well as CD34 staining for correlation to MRI. We demonstrate that sustained Gd enhancement, afforded by Gd equilibrium, increases the detection of pulmonary metastases compared to bolus enhancement and those tumors which enhance at equilibrium are sub-millimetre in size (<0.7 mm(2)) with a similar morphology to early bronchoalveolar cell carcinomas. As Gd-chelates are routinely used in the clinic for detecting tumors by MRI, this methodology is readily transferable to the clinic and advances MRI as a methodology for the detection of small pulmonary tumors.

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.

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

Thermodynamic implications of the gravitationally induced particle creation scenario

Energy Technology Data Exchange (ETDEWEB)

Saha, Subhajit [Indian Institute of Science Education and Research Kolkata, Department of Physical Sciences, Mohanpur, West Bengal (India); Mondal, Anindita [S N Bose National Centre for Basic Sciences, Department of Astrophysics and Cosmology, Kolkata, West Bengal (India)

2017-03-15

A rigorous thermodynamic analysis has been done as regards the apparent horizon of a spatially flat Friedmann-Lemaitre-Robertson-Walker universe for the gravitationally induced particle creation scenario with constant specific entropy and an arbitrary particle creation rate Γ. Assuming a perfect fluid equation of state p = (γ - 1)ρ with (2)/(3) ≤ γ ≤ 2, the first law, the generalized second law (GSL), and thermodynamic equilibrium have been studied, and an expression for the total entropy (i.e., horizon entropy plus fluid entropy) has been obtained which does not contain Γ explicitly. Moreover, a lower bound for the fluid temperature T{sub f} has also been found which is given by T{sub f} ≥ 8 (((3γ)/(2)-1)/((2)/(γ)-1)) H{sup 2}. It has been shown that the GSL is satisfied for (Γ)/(3H) ≤ 1. Further, when Γ is constant, thermodynamic equilibrium is always possible for (1)/(2) < (Γ)/(3H) < 1, while for (Γ)/(3H) ≤ min {(1)/(2), (2γ-2)/(3γ-2)} and (Γ)/(3H) ≥ 1, equilibrium can never be attained. Thermodynamic arguments also lead us to believe that during the radiation phase, Γ ≤ H. When Γ is not a constant, thermodynamic equilibrium holds if H ≥ (27)/(4) γ{sup 2}H{sup 3} (1-(Γ)/(3H)){sup 2}, however, such a condition is by no means necessary for the attainment of equilibrium. (orig.)

Thermodynamic implications of the gravitationally induced particle creation scenario

International Nuclear Information System (INIS)

Saha, Subhajit; Mondal, Anindita

2017-01-01

A rigorous thermodynamic analysis has been done as regards the apparent horizon of a spatially flat Friedmann-Lemaitre-Robertson-Walker universe for the gravitationally induced particle creation scenario with constant specific entropy and an arbitrary particle creation rate Γ. Assuming a perfect fluid equation of state p = (γ - 1)ρ with (2)/(3) ≤ γ ≤ 2, the first law, the generalized second law (GSL), and thermodynamic equilibrium have been studied, and an expression for the total entropy (i.e., horizon entropy plus fluid entropy) has been obtained which does not contain Γ explicitly. Moreover, a lower bound for the fluid temperature T f has also been found which is given by T f ≥ 8 (((3γ)/(2)-1)/((2)/(γ)-1)) H 2 . It has been shown that the GSL is satisfied for (Γ)/(3H) ≤ 1. Further, when Γ is constant, thermodynamic equilibrium is always possible for (1)/(2) < (Γ)/(3H) < 1, while for (Γ)/(3H) ≤ min {(1)/(2), (2γ-2)/(3γ-2)} and (Γ)/(3H) ≥ 1, equilibrium can never be attained. Thermodynamic arguments also lead us to believe that during the radiation phase, Γ ≤ H. When Γ is not a constant, thermodynamic equilibrium holds if H ≥ (27)/(4) γ 2 H 3 (1-(Γ)/(3H)) 2 , however, such a condition is by no means necessary for the attainment of equilibrium. (orig.)

Life, hierarchy, and the thermodynamic machinery of planet Earth.

Science.gov (United States)

Kleidon, Axel

2010-12-01

Throughout Earth's history, life has increased greatly in abundance, complexity, and diversity. At the same time, it has substantially altered the Earth's environment, evolving some of its variables to states further and further away from thermodynamic equilibrium. For instance, concentrations in atmospheric oxygen have increased throughout Earth's history, resulting in an increased chemical disequilibrium in the atmosphere as well as an increased redox gradient between the atmosphere and the Earth's reducing crust. These trends seem to contradict the second law of thermodynamics, which states for isolated systems that gradients and free energy are dissipated over time, resulting in a state of thermodynamic equilibrium. This seeming contradiction is resolved by considering planet Earth as a coupled, hierarchical and evolving non-equilibrium thermodynamic system that has been substantially altered by the input of free energy generated by photosynthetic life. Here, I present this hierarchical thermodynamic theory of the Earth system. I first present simple considerations to show that thermodynamic variables are driven away from a state of thermodynamic equilibrium by the transfer of power from some other process and that the resulting state of disequilibrium reflects the past net work done on the variable. This is applied to the processes of planet Earth to characterize the generation and transfer of free energy and its dissipation, from radiative gradients to temperature and chemical potential gradients that result in chemical, kinetic, and potential free energy and associated dynamics of the climate system and geochemical cycles. The maximization of power transfer among the processes within this hierarchy yields thermodynamic efficiencies much lower than the Carnot efficiency of equilibrium thermodynamics and is closely related to the proposed principle of Maximum Entropy Production (MEP). The role of life is then discussed as a photochemical process that generates

Comparison of the Multiattribute Utility Instruments EQ-5D and SF-6D in a Europe-Wide Population-Based Cohort of Patients with Inflammatory Bowel Disease 10 Years after Diagnosis.

Science.gov (United States)

Huppertz-Hauss, Gert; Aas, Eline; Lie Høivik, Marte; Langholz, Ebbe; Odes, Selwyn; Småstuen, Milada; Stockbrugger, Reinhold; Hoff, Geir; Moum, Bjørn; Bernklev, Tomm

2016-01-01

Background. The treatment of chronic inflammatory bowel disease (IBD) is costly, and limited resources call for analyses of the cost effectiveness of therapeutic interventions. The present study evaluated the equivalency of the Short Form 6D (SF-6D) and the Euro QoL (EQ-5D), two preference-based HRQoL instruments that are broadly used in cost-effectiveness analyses, in an unselected IBD patient population. Methods. IBD patients from seven European countries were invited to a follow-up visit ten years after their initial diagnosis. Clinical and demographic data were assessed, and the Short Form 36 (SF-36) was employed. Utility scores were obtained by calculating the SF-6D index values from the SF-36 data for comparison with the scores obtained with the EQ-5D questionnaire. Results. The SF-6D and EQ-5D provided good sensitivities for detecting disease activity-dependent utility differences. However, the single-measure intraclass correlation coefficient was 0.58, and the Bland-Altman plot indicated numerous values beyond the limits of agreement. Conclusions. There was poor agreement between the measures retrieved from the EQ-5D and the SF-6D utility instruments. Although both instruments may provide good sensitivity for the detection of disease activity-dependent utility differences, the instruments cannot be used interchangeably. Cost-utility analyses performed with only one utility instrument must be interpreted with caution.

Matsubara-Fradkin thermodynamical quantization of Podolsky electrodynamics

International Nuclear Information System (INIS)

Bonin, C. A.; Pimentel, B. M.

2011-01-01

In this work, we apply the Matsubara-Fradkin formalism and the Nakanishi's auxiliary field method to the quantization of the Podolsky electrodynamics in thermodynamic equilibrium. This approach allows us to write consistently the path integral representation for the partition function of gauge theories in a simple manner. Furthermore, we find the Dyson-Schwinger-Fradkin equations and the Ward-Fradkin-Takahashi identities for the Podolsky theory. We also write the most general form for the polarization tensor in thermodynamic equilibrium.

Chemical engineering and thermodynamics using Mat lab

International Nuclear Information System (INIS)

Kim Heon; Kim, Moon Gap; Lee, Hak Yeong; Yeo, Yeong Gu; Ham, Seong Won

2002-02-01

This book consists of twelve chapters and four appendixes about chemical engineering and thermodynamics using Mat lab, which deals with introduction, energy budget, entropy, thermodynamics process, generalization on any fluid, engineering equation of state for PVT properties, deviation of the function, phase equilibrium of pure fluid, basic of multicomponent, phase equilibrium of compound by state equation, activity model and reaction system. The appendixes is about summary of computer program, related mathematical formula and material property of pure component.

A pseudo-equilibrium thermodynamic model of information processing in nonlinear brain dynamics.

Science.gov (United States)

Freeman, Walter J

2008-01-01

Computational models of brain dynamics fall short of performance in speed and robustness of pattern recognition in detecting minute but highly significant pattern fragments. A novel model employs the properties of thermodynamic systems operating far from equilibrium, which is analyzed by linearization near adaptive operating points using root locus techniques. Such systems construct order by dissipating energy. Reinforcement learning of conditioned stimuli creates a landscape of attractors and their basins in each sensory cortex by forming nerve cell assemblies in cortical connectivity. Retrieval of a selected category of stored knowledge is by a phase transition that is induced by a conditioned stimulus, and that leads to pattern self-organization. Near self-regulated criticality the cortical background activity displays aperiodic null spikes at which analytic amplitude nears zero, and which constitute a form of Rayleigh noise. Phase transitions in recognition and recall are initiated at null spikes in the presence of an input signal, owing to the high signal-to-noise ratio that facilitates capture of cortex by an attractor, even by very weak activity that is typically evoked by a conditioned stimulus.

Is applicable thermodynamics of negative temperature for living organisms?

Science.gov (United States)

Atanasov, Atanas Todorov

2017-11-01

During organismal development the moment of sexual maturity can be characterizes by nearly maximum basal metabolic rate and body mass. Once the living organism reaches extreme values of the mass and the basal metabolic rate, it reaches near equilibrium thermodynamic steady state physiological level with maximum organismal complexity. Such thermodynamic systems that reach equilibrium steady state level at maximum mass-energy characteristics can be regarded from the prospective of thermodynamics of negative temperature. In these systems the increase of the internal and free energy is accompanied with decrease of the entropy. In our study we show the possibility the living organisms to regard as thermodynamic system with negative temperature

Computer codes for the evaluation of thermodynamic and transport properties for equilibrium air to 30000 K

Science.gov (United States)

Thompson, Richard A.; Lee, Kam-Pui; Gupta, Roop N.

1991-01-01

The computer codes developed here provide self-consistent thermodynamic and transport properties for equilibrium air for temperatures from 500 to 30000 K over a temperature range of 10 (exp -4) to 10 (exp -2) atm. These properties are computed through the use of temperature dependent curve fits for discrete values of pressure. Interpolation is employed for intermediate values of pressure. The curve fits are based on mixture values calculated from an 11-species air model. Individual species properties used in the mixture relations are obtained from a recent study by the present authors. A review and discussion of the sources and accuracy of the curve fitted data used herein are given in NASA RP 1260.

Thermodynamics in f(R,T) theory of gravity

International Nuclear Information System (INIS)

Sharif, M.; Zubair, M.

2012-01-01

A non-equilibrium picture of thermodynamics is discussed at the apparent horizon of FRW universe in f(R,T) gravity, where R is the Ricci scalar and T is the trace of the energy-momentum tensor. We take two forms of the energy-momentum tensor of dark components and demonstrate that equilibrium description of thermodynamics is not achievable in both cases. We check the validity of the first and second law of thermodynamics in this scenario. It is shown that the Friedmann equations can be expressed in the form of first law of thermodynamics T h dS' h +T h d jmath S' = −dE'+W'dV, where d jmath S' is the entropy production term. Finally, we conclude that the second law of thermodynamics holds both in phantom and non-phantom phases

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

Field-based tests of geochemical modeling codes: New Zealand hydrothermal systems

International Nuclear Information System (INIS)

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1993-12-01

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions

Field-based tests of geochemical modeling codes usign New Zealand hydrothermal systems

International Nuclear Information System (INIS)

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1994-06-01

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions

Thermodynamic Presynthetic Considerations for Ring-Opening Polymerization.

Science.gov (United States)

Olsén, Peter; Odelius, Karin; Albertsson, Ann-Christine

2016-03-14

The need for polymers for high-end applications, coupled with the desire to mimic nature's macromolecular machinery fuels the development of innovative synthetic strategies every year. The recently acquired macromolecular-synthetic tools increase the precision and enable the synthesis of polymers with high control and low dispersity. However, regardless of the specificity, the polymerization behavior is highly dependent on the monomeric structure. This is particularly true for the ring-opening polymerization of lactones, in which the ring size and degree of substitution highly influence the polymer formation properties. In other words, there are two important factors to contemplate when considering the particular polymerization behavior of a specific monomer: catalytic specificity and thermodynamic equilibrium behavior. This perspective focuses on the latter and undertakes a holistic approach among the different lactones with regard to the equilibrium thermodynamic polymerization behavior and its relation to polymer synthesis. This is summarized in a monomeric overview diagram that acts as a presynthetic directional cursor for synthesizing highly specific macromolecules; the means by which monomer equilibrium conversion relates to starting temperature, concentration, ring size, degree of substitution, and its implications for polymerization behavior are discussed. These discussions emphasize the importance of considering not only the catalytic system but also the monomer size and structure relations to thermodynamic equilibrium behavior. The thermodynamic equilibrium behavior relation with a monomer structure offers an additional layer of complexity to our molecular toolbox and, if it is harnessed accordingly, enables a powerful route to both monomer formation and intentional macromolecular design.

