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Entropy, Volume 9, Issue 2 (June 2007), Pages 42-99

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Open AccessArticle Distillation of a Complex Mixture. Part I: High Pressure Distillation Column Analysis: Modeling and Simulation
Entropy 2007, 9(2), 58-72; doi:10.3390/e9020058
Received: 7 December 2006 / Accepted: 14 April 2007 / Published: 25 April 2007
Cited by 1 | PDF Full-text (272 KB) | HTML Full-text | XML Full-text
Abstract
In this analysis, based on the bubble point method, a physical model wasestablished clarifying the interactions (mass and heat) between the species present in thestreams in circulation in the column. In order to identify the externally controlled operatingparameters, the degree of freedom of
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In this analysis, based on the bubble point method, a physical model wasestablished clarifying the interactions (mass and heat) between the species present in thestreams in circulation in the column. In order to identify the externally controlled operatingparameters, the degree of freedom of the column was determined by using Gibbs phase rule.The mathematical model converted to Fortran code and based on the principles of: 1) Globaland local mass conservation balance, 2) Enthalpy balance, and 3) Vapour-liquid equilibriumat each tray, was used to simulate the behavior of the column, concentration distributions,temperature and streams for each phase along the column at high pressure in each tray. Theenergy consumption at the condenser and the boiler was also evaluated using the Starlingequation of state. Full article
Open AccessArticle Entropy Characteristic on Harmonious Unifying Hybrid Preferential Networks
Entropy 2007, 9(2), 73-82; doi:10.3390/e9020073
Received: 27 September 2006 / Accepted: 18 April 2007 / Published: 21 May 2007
Cited by 5 | PDF Full-text (405 KB) | HTML Full-text | XML Full-text
Abstract
Based on the harmonious unifying hybrid preferential model (HUHPM) networkproposed by our group, the entropy characteristic of an un-weighted HUHPM-BA networkand a weighted HUHPM-BBV network are investigated as the total hybrid ratio d/r ischanged. We derive and compute the general relation of the
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Based on the harmonious unifying hybrid preferential model (HUHPM) networkproposed by our group, the entropy characteristic of an un-weighted HUHPM-BA networkand a weighted HUHPM-BBV network are investigated as the total hybrid ratio d/r ischanged. We derive and compute the general relation of the power exponent of the degreedistribution with the entropy by using the Boltzmann-Gibbs entropy (BGS) and the Tsallisnon-extensive entropy (Sq). It is found that the BGS decreases as d/r increases and thecurrent of the BGS along with hybrid ratio d/r or exponent γ of power-law is in agreementbetween numerical simulation and theoretical analysis. The relationship between the Sq andcharacteristic parameter q under different d/r is also given. And the Sq approaches to theBGS when q → 1. These results can provide a better understanding for evolutioncharacteristic in growing complex networks and further applications in networkengineering are of prospective potential. Full article
Open AccessArticle The Natural Philosophy of Work
Entropy 2007, 9(2), 83-99; doi:10.3390/e9020083
Received: 12 February 2007 / Accepted: 1 June 2007 / Published: 7 June 2007
Cited by 13 | PDF Full-text (140 KB) | HTML Full-text | XML Full-text
Abstract
Work, by dissipative structures (DS), imposes delay on energy gradientdegradation. It diverts energy flow into DS maintenance while enhancing energy degradation.DS can be viewed as tradeoffs between enhancing entropy production maximization (themaximum entropy production principle, MEP) by way of convective gradient degradation,and the
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Work, by dissipative structures (DS), imposes delay on energy gradientdegradation. It diverts energy flow into DS maintenance while enhancing energy degradation.DS can be viewed as tradeoffs between enhancing entropy production maximization (themaximum entropy production principle, MEP) by way of convective gradient degradation,and the need to maintain DS form, which is what mediates the convective dissipation. Thistradeoff frameworked the origin of living DS. In the Big Bang, the Universe departedincreasingly from an ordered state of low entropy. As a result the Second Law (locally, dS>or = 0) became an ever more powerful attractor, insuring that work could have only limitedenergy efficiency (utilization / throughput). That is, the ‘>’ in ‘dS > or = 0’ increased onaverage locally as the universe departed further from thermodynamic equilibrium. Energyefficiency becomes significant in the context of possible energy shortage, which impliesembodied agency, implying in turn the possibility of some stability into the future. Energyefficiency is needed in living DS which yet serve MEP by becoming relatively less energyefficient when striving. Biodiversity multiplies modes of energy consumption, alsofurthering MEP by compensating for the diversion of energy flow into the maintenance ofliving DS. Modular (hierarchical) structure is very stable to perturbations, and also generatesthe variety requisite for adaptive flexibility, affording as well evolutionary access toincreased adjacent possibilities. Dynamical rate separation between hierarchical levelsstreamlines energy flows, enhancing orderly energy gradient degradation. I conjecture thatnew levels are interpolated when that fosters MEP overall. Of the three phases of energyflow -- low level conduction, mid level convection, and high level explosion -- orderlyconvection associates with DS form, constraining moderated energy flows, and defusingpotential explosions. Full article

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Open AccessLetter Probability as a Physical Motive
Entropy 2007, 9(2), 42-57; doi:10.3390/e9020042
Received: 1 January 2007 / Accepted: 25 January 2007 / Published: 25 April 2007
Cited by 2 | PDF Full-text (268 KB) | HTML Full-text | XML Full-text
Abstract
Recent theoretical progress in nonequilibrium thermodynamics, linking thephysical principle of Maximum Entropy Production (“MEP”) to the information-theoretical“MaxEnt” principle of scientific inference, together with conjectures from theoreticalphysics that there may be no fundamental causal laws but only probabilities for physicalprocesses, and from evolutionary theory
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Recent theoretical progress in nonequilibrium thermodynamics, linking thephysical principle of Maximum Entropy Production (“MEP”) to the information-theoretical“MaxEnt” principle of scientific inference, together with conjectures from theoreticalphysics that there may be no fundamental causal laws but only probabilities for physicalprocesses, and from evolutionary theory that biological systems expand “the adjacentpossible” as rapidly as possible, all lend credence to the proposition that probability shouldbe recognized as a fundamental physical motive. It is further proposed that spatial order andtemporal order are two aspects of the same thing, and that this is the essence of the secondlaw of thermodynamics. Full article

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