production of entropy
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Author(s):  
Harrison Crecraft

The prevailing interpretations of physics are based on deeply entrenched assumptions, rooted in classical mechanics. Logical implications include: the denial of entropy and irreversible change as fundamental physical properties; the inability to explain random quantum measurements or nonlocality without untestable and implausible metaphysical implications; and the inability to define complexity or explain its evolution. We propose a conceptual model based on empirically justifiable assumptions. The WYSIWYG Conceptual Model (WCM) assumes no hidden properties: “What You can See Is What You Get.” The WCM defines a system’s state in the context of its actual ambient background, and it extends existing models of physical reality by defining entropy and exergy as objective contextual properties of state. The WCM establishes the irreversible production of entropy and the Second law of thermodynamics as a fundamental law of physics. It defines a dissipative system’s measurable rate of internal work as an objective measure of stability of its dissipative process. A dissipative system can follow either of two paths toward higher stability: it can 1) increase its rate of exergy supply (and maximize entropy production) or 2) utilize existing exergy supplies better to increase its internal work rate and functional complexity. These paths guide the evolution of both living and non-living systems.


Author(s):  
Harrison Crecraft

The prevailing interpretations of physics are based on deeply entrenched assumptions, rooted in classical mechanics. Logical implications include: the denial of entropy and irreversible change as fundamental physical properties; the inability to explain random quantum measurements or nonlocality without untestable metaphysical implications; and the inability to define complexity or explain its evolution. We propose a conceptual model based on empirically justifiable assumptions. The WYSIWYG Conceptual Model (WCM) assumes no hidden properties: “What You can See Is What You Get.” The WCM defines a system’s state in the context of its actual ambient background, and it extends existing models of physical reality by defining entropy and exergy as objective contextual properties of state. The WCM establishes the irreversible production of entropy and the Second law of thermodynamics as a fundamental law of physics. It defines a dissipative system’s measurable rate of internal work as an objective measure of stability of its dissipative process. A dissipative system can follow either of two paths toward higher stability: it can 1) increase its rate of exergy supply or 2) utilize existing exergy supplies better to increase its internal work rate and functional complexity. These paths guide the evolution of both living and non-living systems.


Author(s):  
A.N. Morozov

The study statistically describes Brownian motion in a locally nonequilibrium medium, taking into account the production of entropy, and proposes to describe the nonequilibrium fluctuations of the velocity of a Brownian particle using a linear integro-differential equation. The characteristic functions of fluctuations of the Brownian particle velocity are obtained, which make it possible to carry out a complete statistical description of Brownian motion in a medium with the production of entropy. Findings of research show that the variance of these fluctuations increases with time according to the logarithmic law. The correlation function of fluctuations of the Brownian particle velocity is calculated and it is shown that it consists of two terms. The first term, which has a power-law dependence, describes equilibrium fluctuations, and the second, which has a logarithmic dependence, describes nonequilibrium fluctuations


Author(s):  
Alfredo José Constaín Aragón ◽  
Carlos Peña-Guzmán ◽  
Gina Alexandra Peña-Olarte

Mean velocity is a key parameter for understanding, modeling and predicting the complex phenomena of advection and dispersion in natural watercourses, which are threatened by human intervention and river disasters. For this reason, the principles of relative constancy for the value of this parameter, established early by L. Prandtl and L. Leopold in the 20th century, are powerful theoretical tools for those who develop engineering tasks in this field. This article presents updated analyses of these principles, explaining how this constancy depends essentially on the existence of a steady state in the flow, which allows equiprobability in the system, and therefore, a minimum production of entropy. At the same time an equation is developed, as a function of macroscopic parameters, facilitating its interpretation and practical application. This hypothesis is contrasted by reviewing the relative values for those parameters and their effect on the formula, and defining the practical conditions of applicability of the formula. This method of validating the hypothesis is important in hydrometric practice, as flow velocity measurements are the starting point for their description, especially for large rivers where comprehensive assessments are impossible.


Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1021
Author(s):  
Kornelia M. Batko ◽  
Andrzej Ślęzak

The results of experimental studies of volume osmotic fluxes (Jvkr) and fluxes of dissolved substances (Jkr) in a system containing a synthetic Nephrophan® membrane (Orwo VEB Filmfabrik, Wolfen, Germany) set in a horizontal plane are presented. The membrane separated water and aqueous HCl or ammonia solutions or aqueous ammonia and HCl solutions. It was found that for the homogeneity conditions of the solutions Jvk and Jk depend only on the concentration and composition of the solutions. For concentration polarization conditions (where concentration boundary layers are created on both sides), Jvkr and Jkr depend on both the concentration and composition of the solutions and the configuration of the membrane system. The obtained results of the Jvk and Jk flux studies were used to assess the global production of entropy for the conditions of homogeneity of solutions (ΦSk), while Jvkr and Jkr—to assess the global production of entropy for concentration polarization conditions (ΦSkr). In addition, the diffusion-convective effects and the convection effect in the global source of entropy were calculated. The concentration polarization coefficient ζir was related to modified concentration Rayleigh number, e.g., the parameter controlling the transition from non-convective (diffusive) to convective state. This number acts as a switch between two states of the concentration field: convective (with a higher entropy source value) and non-convective (with a lower entropy source value). The operation of this switch indicates the regulatory role of earthly gravity in relation to membrane transport.


Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 815 ◽  
Author(s):  
Stuart Kauffman

In his “What Is Life?” Schrödinger poses three questions: (1) What is the source of order in organisms? (2) How do organisms remain ordered in the face of the Second Law of Thermodynamics? (3) Are new laws of physics required? He answers his first question with his famous “aperiodic solid”. He leaves his second and third questions unanswered. I try to show that his first answer is also the answer to his second question. Aperiodic solids such as protein enzymes are “boundary conditions” that constrain the release of energy into a few degrees of freedom in non-equilibrium processes such that thermodynamic work is done. This work propagates and builds structures and controls processes. These constitute his causally efficacious “code script” controlling development. The constrained release of energy also delays the production of entropy that can be exported from cells as it forms. Therefore, cells remain ordered. This answers his second question. However, “What is life?” must also ask about the diachronic evolution of life. Here, the surprising answer to this extended version of Schrödinger’s third question is that there are no new entailing laws of physics. No laws at all entail the evolution of ours or any biosphere.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2319 ◽  
Author(s):  
David González ◽  
Alberto García-González ◽  
Francisco Chinesta ◽  
Elías Cueto

We address the problem of machine learning of constitutive laws when large experimental deviations are present. This is particularly important in soft living tissue modeling, for instance, where large patient-dependent data is found. We focus on two aspects that complicate the problem, namely, the presence of an important dispersion in the experimental results and the need for a rigorous compliance to thermodynamic settings. To address these difficulties, we propose to use, respectively, Topological Data Analysis techniques and a regression over the so-called General Equation for the Nonequilibrium Reversible-Irreversible Coupling (GENERIC) formalism (M. Grmela and H. Ch. Oettinger, Dynamics and thermodynamics of complex fluids. I. Development of a general formalism. Phys. Rev. E 56, 6620, 1997). This allows us, on one hand, to unveil the true “shape” of the data and, on the other, to guarantee the fulfillment of basic principles such as the conservation of energy and the production of entropy as a consequence of viscous dissipation. Examples are provided over pseudo-experimental and experimental data that demonstrate the feasibility of the proposed approach.


2020 ◽  
Vol 1 (3) ◽  
pp. 29-35
Author(s):  
V.I. Merkulov ◽  
◽  
I.V. Tishchenko ◽  
S.A. Abalakin ◽  
◽  
...  

Most modern aircrafts widely use air conditioning systems in order to ensure comfortable flight conditions for passengers and crew, as well as to cool the equipment of the aircraft. The aircraft in-dustry is developing every year and the requirements for such systems are growing. Preliminary calculations and analysis of such systems are of key importance in their development. Such calcula-tions will help to determine the entire further path of system development and prevent many errors. They also help to regularly improve the performance of systems, in particular, their energy charac-teristics. The main requirements for systems are reliability, energy efficiency, and weight-and-dimensional characteristicss. The paper is devoted to analysis of the efficiency of the system and its individual units. In addition, there is considered separately the influence of third-party factors on the efficiency of the system, in particular, the presence of moisture in the working air flow. This article discusses the results of thermodynamic calculation and analysis by the entropy-statistical method of the air conditioning system in various operating modes. The efficiency of the system as a whole is considered and the influence of imperfection of each of its units in particular is analyzed. The standard parameters of the operation of such systems on airplanes were taken as the initial parameters for calculating the systems. For the analysis, a system with a two-wheel turbo-cooling unit with moisture removal on the high-pressure path was selected. A schematic diagram of the system is given, formulas for calculating the minimum required work to compensate the production of entropy for the units of the system are presented. To ensure the calculations, the software complexes MathCAD, Coolprop and Matlab were used.


2019 ◽  
Vol 44 (4) ◽  
pp. 425-437 ◽  
Author(s):  
Frantisek Marsik ◽  
Bernhard Weigand ◽  
Martin Tomas ◽  
Ondrej Tucek ◽  
Pavel Novotny

Abstract The current work presents a concept that deals with the production of entropy generated by non-equilibrium processes in consequence of mass and energy transfer. The often used concept of endoreversible thermodynamics is based on the non-realistic conjecture that the entire entropy production is realized at the system boundary. In this contribution, an open system in a thermodynamically non-equilibrium state is assumed. Production of entropy is generated due to non-equilibrium processes accompanied by energy conversion. The steady state of the system is maintained by a negative entropy flux. The conclusions for expansion energy conversion, i. e., thermal machines, confirm the general outcomes of the endoreversible thermodynamics. However, the presented conclusions related to non-expansion energy conversion offer a new perspective on the principle of minimum entropy production and the corresponding stability conditions at steady state. The analysis of the energy conversion in closed cycles is presented for fuel cells, i. e., non-expansion energy conversion. The efficiency of the energy conversion is maximal at zero power output. Moreover, the efficiency of the fuel cells, and consequently the efficiency of all non-expansion energy conversion processes, depends on the load and then the maximal possible efficiency can be determined.


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