Reaction Equilibrium of the ω-Transamination of (S)-Phenylethylamine

DEFF Research Database (Denmark)

Voges, Matthias; Abu, Rohana; Deslauriers, Maria Gundersen

2017-01-01

This work focuses on the thermodynamic equilibrium of the ω-transaminase-catalyzed reaction of (S)-phenylethylamine with cyclohexanone to acetophenone and cyclohexylamine in aqueous solution. For this purpose, the equilibrium concentrations of the reaction were experimentally investigated under...... varying reaction conditions. It was observed that the temperature (30 and 37 °C), the pH (between pH 7 and pH 9), as well as the initial reactant concentrations (between 5 and 50 mmol·kg-1) influenced the equilibrium position of the reaction. The position of the reaction equilibrium was moderately shifted...... position to the reactant side. In order to explain these effects, the activity coefficients of the reacting agents were calculated and the activity-based thermodynamic equilibrium constant Kth of the reaction was determined. For this purpose, the activity coefficients of the reacting agents were modeled...

Computing Equilibrium Chemical Compositions

Science.gov (United States)

Mcbride, Bonnie J.; Gordon, Sanford

1995-01-01

Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

Establishment of data base files of thermodynamic data developed by OECD/NEA. Pt. 2. Thermodynamic data of Tc, U, Np, Pu and Am with auxiliary species

International Nuclear Information System (INIS)

Yoshida, Yasushi; Shibata, Masahiro

2005-03-01

Thermodynamic data base for compounds and complexes of actinides and fission products with auxiliary species specialized in modeling requirements for safety assessment of radioactive waste disposal systems are being developed by NEA TDB project of OECD/NEA. In this project, relevant data bases for compounds and complexes of U, Am, Tc, Np and Pu with auxiliary species were updated and published in 2003. JNC established the data base files available for geochemical calculation codes using these updated data. The procedure for establishment and contents of data base files are described in this report. These data base files were prepared as the formats of major geochemical codes PHREEQE, PHREEQC, EQ3/6 and Geochemist's workbench. Additionally modification for data in the thermodynamic data base files which had been already published by JNC was also done. This procedure and revised data bases are shown in the appendix of this report. (author)

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.

Removal of ibuprofen, naproxen and carbamazepine in aqueous solution onto natural clay: equilibrium, kinetics, and thermodynamic study

Science.gov (United States)

Khazri, Hassen; Ghorbel-Abid, Ibtissem; Kalfat, Rafik; Trabelsi-Ayadi, Malika

2017-10-01

This study aimed to describe the adsorption of three pharmaceuticals compounds (ibuprofen, naproxen and carbamazepine) onto natural clay on the basis of equilibrium parameters such as a function of time, effect of pH, varying of the concentration and the temperature. Adsorption kinetic data were modeled using the Lagergren's first-order and the pseudo-second-order kinetic equations. The kinetic results of adsorption are described better using the pseudo-second order model. The isotherm results were tested in the Langmuir, Freundlich and Dubinin-Radushkevich models. The thermodynamic parameters obtained indicate that the adsorption of pharmaceuticals on the clay is a spontaneous and endothermic process.

Equilibrium, kinetic and thermodynamic studies of adsorption of Pb(II) from aqueous solution onto Turkish kaolinite clay

International Nuclear Information System (INIS)

Sari, Ahmet; Tuzen, Mustafa; Citak, Demirhan; Soylak, Mustafa

2007-01-01

The adsorption of Pb(II) onto Turkish (Bandirma region) kaolinite clay was examined in aqueous solution with respect to the pH, adsorbent dosage, contact time, and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity was found as 31.75 mg/g at pH 5 and 20 deg. C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. The mean free energy of adsorption (13.78 kJ/mol) indicated that the adsorption of Pb(II) onto kaolinite clay may be carried out via chemical ion-exchange mechanism. Thermodynamic parameters, free energy (ΔG o ), enthalpy (ΔH o ) and entropy (ΔS o ) of adsorption were also calculated. These parameters showed that the adsorption of Pb(II) onto kaolinite clay was feasible, spontaneous and exothermic process in nature. Furthermore, the Lagergren-first-order, pseudo-second-order and the intraparticle diffusion models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetics

Ternary Vapor–Liquid Equilibrium Measurements and Modeling of Ethylene Glycol (1) + Water (2) + Methane (3) Systems at 6 and 12.5 MPa

DEFF Research Database (Denmark)

Kruger, Francois J.; Danielsen, Marie V.; Kontogeorgis, Georgios M.

2018-01-01

Novel technologies in the field of subsea gasprocessing include the development of natural gas dehydration facilities, which may operate at high pressure due to their proximity to reservoirs. For the qualification and design of these processing units, ternary vapor−liquid equilibrium data...... are required to validate the thermodynamic models used in the design process. For this purpose, 16 new ternary data points were measured for ethylene glycol (1) + water (2) + methane (3) at 6.0 and 12.5 MPa with temperatures ranging from 288to 323 K and glycol content above 90 wt %. Glycol in gas (y1),water...

PROCEDURES FOR THE DERIVATION OF EQUILIBRIUM ...

Science.gov (United States)

This equilibrium partitioning sediment benchmark (ESB) document describes procedures to derive concentrations for 32 nonionic organic chemicals in sediment which are protective of the presence of freshwater and marine benthic organisms. The equilibrium partitioning (EqP) approach was chosen because it accounts for the varying biological availability of chemicals in different sediments and allows for the incorporation of the appropriate biological effects concentration. This provides for the derivation of benchmarks that are causally linked to the specific chemical, applicable across sediments, and appropriately protective of benthic organisms. EqP can be used to calculate ESBs for any toxicity endpoint for which there are water-only toxicity data; it is not limited to any single effect endpoint. For the purposes of this document, ESBs for 32 nonionic organic chemicals, including several low molecular weight aliphatic and aromatic compounds, pesticides, and phthalates, were derived using Final Chronic Values (FCV) from Water Quality Criteria (WQC) or Secondary Chronic Values (SCV) derived from existing toxicological data using the Great Lakes Water Quality Initiative (GLI) or narcosis theory approaches. These values are intended to be the concentration of each chemical in water that is protective of the presence of aquatic life. For nonionic organic chemicals demonstrating a narcotic mode of action, ESBs derived using the GLI approach specifically for fres

A New Thermodynamics from Nuclei to Stars

Directory of Open Access Journals (Sweden)

Dieter H.E. Gross

2004-03-01

Full Text Available Abstract: Equilibrium statistics of Hamiltonian systems is correctly described by the microcanonical ensemble. Classically this is the manifold of all points in the N-body phase space with the given total energy. Due to Boltzmann's principle, eS=tr(δ(E-H, its geometrical size is related to the entropy S(E,N,.... This definition does not invoke any information theory, no thermodynamic limit, no extensivity, and no homogeneity assumption, as are needed in conventional (canonical thermo-statistics. Therefore, it describes the equilibrium statistics of extensive as well of non-extensive systems. Due to this fact it is the fundamental definition of any classical equilibrium statistics. It can address nuclei and astrophysical objects as well. All kind of phase transitions can be distinguished sharply and uniquely for even small systems. It is further shown that the second law is a natural consequence of the statistical nature of thermodynamics which describes all systems with the same -- redundant -- set of few control parameters simultaneously. It has nothing to do with the thermodynamic limit. It even works in systems which are by far than any thermodynamic "limit".

Adsorption of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin: Equilibrium, kinetics and thermodynamics study

International Nuclear Information System (INIS)

Solgy, Mostafa; Taghizadeh, Majid; Ghoddocynejad, Davood

2015-01-01

Highlights: • Adsorption of uranium from sulphate solutions by an anion exchange resin. • The effects of pH, contact time and adsorbent dosage were investigated. • The adsorption equilibrium is well described by the Freundlich isotherm model. • The adsorption kinetics can be predicted by the pseudo second-order model. • The adsorption is a physical, spontaneous and endothermic process. - Abstract: In the present study, adsorption of uranium from sulphate solutions was evaluated using Amberlite IRA-402 resin. The variation of adsorption process was investigated in batch sorption mode. The parameters studied were pH, contact time and adsorbent dosage. Langmuir and Freundlich isotherm models were used in order to present a mathematical description of the equilibrium data at three different temperatures (25 °C, 35 °C and 45 °C). The final results confirmed that the equilibrium data tend to follow Freundlich isotherm model. The maximum adsorption capacity of Amberlite IRA-402 for uranium(VI) was evaluated to be 213 mg/g for the Langmuir model at 25 °C. The adsorption of uranium on the mentioned anion exchange resin was found to follow the pseudo-second order kinetic model, indicating that chemical adsorption was the rate limiting-step. The values of thermodynamic parameters proved that adsorption process of uranium onto Amberlite IRA-402 resin could be considered endothermic (ΔH > 0) and spontaneous (ΔG < 0)

Solubility of unirradiated UO2 fuel in aqueous solutions. Comparison between experimental and calculated (EQ3/6) data

International Nuclear Information System (INIS)

Ollila, K.

1995-11-01

The solubility behaviour of unirradiated UO 2 pellets was studied under oxic (air-saturated) and anoxic (N 2 ) conditions in deionized water, in sodium bicarbonate solutions with varying bicarbonate content (60 - 600 ppm), in Allard groundwater simulating granitic fresh groundwater conditions, and in bentonite water simulating the effects of bentonite on granitic fresh groundwater (25 deg C). The release of uranium was measured during static batch dissolution experiments of long duration (2-6 years). A comparison was made with the theoretical solubility data calculated with the geochemical code EQ3/6 in order to evaluate solubility (steady state) limiting factors. (orig.) (26 refs., 32 figs., 13 tabs.)

On Thermodynamics Problems in the Single-Phase-Lagging Heat Conduction Model

Directory of Open Access Journals (Sweden)

Shu-Nan Li

2016-11-01

Full Text Available Thermodynamics problems for the single-phase-lagging (SPL model have not been much studied. In this paper, the violation of the second law of thermodynamics by the SPL model is studied from two perspectives, which are the negative entropy production rate and breaking equilibrium spontaneously. The methods for the SPL model to avoid the negative entropy production rate are proposed, which are extended irreversible thermodynamics and the thermal relaxation time. Modifying the entropy production rate positive or zero is not enough to avoid the violation of the second law of thermodynamics for the SPL model, because the SPL model could cause breaking equilibrium spontaneously in some special circumstances. As comparison, it is shown that Fourier’s law and the CV model cannot break equilibrium spontaneously by analyzing mathematical energy integral.

Equilibrium, Kinetic and Thermodynamic Study of Removal of Eosin Yellow from Aqueous Solution Using Teak Leaf Litter Powder.

Science.gov (United States)

Oyelude, Emmanuel O; Awudza, Johannes A M; Twumasi, Sylvester K

2017-09-22

Low-cost teak leaf litter powder (TLLP) was prepared as possible substitute for activated carbon. The feasibility of using the adsorbent to remove eosin yellow (EY) dye from aqueous solution was investigated through equilibrium adsorption, kinetic and thermodynamic studies. The removal of dye from aqueous solution was feasible but influenced by temperature, pH, adsorbent dosage and contact time. Variation in the initial concentration of dye did not influence the equilibrium contact time. Optimum adsorption of dye occurred at low adsorbent dosages, alkaline pH and high temperatures. Langmuir isotherm model best fit the equilibrium adsorption data and the maximum monolayer capacity of the adsorbent was 31.64 mg g -1 at 303 K. The adsorption process was best described by pseudo-second order kinetic model at 303 K. Boundary layer diffusion played a key role in the adsorption process. The mechanism of uptake of EY by TLLP was controlled by both liquid film diffusion and intraparticle diffusion. The values of mean adsorption free energy, E (7.91 kJ mol -1 ), and standard enthalpy, ΔH° (+13.34 kJ mol -1 ), suggest physical adsorption. The adsorption process was endothermic and spontaneous. Teak leaf litter powder is a promising low-cost adsorbent for treating wastewaters containing eosin yellow.

