ARTICLE | doi:10.20944/preprints202204.0133.v1
Subject: Materials Science, Metallurgy Keywords: Copper recovery; Thermodynamic equilibrium; Reduction experiment
Online: 14 April 2022 (12:12:46 CEST)
This work discussed the advantages of reducing copper in molten copper slag with low S content. FactSage calculated the distribution of copper at equilibrium under different sulfur content. The effect of sulfur content on copper recovery under different oxygen partial pressures was pointed out. The effect of sulfur content on copper recovery in the actual reduction process was explored through experimental research. Under the condition of low sulfur, the Recovery of copper and the stability of the experiment have an ideal results.
ARTICLE | doi:10.20944/preprints202109.0172.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: thermodynamic; enthalpy change; viscosity; activation energy; structure
Online: 9 September 2021 (10:49:51 CEST)
With the increased use of laterite nickel ore, the impact of high Al2O3 slag on blast furnace smelting has gradually increased. In this paper, the effects of slag basicity and Al2O3 content on slag viscosity and enthalpy change under constant temperature conditions was investigated. The changes in slag structure were analyzed by activation energy and Fourier Transform Infrared (FT-IR) spectroscopy. The relationship between slag components and slag temperature and viscosity when slag heat is reduced was investigated. The results showed that the viscosity first slightly decreased and then significantly increased with increasing basicity at constant temperature. With the addition of Al2O3 content, the viscosity of the slag increases. The activation energy increases with increasing slag basicity and Al2O3. With increasing basicity, the [SiO4]4- tetrahedral unit trough depth becomes shallow, the [AlO4]5- asymmetric stretching band migrates to lower wave numbers, and the slag structure depolymerizes. With the increase of Al2O3 content, the trough of [SiO4]4- tetrahedra deepens and the center of the symmetric stretching band moves to a higher wave number. The [AlO4]5- asymmetric stretching band becomes obvious, indicating the complexity of the slag structure. When the heat decreases, the slag temperature increases as the basicity increases, and the slag thermal stability is better at the basicity of 0.95-1.05. As the Al2O3 content increases, the thermal stability of the slag becomes worse.
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: non conformal repellers; dimension theory; thermodynamic formalism
Online: 2 April 2021 (13:53:28 CEST)
In this paper we use the additive thermodynamic formalism to obtain new bounds of the Hausdorff and box-counting dimension of certain non conformal hyperbolic repellers defined by piecewise smooth expanding maps on a $d$-dimensional smooth manifold $M$.
ARTICLE | doi:10.20944/preprints202106.0110.v1
Subject: Materials Science, Biomaterials Keywords: Thermodynamic modeling; CALPHAD; molten salt; molten salt reactor; thermodynamic database; modified quasichemical model; fluoride salt; chloride salt; salt system
Online: 3 June 2021 (11:50:13 CEST)
olten salt reactors (MSRs) utilize salts as coolant or as the fuel and coolant together with fissile isotopes dissolved in the salt. It is necessary to therefore understand the behavior of the salts to effectively design, operate, and regulate such reactors, and thus there is a need for thermodynamic models for the salt systems. Molten salts, however, are difficult to represent as they exhibit short range order that is dependent on both composition and temperature. A widely useful approach is the modified quasichemical model in the quadruplet approximation that provides for consideration of first and second nearest neighbor coordination and interactions. Its use in the CALPHAD ap-proach to system modeling requires fitting parameters using standard thermodynamic data such as phase equilibria, heat capacity, and others. Shortcoming of the model is its inability to directly vary coordination numbers with composition or temperature. Another issue is the difficulty in fitting model parameters using regression methods without already having very good initial values. The proposed paper will discuss these issues and note some practical methods for the effective genera-tion of useful models.
ARTICLE | doi:10.20944/preprints202003.0470.v1
Subject: Biology, Other Keywords: EthA; ethionamide resistance; BVMO; molecular dynamics; thermodynamic integration
Online: 31 March 2020 (23:21:53 CEST)
Mutation in the ethionamide (ETH) activating enzyme, EthA, is the main factor determining resistance to this drug, used to treat TB patients infected with MDR and XDR Mycobacterium tuberculosis isolates. Many mutations in EthA of ETH resistant (ETH-R) isolates have been described but their roles in resistance remain uncharacterized, partly because structural studies on the enzyme are lacking. Thus, we took a two-tier approach to evaluate two mutations (Y50C and T453I) found in ETH-R clinical isolates. First, we used a combination of comparative modeling, molecular docking, and molecular dynamics to build an EthA model in complex with ETH that has hallmark features of structurally characterized homologs. Second, we used free energy computational calculations for the reliable prediction of relative free energies between the wild type and mutant enzymes. The ΔΔG values for Y50C and T453I mutant enzymes in complex with FADH2-NADP-ETH were 3.34 (+/−0.55) and 8.11 (+/−0.51) kcal/mol, respectively, compared to the wild type complex. The positive ΔΔG values indicate that the wild type complex is more stable than the mutants, with the T453I complex being the least stable. These are the first results shedding light on the molecular basis of ETH resistance, namely reduced complex stability of mutant EthA.
