scholarly journals Multiscale Thermodynamics

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 165
Author(s):  
Miroslav Grmela
Keyword(s):  
Complex Systems ◽  
Equilibrium Thermodynamics ◽  
Classical Equilibrium ◽  
Far From Equilibrium ◽  
Special Case

Multiscale thermodynamics is a theory of the relations among the levels of investigation of complex systems. It includes the classical equilibrium thermodynamics as a special case, but it is applicable to both static and time evolving processes in externally and internally driven macroscopic systems that are far from equilibrium and are investigated at the microscopic, mesoscopic, and macroscopic levels. In this paper we formulate multiscale thermodynamics, explain its origin, and illustrate it in mesoscopic dynamics that combines levels.

scholarly journals Covariant Relativistic Non-Equilibrium Thermodynamics of Multi-Component Systems

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1034
Author(s):  
Wolfgang Muschik
Keyword(s):  
Momentum Flux ◽  
Equilibrium Thermodynamics ◽  
Equilibrium Conditions ◽  
Component Mixture ◽  
Component Systems ◽  
General Relativistic ◽  
Entropy Flux ◽  
Special Case ◽  
Multi Component System ◽  
Non Equilibrium

Non-equilibrium and equilibrium thermodynamics of an interacting component in a relativistic multi-component system is discussed covariantly by exploiting an entropy identity. The special case of the corresponding free component is considered. Equilibrium conditions and especially the multi-component Killing relation of the 4-temperature are discussed. Two axioms characterize the mixture: additivity of the energy momentum tensors and additivity of the 4-entropies of the components generating those of the mixture. The resulting quantities of a single component and of the mixture as a whole, energy, energy flux, momentum flux, stress tensor, entropy, entropy flux, supply and production are derived. Finally, a general relativistic 2-component mixture is discussed with respect to their gravitation generating energy–momentum tensors.

The Evolution of Complex Systems

1988 ◽  
Vol 43 (1) ◽  
pp. 73-77
Author(s):  
G. L. Hofacker ◽  
R. D. Levine
Keyword(s):  
Complex Systems ◽  
Maximum Entropy ◽  
Transition Probabilities ◽  
Maximum Entropy Principle ◽  
Average Energy ◽  
Entropy Principle ◽  
Fundamental Equations ◽  
Special Case ◽  
Extremal Properties

Abstract A principle of evolution of highly complex systems is proposed. It is based on extremal properties of the information I (X, Y) characterizing two states X and Y with respect to each other, I(X, Y) = H(Y) -H(Y/X), where H(Y) is the entropy of state Y,H (Y/X) the entropy in state Y given the probability distribu­tion P(X) and transition probabilities P(Y/X).As I(X, Y) is maximal in P(Y) but minimal in P(Y/X), the extremal properties of I(X, Y) con­stitute a principle superior to the maximum entropy principle while containing the latter as a special case. The principle applies to complex systems evolving with time where fundamental equations are unknown or too difficult to solve. For the case of a system evolving from X to Y it is shown that the principle predicts a canonic distribution for a state Y with a fixed average energy .

scholarly journals Sustainability at the Edge of Chaos: Its Limits and Possibilities in Public Health

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Christopher G. Hudson ◽  
Yvonne M. Vissing
Keyword(s):  
Public Health ◽  
Health Care ◽  
Complex Systems ◽  
Systems Theory ◽  
Equilibrium Conditions ◽  
Edge Of Chaos ◽  
Evaluative Criteria ◽  
Far From Equilibrium ◽  
Central Meaning ◽  
Policy And Planning

This paper critically reviews the expanding literature on applications of sustainability to healthcare policy and planning. It argues that the concept has been overgeneralized and has become a buzzword masking disparate agendas. It ignores the insights of the newest generation of systems theory on complex systems on the ubiquity of far-from-equilibrium conditions. Yet, a central meaning often ascribed to sustainability is the level continuation of healthcare programs and their institutionalization. Sustainability is only coherent in health care when it is more narrowly delimited to involve public health and treated as only one of several evaluative criteria that informs not only the continuation of programs but more often their expansion or contraction as needs dynamically change.