Comparison of the Multiattribute Utility Instruments EQ-5D and SF-6D in a Europe-Wide Population-Based Cohort of Patients with Inflammatory Bowel Disease 10 Years after Diagnosis

Directory of Open Access Journals (Sweden)

Gert Huppertz-Hauss

2016-01-01

Full Text Available Background. The treatment of chronic inflammatory bowel disease (IBD is costly, and limited resources call for analyses of the cost effectiveness of therapeutic interventions. The present study evaluated the equivalency of the Short Form 6D (SF-6D and the Euro QoL (EQ-5D, two preference-based HRQoL instruments that are broadly used in cost-effectiveness analyses, in an unselected IBD patient population. Methods. IBD patients from seven European countries were invited to a follow-up visit ten years after their initial diagnosis. Clinical and demographic data were assessed, and the Short Form 36 (SF-36 was employed. Utility scores were obtained by calculating the SF-6D index values from the SF-36 data for comparison with the scores obtained with the EQ-5D questionnaire. Results. The SF-6D and EQ-5D provided good sensitivities for detecting disease activity-dependent utility differences. However, the single-measure intraclass correlation coefficient was 0.58, and the Bland-Altman plot indicated numerous values beyond the limits of agreement. Conclusions. There was poor agreement between the measures retrieved from the EQ-5D and the SF-6D utility instruments. Although both instruments may provide good sensitivity for the detection of disease activity-dependent utility differences, the instruments cannot be used interchangeably. Cost-utility analyses performed with only one utility instrument must be interpreted with caution.

Elements of chemical thermodynamics

CERN Document Server

Nash, Leonard K

2005-01-01

This survey of purely thermal data in calculating the position of equilibrium in a chemical reaction highlights the physical content of thermodynamics, as distinct from purely mathematical aspects. 1970 edition.

Ch. 33 Modeling: Computational Thermodynamics

International Nuclear Information System (INIS)

Besmann, Theodore M.

2012-01-01

This chapter considers methods and techniques for computational modeling for nuclear materials with a focus on fuels. The basic concepts for chemical thermodynamics are described and various current models for complex crystalline and liquid phases are illustrated. Also included are descriptions of available databases for use in chemical thermodynamic studies and commercial codes for performing complex equilibrium calculations.

Telon Blue AGLF Adsorption by NiO Based Nanomaterials:Equilibrium, Kinetic And Thermodynamic Approach

Directory of Open Access Journals (Sweden)

Gizem Biçer

2017-06-01

Full Text Available In this study, the effects of adsorption parameters such as initial pH, initial dye concentration, temperature and adsorbent dosage on the colour removal from aqueous solution containing Telon Blue AGLF(TB AGLF textile dye were investigated by NiO based nanomaterials and then the compliance of the equilibrium data with the different isotherm models in the literature was evaluated. In the next step, the adsorption sytem was analyzed in terms of kinetics and thermodynamics. At the end of the study, XRD, SEM and FTIR analysis methods were used for the particle characterization. As a result of the experimental studies, it was detected the successful use of NiO based nanomaterials synthesized by aqueous solution method rarely seen in literature for colour removal. Through this study, it is believed that the additional contributions are provided to the scientific investigations about the recovery of the water resources.

The Markov process admits a consistent steady-state thermodynamic formalism

Science.gov (United States)

Peng, Liangrong; Zhu, Yi; Hong, Liu

2018-01-01

The search for a unified formulation for describing various non-equilibrium processes is a central task of modern non-equilibrium thermodynamics. In this paper, a novel steady-state thermodynamic formalism was established for general Markov processes described by the Chapman-Kolmogorov equation. Furthermore, corresponding formalisms of steady-state thermodynamics for the master equation and Fokker-Planck equation could be rigorously derived in mathematics. To be concrete, we proved that (1) in the limit of continuous time, the steady-state thermodynamic formalism for the Chapman-Kolmogorov equation fully agrees with that for the master equation; (2) a similar one-to-one correspondence could be established rigorously between the master equation and Fokker-Planck equation in the limit of large system size; (3) when a Markov process is restrained to one-step jump, the steady-state thermodynamic formalism for the Fokker-Planck equation with discrete state variables also goes to that for master equations, as the discretization step gets smaller and smaller. Our analysis indicated that general Markov processes admit a unified and self-consistent non-equilibrium steady-state thermodynamic formalism, regardless of underlying detailed models.

Molecular thermodynamics of polymer melts at interfaces

International Nuclear Information System (INIS)

Theodorou, D.N.

1988-09-01

A lattice model is developed for the prediction of structure and thermodynamic properties at free polymer melt surfaces and polymer melt/solid interfaces. Density variations in the interfacial region are taken into account by introducing voids in the lattice, in the spirit of the equation of state theory of Sanchez and Lacombe. Intramolecular energy (chain stiffness) effects are explicitly incorporated. The model is derived through a rigorous statistical mechanical and thermodynamic analysis, which is based on the concept of availability. Two cases are considered: ''full equilibrium,'' whereby the interfacial polymer is taken as free to exchange heat, work and mass with a bulk polymer phase at given temperature and pressure; and ''restricted equilibrium,'' whereby a thin polymer film is allowed to equilibrate locally in response to ambient temperature and pressure, but in which chains do not necessarily have the same chemical potential as in the unconstrained bulk. Techniques are developed for calculating surface tension, adhesion tension, density profiles, chain shape, bond orientation, as well as the distribution of segments of various orders in the interfacial region. 28 refs., 6 figs

Thermodynamic approach to biomass gasification; Approche thermodynamique des transformations de la biomasse

Energy Technology Data Exchange (ETDEWEB)

Boissonnet, G.; Seiler, J.M.

2003-07-01

The document presents an approach of biomass transformation in presence of steam, hydrogen or oxygen. Calculation results based on thermodynamic equilibrium are discussed. The objective of gasification techniques is to increase the gas content in CO and H{sub 2}. The maximum content in these gases is obtained when thermodynamic equilibrium is approached. Any optimisation action of a process. will, thus, tend to approach thermodynamic equilibrium conditions. On the other hand, such calculations can be used to determine the conditions which lead to an increase in the production of CO and H{sub 2}. An objective is also to determine transformation enthalpies that are an important input for process calculations. Various existing processes are assessed, and associated thermodynamic limitations are evidenced. (author)

Modeling of thermodynamic non-equilibrium flows around cylinders and in channels

Science.gov (United States)

Sinha, Avick; Gopalakrishnan, Shiva

2017-11-01

Numerical simulations for two different types of flash-boiling flows, namely shear flow (flow through a de-Laval nozzle) and free shear flow (flow past a cylinder) are carried out in the present study. The Homogenous Relaxation Model (HRM) is used to model the thermodynamic non-equilibrium process. It was observed that the vaporization of the fluid stream, which was initially maintained at a sub-cooled state, originates at the nozzle throat. This is because the fluid accelerates at the vena-contracta and subsequently the pressure falls below the saturation vapor pressure, generating a two-phase mixture in the diverging section of the nozzle. The mass flow rate at the nozzle was found to decrease with the increase in fluid inlet temperature. A similar phenomenon also occurs for the free shear case due to boundary layer separation, causing a drop in pressure behind the cylinder. The mass fraction of vapor is maximum at rear end of the cylinder, where the size of the wake is highest. As the back pressure is reduced, severe flashing behavior was observed. The numerical simulations were validated against available experimental data. The authors gratefully acknowledge funding from the public-private partnership between DST, Confederation of Indian Industry and General Electric Pvt. Ltd.

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.

On Thermodynamic Interpretation of Transfer Entropy

Directory of Open Access Journals (Sweden)

Don C. Price

2013-02-01

Full Text Available We propose a thermodynamic interpretation of transfer entropy near equilibrium, using a specialised Boltzmann’s principle. The approach relates conditional probabilities to the probabilities of the corresponding state transitions. This in turn characterises transfer entropy as a difference of two entropy rates: the rate for a resultant transition and another rate for a possibly irreversible transition within the system affected by an additional source. We then show that this difference, the local transfer entropy, is proportional to the external entropy production, possibly due to irreversibility. Near equilibrium, transfer entropy is also interpreted as the difference in equilibrium stabilities with respect to two scenarios: a default case and the case with an additional source. Finally, we demonstrated that such a thermodynamic treatment is not applicable to information flow, a measure of causal effect.

Improved thermodynamic treatment of vacancy-mediated diffusion and creep

Czech Academy of Sciences Publication Activity Database

Fischer, F. D.; Hackl, K.; Svoboda, Jiří

2016-01-01

Roč. 108, APR (2016), s. 347-354 ISSN 1359-6454 R&D Projects: GA ČR(CZ) GA15-06390S Institutional support: RVO:68081723 Keywords : Thermodynamics * Non-equilibrium * Diffusion * Vacancies * Thermodynamic extremal principle Subject RIV: BJ - Thermodynamics Impact factor: 5.301, year: 2016

Capability Assessment of the Equilibrium Field System in KTX

International Nuclear Information System (INIS)

Luo Bing; You Wei; Tan Mingsheng; Bai Wei; Mao Wenzhe; Li Hong; Liu Adi; Lan Tao; Xie Jinlin; Liu Wandong; Luo Zhengping; Xiao Bingjia; Guo Yong

2016-01-01

Radial equilibrium of the KTX plasma column is maintained by the vertical field which is produced by the equilibrium field coils. The equilibrium is also affected by the eddy current, which is generated by the coupling of copper shell, plasma and poloidal field coils. An equivalent circuit model is developed to analyze the dynamic performance of equilibrium field coils, without auxiliary power input to equilibrium field coils and passive conductors. Considering the coupling of poloidal field coils, copper shell and plasma, the evolution of spatial distribution of the eddy current density on the copper shell is estimated by finite element to analyze the effect of shell to balance. The simulation results show that the copper shell and equilibrium field coils can provide enough vertical field to balance 1 MA plasma current in phase 1 of a KTX discharge. Auxiliary power supply on the EQ coils is necessary to control the horizontal displacement of KTX due to the finite resistance effect of the shell. (paper)

Application of Equilibrium Partitioning Theory to Soil PAH Contamination (External Review Draft)

Science.gov (United States)

In March 2004, ORD's Ecological Risk Assessment Support Center (ERASC) received a request from the Ecological Risk Assessment Forum (ERAF) to provide insight into the issue of whether equilibrium partitioning (EqP) techniques can be used to predict the toxicity of polycyclic arom...

Departures from local thermodynamic equilibrium in cutting arc plasmas derived from electron and gas density measurements using a two-wavelength quantitative Schlieren technique

International Nuclear Information System (INIS)

Prevosto, L.; Mancinelli, B.; Artana, G.; Kelly, H.

2011-01-01

A two-wavelength quantitative Schlieren technique that allows inferring the electron and gas densities of axisymmetric arc plasmas without imposing any assumption regarding statistical equilibrium models is reported. This technique was applied to the study of local thermodynamic equilibrium (LTE) departures within the core of a 30 A high-energy density cutting arc. In order to derive the electron and heavy particle temperatures from the inferred density profiles, a generalized two-temperature Saha equation together with the plasma equation of state and the quasineutrality condition were employed. Factors such as arc fluctuations that influence the accuracy of the measurements and the validity of the assumptions used to derive the plasma species temperature were considered. Significant deviations from chemical equilibrium as well as kinetic equilibrium were found at elevated electron temperatures and gas densities toward the arc core edge. An electron temperature profile nearly constant through the arc core with a value of about 14000-15000 K, well decoupled from the heavy particle temperature of about 1500 K at the arc core edge, was inferred.

CO2 Capture with Liquid-Liquid Phase Change Solvents: A Thermodynamic Study

DEFF Research Database (Denmark)

Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

2017-01-01

by the quaternary H2O-DEEAMAPA-CO2 system which gives liquid-liquid phase split when reacted with carbon dioxide. A total of 94 model parameters and 6 thermodynamic properties were fitted to approximately 1500 equilibrium and thermal experimental data consisting of pureamine vapor pressure (Pvap), vapor...

Adsorption of basic dye on high-surface-area activated carbon prepared from coconut husk: Equilibrium, kinetic and thermodynamic studies

Energy Technology Data Exchange (ETDEWEB)

Tan, I.A.W.; Ahmad, A.L. [School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang (Malaysia); Hameed, B.H. [School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang (Malaysia)], E-mail: chbassim@eng.usm.my

2008-06-15

Adsorption isotherm and kinetics of methylene blue on activated carbon prepared from coconut husk were determined from batch tests. The effects of contact time (1-30 h), initial dye concentration (50-500 mg/l) and solution temperature (30-50 {sup o}C) were investigated. Equilibrium data were fitted to Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The equilibrium data were best represented by Langmuir isotherm model, showing maximum monolayer adsorption capacity of 434.78 mg/g. The kinetic data were fitted to pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and was found to follow closely the pseudo-second-order kinetic model. Thermodynamic parameters such as standard enthalpy ({delta}H{sup o}), standard entropy ({delta}S{sup o}) and standard free energy ({delta}G{sup o}) were evaluated. The adsorption interaction was found to be exothermic in nature. Coconut husk-based activated carbon was shown to be a promising adsorbent for removal of methylene blue from aqueous solutions.