ARTICLE | doi:10.20944/preprints201906.0188.v1
Subject: Physical Sciences, Other Keywords: electromagnetism; brain oscillator; quasiphoton; thermodynamic, kinetic; quantum correlations
Online: 20 June 2019 (03:32:22 CEST)
The physics of the human brain has two components – basic physics common to all mammals and the physics of thinking inherent only in man. The development of the mental component of the structural and functional organization of the brain in phylogeny was associated with the chiral factor of the external environment, and in ontogenesis - with the social factor. The sensitivity of the brain to these factors was based on the single-connected nature of its aqueous basis, the mechanism of electromagnetic induction, and the features of the thermodynamics of the brain in a state of night sleep. In order to unify the description of the mechanism of electromagnetic processes in the brain, the concept of a quasiphoton has been introduced, combining all forms of excitation of electronic and molecular-cellular structures of the brain. Equivalent schemes of vibrational contours of neural network elements and macrostructures of the brain are proposed. Estimates of the kinetic parameters (activation energy, velocity) of the physical processes underlying the energy-information exchange of the brain with the external environment are made. Mechanisms of operative (physical) and permanent (chemical) memory of the brain, including a model of nonlocal quantum correlations, are discussed.
ARTICLE | doi:10.20944/preprints202204.0229.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Solar energy; Refrigeration; Absorption-compression; Energy saving; Thermodynamic model
Online: 26 April 2022 (06:03:27 CEST)
Solar assisted hybrid cooling systems are promising for the energy saving of refrigeration systems. In most cases, the solar thermal gain is only able to power the heat-driven process of facilities in part of the working period. Therefore, the reduction of compressor power strongly depends upon the duration of heat-driven processes, which has not been addressed properly. Motivated by such knowledge gap, the thermodynamic understanding of solar assisted hybrid cooling systems is deepened through considering the duration in heat-driven processes. Three absorption-compression integrated cooling cycles were taken as examples. It is found that optimal parameters, e.g., inter-stage pressure and temperature, corresponding to various performance indicators trend to be identical, as the duration of heat-driven processes is taken into account. Furthermore, the optimal parameter for different working conditions was obtained. It is displayed that the dimensionless optimal intermediate temperature of layout with the cascade condensation process varies slightly, e.g., 4%, for different conditions. Moreover, the fall of compressor power in entire working periods is nearly independent upon the intermediate temperature. The paper is favorable for the efficient design and operation of solar assisted hybrid cooling systems.
Subject: Earth Sciences, Environmental Sciences Keywords: EEA; Neandertal extinction; thermodynamic population models; sustainability; exergy footprint
Online: 14 June 2019 (04:28:31 CEST)
A thermodynamic analysis of population dynamics and of sustainability provides rigor to many important issues. In this work, the “system Society” is analysed in connection with the “system Environment” using an exergy metric, and the method includes an internalization of the Externalities (Capital, Labour, Environmental effects) conducted on the basis of a “system+ environment” balance. In this perspective, this study investigates the Late Pleistocene extinction of the Homo Neandertalensis, which took place in a geologically short time and in the presence of a competing species, the Homo Sapiens. The case in study is not trivial, and its choice not casual: in those times, the only factor that could lead to an advantage of one group over the other was their respective resource use intensity. A specific indicator, the Exergy Footprint, is here applied to measure the total amount of primary resources required to produce a certain (material or immaterial) commodity, including the resources needed for the physical survival of the individuals. On the basis of the available data, the results show that the EF of the Neandertal was higher than that of the Sapiens, and that, both species sharing the same ecological niche in a time of dwindling resources, the less frugal was also more fragile in an evolutionary sense.
ARTICLE | doi:10.20944/preprints202111.0375.v1
Subject: Chemistry, Physical Chemistry Keywords: Fenclorim; Clopyralid; Vapor pressures; Phase transitions; Heat capacities; Thermodynamic stability
Online: 22 November 2021 (10:44:06 CET)
The present work reports an experimental thermodynamic study of two nitrogen heterocyclic organic compounds, fenclorim and clopyralid, that have been used as herbicides. The sublimation vapor pressures of fenclorim (4,6-dichloro-2-phenylpyrimidine) and of clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) were measured, at different temperatures, using a Knudsen mass-loss effusion technique. The vapor pressures of both crystalline and liquid (including supercooled liquid) phases of fenclorim were also determined using a static method based on capacitance diaphragm manometers. The experimental results enabled accurate determination of the standard molar enthalpies, entropies and Gibbs energies of sublimation for both compounds and of vaporization for fenclorim, allowing a phase diagram representation of the (p,T) results, in the neighborhood of the triple point of this compound. The temperatures and molar enthalpies of fusion of the two compounds studied were determined using differential scanning calorimetry. The standard isobaric molar heat capacities of the two crystalline compounds were determined at 298.15 K, using drop calorimetry. The gas phase thermodynamic properties of the two compounds were estimated through ab initio calculations, at the G3(MP2)//B3LYP level, and their thermodynamic stability was evaluated in the gaseous and crystalline phases, considering the calculated values of the standard Gibbs energies of formation, at 298.15 K.
