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Extremal Principles In Non-equilibrium Thermodynamics
Energy dissipation and entropy production extremal principles are ideas developed within non-equilibrium thermodynamics that attempt to predict the likely steady states and dynamical structures that a physical system might show. The search for extremum principles for non-equilibrium thermodynamics follows their successful use in other branches of physics.Ziegler, H., (1983). ''An Introduction to Thermomechanics'', North-Holland, Amsterdam, According to Kondepudi (2008), and to Grandy (2008),Grandy, W.T., Jr (2008). ''Entropy and the Time Evolution of Macroscopic Systems'', Oxford University Press, Oxford, . there is no general rule that provides an extremum principle that governs the evolution of a far-from-equilibrium system to a steady state. According to Glansdorff and Prigogine (1971, page 16), irreversible processes usually are not governed by global extremal principles because description of their evolution requires differential equations which are not self-adjoint, but local ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entropy Production
Entropy production (or generation) is the amount of entropy which is produced in any irreversible processes such as heat and mass transfer processes including motion of bodies, heat exchange, fluid flow, substances expanding or mixing, anelastic deformation of solids, and any irreversible thermodynamic cycle, including thermal machines such as power plants, heat engines, refrigerators, heat pumps, and air conditioners. In the dual representation entropy–exergy for accounting the second law of thermodynamics it can be expressed in equivalent terms of exergy disruption. Short history Entropy is produced in irreversible processes. The importance of avoiding irreversible processes (hence reducing the entropy production) was recognized as early as 1824 by Carnot. In 1865 Rudolf Clausius expanded his previous work from 1854 on the concept of "unkompensierte Verwandlungen" (uncompensated transformations), which, in our modern nomenclature, would be called the entropy production. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilya Prigogine
Viscount Ilya Romanovich Prigogine (; russian: Илья́ Рома́нович Приго́жин; 28 May 2003) was a physical chemist and Nobel laureate noted for his work on dissipative structures, complex systems, and irreversibility. Biography Prigogine was born in Moscow a few months before the Russian Revolution of 1917, into a Jewish family. His father, Ruvim Abramovich Prigogine, was a chemical engineer at the Imperial Moscow Technical School; his mother, Yulia Vikhman, was a pianist. Because the family was critical of the new Soviet system, they left Russia in 1921. They first went to Germany and in 1929, to Belgium, where Prigogine received Belgian nationality in 1949. His brother Alexandre (1913–1991) became an ornithologist. Prigogine studied chemistry at the Free University of Brussels, where in 1950, he became professor. In 1959, he was appointed director of the International Solvay Institute in Brussels, Belgium. In that year, he also started teaching at the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluctuation Theorem
The fluctuation theorem (FT), which originated from statistical mechanics, deals with the relative probability that the entropy of a system which is currently away from thermodynamic equilibrium (i.e., maximum entropy) will increase or decrease over a given amount of time. While the second law of thermodynamics predicts that the entropy of an isolated system should tend to increase until it reaches equilibrium, it became apparent after the discovery of statistical mechanics that the second law is only a statistical one, suggesting that there should always be some nonzero probability that the entropy of an isolated system might spontaneously ''decrease''; the fluctuation theorem precisely quantifies this probability. Statement Roughly, the fluctuation theorem relates to the probability distribution of the time-averaged irreversible entropy production, denoted \overline_t. The theorem states that, in systems away from equilibrium over a finite time ''t'', the ratio between the probab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-equilibrium Thermodynamics
Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of macroscopic quantities (non-equilibrium state variables) that represent an extrapolation of the variables used to specify the system in thermodynamic equilibrium. Non-equilibrium thermodynamics is concerned with transport processes and with the rates of chemical reactions. Almost all systems found in nature are not in thermodynamic equilibrium, for they are changing or can be triggered to change over time, and are continuously and discontinuously subject to flux of matter and energy to and from other systems and to chemical reactions. Some systems and processes are, however, in a useful sense, near enough to thermodynamic equilibrium to allow description with useful accuracy by currently known non-equilibrium thermodynamics. Nevertheless, many natural systems and processes will always remain far beyond the scope o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-organization
Self-organization, also called spontaneous order in the social sciences, is a process where some form of overall order arises from local interactions between parts of an initially disordered system. The process can be spontaneous when sufficient energy is available, not needing control by any external agent. It is often triggered by seemingly random fluctuations, amplified by positive feedback. The resulting organization is wholly decentralized, distributed over all the components of the system. As such, the organization is typically robust and able to survive or self-repair substantial perturbation. Chaos theory discusses self-organization in terms of islands of predictability in a sea of chaotic unpredictability. Self-organization occurs in many physical, chemical, biological, robotic, and cognitive systems. Examples of self-organization include crystallization, thermal convection of fluids, chemical oscillation, animal swarming, neural circuits, and black markets. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayleigh–Bénard Convection