Equilibrium Kinetics and Thermodynamic Studies of the Adsorption of Tartrazine and Sunset Yellow

Directory of Open Access Journals (Sweden)

F. O. Okeola

2017-04-01

Full Text Available Batch adsorption experiment was carried out on freema (combination of Tartrazine and Sunset Yellow an adsorbent prepared from moringa pod. The adsorption capacity of the adsorbent was determined. Effect of such factors as initial concentration of the adsorbate solution, contact time with the adsorbent, pH of the dye solution, and temperature of the dye solution on the adsorption capacity of the absorbent was determined. The result showed that the optimum adsorption was attained at pH of 3, adsorption equilibrium was attained within 60 min. The adsorption capacity increases with increase in initial concentration of the dye solution. The result of the kinetics study showed that the adsorption process was better described by the pseudo-second order rate equation. The adsorption process fitted well with both Freundlich (R2 = 0.983 and Langmuir (R2 = 0.933 models. Thermodynamic result showed ΔH and ΔS were all negative. Gibbs free energy change (ΔG increases with increase in temperature of the dye solution.

Biosorption of Cr(VI from AqueousSolution Using New Adsorbent: Equilibrium and Thermodynamic Study

Directory of Open Access Journals (Sweden)

Israa G. Zainal

2010-01-01

Full Text Available Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from polluted water. In the present study cinnamon was utilized for Cr(VI removal from aqueous solutions.It was found that a time of two hours was sufficient for sorption to attain equilibrium. The optimum pH was 2 for Cr(VI removal. Temprature has little influence on the biosorption process. The Cr(VI removal decreased with increase in temperature. The biosorption data was well fitted to Dubinin - Radushkevich (D-R, Freundlich and Tempkin adsorption isotherm models, although the correlation coefficient of Langmuir model was high but the calculated adsorption capacity did not agree with the experimental. The thermodynamic study reveals that the biosorption process is spontaneous and the spontaneity decreased with temperature increase and the process is exothermic accompanied by highly ordered adsorbate at the solid liquid interface. ΔH° values were negative and lie in the range of physical adsorption.

On the modelling of microsegregation in steels involving thermodynamic databases

International Nuclear Information System (INIS)

You, D; Bernhard, C; Michelic, S; Wieser, G; Presoly, P

2016-01-01

A microsegregation model involving thermodynamic database based on Ohnaka's model is proposed. In the model, the thermodynamic database is applied for equilibrium calculation. Multicomponent alloy effects on partition coefficients and equilibrium temperatures are accounted for. Microsegregation and partition coefficients calculated using different databases exhibit significant differences. The segregated concentrations predicted using the optimized database are in good agreement with the measured inter-dendritic concentrations. (paper)

Thermodynamically based constraints for rate coefficients of large biochemical networks.

Science.gov (United States)

Vlad, Marcel O; Ross, John

2009-01-01

Wegscheider cyclicity conditions are relationships among the rate coefficients of a complex reaction network, which ensure the compatibility of kinetic equations with the conditions for thermodynamic equilibrium. The detailed balance at equilibrium, that is the equilibration of forward and backward rates for each elementary reaction, leads to compatibility between the conditions of kinetic and thermodynamic equilibrium. Therefore, Wegscheider cyclicity conditions can be derived by eliminating the equilibrium concentrations from the conditions of detailed balance. We develop matrix algebra tools needed to carry out this elimination, reexamine an old derivation of the general form of Wegscheider cyclicity condition, and develop new derivations which lead to more compact and easier-to-use formulas. We derive scaling laws for the nonequilibrium rates of a complex reaction network, which include Wegscheider conditions as a particular case. The scaling laws for the rates are used for clarifying the kinetic and thermodynamic meaning of Wegscheider cyclicity conditions. Finally, we discuss different ways of using Wegscheider cyclicity conditions for kinetic computations in systems biology.

Thermodynamics II essentials

CERN Document Server

REA, The Editors of

2013-01-01

REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Thermodynamics II includes review of thermodynamic relations, power and refrigeration cycles, mixtures and solutions, chemical reactions, chemical equilibrium, and flow through nozzl

Cluster emission at pre-equilibrium stage in Heavy Nuclear Reactions. A Model considering the Thermodynamics of Small Systems

International Nuclear Information System (INIS)

Bermudez Martinez, A.; Damiani, D.; Guzman Martinez, F.; Rodriguez Hoyos, O.; Rodriguez Manso, A.

2015-01-01

Cluster emission at pre-equilibrium stage, in heavy ion fusion reactions of 12 C and 16 O nuclei with 116 Sn, 208 Pb, 238 U are studied. the energy of the projectile nuclei was chosen at 0.25GeV, 0.5GeV and 1GeV. A cluster formation model is developed in order to calculate the cluster size. Thermodynamics of small systems was used in order to examine the cluster behavior inside the nuclear media. This model is based on considering two phases inside the compound nucleus, on one hand the nuclear media phase, and on the other hand the cluster itself. The cluster acts like an instability inside the compound nucleus, provoking an exchange of nucleons with the nuclear media through its surface. The processes were simulated using Monte Carlo methods. We obtained that the cluster emission probability shows great dependence on the cluster size. This project is aimed to implement cluster emission processes, during the pre-equilibrium stage, in the frame of CRISP code (Collaboration Rio-Sao Paulo). (Author)

Contact symmetries and Hamiltonian thermodynamics

International Nuclear Information System (INIS)

Bravetti, A.; Lopez-Monsalvo, C.S.; Nettel, F.

2015-01-01

It has been shown that contact geometry is the proper framework underlying classical thermodynamics and that thermodynamic fluctuations are captured by an additional metric structure related to Fisher’s Information Matrix. In this work we analyse several unaddressed aspects about the application of contact and metric geometry to thermodynamics. We consider here the Thermodynamic Phase Space and start by investigating the role of gauge transformations and Legendre symmetries for metric contact manifolds and their significance in thermodynamics. Then we present a novel mathematical characterization of first order phase transitions as equilibrium processes on the Thermodynamic Phase Space for which the Legendre symmetry is broken. Moreover, we use contact Hamiltonian dynamics to represent thermodynamic processes in a way that resembles the classical Hamiltonian formulation of conservative mechanics and we show that the relevant Hamiltonian coincides with the irreversible entropy production along thermodynamic processes. Therefore, we use such property to give a geometric definition of thermodynamically admissible fluctuations according to the Second Law of thermodynamics. Finally, we show that the length of a curve describing a thermodynamic process measures its entropy production

Equilibrium Molecular Thermodynamics from Kirkwood Sampling

OpenAIRE

Somani, Sandeep; Okamoto, Yuko; Ballard, Andrew J.; Wales, David J.

2015-01-01

We present two methods for barrierless equilibrium sampling of molecular systems based on the recently proposed Kirkwood method (J. Chem. Phys. 2009, 130, 134102). Kirkwood sampling employs low-order correlations among internal coordinates of a molecule for random (or non-Markovian) sampling of the high dimensional conformational space. This is a geometrical sampling method independent of the potential energy surface. The first method is a variant of biased Monte Carlo, wher...

Understanding of surface pit formation mechanism of GaN grown in MOCVD based on local thermodynamic equilibrium assumption

Science.gov (United States)

Zhi-Yuan, Gao; Xiao-Wei, Xue; Jiang-Jiang, Li; Xun, Wang; Yan-Hui, Xing; Bi-Feng, Cui; De-Shu, Zou

2016-06-01

Frank’s theory describes that a screw dislocation will produce a pit on the surface, and has been evidenced in many material systems including GaN. However, the size of the pit calculated from the theory deviates significantly from experimental result. Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN, we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same. If the kinetic process is too vigorous or too slow to reach a balance, the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state. When the curvature at the center of the dislocation core reaches the critical value 1/r 0, at the edge of the spiral, the accelerating rate of the curvature may not fall to zero, so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204009 and 61204011) and the Beijing Municipal Natural Science Foundation, China (Grant No. 4142005).

Thermodynamics and economics

International Nuclear Information System (INIS)

Mansson, B.A.

1990-01-01

Economics, as the social science most concerned with the use and distribution of natural resources, must start to make use of the knowledge at hand in the natural sciences about such resources. In this, thermodynamics is an essential part. In a physicists terminology, human economic activity may be described as a dissipative system which flourishes by transforming and exchanging resources, goods and services. All this involves complex networks of flows of energy and materials. This implies that thermodynamics, the physical theory of energy and materials flows, must have implications for economics. On another level, thermodynamics has been recognized as a physical theory of value, with value concepts similar to those of economic theory. This paper discusses some general aspects of the significance of non-equilibrium thermodynamics for economics. The role of exergy, probably the most important of the physical measures of value, is elucidated. Two examples of integration of thermodynamics with economic theory are reviewed. First, a simple model of a steady-state production system is sued to illustrate the effects of thermodynamic process constraints. Second, the framework of a simple macroeconomic growth model is used to illustrate how some thermodynamic limitations may be integrated in macroeconomic theory

Thermodynamic metrics and optimal paths.

Science.gov (United States)

Sivak, David A; Crooks, Gavin E

2012-05-11

A fundamental problem in modern thermodynamics is how a molecular-scale machine performs useful work, while operating away from thermal equilibrium without excessive dissipation. To this end, we derive a friction tensor that induces a Riemannian manifold on the space of thermodynamic states. Within the linear-response regime, this metric structure controls the dissipation of finite-time transformations, and bestows optimal protocols with many useful properties. We discuss the connection to the existing thermodynamic length formalism, and demonstrate the utility of this metric by solving for optimal control parameter protocols in a simple nonequilibrium model.

A theoretical view on the thermodynamic cis-trans equilibrium of dihalo ruthenium olefin metathesis (pre-)catalysts

KAUST Repository

Pump, Eva

2015-02-24

Abstract: This work was conducted to provide an overview on the position of the thermodynamic cis–trans equilibrium of 85 conventional and X-chelated alkylidene-ruthenium complexes (X=O, S, Se, N, P, Cl, I, Br). The reported energies (ΔE) were obtained through single-point calculations with M06 functional and TZVP basis set from BP86/SVP-optimized cis- and trans-dichloro geometries and using the polarizable continuum model to simulate the influence of the solvent. Dichloromethane and toluene were selected as examples for solvents with high and low dielectric constants. The obtained relative stabilities of the cis- and trans-dihalo derivatives of the respective alkylidene complexes will serve for a better explanation of their catalytic activity as has been disclosed herein with selected examples.Graphical abstract: [Figure not available: see fulltext.

Ecosystem thermodynamics

International Nuclear Information System (INIS)

Gomez Palacio, German Rau

1998-01-01

Ecology is no more a descriptive and self-sufficient science. Many viewpoints are needed simultaneously to give a full coverage of such complex systems: ecosystems. These viewpoints come from physics, chemistry, and nuclear physics, without a new far from equilibrium thermodynamics and without new mathematical tools such as catastrophe theory, fractal theory, cybernetics and network theory, the development of ecosystem science would never have reached the point of today. Some ideas are presented about the importance that concept such as energy, entropy, exergy information and none equilibrium have in the analysis of processes taking place in ecosystems

Modelling reactive material transport in the near field of a repository for radioactive waste. Coupling the EMOS near field modules CLAYPOS and LOPOS with thermodynamic equilibrium calculations

International Nuclear Information System (INIS)

Moog, H.C.; Keesmann, S.M.

2007-02-01

This paper reports on the project ''Coupling transport models with thermodynamic equilibrium calculations'' - short title EQLINK, promotion code number 02 E 9723 - in the which the scope for coupling thermodynamic equilibrium model calculations with EMOS was expanded and improved. The first step was to inquire into the current state of research on radiolytic processes. It transpired that there is currently no conclusive description of radiolytic processes. The existing descriptions are too complex and too narrowly geared to specific scenarios to allow a general view on radiolytic processes, which would be a prerequisite for creating suitable long-term geochemical safety analysis modules. It appears that the approximation calculations implemented in EMOS tend to overestimate rather than underestimate radiolytic gas formation. The thermodynamic database which is used at GRS (Society for Plant and Reactor Safety) as a basis for coupled transport calculations has been updated. For this purpose the radionuclide database of the Institut fuer Nukleare Entsorgung (INE = Institute for Nuclear Disposal) was converted to an in-house format which permits creating parameter files for specific requirements. The data of the INE comprise thermodynamic parameters such as equilibrium constants, Gibbs free enthalpies of formation, enthalpies and entropies of formation and Pitzer parameters, which are required for model calculations on high-saline solutions. The database for low-saline solutions which had been developed by PSI/NAGRA for calculations with CLAYPOS was also adopted. Both parameter sets were subjected to test calculations to detect any errors that might have occurred during the data transfer. It is thus now possible to perform coupled transport calculations with the EMOS modules LOPOS and CLAYPOS according to the state of the art of geochemical research. The EQLINK interface which had been developed in an earlier project, titled ''Development of a model for describing the

Cross-cultural measurement equivalence of the 5-level EQ-5D (EQ-5D-5L) in patients with type 2 diabetes mellitus in Singapore.