ARTICLE | doi:10.20944/preprints202105.0019.v1
Subject: Engineering, Automotive Engineering Keywords: OLP; Thermodynamic Data Basis; EOS Modeling; Process Simulation; Aspen-Hysys
Online: 4 May 2021 (13:49:18 CEST)
In this work, the thermodynamic data basis and EOS modeling necessary to simulate the fractionation of organic liquid products (OLP), a liquid reaction product obtained by thermal catalytic cracking of palm oil at 450ºC, 1.0 atmosphere, with 10% (wt.) Na2CO3 as catalyst, in multistage countercurrent absorber/stripping columns using SC-CO2 as solvent, with Aspen-Hysys was systematically investigated. The chemical composition of OLP was used to predict the physical (), thermo-physical properties (Tb, Tc, Pc, Vc), and acentric factor () of all the compounds present in OLP by applying the group contribution methods of Marrero-Gani, Han-Peng, Marrero-Pardillo, Constantinou-Gani, Joback and Reid, and Vetere. The RK-Aspen (EOS) used as thermodynamic fluid package, applied to correlate the experimental phase equilibrium data of binary systems organic liquid products compounds (OLP)-i/CO2 available in the literature. The group contribution methods selected based on the lowest relative average deviation by computing Tb, Tc, Pc, Vc, and . For n-alkanes, the method of Marrero-Gani selected for the prediction of Tc, Pc and Vc, and that of Han-Peng for . For alkenes, the method of Marrero-Gani selected for the prediction of Tb and Tc, Marrero-Pardillo for Pc and Vc, and Han-Peng for . For unsubstituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of Tb, Marrero-Gani for Tc, Joback for Pc and Vc, and the undirected method of Vetere for . For substituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of Tb and Pc, Marrero-Gani for Tc and Vc, and the undirected method of Vetere for . For aromatic hydrocarbon, the method of Joback selected for the prediction of Tb, Constantinou-Gani for Tc and Vc, Marrero-Gani for Pc, and the undirected method of Vetere for . The regressions show that RK-Aspen EOS was able to describe the experimental phase equilibrium data for all the binary pairs undecane-CO2, tetradecane-CO2, pentadecane-CO2, hexadecane-CO2, octadecane-CO2, palmitic acid-CO2, and oleic acid-CO2, showing average absolute deviation (AADx) between 0.8% and 1.25% for the liquid phase and (AADy) between 0.01% to 0.66% for gaseous phase.
ARTICLE | doi:10.20944/preprints202104.0609.v1
Subject: Physical Sciences, Acoustics Keywords: nanoscale system; quantum transport; Coulomb blockade; entropy measurement; thermodynamic relations
Online: 22 April 2021 (13:29:10 CEST)
The entropy of a system gives a powerful insight into its microscopic degrees of freedom, however standard experimental ways of measuring entropy through heat capacity are hard to apply to nanoscale systems, as they require the measurement of increasingly small amounts of heat. Two alternative entropy measurement methods have been recently proposed for nanodevices: through charge balance measurements and transport properties. We describe a self-consistent thermodynamic framework for treating few-electron nanodevices which incorporates both existing entropy measurement methods, whilst highlighting several ongoing misconceptions. We show that both methods can be described as special cases of a more general relation and prove its applicability in systems with complex microscopic dynamics – those with many excited states of various degeneracies.
ARTICLE | doi:10.20944/preprints202012.0119.v2
Subject: Earth Sciences, Atmospheric Science Keywords: Pedostructure; Systemic modelling; Systemic variables, hydro-thermodynamic equilibrium; Gibbs free energy; Fundamental thermodynamic variables; molecular, real and Eulerian fluxes, hydric conductivity of the pedostructure.
Online: 29 December 2020 (17:15:56 CET)
The subject of this article is the dynamics of water in a soil pedostructure sample whose internal environment is subjected to a potential gradient created by the departure of water through surface evaporation. This work refers entirely to the results and conclusions of a fundamental theoretical study focused on the molecular thermodynamic equilibrium of the two aqueous phases of the soil pedostructure. The new concepts and descriptive variables of the hydro-thermodynamic equilibrium state of the soil medium, which have been established at the molecular level of the fluid phases of the pedostructure (water and air) in a previous article, are recalled here in the systemic paradigm of hydrostructural pedology. They allow access to the molecular description of water migration in the soil and go beyond the classical mono-scale description of soil water dynamics. We obtain a hydro-thermodynamic description of the soil's pedostructure at different hydro-functional scale levels including those relating to the water molecule and its atoms. The experimental results show a perfect agreement with the theory, validating at the same time the systemic approach which was the framework.