In fluid thermodynamics, Rayleigh–Bénard convection is a type of natural convection, occurring in a planar horizontal layer of fluid heated from below, in which the fluid develops a regular pattern of convection cells known as Bénard cells. Bénard–Rayleigh convection is one of the most commonly studied convection phenomena because of its analytical and experimental accessibility. The convection patterns are the most carefully examined example of self-organizing nonlinear systems. Buoyancy, and hence gravity, are responsible for the appearance of convection cells. The initial movement is the upwelling of less-dense fluid from the warmer bottom layer. This upwelling spontaneously organizes into a regular pattern of cells. Physical processes The features of Bénard convection can be obtained by a simple experiment first conducted by Henri Bénard, a French physicist, in 1900. Development of convection The experimental set-up uses a layer of liquid, e.g. water, between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudolf Clausius
Rudolf Julius Emanuel Clausius (; 2 January 1822 – 24 August 1888) was a German physicist and mathematician and is considered one of the central founding fathers of the science of thermodynamics. By his restatement of Sadi Carnot's principle known as the Carnot cycle, he gave the theory of heat a truer and sounder basis. His most important paper, "On the Moving Force of Heat", published in 1850, first stated the basic ideas of the second law of thermodynamics. In 1865 he introduced the concept of entropy. In 1870 he introduced the virial theorem, which applied to heat. Life Clausius was born in Köslin (now Koszalin, Poland) in the Province of Pomerania in Prussia. His father was a Protestant pastor and school inspector, and Rudolf studied in the school of his father. In 1838, he went to the Gymnasium in Stettin. Clausius graduated from the University of Berlin in 1844 where he had studied mathematics and physics since 1840 with, among others, Gustav Magnus, Peter Gustav Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Ziegler (physicist)
Hans Ziegler was born in Winterthur, Switzerland, on 5 September 1910, and died in Estes Park, Colorado, on 5 August 1985. He was raised and spent his early career in Switzerland but much of his later career in the United States. Hans Ziegler was a respected academic and was the author of a number of well respected textbooks on engineering and thermodynamics, which were translated into other languages, and re-issued in new editions. In non-equilibrium thermodynamics Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of macroscopic quantities (non-equilibrium state variables) that represent an ext ..., he considered a 'principle of maximum dissipation rate'. He was also an early proponent of a 'principle of maximum rate of entropy production', which is closely related to a 'principle of maximum dissipation rate'. The range of applicability and validity or invalidit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Ziman
John Michael Ziman (16 May 1925 – 2 January 2005) was a British-born New Zealand physicist and Humanism, humanist who worked in the area of condensed matter physics. He was a spokesman for science, as well as a teacher and author. Ziman was born in Cambridge, England, in 1925. His parents were Solomon Netheim Ziman and, Nellie Frances, née Gaster. The family emigrated to New Zealand when Ziman was a baby. He obtained his early education at Hamilton High School, New Zealand, Hamilton High School and the Victoria University College. He obtained his PhD from Balliol College, Oxford and did his early research on the theory of electrons in liquid metals at the University of Cambridge. In 1964 he was appointed professor of theoretical physics at University of Bristol, where he wrote his ''Elements Of Advanced Quantum Theory'' (1969) which explains the rudiments of quantum field theory with an elementary condensed matter slant. During this period, his interests shifted towards the ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hendrik Casimir
Hendrik Brugt Gerhard Casimir (15 July 1909 – 4 May 2000) was a Dutch physicist best known for his research on the two-fluid model of superconductors (together with C. J. Gorter) in 1934 and the Casimir effect (together with D. Polder) in 1948. Biography Casimir was born 15 July 1909. He studied theoretical physics at the University of Leiden under Paul Ehrenfest, where he received his Ph.D. in 1931. His Ph.D. thesis dealt with the quantum mechanics of a rigid spinning body and the group theory of the rotations of molecules. During that time he also spent some time in Copenhagen with Niels Bohr, where he helped Bohr support the latter's hypothesis of the " gunslinger effect" with mock shoot-outs on campus. From 1932 to mid-1933, Casimir worked as an assistant to Wolfgang Pauli at ETH Zurich. During this period, he worked on the relativistic theory of the electron, in particular, evaluating deviations of the Klein-Nishina equation in the case of bound electrons. To attack th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diederik Korteweg
Diederik Johannes Korteweg (31 March 1848 – 10 May 1941) was a Dutch mathematician. He is now best remembered for his work on the Korteweg–de Vries equation, together with Gustav de Vries. Early life and education Diederik Korteweg's father was a judge in 's-Hertogenbosch, Netherlands. Korteweg received his schooling there, studying at a special academy which prepared students for a military career. However, he decided against a military career and, making the first of his changes of direction, he began his studies at the Polytechnical School of Delft. Korteweg originally intended to become an engineer but, although he maintained an interest in mechanics and other applications of mathematics throughout his life, his love of mathematics made him change direction for the second time when he was not enjoying the technical courses at Delft. He decided to terminate his course and pull out of his studies so that he could concentrate on mathematics. He then enrolled in mathematics an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-equilibrium Thermodynamics
Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of macroscopic quantities (non-equilibrium state variables) that represent an extrapolation of the variables used to specify the system in thermodynamic equilibrium. Non-equilibrium thermodynamics is concerned with transport processes and with the rates of chemical reactions. Almost all systems found in nature are not in thermodynamic equilibrium, for they are changing or can be triggered to change over time, and are continuously and discontinuously subject to flux of matter and energy to and from other systems and to chemical reactions. Some systems and processes are, however, in a useful sense, near enough to thermodynamic equilibrium to allow description with useful accuracy by currently known non-equilibrium thermodynamics. Nevertheless, many natural systems and processes will always remain far beyond the scope o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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