Science.gov (United States)

Wang, Ye; Tan, Ngiap-Chuan; Tay, Ee-Guan; Thumboo, Julian; Luo, Nan

2015-07-16

This study aimed to assess the measurement equivalence of the 5-level EQ-5D (EQ-5D-5L) among the English, Chinese, and Malay versions. A convenience sample of patients with type 2 diabetes mellitus were enrolled from a public primary health care institution in Singapore. The survey questionnaire comprised the EQ-5D-5L and questions assessing participants' socio-demographic and clinical characteristics. Multiple linear regression models were used to assess the difference in EQ-5D-5L index (calculated using an interim algorithm) and EQ-visual analog scale (EQ-VAS) scores across survey language (Chinese vs. English, Malay vs. English, and Malay vs. Chinese). Measurement equivalence was examined by comparing the 90% confidence interval of difference in the EQ-5D-5L index and EQ-VAS scores with a pre-determined equivalence margin. Multiple logistic regression models were used to assess the response patterns of the 5 Likert-type items of the EQ-5D-5L across survey language. Equivalence was demonstrated between the Chinese and English versions and between the Malay and English versions of the EQ-5D-5L index scores. Equivalence was also demonstrated between the Chinese and English versions and between the Malay and Chinese versions of the EQ-VAS scores. Equivalence could not be determined between the Malay and Chinese versions of the EQ-5D-5L index score and between the Malay and English versions of the EQ-VAS score. No significant difference was found in responses to EQ-5D-5L items between any languages, except that patients who chose to complete the Chinese version were more likely to report "no problems" in mobility compared to those who completed the Malay version of the questionnaire. This study provided evidence for the measurement equivalence of the different language versions of EQ-5D-5L in Singapore.

Equilibrium Crystal Shape of BaZrO{sub 3} and Space Charge Formation in the (011) Surface by Using Ab-Initio Thermodynamics

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji-Su; Kim, Yeong-Cheol [Korea University of Technology and Education, Cheonan (Korea, Republic of)

2017-01-15

We investigated the equilibrium crystal shape of BaZrO{sub 3} and the space charge formation in an O-terminated (011) surface by using ab-initio thermodynamics. Twenty-two low-indexed (001), (011), and (111) surfaces were calculated to analyze their surface Gibbs-free energy under the stable condition of BaZrO{sub 3}. Based on the Gibbs-Wulff theorem, the equilibrium crystal shape of BaZrO{sub 3} changed from cubic to decaoctahedral with decreasing Ba chemical potential. The dominant facets of BaZrO{sub 3} were {001} and {011}, which were well consistent with experimental observations. The space charge formation in the (011) surface was evaluated using the space-charge model. We found that the (011) surface was even more resistive than the (001) surface.

Thermodynamics of adaptive molecular resolution.

Science.gov (United States)

Delgado-Buscalioni, R

2016-11-13

A relatively general thermodynamic formalism for adaptive molecular resolution (AMR) is presented. The description is based on the approximation of local thermodynamic equilibrium and considers the alchemic parameter λ as the conjugate variable of the potential energy difference between the atomistic and coarse-grained model Φ=U (1) -U (0) The thermodynamic formalism recovers the relations obtained from statistical mechanics of H-AdResS (Español et al, J. Chem. Phys. 142, 064115, 2015 (doi:10.1063/1.4907006)) and provides relations between the free energy compensation and thermodynamic potentials. Inspired by this thermodynamic analogy, several generalizations of AMR are proposed, such as the exploration of new Maxwell relations and how to treat λ and Φ as 'real' thermodynamic variablesThis article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'. © 2016 The Author(s).

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.

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

PROCEDURES FOR THE DERIVATION OF EQUILIBRIUM PARTITIONING SEDIMENT BENCHMARKS (ESBS) FOR THE PROTECTION OF BENTHIC ORGANISMS: COMPENDIUM OF TIER 2 VALUES FOR NONIONIC ORGANICS

Science.gov (United States)

This equilibrium partitioning sediment benchmark (ESB) document describes procedures to derive concentrations for 32 nonionic organic chemicals in sediment which are protective of the presence of freshwater and marine benthic organisms. The equilibrium partitioning (EqP) approach...

Quantum Rényi relative entropies affirm universality of thermodynamics.

Science.gov (United States)

Misra, Avijit; Singh, Uttam; Bera, Manabendra Nath; Rajagopal, A K

2015-10-01

We formulate a complete theory of quantum thermodynamics in the Rényi entropic formalism exploiting the Rényi relative entropies, starting from the maximum entropy principle. In establishing the first and second laws of quantum thermodynamics, we have correctly identified accessible work and heat exchange in both equilibrium and nonequilibrium cases. The free energy (internal energy minus temperature times entropy) remains unaltered, when all the entities entering this relation are suitably defined. Exploiting Rényi relative entropies we have shown that this "form invariance" holds even beyond equilibrium and has profound operational significance in isothermal process. These results reduce to the Gibbs-von Neumann results when the Rényi entropic parameter α approaches 1. Moreover, it is shown that the universality of the Carnot statement of the second law is the consequence of the form invariance of the free energy, which is in turn the consequence of maximum entropy principle. Further, the Clausius inequality, which is the precursor to the Carnot statement, is also shown to hold based on the data processing inequalities for the traditional and sandwiched Rényi relative entropies. Thus, we find that the thermodynamics of nonequilibrium state and its deviation from equilibrium together determine the thermodynamic laws. This is another important manifestation of the concepts of information theory in thermodynamics when they are extended to the quantum realm. Our work is a substantial step towards formulating a complete theory of quantum thermodynamics and corresponding resource theory.

Thermodynamics in Loop Quantum Cosmology

International Nuclear Information System (INIS)

Li, L.F.; Zhu, J.Y.

2009-01-01

Loop quantum cosmology (LQC) is very powerful to deal with the behavior of early universe. Moreover, the effective loop quantum cosmology gives a successful description of the universe in the semiclassical region. We consider the apparent horizon of the Friedmann-Robertson-Walker universe as a thermodynamical system and investigate the thermodynamics of LQC in the semiclassical region. The effective density and effective pressure in the modified Friedmann equation from LQC not only determine the evolution of the universe in LQC scenario but also are actually found to be the thermodynamic quantities. This result comes from the energy definition in cosmology (the Misner-Sharp gravitational energy) and is consistent with thermodynamic laws. We prove that within the framework of loop quantum cosmology, the elementary equation of equilibrium thermodynamics is still valid.

Statistical Thermodynamics and Microscale Thermophysics

Science.gov (United States)

Carey, Van P.

1999-08-01

Many exciting new developments in microscale engineering are based on the application of traditional principles of statistical thermodynamics. In this text Van Carey offers a modern view of thermodynamics, interweaving classical and statistical thermodynamic principles and applying them to current engineering systems. He begins with coverage of microscale energy storage mechanisms from a quantum mechanics perspective and then develops the fundamental elements of classical and statistical thermodynamics. Subsequent chapters discuss applications of equilibrium statistical thermodynamics to solid, liquid, and gas phase systems. The remainder of the book is devoted to nonequilibrium thermodynamics of transport phenomena and to nonequilibrium effects and noncontinuum behavior at the microscale. Although the text emphasizes mathematical development, Carey includes many examples and exercises to illustrate how the theoretical concepts are applied to systems of scientific and engineering interest. In the process he offers a fresh view of statistical thermodynamics for advanced undergraduate and graduate students, as well as practitioners, in mechanical, chemical, and materials engineering.

The impact of a revised EQ-5D population scoring on preference-based utility scores in an inflammatory arthritis cohort.

LENUS (Irish Health Repository)

Adams, Roisin

2012-02-01

BACKGROUND AND OBJECTIVE: It is well established that there are problems with the EQ-5D. This is due to the original scoring methods used and how negative time trade-off (TTO) values were treated. A revised scoring method has been published. This article applies this to an inflammatory arthritis cohort. The objective is to examine the impact of a revised scoring system for the EQ-5D (UK) TTO on the utility estimates and in the case of rheumatoid arthritis, to explore the impact of using different utility metrics on the incremental cost-effectiveness ratio (ICER) results of an economic model. METHODS: A total of 504 patients with inflammatory arthritis were rescored using revised EQ-5D scoring, which uses an episodic random utility model to deal with negative TTO values. Differences in utility scores were compared and the new mapping coefficients were obtained. These were then used in an economic model to examine the impact on the ICER. RESULTS: In rheumatoid arthritis, the overall change is less for the revised EQ-5D scoring than with the original EQ-5D (TTO) but greater than the SF-6D: EQ-5D UK -0.22 (95% confidence interval [CI] -0.30 to -0.15), revised EQ-5D UK -0.16 (95% CI -0.21 to -0.10) and SF-6D -0.08 (95% CI -0.11 to -0.05). A similar trend is seen in the psoriatic arthritis group. The economic model produced different ICERs, when different utility measures were used; EQ-5D (TTO) euro42,402, SF-6D euro111,788, and revised EQ-5D (TTO) euro57,747. CONCLUSION: In the context of inflammatory arthritis, this article demonstrates that a revised scoring for EQ-5D may have a significant impact on utility estimates and on the output of the economic model.

International thermodynamic tables of the fluid state propylene (propene)

CERN Document Server

Angus, S; De Reuck, K M

2013-01-01

International Thermodynamic Tables of the Fluid State - 7 Propylene (Propene) is a compilation of internationally agreed values of the equilibrium thermodynamic properties of propylene. This book is composed of three chapters, and begins with the presentation of experimental result of thermodynamic studies compared with the equations used to generate the tables. The succeeding chapter deals with correlating equations for thermodynamic property determination of propylene. The last chapter provides the tabulations of the propylene's thermodynamic properties and constants. This book will prove

Nonequilibrium thermodynamics and information theory: basic concepts and relaxing dynamics

International Nuclear Information System (INIS)

Altaner, Bernhard

2017-01-01

Thermodynamics is based on the notions of energy and entropy. While energy is the elementary quantity governing physical dynamics, entropy is the fundamental concept in information theory. In this work, starting from first principles, we give a detailed didactic account on the relations between energy and entropy and thus physics and information theory. We show that thermodynamic process inequalities, like the second law, are equivalent to the requirement that an effective description for physical dynamics is strongly relaxing. From the perspective of information theory, strongly relaxing dynamics govern the irreversible convergence of a statistical ensemble towards the maximally non-commital probability distribution that is compatible with thermodynamic equilibrium parameters. In particular, Markov processes that converge to a thermodynamic equilibrium state are strongly relaxing. Our framework generalizes previous results to arbitrary open and driven systems, yielding novel thermodynamic bounds for idealized and real processes. (paper)

GEODAT. Development of thermodynamic data for the thermodynamic equilibrium modeling of processes in deep geothermal formations. Combined report; GEODAT. Entwicklung von thermodynamischen Daten zur thermodynamischen Gleichgewichtsmodellierung von Prozessen in tiefen, geothermalen Schichten. Synthesebericht

Energy Technology Data Exchange (ETDEWEB)

Moog, Helge C. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany); Regenspurg, Simona [GeoForschungsZentrum Potsdam (Germany); Voigt, Wolfgang [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Anorganische Chemie

2015-02-15

The concept for geothermal energy application for electricity generation can be differentiated into three compartments: In the geologic compartment cooled fluid is pressed into a porous or fractured rock formation, in the borehole compartment a hot fluid is pumped to the surface and back into the geothermal reservoir, in the aboveground facility the energy is extracted from the geothermal fluid by heat exchangers. Pressure and temperature changes influence the thermodynamic equilibrium of a system. The modeling of a geothermal system has therefore to consider besides the mass transport the heat transport and consequently changing solution compositions and the pressure/temperature effected chemical equilibrium. The GEODAT project is aimed to simulate the reactive mass transport in a geothermal reservoir in the North German basin (Gross Schoenebeck). The project was performed by the cooperation of three partners: Geoforschungsinstitut Potsdam, Bergakademie Freiberg and GRS.

EQ DAN AQ DALAM PENGEMBANGAN PROFESIONALISME PUSTAKAWAN

Directory of Open Access Journals (Sweden)

Aris Nurohman

2016-05-01

EQ and AQ in developing of librarian profession will aid to self control and emotion management. By EQ and AQ will aid librarians able to manage self complexity, so it will bear intellectual, skill, behavior, leadership, good personality, smart, creative, progressive and broad horizon.

Thermodynamic properties of UF sub 6 measured with a ballistic piston compressor

Science.gov (United States)

Sterritt, D. E.; Lalos, G. T.; Schneider, R. T.

1973-01-01

From experiments performed with a ballistic piston compressor, certain thermodynamic properties of uranium hexafluoride were investigated. Difficulties presented by the nonideal processes encountered in ballistic compressors are discussed and a computer code BCCC (Ballistic Compressor Computer Code) is developed to analyze the experimental data. The BCCC unfolds the thermodynamic properties of uranium hexafluoride from the helium-uranium hexafluoride mixture used as the test gas in the ballistic compressor. The thermodynamic properties deduced include the specific heat at constant volume, the ratio of specific heats for UF6, and the viscous coupling constant of helium-uranium hexafluoride mixtures.

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.

Thermodynamic modelling of phase equilibrium in system Ti-B-Si-C, synthesis and phases composition of borides and carbides layers on titanic alloyVT-1 at electron beam treatment in vacuum

Science.gov (United States)

Smirnyagina, N. N.; Khaltanova, V. M.; Lapina, A. E.; Dasheev, D. E.