ARTICLE | doi:10.20944/preprints201803.0203.v1
Subject: Physical Sciences, General & Theoretical Physics Keywords: DNA; DNA nanotechnology; patchy particles; Wertheim theory; thermodynamic integration; phase coexistence
Online: 25 March 2018 (16:14:27 CEST)
We present a numerical study in which large-scale bulk simulations of self-assembled DNA constructs have been carried out with a realistic coarse-grained model. The investigation aims at obtaining a precise, albeit numerically demanding, estimate of the free energy for such systems. We then, in turn, use these accurate results to validate a recently proposed theoretical approach that builds on a liquid-state theory, the Wertheim theory, to compute the phase diagram of all-DNA fluids. This hybrid theoretical/numerical approach, based on the lowest order virial expansion and a nearest-neighbor DNA model, can provide, in an undemanding way, a thermodynamic description of DNA associating fluids that is in semi-quantitative agreement with experiments. We show that the predictions of such scheme are as accurate as the ones obtained with more sophisticated methods. We also demonstrate the flexibility of the approach by incorporating non-trivial additional contributions that go beyond the nearest-neighbor model to compute the DNA hybridization free energy.
ARTICLE | doi:10.20944/preprints202205.0401.v1
Subject: Engineering, Civil Engineering Keywords: ecological cement; cementitious system; thermodynamic; calcium silicate hydrate; tricalcium silicate; GEM-Selektor
Online: 30 May 2022 (11:41:13 CEST)
Ecological ternary cements (ECP) were perpared with powders of phosphogypsum (PG), fly ash (FA) and portland cement (PC). The evolution mechanism of the hydration product structure was characterized through macro and micro experiments.The thermodynamic characteristics of solid phase, solid solution phase and aqueous solution in process of hydration about phosphogypsum-fly ash-cement ternary cementitious system were studied based on the Gibbs-free-energy C-S-H thermodynamic model and GEM-Selektor software, and compared with experimental results. The results show that in the hydration reaction the thermodynamic interaction between mineral single-phase and hydration products plays an important role in the spatio-temporal distribution of ions in the cementitious system. The values of CaO、SiO2Hand H2Ohyd gradually increased with the increase of Ca/Si ratio, while the values of CaOext and H2OOH showed a positive proportional relationship, and the values of SiO2H and SiO2 showed an inverse proportional relationship. GEM-Selektor is accurate in the simulation calculation of the total amount of AFt and AFm mineral phases which quantitatively analysis the correlation between C-S-H gels formation and C3S with complex decomposition ion groups.
ARTICLE | doi:10.20944/preprints202110.0437.v1
Subject: Engineering, Energy & Fuel Technology Keywords: heating cycles; thermodynamic cycles; thermodynamics; temperature difference utilization; heating; cooling; cogeneration; thermal science
Online: 28 October 2021 (13:00:46 CEST)
Thermodynamic cycles are not only the core concepts of thermal science, but also key approaches to energy conversion and utilization. So far, power cycles and refrigeration cycles have been the only two general classes of thermodynamic cycles. While diverse types of systems have been developed to perform thermodynamic cycles, no new general classes of thermodynamic cycles have been proposed. Based on the basic principles of thermodynamics, here we propose and analyze a new general class of thermodynamic cycles named class 1 heating cycles (HC-1s). Two basic forms of HC-1s are obtained by connecting six essential thermodynamic processes in the proper order and forming a thermodynamic cycle. HC-1s present the simplest and most general approach to utilizing the temperature difference between a high-temperature heat source and a medium-temperature heat sink to achieve efficient medium-temperature heating and/or low-temperature cooling. HC-1s fill the gaps that have existed since the origin of thermal science, and they will play significant roles in energy conservation and emission reduction.
ARTICLE | doi:10.20944/preprints202201.0354.v2
Subject: Life Sciences, Biophysics Keywords: origin of life; disspative structuring; prebiotic chemistry; abiogenisis; non-equilibrium thermodynamics; thermodynamic dissipation theory
Online: 31 January 2022 (13:13:26 CET)
There is little doubt that life's origin followed from the known physical and chemical laws of Nature. The most general scientific framework incorporating the laws of Nature and applicable to most known processes to good approximation, is that of thermodynamics and its extensions to treat out-of-equilibrium phenomena. The event of the origin of life should therefore also be amenable to such an analysis. In this paper, I describe the non-equilibrium thermodynamic foundations of the origin of life for the non-expert. This ``Thermodynamic Dissipation Theory for the Origin of Life'' is founded on Classical Irreversible Thermodynamic theory developed by Lars Onsager, Ilya Prigogine, and coworkers.
