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Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach
We consider nonequilibrium (NEQ) states such as supercooled liquids and glasses that are described with the use of internal variables. We classify the latter by the state-dependent hierarchy of relaxation times to assess their relevance for irreversible contributions. Given an observation time [Form...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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MDPI
2018
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7512666/ https://www.ncbi.nlm.nih.gov/pubmed/33265240 http://dx.doi.org/10.3390/e20030149 |
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author | Gujrati, Purushottam D. |
author_facet | Gujrati, Purushottam D. |
author_sort | Gujrati, Purushottam D. |
collection | PubMed |
description | We consider nonequilibrium (NEQ) states such as supercooled liquids and glasses that are described with the use of internal variables. We classify the latter by the state-dependent hierarchy of relaxation times to assess their relevance for irreversible contributions. Given an observation time [Formula: see text] , we determine the window of relaxation times that divide the internal variables into active and inactive groups, the former playing a central role in the NEQ thermodynamics. Using this thermodynamics, we determine (i) a bound on the NEQ entropy and on the residual entropy and (ii) the nature of the isothermal relaxation of the entropy and the enthalpy in accordance with the second law. A theory that violates the second law such as the entropy loss view is shown to be internally inconsistent if we require it to be consistent with experiments. The inactive internal variables still play an indirect role in determining the temperature [Formula: see text] and the pressure [Formula: see text] of the system, which deviate from their external values. |
format | Online Article Text |
id | pubmed-7512666 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-75126662020-11-09 Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach Gujrati, Purushottam D. Entropy (Basel) Article We consider nonequilibrium (NEQ) states such as supercooled liquids and glasses that are described with the use of internal variables. We classify the latter by the state-dependent hierarchy of relaxation times to assess their relevance for irreversible contributions. Given an observation time [Formula: see text] , we determine the window of relaxation times that divide the internal variables into active and inactive groups, the former playing a central role in the NEQ thermodynamics. Using this thermodynamics, we determine (i) a bound on the NEQ entropy and on the residual entropy and (ii) the nature of the isothermal relaxation of the entropy and the enthalpy in accordance with the second law. A theory that violates the second law such as the entropy loss view is shown to be internally inconsistent if we require it to be consistent with experiments. The inactive internal variables still play an indirect role in determining the temperature [Formula: see text] and the pressure [Formula: see text] of the system, which deviate from their external values. MDPI 2018-02-26 /pmc/articles/PMC7512666/ /pubmed/33265240 http://dx.doi.org/10.3390/e20030149 Text en © 2018 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Gujrati, Purushottam D. Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach |
title | Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach |
title_full | Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach |
title_fullStr | Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach |
title_full_unstemmed | Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach |
title_short | Hierarchy of Relaxation Times and Residual Entropy: A Nonequilibrium Approach |
title_sort | hierarchy of relaxation times and residual entropy: a nonequilibrium approach |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7512666/ https://www.ncbi.nlm.nih.gov/pubmed/33265240 http://dx.doi.org/10.3390/e20030149 |
work_keys_str_mv | AT gujratipurushottamd hierarchyofrelaxationtimesandresidualentropyanonequilibriumapproach |