2017-01-01

Composite layers on the basis of carbides and borides the titan and silicon on titanic alloy VT-1 are generated at diffused saturation in vacuum. Formation in a composite of MAX phase Ti3SiC2 is shown. Thermodynamic research of phase equilibrium in systems Ti-Si-C and Ti-B-C in the conditions of high vacuum is executed. The thermodynamics, formation mechanisms of superfirm layers borides and carbides of the titan and silicon are investigated.

Elimination of carbon vacancies in 4H-SiC employing thermodynamic equilibrium conditions at moderate temperatures

Energy Technology Data Exchange (ETDEWEB)

Ayedh, H. M.; Svensson, B. G. [University of Oslo, Department of Physics/Center for Materials Science and Nanotechnology, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Nipoti, R. [Consiglio Nazionale delle Ricerche, Istituto di Microelettronica e Microsistemi, Sezione di Bologna (CNR-IMM of Bologna), I-40129 Bologna (Italy); Hallén, A. [Royal Institute of Technology, School of Information and Communication Technology (ICT), SE-164 40 Kista-Stockholm (Sweden)

2015-12-21

The carbon vacancy (V{sub C}) is a major point defect in high-purity 4H-SiC epitaxial layers limiting the minority charge carrier lifetime. In layers grown by chemical vapor deposition techniques, the V{sub C} concentration is typically in the range of 10{sup 12 }cm{sup −3}, and after device processing at temperatures approaching 2000 °C, it can be enhanced by several orders of magnitude. In the present study, both as-grown layers and a high-temperature processed one have been annealed at 1500 °C and the V{sub C} concentration is demonstrated to be strongly reduced, exhibiting a value of only a few times 10{sup 11 }cm{sup −3} as determined by deep-level transient spectroscopy measurements. The value is reached already after annealing times on the order of 1 h and is evidenced to reflect thermodynamic equilibrium under C-rich ambient conditions. The physical processes controlling the kinetics for establishment of the V{sub C} equilibrium are estimated to have an activation energy below ∼3 eV and both in-diffusion of carbon interstitials and out-diffusion of V{sub C}'s are discussed as candidates. This concept of V{sub C} elimination is flexible and readily integrated in a materials and device processing sequence.

Unified geometric description of black hole thermodynamics

International Nuclear Information System (INIS)

Alvarez, Jose L.; Quevedo, Hernando; Sanchez, Alberto

2008-01-01

In the space of thermodynamic equilibrium states we introduce a Legendre invariant metric which contains all the information about the thermodynamics of black holes. The curvature of this thermodynamic metric becomes singular at those points where, according to the analysis of the heat capacities, phase transitions occur. This result is valid for the Kerr-Newman black hole and all its special cases and, therefore, provides a unified description of black hole phase transitions in terms of curvature singularities.

Non-Equilibrium Radiative Transfer in Structured Atmospheres

National Research Council Canada - National Science Library

Picard, R. H; Winick, J. R; Wintersteiner, P. P

2002-01-01

... passage of both atmospheric gravity waves and transient frontal disturbances or bores. The infrared emissions from this part of the atmosphere are already typically not in local thermodynamic equilibrium (LTE...

Thermodynamic description of the Al-Cu-Mg-Mn-Si quinary system and its application to solidification simulation

International Nuclear Information System (INIS)

Chang, Keke; Liu, Shuhong; Zhao, Dongdong; Du, Yong; Zhou, Liangcai; Chen, Li

2011-01-01

By means of the first-principles calculations, the enthalpy of formation for the quaternary phase in the Al-Cu-Mg-Si system was computed. A set of self-consistent thermodynamic parameters for the Al-Cu-Mg-Si and Al-Cu-Mn-Si systems was then obtained using CALPHAD approach taking into account the reliable experimental data and the first-principles calculations. The thermodynamic database for the Al-Cu-Mg-Mn-Si system was developed based on the constituent binary, ternary, and quaternary systems. Comprehensive comparisons between the calculated and measured phase diagrams and invariant reactions showed that the experimental information was satisfactorily accounted for by the present thermodynamic description. The obtained database was used to describe the solidification behavior of Al alloys B319.1 (90.2Al-6Si-3.5Cu-0.3Mg, in wt.%) and B319.1 + xMn (x = 0.5-2, in wt.%) under Gulliver-Scheil non-equilibrium condition. The reliability of the present thermodynamic database was also verified by the good agreement between calculation and experiment for Gulliver-Scheil non-equilibrium solidification.

A thermodynamic data base for Tc to calculate equilibrium solubilities at temperatures up to 300 deg C

International Nuclear Information System (INIS)

Puigdomenech, I.; Bruno, J.

1995-04-01

Thermodynamic data has been selected for solids and aqueous species of technetium. Equilibrium constants have been calculated in the temperature range 0 to 300 deg C at a pressure of 1 bar for T r Cdeg pm values for mononuclear hydrolysis reactions. The formation constants for chloro complexes of Tc(V) and Tc(IV), whose existence is well established, have been estimated. The majority of entropy and heat capacity values in the data base have also been estimated, and therefore temperature extrapolations are largely based on estimations. The uncertainties derived from these calculations are described. Using the data base developed in this work, technetium solubilities have been calculated as a function of temperature for different chemical conditions. The implications for the mobility of Tc under nuclear repository conditions are discussed. 70 refs

Thermodynamics of phase-separating nanoalloys: Single particles and particle assemblies

Science.gov (United States)

Fèvre, Mathieu; Le Bouar, Yann; Finel, Alphonse

2018-05-01

The aim of this paper is to investigate the consequences of finite-size effects on the thermodynamics of nanoparticle assemblies and isolated particles. We consider a binary phase-separating alloy with a negligible atomic size mismatch, and equilibrium states are computed using off-lattice Monte Carlo simulations in several thermodynamic ensembles. First, a semi-grand-canonical ensemble is used to describe infinite assemblies of particles with the same size. When decreasing the particle size, we obtain a significant decrease of the solid/liquid transition temperatures as well as a growing asymmetry of the solid-state miscibility gap related to surface segregation effects. Second, a canonical ensemble is used to analyze the thermodynamic equilibrium of finite monodisperse particle assemblies. Using a general thermodynamic formulation, we show that a particle assembly may split into two subassemblies of identical particles. Moreover, if the overall average canonical concentration belongs to a discrete spectrum, the subassembly concentrations are equal to the semi-grand-canonical equilibrium ones. We also show that the equilibrium of a particle assembly with a prescribed size distribution combines a size effect and the fact that a given particle size assembly can adopt two configurations. Finally, we have considered the thermodynamics of an isolated particle to analyze whether a phase separation can be defined within a particle. When studying rather large nanoparticles, we found that the region in which a two-phase domain can be identified inside a particle is well below the bulk phase diagram, but the concentration of the homogeneous core remains very close to the bulk solubility limit.

ENIGMATIC RECURRENT PULSATIONAL VARIABILITY OF THE ACCRETING WHITE DWARF EQ LYN (SDSS J074531.92+453829.6)

Energy Technology Data Exchange (ETDEWEB)

Mukadam, Anjum S.; Szkody, Paula [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Townsley, D. M.; Brockett, T. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Gaensicke, B. T.; Parsons, S. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Southworth, J. [Astrophysics Group, Keele University, Staffordshire ST5 5BG (United Kingdom); Hermes, J. J.; Montgomery, M. H.; Winget, D. E.; Harrold, S. [Department of Astronomy, University of Texas at Austin, Austin, TX 78759 (United States); Tovmassian, G.; Zharikov, S. [Observatorio Astronomico Nacional SPM, Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ensenada, BC (Mexico); Drake, A. J. [Department of Astronomy and the Center for Advanced Computing Research, California Institute of Technology, Pasadena, CA 91225 (United States); Henden, A. [American Association of Variable Star Observers, 25 Birch Street, Cambridge, MA 02138 (United States); Rodriguez-Gil, P. [Departamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38204 Santa Cruz de Tenerife (Spain); Sion, E. M. [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Zola, S.; Szymanski, T. [Astronomical Observatory, Jagiellonian University, ul. Orla 171, PL-30-244 Krakow (Poland); Pavlenko, E. [Crimean Astrophysical Observatory, Crimea 98409 (Ukraine); and others

2013-09-15

Photometric observations of the cataclysmic variable EQ Lyn (SDSS J074531.92+453829.6), acquired from 2005 October to 2006 January, revealed high-amplitude variability in the range 1166-1290 s. This accreting white dwarf underwent an outburst in 2006 October, during which its brightness increased by at least five magnitudes, and it started exhibiting superhumps in its light curve. Upon cooling to quiescence, the superhumps disappeared and it displayed the same periods in 2010 February as prior to the outburst within the uncertainties of a couple of seconds. This behavior suggests that the observed variability is likely due to nonradial pulsations in the white dwarf star, whose core structure has not been significantly affected by the outburst. The enigmatic observations begin with an absence of pulsational variability during a multi-site campaign conducted in 2011 January-February without any evidence of a new outburst; the light curve is instead dominated by superhumps with periods in the range of 83-87 minutes. Ultraviolet Hubble Space Telescope time-series spectroscopy acquired in 2011 March reveals an effective temperature of 15,400 K, placing EQ Lyn within the broad instability strip of 10,500-16,000 K for accreting pulsators. The ultraviolet light curve with 90% flux from the white dwarf shows no evidence of any pulsations. Optical photometry acquired during 2011 and Spring 2012 continues to reflect the presence of superhumps and an absence of pulsations. Subsequent observations acquired in 2012 December and 2013 January finally indicate the disappearance of superhumps and the return of pulsational variability with similar periods as previous data. However, our most recent data from 2013 March to May reveal superhumps yet again with no sign of pulsations. We speculate that this enigmatic post-outburst behavior of the frequent disappearance of pulsational variability in EQ Lyn is caused either by heating the white dwarf beyond the instability strip due to an

Thermodynamic properties of organic compounds estimation methods, principles and practice

CERN Document Server

Janz, George J

1967-01-01

Thermodynamic Properties of Organic Compounds: Estimation Methods, Principles and Practice, Revised Edition focuses on the progression of practical methods in computing the thermodynamic characteristics of organic compounds. Divided into two parts with eight chapters, the book concentrates first on the methods of estimation. Topics presented are statistical and combined thermodynamic functions; free energy change and equilibrium conversions; and estimation of thermodynamic properties. The next discussions focus on the thermodynamic properties of simple polyatomic systems by statistical the

Establishment of data base files of thermodynamic data developed by OECD/NEA. Part 4. Addition of thermodynamic data for iron, tin and thorium

International Nuclear Information System (INIS)

Yoshida, Yasushi; Kitamura, Akira

2014-12-01

Thermodynamic data for compounds and complexes of elements with auxiliary species specialized in modeling requirements for safety assessments of radioactive waste disposal systems have been developed by the Thermochemical Data Base (TDB) project of the Nuclear Energy Agency in the Organization for Economic Co-operation and Development (OECD/NEA). Recently, thermodynamic data for aqueous complexes, solids and gases of thorium, tin and iron (Part 1) have been published in 2008, 2012 and 2013, respectively. These thermodynamic data have been selected on the basis of NEA’s guidelines which describe peer review and data selection, extrapolation to zero ionic strength, assignment of uncertainty, and temperature correction; therefore the selected data are considered to be reliable. The reliability of selected thermodynamic data of TDB developed by Japan Atomic Energy Agency (JAEA-TDB) has been confirmed by comparing with selected data by the NEA. For this comparison, text files of the selected data on some geochemical calculation programs are required. In the present report, the database files for the NEA’s TDB with addition of selected data for iron, tin and thorium to the previous files have been established for use of PHREEQC, Geochemist’s Workbench and EQ3/6. In addition, as an example of confirmation of quality, dominant species in iron TDB were compared in Eh-pH diagram and differences between JAEA-TDB and NEA-TDB were shown. Data base files established in the present study will be at the Website of thermodynamic, sorption and diffusion database in JAEA (http://migrationdb.jaea.go.jp/). A CD-ROM is attached as an appendix. (J.P.N.)

Small Systems and Limitations on the Use of Chemical Thermodynamics

Science.gov (United States)

Tovbin, Yu. K.

2018-01-01

Limitations on using chemical thermodynamics to describe small systems are formulated. These limitations follow from statistical mechanics for equilibrium and nonequilibrium processes and reflect (1) differences between characteristic relaxation times in momentum, energy, and mass transfer in different aggregate states of investigated systems; (2) achievements of statistical mechanics that allow us to determine criteria for the size of smallest region in which thermodynamics can be applied and the scale of the emergence of a new phase, along with criteria for the conditions of violating a local equilibrium. Based on this analysis, the main thermodynamic results are clarified: the phase rule for distorted interfaces, the sense and area of applicability of Gibbs's concept of passive forces, and the artificiality of Kelvin's equation as a result of limitations on the thermodynamic approach to considering small bodies. The wrongness of introducing molecular parameters into thermodynamic derivations, and the activity coefficient for an activated complex into the expression for a reaction rate constant, is demonstrated.