ARTICLE | doi:10.20944/preprints202107.0701.v1
Subject: Engineering, Automotive Engineering Keywords: Plasma arc welding; thermodynamic; material flow; velocity distribution; welding current, Marangoni force; Shear force
Online: 30 July 2021 (12:34:53 CEST)
The material flow dynamic and velocity distribution on the melted domain surface play a crucial role on the joint quality and formation of welding defects. In this study, authors investigated the effects of the low and high currents of plasma arc welding on the material flow and thermodynamics of molten pool and its relationship to the welding defects. The high-speed video camera (HSVC) was used to observe the convection of the melted domain and welded-joint appearance. Furthermore, to consider the Marangoni force activation, the temperature on the melted domain was measured by a thermal HSVC. The results revealed that the velocity distribution on the weld surface was higher than that inside the molten weld pool due to the difference of the massive density between the air and the steel. Moreover, in the case of low welding current (80A) the convection speed of molten was faster than that of the high welding current case (160A) owing to the difference of main driving forces direction and strength, which leading to undercut and humping defects on the weld surface and excessive convex (burn-through) defect at the bottom weld side, respectively. The medium welding current (120A) had two convection patterns with the main flow in backward direction, which resulted in better welding quality without defect. The interaction between the shear force and Marangoni force played a solid state on the convection and heat transportation processes in the plasma arc welding process.
ARTICLE | doi:10.20944/preprints201707.0029.v1
Subject: Engineering, Energy & Fuel Technology Keywords: coal-fired power plants; waste heat utilization; thermodynamic analysis; exergy analysis; techno-economic analysis
Online: 12 July 2017 (15:18:32 CEST)
In this paper, an improved system to efficiently utilize the low-temperature waste heat (WHUS) from the flue gas of coal-fired power plants is proposed based on heat cascade. The essence of the proposed system is that the waste heat of exhausted flue gas is not only used to preheat air for assisting coal combustion as usual but also to heat up feedwater and the low-pressure steam extraction. Preheated by both the exhaust flue gas in the boiler island and the low-pressure steam extraction in the turbine island, thereby part of the flue gas heat in the air preheater can be saved and introduced to heat the feedwater and the high-temperature condensed water. Consequently, part of the high-pressure steam is saved for further expansion in the steam turbine, which obtains additional net power output. Based on the design data of a typical 1000 MW ultra-supercritical coal-fired power plant in China, in-depth analysis of the energy-saving characteristics of the optimized WHUS and the conventional WHUS is conducted. When the optimized WHUS is adopted in a typical 1000 MW unit, net power output increases by 19.51 MW, exergy efficiency improves to 45.46%, and net annual revenue reaches 4.741 million USD. In terms of the conventional WHUS, these aforementioned performance parameters are only 5.83 MW, 44.80% and 1.244 million USD, respectively. The research of this paper can provide a feasible energy-saving option for coal-fired power plants.
ARTICLE | doi:10.20944/preprints202111.0040.v1
Subject: Engineering, Energy & Fuel Technology Keywords: heating cycles; thermodynamic cycles; thermodynamics; temperature difference utilization; heating; cold energy utilization; sustainable energy; cogeneration; thermal science
Online: 2 November 2021 (10:49:58 CET)
Considering the significance of thermodynamic cycles in the global energy system, it is necessary to develop new general classes of thermodynamic cycles to relieve current energy and environmental problems. Inspired by the relationship between power cycles and refrigeration cycles, we realize that general classes of thermodynamic cycles should occur in pairs with opposite functions. Here we reverse class 1 heating cycles to obtain another new general class of thermodynamic cycles named class 2 heating cycles (HC-2s). HC-2s have two basic forms, and each contains six thermodynamic processes. HC-2s present the simplest and most general approach to utilizing the temperature difference between a medium-temperature heat source and a low-temperature heat sink to achieve efficient high-temperature heating. HC-2s fill the gaps that have existed since the origin of thermal science, and they will play significant roles in the global sustainable energy system.
Subject: Physical Sciences, Condensed Matter Physics Keywords: solids; quantum linear harmonic oscillator; classical linear oscillator; partition function; Hamiltonian; position fluctuations; Hamilton function; thermodynamic properties
Online: 19 June 2019 (08:06:19 CEST)
As known all physical properties of solids are described well by the system of quantum linear harmonic oscillators. It is shown in the present paper that the system consisting of classical linear harmonic oscillators having temperature dependent masses or (and) frequencies has the same partition function as the system consisting of quantum linear harmonic oscillators having temperature independent masses and frequencies while the means of the square displacements of the positions of the oscillators from their mean positions for the system consisting of classical linear harmonic oscillators having: the temperature dependent masses; temperature dependent frequencies; and temperature dependent masses and frequencies differ from each other and from that of the system consisting of quantum linear harmonic oscillators, and hence, the system consisting of classical linear harmonic oscillators describes well the thermodynamic properties of the system consisting of quantum linear harmonic oscillators and solids.
