Signe Kjelstrup – författare

The book covers recent developments in the theory of non-equilibrium thermodynamics and its applications. Four chapters are devoted to the foundations; an overview chapter is followed by recent results addressing the underlying principles of the theory. The applications are concerned with bulk systems, with heterogeneous systems where interfaces are central and with process units in industry where entropy production minimization is useful. There is also a collection of chapters under the heading mesoscopic non-equilibrium thermodynamics, giving in the end an overview of extensions of the theory into the non-linear regime. Bringing the literature up to date and detailing new approaches in this area of research, it is aimed at a predominantly, but not exclusively, academic audience of practitioners of thermodynamics and energy conversion.

This volume contains the collected works of the eminent chemist and physicist Lars Onsager, one of the most influential scientists of the 20th Century.The volume includes Onsager's previously unpublished PhD thesis, a biography by H C Longuet-Higgins and M E Fisher, an autobiographical commentary, selected photographs, and a list of Onsager discussion remarks in print.Onsager's scientific achievements were characterized by deep insights into the natural sciences. His two best-known accomplishments are his reciprocal relations for irreversible processes, for which he received the 1968 Nobel Prize in Chemistry, and his explicit solution of the two-dimensional Ising model, a mathematical tour de force that created a sensation when it appeared. In addition, he made significant theoretical contributions to other fields, including electrolytes, colloids, superconductivity, turbulence, ice, electrons in metals, and dielectrics.In this volume, Onsager's contributions are divided into the following fields: irreversible processes; the Ising model; electrolytes; colloids; helium II and vortex quantization; off-diagonal long-range order and flux quantization; electrons in metal; turbulence; ion recombination; fluctuation theory; dielectrics; ice and water; biology; Mathieu functions. The different fields are evaluated by leading experts. The commentators are P W Anderson, R Askey, A Chorin, C Domb, R J Donnelly, W Ebeling, J-C Justice, H N W Lekkerkerker, P Mazur, H P McKean, J F Nagle, T Odijk, A B Pippard, G Stell, G H Weiss, and C N Yang.

This book utilizes non-equilibrium thermodynamics to describe transport in complex, heterogeneous media. There are large coupling effects between transport of heat, mass, charge and chemical reactions at surfaces, and it is important to know how one should properly integrate across systems where different phases are in contact. There is no other book available today that gives a prescription of how to set up flux equations for transports across heterogeneous systems.

This book grew out of an idea to study properties of small subsystems of a large reservoir. Observations were at the time not explainable with standard thermodynamics. But the theory of Hill on thermodynamics of small systems provided the systematic procedure needed to address the problem. Following Hill, thermodynamics can be formulated for the nanoscale!The purpose of this book is to expand and demonstrate Hill's theory. The theory adds a new term to the fundamental Gibbs equation, that is specific for systems at the nanoscale. The properties that follow may be counter intuitive. The equation of state for a small system, for instance, is not given once and for all. We shall see that it changes with the environmental variables that control the small system. The statistical mechanical machinery remains as before, however.The world of small systems challenges the standard knowledge; that the number of particles in a system must be very large for thermodynamic equations to apply. We shall see that thermodynamic equations apply perfectly well also for small particle numbers, provided that small-system effects are accounted for correctly. In the world where size and shape are central, we shall find that equations of state can be used down to one particle in a box! There are scaling laws, which help us determine and understand the large system limit better!In the first part, the authors highlight the basic idea of the theory and provide a more systematic method, than used before. In the second part, the authors demonstrate the power of the theory in a set of central applications of nanoscience in and away from equilibrium, for other scientists to be inspired for further use.

This book presents the theory of non-equilibrium thermodynamics in a pedagogical and practical way that targets engineering applications. In it, tools to take advantage of the second as well as the first law of thermodynamics are provided.The book starts by explaining how the entropy production is the cornerstone of non-equilibrium thermodynamics — the basis to describe coupled transport phenomena, which are highly relevant for several renewable energy technologies. The book also uses entropy production as the foundation for a systematic methodology to analyze and improve energy efficiency, and shows how entropy production can be used to test the consistency of transport models. The link between transport theory and energy efficiency is also shown, and the relationship to exergy analysis is demonstrated. The theory is applied using examples from practical cases like evaporation, heat exchange, reactor optimization, distillation and more.Non-Equilibrium Thermodynamics for Engineering Applications may be used as a textbook for undergraduate and graduate university curricula containing thermodynamics or energy conversion issues at large, chemical and mechanical engineering, applied chemistry and applied physics.

The purpose of this book is to encourage the use of non-equilibrium thermodynamics to describe transport in complex, heterogeneous media. With large coupling effects between the transport of heat, mass, charge and chemical reactions at surfaces, it is important to know how one should properly integrate across systems where different phases are in contact. No other book gives a prescription of how to set up flux equations for transports across heterogeneous systems.The authors apply the thermodynamic description in terms of excess densities, developed by Gibbs for equilibrium, to non-equilibrium systems. The treatment is restricted to transport into and through the surface. Using local equilibrium together with the balance equations for the surface, expressions for the excess entropy production of the surface and of the contact line are derived. Many examples are given to illustrate how the theory can be applied to coupled transport of mass, heat, charge and chemical reactions; in phase transitions, at electrode surfaces and in fuel cells. Molecular simulations and analytical studies are used to add insight.

Kjelstrup, Bedeaux, Johannessen, and Gross describe what non-equilibrium thermodynamics is in a simple and practical way and how it can add to engineering design. They explain how to describe proper equations of transport that are more precise than those used so far, and how to use them to understand the waste of energy resources in central process units in the industry. The authors introduce the entropy balance as an additional equation to use in engineering; to create consistent thermodynamic models, and to systematically minimize energy losses that are connected with the transport of heat, mass, charge and momentum.Non-equilibrium Thermodynamics for Engineers teaches the essence of non-equilibrium thermodynamics and its applications at a level comprehensible to engineering students, practitioner engineers, and scientists working on industrial problems. The book may be used as a textbook in basic engineering curricula or graduate courses.