The Lewis Chemical Equilibrium Program with parametric study capability

Science.gov (United States)

Sevigny, R.

1981-01-01

The program was developed to determine chemical equilibrium in complex systems. Using a free energy minimization technique, the program permits calculations such as: chemical equilibrium for assigned thermodynamic states; theoretical rocket performance for both equilibrium and frozen compositions during expansion; incident and reflected shock properties; and Chapman-Jouget detonation properties. It is shown that the same program can handle solid coal in an entrained flow coal gasification problem.

Non-equilibrium thermodynamics theory of econometric source discovery for large data analysis

Science.gov (United States)

van Bergem, Rutger; Jenkins, Jeffrey; Benachenhou, Dalila; Szu, Harold

2014-05-01

Almost all consumer and firm transactions are achieved using computers and as a result gives rise to increasingly large amounts of data available for analysts. The gold standard in Economic data manipulation techniques matured during a period of limited data access, and the new Large Data Analysis (LDA) paradigm we all face may quickly obfuscate most tools used by Economists. When coupled with an increased availability of numerous unstructured, multi-modal data sets, the impending 'data tsunami' could have serious detrimental effects for Economic forecasting, analysis, and research in general. Given this reality we propose a decision-aid framework for Augmented-LDA (A-LDA) - a synergistic approach to LDA which combines traditional supervised, rule-based Machine Learning (ML) strategies to iteratively uncover hidden sources in large data, the artificial neural network (ANN) Unsupervised Learning (USL) at the minimum Helmholtz free energy for isothermal dynamic equilibrium strategies, and the Economic intuitions required to handle problems encountered when interpreting large amounts of Financial or Economic data. To make the ANN USL framework applicable to economics we define the temperature, entropy, and energy concepts in Economics from non-equilibrium molecular thermodynamics of Boltzmann viewpoint, as well as defining an information geometry, on which the ANN can operate using USL to reduce information saturation. An exemplar of such a system representation is given for firm industry equilibrium. We demonstrate the traditional ML methodology in the economics context and leverage firm financial data to explore a frontier concept known as behavioral heterogeneity. Behavioral heterogeneity on the firm level can be imagined as a firm's interactions with different types of Economic entities over time. These interactions could impose varying degrees of institutional constraints on a firm's business behavior. We specifically look at behavioral heterogeneity for firms

Biochemical thermodynamics: applications of Mathematica.

Science.gov (United States)

Alberty, Robert A

2006-01-01

The most efficient way to store thermodynamic data on enzyme-catalyzed reactions is to use matrices of species properties. Since equilibrium in enzyme-catalyzed reactions is reached at specified pH values, the thermodynamics of the reactions is discussed in terms of transformed thermodynamic properties. These transformed thermodynamic properties are complicated functions of temperature, pH, and ionic strength that can be calculated from the matrices of species values. The most important of these transformed thermodynamic properties is the standard transformed Gibbs energy of formation of a reactant (sum of species). It is the most important because when this function of temperature, pH, and ionic strength is known, all the other standard transformed properties can be calculated by taking partial derivatives. The species database in this package contains data matrices for 199 reactants. For 94 of these reactants, standard enthalpies of formation of species are known, and so standard transformed Gibbs energies, standard transformed enthalpies, standard transformed entropies, and average numbers of hydrogen atoms can be calculated as functions of temperature, pH, and ionic strength. For reactions between these 94 reactants, the changes in these properties can be calculated over a range of temperatures, pHs, and ionic strengths, and so can apparent equilibrium constants. For the other 105 reactants, only standard transformed Gibbs energies of formation and average numbers of hydrogen atoms at 298.15 K can be calculated. The loading of this package provides functions of pH and ionic strength at 298.15 K for standard transformed Gibbs energies of formation and average numbers of hydrogen atoms for 199 reactants. It also provides functions of temperature, pH, and ionic strength for the standard transformed Gibbs energies of formation, standard transformed enthalpies of formation, standard transformed entropies of formation, and average numbers of hydrogen atoms for 94

Composition and thermochemistry of the equilibrium vapour of the systems NaI-FeI2 and NaI-PbI2

International Nuclear Information System (INIS)

Hilpert, K.; Gerads, H.; Koberts, D.; Miller, M.

1987-01-01

The vaporization of NaI/FeI 2 and NaI/PbI 2 samples of equimolar composition was investigated was investigated in the temperature ranges between 574 to 683 K and 562 to 669 K, respectively, by using the mass spectrometric Knudsen effusion method. The gaseous species I, I 2 , NaI, (NaI) 2 , FeI 2 , (FeI 2 ) 2 , FeI 3 , NaFeI 3 , and Na 2 FeI 4 (NaI-FeI 2 system) as well as NaI, (NaI) 2 , PbI 2 , (PbI 2 ) 2 , and NaPbI 3 (NaI-PbI 2 system) are present in the equilibrium vapours. The equilibrium partial pressures of these species were determined with the exception of I, I 2 , and FeI 3 . Enthalpies and entropies of dissociation resulted for the reactions NaFeI 3 (g) ↔ NaI(g)+FeI 2 (g) (1), Na 2 FeI 4 (g) ↔ 2NaI(g)+FeI 2 (g) and (2) NaPbI 3 (g) ↔ NaI(g)+PbI 2 (g) (3) as Δ d H 298 0 (Eq. (1)) = 184±5 kJ mol -1 , Δ d S 298 0 (Eq. (1)) = 143±8 J mol -1 K -1 ; Δ d H 298 0 (Eq. (2)) = 333±9 kJ mol -1 , Δ d S 298 0 (Eq. (2)) = 274±14 J mol -1 K -1 ; and Δ d H 298 0 (Eq. (3)) = 168±5 kJ mol -1 , Δ d S 298 0 (Eq. (3)) = 151±9 J mol -1 K -1 . Equilibrium constants for these reactions are additionally given. The pressures of NaFeI 3 (g) and NaPbI 3 (g) as all as their enthalpies of dissociation are discussed with respect to their significance of semi empirical rules. (orig.)

Equilibrium, kinetic and thermodynamic studies on the adsorption of m-cresol onto micro- and mesoporous carbon

International Nuclear Information System (INIS)

Kennedy, L. John; Vijaya, J. Judith; Sekaran, G.; Kayalvizhi, K.

2007-01-01

Investigations were conducted in batch mode to study the adsorption behaviour of m-cresol on a porous carbon prepared from rice husk (RHAC) by varying the parameters such as agitation time, m-cresol concentration (50-300 mg/l), pH (2.5-10) and temperature (293-323 K). Studies showed that the adsorption decreased with increase in pH and temperature. The isotherm data were fitted to Langmuir, Freundlich, and Dubinin-Radushkevic (D-R) models. The kinetic models such as pseudo-first-order, pseudo-second-order and intraparticle diffusion models were selected to understand the reaction pathways and mechanism of adsorption process. The thermodynamic equilibrium coefficients obtained at different temperatures were used to evaluate the thermodynamic constants ΔG o , ΔH o and ΔS o . The sorption process was found to be exothermic in nature (ΔH o : -23.46 to -25.40 kJ/mol) with a decrease in entropy (ΔS o : -19.44 to -35.87 J/(mol K)). The negative value of Gibbs free energy, ΔG o indicates that the adsorption occurs via a spontaneous process. The decrease in the value of -ΔG o from 17.70 to 13.54 kJ/mol with increase in pH and temperature indicates that the adsorption of m-cresol onto activated carbon is less favourable at higher temperature and pH range. The influence of mesopore and a possible mechanism of adsorption is also suggested

Decay to Equilibrium for Energy-Reaction-Diffusion Systems

KAUST Repository

Haskovec, Jan

2018-02-06

We derive thermodynamically consistent models of reaction-diffusion equations coupled to a heat equation. While the total energy is conserved, the total entropy serves as a driving functional such that the full coupled system is a gradient flow. The novelty of the approach is the Onsager structure, which is the dual form of a gradient system, and the formulation in terms of the densities and the internal energy. In these variables it is possible to assume that the entropy density is strictly concave such that there is a unique maximizer (thermodynamical equilibrium) given linear constraints on the total energy and suitable density constraints. We consider two particular systems of this type, namely, a diffusion-reaction bipolar energy transport system, and a drift-diffusion-reaction energy transport system with confining potential. We prove corresponding entropy-entropy production inequalities with explicitly calculable constants and establish the convergence to thermodynamical equilibrium, first in entropy and later in L norm using Cziszár–Kullback–Pinsker type inequalities.

Decay to Equilibrium for Energy-Reaction-Diffusion Systems

KAUST Repository

Haskovec, Jan; Hittmeir, Sabine; Markowich, Peter A.; Mielke, Alexander

2018-01-01

We derive thermodynamically consistent models of reaction-diffusion equations coupled to a heat equation. While the total energy is conserved, the total entropy serves as a driving functional such that the full coupled system is a gradient flow. The novelty of the approach is the Onsager structure, which is the dual form of a gradient system, and the formulation in terms of the densities and the internal energy. In these variables it is possible to assume that the entropy density is strictly concave such that there is a unique maximizer (thermodynamical equilibrium) given linear constraints on the total energy and suitable density constraints. We consider two particular systems of this type, namely, a diffusion-reaction bipolar energy transport system, and a drift-diffusion-reaction energy transport system with confining potential. We prove corresponding entropy-entropy production inequalities with explicitly calculable constants and establish the convergence to thermodynamical equilibrium, first in entropy and later in L norm using Cziszár–Kullback–Pinsker type inequalities.

Validation of Ulchin Units 1, 2 CONTEMPT Model Prior to the Production of EQ Envelope Curve

International Nuclear Information System (INIS)

Hwang, Su Hyun; Kim, Min Ki; Hong, Soon Joon; Lee, Byung Chul; Suh, Jeong Kwan; Lee, Jae Yong; Song, Dong Soo

2010-01-01

The Ulchin Units 1, 2 will be refurbished with RSG (Replacement of Steam Generator) and PU (Power Uprate). The current EQ (Environmental Qualification) envelope curve should be modified according to RSG and PU. The containment P/T (Pressure/Temperature) analysis in Ulchin Units 1, 2 FSAR was done using EDF computer program PAREO6. PAREO6 uses the same assumptions as the US NRC CONTEMPT program, and the results given by both programs are in good agreement. It is utilized to determine pressure and temperature variations in a PWR containment subsequent to a reactor coolant or secondary system pipe break. But PAREO6 cannot be available to the production of EQ envelope curve, so CONTEMPT code should be used instead of PAREO6. It is essential to validate the CONTEMPT OSG (Original Steam Generator) model prior to the production of EQ envelope curve considering RSG and PU. This study has been performed to validate the CONTEMPT model of Ulchin Units 1, 2 by comparing the CONTEMPT results with the PAERO6 results in Ulchin Units 1, 2 FSAR

Validation of Ulchin Units 1, 2 CONTEMPT Model Prior to the Production of EQ Envelope Curve

Energy Technology Data Exchange (ETDEWEB)

Hwang, Su Hyun; Kim, Min Ki; Hong, Soon Joon; Lee, Byung Chul [FNC Technology Co., SNU, Seoul (Korea, Republic of); Suh, Jeong Kwan; Lee, Jae Yong; Song, Dong Soo [KEPCO Research Institute, Daejeon (Korea, Republic of)

2010-10-15

The Ulchin Units 1, 2 will be refurbished with RSG (Replacement of Steam Generator) and PU (Power Uprate). The current EQ (Environmental Qualification) envelope curve should be modified according to RSG and PU. The containment P/T (Pressure/Temperature) analysis in Ulchin Units 1, 2 FSAR was done using EDF computer program PAREO6. PAREO6 uses the same assumptions as the US NRC CONTEMPT program, and the results given by both programs are in good agreement. It is utilized to determine pressure and temperature variations in a PWR containment subsequent to a reactor coolant or secondary system pipe break. But PAREO6 cannot be available to the production of EQ envelope curve, so CONTEMPT code should be used instead of PAREO6. It is essential to validate the CONTEMPT OSG (Original Steam Generator) model prior to the production of EQ envelope curve considering RSG and PU. This study has been performed to validate the CONTEMPT model of Ulchin Units 1, 2 by comparing the CONTEMPT results with the PAERO6 results in Ulchin Units 1, 2 FSAR

Application of thermodynamics to silicate crystalline solutions

Science.gov (United States)

Saxena, S. K.

1972-01-01

A review of thermodynamic relations is presented, describing Guggenheim's regular solution models, the simple mixture, the zeroth approximation, and the quasi-chemical model. The possibilities of retrieving useful thermodynamic quantities from phase equilibrium studies are discussed. Such quantities include the activity-composition relations and the free energy of mixing in crystalline solutions. Theory and results of the study of partitioning of elements in coexisting minerals are briefly reviewed. A thermodynamic study of the intercrystalline and intracrystalline ion exchange relations gives useful information on the thermodynamic behavior of the crystalline solutions involved. Such information is necessary for the solution of most petrogenic problems and for geothermometry. Thermodynamic quantities for tungstates (CaWO4-SrWO4) are calculated.