ARTICLE | doi:10.20944/preprints201905.0100.v1
Subject: Engineering, Control & Systems Engineering Keywords: Dual-Miller cycle; thermodynamic analysis; power; ecological coefficient of performance; thermal efficiency; entropy generation; multi-objective optimization
Online: 9 May 2019 (11:27:49 CEST)
Although different assessments and evaluations of Dual-Miller cycle performed, specified output power and thermal performance associated with engine determined. Besides, multi objective optimization of thermal efficiency, Ecological Coefficient of performance ( ) and Ecological function ( ) by the mean of NSGA-II technique and thermodynamic analysis performed. The Pareto optimal frontier obtaining the best optimum solution is chosen by fuzzy Bellman-Zadeh, LINMAP, and TOPSIS decision-making techniques. Based on the results, performances of dual-Miller cycles and their optimization are improved.
ARTICLE | doi:10.20944/preprints201810.0722.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: cosmology; Bianchi Type I; particle creation; open thermodynamic system; constant deceleration parameter; accelerated expansion; late time acceleration
Online: 30 October 2018 (09:36:05 CET)
A study of Bianchi Type I cosmological model is undertaken in the framework of creation of particles. To accommodate the creation of new particles, the universe is regarded as an Open thermodynamical system. The energy conservation equation is modified with the incorporation of a creation pressure in the energy momentum tensor. Exact solutions of the field equations are obtained (i) for a particular choice of the particle creation function and (ii) by considering the deceleration parameter to be constant. In the first model the behavior of the solution at late times is investigated. The physical aspects of the model have also been discussed. In the case of the second model we have restricted our analysis to the power law behaviour for the average scale factor. This leads to a particular form for the particle creation function. The behavior of the solution is investigated and the physical aspects of the model have also been discussed for the matter dominated era.
REVIEW | doi:10.20944/preprints202203.0170.v2
Subject: Life Sciences, Molecular Biology Keywords: cancer; DNA informational entropy; cell compartmentation; evolutionary Biology; lactate dehydrogenase (LDH); lactic acid; metabolism; thermodynamic entropy; Warburg effect
Online: 17 March 2022 (03:37:53 CET)
Attempts to find and quantify the supposed low entropy of organisms and its preservation are revised. Absolute entropy of the mixed components of non-living biomass (around -1.6 x 103 J K-1 L-1) is the reference to which other entropy decreases would be ascribed to life. Compartmentation of metabolites and departure from the equilibrium of metabolic reactions account for 1 and 40-50 J K-1 L-1, respectively, decreases of entropy and, though small, are distinctive features of living tissues. DNA and proteins do not supply significant decreases of thermodynamic entropy, but their low informational entropy is relevant for life and its evolution. No other living feature contributes significantly to the low entropy associated to life. The photosynthetic conversion of radiant energy to biomass energy accounts for the most of entropy (2.8 x 105 J K-1 carbon kg-1) produced by living beings. The comparative very low entropy produced in other processes (around 4.8 x102 J K-1 L-1 day-1 in human body) must be rapidly exported outside as heat to preserve the low entropy decreases due to compartmentation and non-equilibrium metabolism. Enzymes and genes are described whose control minimize the rate of production of entropy and could explain selective pressures in biological evolution and the rapid proliferation of cancer cells.
ARTICLE | doi:10.20944/preprints202012.0263.v1
Subject: Physical Sciences, Acoustics Keywords: Liquid-vapour phase transition; metals; thermodynamic perturbation theory; coupling-parameter expansion; critical point parameters; universal aspects; scaled variables.
Online: 10 December 2020 (13:40:39 CET)
The first objective of this paper is to investigate the scaling behavior of liquid-vapor phase transition in FCC and BCC metals starting from the zero-temperature four-parameter formula for cohesive energy. The effective potentials between the atoms in the solid are determined using lattice inversion techniques as a function of scaling variables in the above formula. These potentials are split into repulsive and attractive parts as per the Weeks-Chandler-Anderson prescription, and used in the coupling-parameter expansion for solving the Ornstein-Zernike equation supplemented with an accurate closure. Thermodynamic quantities obtained via the correlation functions are used to obtain critical point parameters and liquid-vapor phase diagrams. Their dependence on the scaling variables in the cohesive energy formula are also determined. Equally important second objective of the paper is to revisit coupling parameter expansion for solving the Ornstein-Zernike equation. The Newton-Armijo non-linear solver and Krylov-space based linear solvers are employed in this regard. These methods generate a robust algorithm that can be used to span the entire fluid region, except very low temperatures. Accuracy of the method is established by comparing the phase diagrams with those obtained via computer simulation. Avoidance of the 'no-solution-region' of Ornstein-Zernike equation in coupling-parameter expansion is also discussed. Details of the method and the complete algorithm provided here would make this technique more accessible to researchers investigating thermodynamic properties of one component fluids.