scholarly journals Stochastic Thermodynamics of Oscillators' Networks

2018 ◽  
Author(s):  
Simone Borlenghi ◽  
Anna Delin
Keyword(s):  
Entropy Production ◽  
Time Reversal ◽  
Detailed Balance ◽  
Nonlinear Oscillators ◽  
Time Reversal Symmetry ◽  
Equilibrium Thermodynamics ◽  
Stochastic Thermodynamics ◽  
Far From Equilibrium ◽  
Fokker Planck Equations ◽  
Kontorova Model

We apply the stochastic thermodynamics formalism to describe the dynamics of systems of complex Langevin and Fokker-Planck equations. We provide in particular a simple and general recipe to calculate thermodynamical currents, dissipated and propagating heat for networks of nonlinear oscillators. By using the Hodge decomposition of thermodynamical forces and fluxes, we derive a formula for entropy production that generalises the notion of non-potential forces and makes transparent the breaking of detailed balance and of time reversal symmetry for states arbitrarily far from equilibrium. Our formalism is then applied to describe the off-equilibrium thermodynamics of a few examples, notably a continuum ferromagnet, a network of classical spin-oscillators and the Frenkel-Kontorova model of nano friction.

Epistemology and the Physicist

1988 ◽  
Vol 2 (2) ◽  
pp. 307-316
Author(s):  
Isabelle Stengers
Keyword(s):  
Physical Theory ◽  
The Other ◽  
Theoretical Interpretation ◽  
Equilibrium Thermodynamics ◽  
Theory Of Evolution ◽  
Strategic Role ◽  
Far From Equilibrium ◽  
The One ◽  
Historical Function ◽  
Modern Form

The ArgumentIn this answer to “Evolutionism as a Modern Form of Mechanicism”(SiC 2(2): 287–306) I discuss the strange double use the authors make of their reference to Kant in order to deny the relevance of far-from-equilibrium thermodynamics, and more generally, of the physical irreversibility question in the problem of evolution.On the one hand, the authors quite legitimately use a materialist version of Kantian apriorism in the guise of “means of cognition” presupposed by any physical theory. But on the other hand, they accept a theoretical interpretation of physical irreversibility (as introduced in physics via statistical supplementary conditions) whose precise historical function was to occult the intrinsic difference between the cognitive means of dynamics and those of thermodynamics in order to promote a mechanistic unification of physics.I thus argue that at stake is not the case of such or such a physicist transgressing the border between philosophy and natural science as defended by von Borzeszkowski and Wahsner, but rather the very interpretation of irreversibility accepted by most physicists (including von Borzeszkowski and Wahsner) since Boltzmann. In contrast, Prigogine's enterprise could be understood as an attempt to take the notion of cognitive means seriously, by approaching the problem of evolution (and not by proposing a theory of evolution) via the problem of the relevance of these means.I conclude with comments on the strategic role Kant is still made to play today by physicists who wish to transform dissents in physical theory into philosophical ones and by philosophers who wish to judge scientists instead of trying to understand them.

The Reliability of Military Aircraft—A User's Point of View

1966 ◽  
Vol 70 (663) ◽  
pp. 407-408
Author(s):  
J. Mackenzie
Keyword(s):  
Complex Systems ◽  
Air Force ◽  
Point Of View ◽  
Military Aircraft ◽  
Royal Air Force ◽  
Minimum Support ◽  
Performance Requirements ◽  
Stringent Performance ◽  
Special Case ◽  
Adequate Reliability

I have been asked to express a user's viewpoint of what is required to ensure the adequate Reliability of military aircraft before their introduction into service, and to outline briefly what the Operational Requirements staff of the Royal Air Force are now doing to assist in this.The problem of unreliability arises, particularly for military aircraft, from the increasingly complex systems which are needed to meet our stringent performance requirements. The reliability of equipment has not kept pace, and this has led to difficult and costly maintenance problems. These difficulties are further emphasised by tactical requirements which demand minimum maintenance in the field. The nature of STOL/VTOL operational aircraft and the need to deploy them with minimum support facilities is a special case where reliability is of outstanding importance.

Sign in / Sign up

Export Citation Format

Share Document