Kinetics, equilibrium and thermodynamic studies on biosorption of Ag(I) from aqueous solution by macrofungus Pleurotus platypus.

Science.gov (United States)

Das, Devlina; Das, Nilanjana; Mathew, Lazar

2010-12-15

Reports are available on silver binding capacity of some microorganisms. However, reports on the equilibrium studies on biosorption of silver by macrofungi are seldom known. The present study was carried out in a batch system using dead biomass of macrofungus Pleurotus platypus for the sorption of Ag(I). P. platypus exhibited the highest silver uptake of 46.7 mg g(-1) of biomass at pH 6.0 in the presence of 200 mg L(-1) Ag(I) at 20°C. Kinetic studies based on fractional power, zero order, first order, pseudo-first order, Elovich, second order and pseudo-second order rate expressions have been carried out. The results showed a very good compliance with the pseudo-first order model. The experimental data were analyzed using two parameter isotherms (Langmuir, Freundlich, Dubinin-Radushkevich, Temkin and Halsey), three parameter isotherms (Redlich-Peterson, Sips, Khan, Koble-Corrigan, Hill, Toth, Radke-Prausmitz, Jossens, Langmuir-Freundlich), four parameter isotherms (Weber-van Vliet, Fritz-Schlunder, Baudu) and five parameter isotherm (Fritz-Schlunder). Thermodynamic parameters of the biosorption (ΔG, ΔH and ΔS) were also determined. The present study confirmed that macrofungus P. platypus may be used as a cost effective efficient biosorbent for the removal of Ag(I) ions from aqueous solution. Copyright © 2010 Elsevier B.V. All rights reserved.

Correction to: Comparing the UK EQ-5D-3L and English EQ-5D-5L Value Sets

NARCIS (Netherlands)

B. Mulhern (Brendan); Feng, Y. (Yan); K.K. Shah (Koonal); M.F. Janssen (Bas); M. Herdman (Michael); van Hout, B. (Ben); N. Devlin (Nancy)

2018-01-01

textabstractThe article Comparing the UK EQ-5D-3L and English EQ-5D-5L Value Sets, written by Brendan Mulhern, Yan Feng, Koonal Shah, Mathieu F. Janssen, Michael Herdman, Ben van Hout, Nancy Devlin was originally published electronically on the publisher’s internet portal (currently SpringerLink) on

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

Standard Gibbs energies of formation and equilibrium constants from ab-initio calculations: Covalent dimerization of NO2 and synthesis of NH3

International Nuclear Information System (INIS)

Awasthi, Neha; Ritschel, Thomas; Lipowsky, Reinhard; Knecht, Volker

2013-01-01

Highlights: • ΔG and K eq for NO 2 dimerization and NH 3 synthesis calculated via ab-initio methods. • Vis-á-vis experiments, W1 and CCSD(T) are accurate and G3B3 also does quite well. • CBS-APNO most accurate for NH 3 reaction but shows limitations in modeling NO 2 . • Temperature dependence of ΔG and K eq is calculated for the NH 3 reaction. • Good agreement of calculated K eq with experiments and the van’t Hoff approximation. -- Abstract: Standard quantum chemical methods are used for accurate calculation of thermochemical properties such as enthalpies of formation, entropies and Gibbs energies of formation. Equilibrium reactions are widely investigated and experimental measurements often lead to a range of reaction Gibbs energies and equilibrium constants. It is useful to calculate these equilibrium properties from quantum chemical methods in order to address the experimental differences. Furthermore, most standard calculation methods differ in accuracy and feasibility of the system size. Hence, a systematic comparison of equilibrium properties calculated with different numerical algorithms would provide a useful reference. We select two well-known gas phase equilibrium reactions with small molecules: covalent dimer formation of NO 2 (2NO 2 ⇌ N 2 O 4 ) and the synthesis of NH 3 (N 2 + 3 H 2 ⇌ 2NH 3 ). We test four quantum chemical methods denoted by G3B3, CBS-APNO, W1 and CCSD(T) with aug-cc-pVXZ basis sets (X = 2, 3, and 4), to obtain thermochemical data for NO 2 , N 2 O 4 , and NH 3 . The calculated standard formation Gibbs energies Δ f G° are used to calculate standard reaction Gibbs energies Δ r G° and standard equilibrium constants K eq for the two reactions. Standard formation enthalpies Δ f H° are calculated in a more reliable way using high-level methods such as W1 and CCSD(T). Standard entropies S° for the molecules are calculated well within the range of experiments for all methods, however, the values of standard formation

The structural phase diagram and oxygen equilibrium partial pressure of YBa 2Cu 3O 6+ x studied by neutron powder diffraction and gas volumetry

Science.gov (United States)

Andersen, N. H.; Lebech, B.; Poulsen, H. F.

1990-12-01

An experimental technique based on neutron powder diffraction and gas volumetry is presented and used to study the structural phase diagram of YBa 2Cu 3O 6+ x under equilibrium conditions in an extended part of ( x, T)-phase (0.15< x<0.92 and 25° C< T<725°C). Our experimental observations lend strong support to a recent two-dimensional anisotropic next-nearest-neighbour Ising model calculation (the ASYNNNI model) of the basal plane oxygen ordering based of first principle interaction parameters. Simultaneous measurements of the oxygen equilibrium partial pressure show anomalies, one of which proves the thermodynamic stability of the orthorhombic OII double cell structure. Striking similarity with predictions of recent model calculations support that another anomaly may be interpreted to result from local one-dimensional fluctuations in the distribution of oxygen atoms in the basal plane of tetragonal YBCO. Our pressure data also indicate that x=0.92 is a maximum obtainable oxygen concentration for oxygen pressures below 760 Torr.

Fe-solubility of Ni7S6 and Ni9S8: Thermodynamic analysis

International Nuclear Information System (INIS)

Waldner, P.

2011-01-01

Experimental data on phase equilibria have been used for thermodynamic analysis of the iron solubility of the nickel sulfides Ni 7 S 6 and Ni 9 S 8 . For both compounds, a two-sublattice approach within the framework of the compound energy formalism has been applied to perform Gibbs free energy modelling at 0.1 MPa total pressure consistently embedded in recent thermodynamic assessment studies of other iron-nickel-sulfides. The predicted maxima of iron solubility around 3 at% of Ni 7 S 6 and 5.5 at% of Ni 9 S 8 are confirmed by experimental data. The calculations of complex ternary phase relations with Fe-bearing Ni 7 S 6 and Ni 9 S 8 gain further improvement. The first internally consistent description of all thermodynamically stable phases known in the literature for the iron-nickel-sulfur system is completed.

thermodynamics of ion exchange equilibrium for some uni

African Journals Online (AJOL)

a

equilibrium studies [9-30], extending over a wide range of composition of solution and ... by dissolving their corresponding potassium salts (Analytical grade) in distilled ... calculated from which average value of K for that set of experiment was ...

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.

Considerations about the correct evaluation of sorption thermodynamic parameters from equilibrium isotherms

International Nuclear Information System (INIS)

Salvestrini, Stefano; Leone, Vincenzo; Iovino, Pasquale; Canzano, Silvana; Capasso, Sante

2014-01-01

Highlights: • Different methods to derive sorption thermodynamic parameters have been discussed. • ΔG° and, ΔS° values depend on the selected standard states. • Isosteric heat values help in evaluating the applicability of the sorption models. -- Abstract: This is a comparative analysis of popular methods currently in use to derive sorption thermodynamic parameters from temperature dependence of sorption isotherms. It is emphasized that the standard and isosteric thermodynamic parameters have sharply different meanings. Moreover, it is shown with examples how the sorption model adopted conditions the standard state and consequently the value of ΔG° and ΔS°. These trivial but often neglected aspects should carefully be considered when comparing thermodynamic parameters from different literature sources. An effort by the scientific community is needed to define criteria for the choice of the standard state in sorption processes

An analysis of Euroqol EQ-5D and Manchester Oxford Foot Questionnaire scores six months following podiatric surgery.

Science.gov (United States)

Maher, Anthony J; Kilmartin, Timothy E

2012-07-09

In the United Kingdom patient-reported outcome measures (PROMS) have been adopted as a key measure of foot surgery outcomes. The intention of this study was to evaluate the responsiveness of a regional outcome measure; the Manchester Oxford Foot Questionnaire (MOXFQ) and a generic measure; the EuroQol EQ-5D, in the context of day care Podiatric Surgery. A prospective audit of 375 consecutive day care surgical admissions was undertaken. All patients attending for surgery, who agreed to participate, were included. Pre operation patients completed the MOXFQ and the EQ-5D. Both questionnaires were completed again at 6 months post operation. Additional data was collected on patient demographics, surgical procedures and complications. Few complications were encountered and most patients (84%) returned for a final review 6 months post operation. Mean MOXFQ scores improved for each domain: pain; 51.7 pre-operation, reduced to 16.5 post-operation, walking; 50.2 reduced to 14.1 and social interaction; 45.7 reduced to 10.6. The minimal clinically important differences (MCID) estimates for the pain domain were exceeded by 82.6% of patients, while 74.8% exceeded the MCID for walking and 68.5% exceeded the MCID for social interaction. A small number of patients (2.9%) deteriorated across all three MOXFQ domains.The EQ-5D Index, summary of health related quality of life, improved from 0.66 pre-operation to 0.86 post operation. The EQ-5D index MCID was exceeded by 79.2% of patients. Index scores deteriorated for 1.8% of patients following surgery. Effect sizes measured following surgery were largest for the MOXFQ domains: Walking; 1.39, Pain; 1.52 and Social Interaction: 1.39. The EQ-5D index effect size was 0.83. The EQ-5D visual analogue scale (VAS) was not influenced by surgery. Both the MOXFQ and EQ-5D index (but not the VAS) appear sensitive to changes in health status at 6 months following elective foot surgery. Both instruments were particularly responsive to changes

Biosorption of bovine serum albumin by Ulva lactuca biomass from industrial wastewater: Equilibrium, kinetic and thermodynamic study

International Nuclear Information System (INIS)

Rathinam, Aravindhan; Zou, Linda

2010-01-01

Batch biosorption experiments have been carried out for the removal of bovine serum albumin (BSA) from simulated industrial wastewater onto Ulva lactuca seaweed. Various vital parameters influencing the biosorption process such as initial concentration of BSA, pH of the solution, adsorbent dosage and temperature have been determined. The biosorption kinetics follows a pseudo-second order kinetic model. Equilibrium isotherm studies demonstrate that the biosorption followed the Freundlich isotherm model, which implies a heterogeneous sorption phenomenon. Various thermodynamic parameters such as changes in enthalpy, free energy and entropy have been calculated. The positive value of ΔH o and the negative value of ΔG o show that the sorption process is endothermic and spontaneous. The positive value of change in entropy ΔS o shows increased randomness at the solid-liquid interface during the biosorption of BSA onto U. lactuca seaweed.

Ruppeiner theory of black hole thermodynamics

International Nuclear Information System (INIS)

Aman, Jan E; Bedford, James; Grumiller, Daniel; Pidokrajt, Narit; Ward, John

2007-01-01

The Ruppeiner metric as determined by the Hessian of the Gibbs surface provides a geometric description of thermodynamic systems in equilibrium. An interesting example is a black hole in equilibrium with its own Hawking radiation. In this article, we present results from the Ruppeiner study of various black hole families from different gravity theories e.g. 2D dilaton gravity, BTZ, general relativity and higher-dimensional Einstein-Maxwell gravity

A New Application for Radioimmunoassay: Measurement of Thermodynamic Constants.

Science.gov (United States)

Angstadt, Carol N.; And Others

1983-01-01

Describes a laboratory experiment in which an equilibrium radioimmunoassay (RIA) is used to estimate thermodynamic parameters such as equilibrium constants. The experiment is simple and inexpensive, and it introduces a technique that is important in the clinical chemistry and research laboratory. Background information, procedures, and results are…

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.

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)

Thermodynamic and experimental studies of the CVD of A-15 superconductors. I

International Nuclear Information System (INIS)

Madar, R.; Weiss, F.; Fruchart, R.; Bernard, C.

1978-01-01

This paper deals with the experimental and thermodynamic study of the chemical vapor deposition (CVD) synthesis of Nb 3 Ga layers on various metallic and insulating substrates using the coreduction of mixed halides by hydrogen. Thermodynamic equilibrium in the seven-component system Nb-Ga-H-Cl-Si-O-Ar has been calculated using the method of minimization of the system Gibbs free energy as a function of the variables directly available in the CVD system. The chosen variables were the chloride ratio, the reduction and dilution parameters and the temperature of the deposition zone. The equilibrium compositions were calculated for the two composition limits of the A-15 phase: NbGasub(0.15) and Nb 3 Ga. They are presented in the form of CVD phase diagrams. A CVD reactor has been set up and more than one hundred measurements have been made in order to check the validity of the equilibrium calculations. The comparisons between equilibrium and experimental results show a good agreement and lead to a better understanding of the chemistry and thermodynamics of the system. (Auth.)