REVIEW | doi:10.20944/preprints202010.0250.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: Thermodynamic formalism; neuronal networks dynamics; maximum entropy principle; free energy and pressure; linear response; large deviations, ergodic theory
Online: 12 October 2020 (15:28:38 CEST)
The Thermodynamic Formalism provides a rigorous mathematical framework to study quantitative and qualitative aspects of dynamical systems. At its core there is a variational principle and corresponding, in its simplest form, to the Maximum Entropy principle, used as a statistical inference procedure to represent, by specific probability measures (Gibbs measures), the collective behaviour of complex systems. This framework has found applications in different domains of scienThe Thermodynamic Formalism provides a rigorous mathematical framework to study quantitative and qualitative aspects of dynamical systems. At its core there is a variational principle and corresponding, in its simplest form, to the Maximum Entropy principle, used as a statistical inference procedure to represent, by specific probability measures (Gibbs measures), the collective behaviour of complex systems. This framework has found applications in different domains of science, in particular, has been fruitful and influential in neurosciences. In this article, we review how the Thermodynamic Formalism can be exploited in the field of theoretical neuroscience, as a conceptual and operational tool, to link the dynamics of interacting neurons and the statistics of action potentials from either experimental data or mathematical models. We comment on perspectives and open problems in theoretical neuroscience that could be addressed within this formalism.ce, in particular, has been fruitful and influential in neurosciences. In this article, we review how the Thermodynamic Formalism can be exploited in the field of theoretical neuroscience, as a conceptual and operational tool, to link the dynamics of interacting neurons and the statistics of action potentials from either experimental data or mathematical models. We comment on perspectives and open problems in theoretical neuroscience that could be addressed within this formalism.
REVIEW | doi:10.20944/preprints201609.0089.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: generalized thermodynamic optimization; iron and steel production processes; finite time thermodynamics; constructal theory; entransy theory; metallurgical process engineering
Online: 26 September 2016 (09:51:14 CEST)
Combining modern thermodynamics theory branches, including finite time thermodynamics or entropy generation minimization, constructal theory and entransy theory, with metallurgical process engineering, this paper provides a new exploration on generalized thermodynamic optimization theory for iron and steel production processes. The theoretical core is to thermodynamically optimize performances of elemental packages, working procedure modules, functional subsystems, and whole process of iron and steel production processes with real finite-resource and/or finite-size constraints with various irreversibilities toward saving energy, decreasing consumption, reducing emission and increasing yield, and to achieve the comprehensive coordination among the material flow, energy flow and environment of the hierarchical process systems. A series of application cases of the theory are reviewed. It can provide a new angle of view for the iron and steel production processes from thermodynamics, and can also provide some guidelines for other process industries.
ARTICLE | doi:10.20944/preprints201806.0114.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: computational neuroscience; spike train statistics; maximum entropy principle; large deviation theory; out-of-equilibrium statistical mechanics; thermodynamic formalism; entropy production
Online: 7 June 2018 (11:06:22 CEST)
We consider the maximum entropy Markov chain inference approach to characterize the collective statistics of neuronal spike trains, focusing on the statistical properties of the inferred model. We review large deviations techniques useful in this context to describe properties of accuracy and convergence in terms of sampling size. We use these results to study the statistical fluctuation of correlations, distinguishability and irreversibility of maximum entropy Markov chains. We illustrate these applications using simple examples where the large deviation rate function is explicitly obtained for maximum entropy models of relevance in this field.
ARTICLE | doi:10.20944/preprints202207.0005.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Maroon gas; synthetic natural gas; Pink Hydrogen; hydrogen source-water, hydrogen source-hydrocarbon; energy efficient hydro-gen; Thermodynamic simulations; FACTSAGE; DWSIM
Online: 1 July 2022 (07:55:58 CEST)
This paper describes a novel concept of producing energy efficient ”Maroon enriched natural gas “ and then Pink hydrogen” from any hydrocarbon base. The key idea is the extraction of hydrogen from water in addition to that from the hydrocarbon in an optimal fashion. This has the benefit of higher water vapor to CO2 exhaust ratio than conventional carbonaceous fuels when generating energy via combustion, a prudent step in achieving Netzero goals in a shorter time, and creating energy independence in most places.. The process of production makes concentrated CO2 available for use and or sequestration. The process also maximizes use of renewable electricity in hydrogen generation, and maximizes use of existing infrastructure, with a minimum capital cost by energy recycle in the process. The process design applies sound thermodynamic principles which evolved during the nineteenth century, and mimics the geochemical processes going on in some of the natural 'colorless hydrogen'.
ARTICLE | doi:10.20944/preprints202106.0175.v1
Subject: Physical Sciences, Acoustics Keywords: Ornstein-Zernike equation; coupling-parameter expansion; thermodynamic perturbation theory; adhesive hard-sphere model; liquid-vapor phase transition; generalized Lennard-Jonnes potential.
Online: 7 June 2021 (12:42:22 CEST)
The objective of this paper is to investigate the convergence of coupling-parameter expansion-based solutions to Ornstein-Zernike equation in liquid state theory. The analytically solved Baxter's adhesive hard sphere model is analyzed first using coupling-parameter expansion. It is found that the expansion provides accurate approximations to solutions - including the liquid-vapor phase diagram - in most parts of the phase plane. However, it fails to converge in the region where the model has only complex solutions. Similar analysis and results are, then, obtained using analytical solutions within the mean spherical approximation for the hard-core Yukawa potential. Next, convergence of the expansion is analyzed for the Lennard-Jonnes potential using an accurate density-dependent bridge function in the closure relation. Numerical results are presented which show convergence of correlation functions, compressibility versus density profiles, etc., in the single as well as two phase regions. Computed liquid-vapor phase diagrams, using two independent schemes employing the converged profiles, compare excellently with simulation data. Results obtained for the generalized Lennard-Jonnes potential, with varying repulsive exponent, also compare well with simulation data. All these results together establish the coupling-parameter expansion as a practical tool for studying single component fluid phases modeled via general pair-potentials.
CONCEPT PAPER | doi:10.20944/preprints202104.0686.v1
Subject: Biology, Anatomy & Morphology Keywords: H2O networks; Aqua biomolecule complexes; Thermodynamic mechanism; “Aquamoleculosome"; Entropic systems biology; Self-organized criticality (SOC); Self-organization triggering factor (SOTF); Bioinformatics of aquamoleculomics.
Online: 26 April 2021 (20:02:20 CEST)
Systems biology has been established for more than a decade in the post-genomic era. With the help of the computational and mathematical tools, systems biology reconstitutes the entire scenario of the cell, tissue and even organism from the pieces data generated in the past decades. However, the modern biology is mainly focusing on the structure and function of the biomolecule, cell, tissue or organ, which are far from the essence of the life because of missing thermodynamic information. It is doubtable that the current systems biology-based omics is no-how to fully understand the dynamic courses of the structure, function and information in life. For this reason, we promote a novel concept of aquamoleculomics, in which the biological structure and function as well as thermodynamic characteristics and bioinformation of the aquamolecule complexes are included in this theoretical model of systems biology. Water is mother of life, matter and matrix of organism. Indeed, the fundamental roles of H2O molecules in biological processes might be dramatically underestimated. Extremely speaking, H2O networks in the living system might be engaged in all the biological processes including building all the biological structures, the residential places of the motherhood molecules as the honeycombs of honeybees.
ARTICLE | doi:10.20944/preprints202209.0394.v1
Subject: Physical Sciences, General & Theoretical Physics Keywords: Second Law of thermodynamics; Universe as a closed thermodynamic system; entropy of the Universe; temperature of the Universe; quantum state of the Universe; information within the Universe; complexity of the Universe
Online: 26 September 2022 (10:40:58 CEST)
A simple line of reasoning, based on the most fundamental concepts of thermodynamics, yields some intriguing results for a better understanding of the processes occurring in the observable Universe. Gravitational mass must be continuously generated within an expanding thermodynamic system for this system to remain closed. The Second Law is a direct consequence of this production of mass. Simple expressions for the entropy and temperature of the Universe were obtained and the results agree well with observable values. Furthermore, it is demonstrated that the conservation laws within the Universe are independent of its energy density. Based on the solution for the quantum state of the Universe, it is conjectured that the Second Law is incomplete and must be complemented to a conservation law, which takes into account the growth of the amount of information within the Universe. Once the Second Law is complemented to a conservation law, the importance of mass generation within the Universe becomes well pronounced – not only gravitational effects play the role of an organising force, but also the amount of mass within the Universe defines both the amount of information within the Universe and the level of the Universe’s complexity.
HYPOTHESIS | doi:10.20944/preprints202104.0760.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Complementary and alternative medicine; Traditional Chinese medicine (TCM); Thermodynamic mechanism; Entropic systems biology; Self-organized criticality (SOC); Self-organization triggering factor (SOTF); Wuxing (five phases), Qi, Meridians (Jingluo); Acupuncture points; Chinese herbs; Aquamoleculomics; Modernization of TCM
Online: 28 April 2021 (17:12:29 CEST)
As a complementary and alternative medicine in the western countries for decades, traditional Chinese medicine (TCM) has been used for more than 2000 years in China. Because of the characteristics of the philosophical style and the unknown mechanism of action, TCM sometimes has been biasedly described as "fraught with pseudoscience". From the scientific basis of the systems biology, here we promoted a novel medical model called the entropic systems medicine which could be applied to scientize TCM in future. In entropic systems medicine, TCM and Western modern biomedicine target the different variables of the entropic system. For instance, while Western modern biomedicine directly targets the phenotypes and its SOCs of macrostates, TCM differently targets the microstates, entropy and entropic force to generate SOTFs gradually causing the differentiated syndromes to be slowly rearranged. The prerequisites to modernize TCM are the entropic systems biology having been well established so that the variables could be precisely monitored and mathematically calculated.