Effects of the porous medium and water-silver biological nanofluid on the performance of a newly designed heat sink by using first and second laws of thermodynamics

The aim of this numerical investigation is to evaluate the laminar forced convection of biologically synthesized water-silver nanofluid through a heat sink(HS)filled with porous foam(PHS)using first and second laws of thermodynamics.The impacts of inlet velocity(V=0.5–3 m·s^-1)and volume fraction of nanofluid(φ=0–1%)on the performance metrics of HS are assessed and the outcomes are compared with those of the non-porous HS(NHS).The outcomes revealed that for both the PHS and NHS,the increase of V causes an intensification in convection coefficient,pumping power,and entropy generation due to fluid friction,while the maximum CPU temperature,thermal resistance,and entropy generation due to the heat transfer reduces by boosting V.Also,it was found that the augmentation of V results in intensification in convection coefficient,pumping power,overall hydrothermal performance,and frictional entropy generation,while the opposite is true for maximum CPU temperature,thermal resistance,and thermal entropy generation.Furthermore,it was reported that,except forφ=0.5%,the overall hydrothermal performance of NHS is better than that of PHS,while PHS has better second-law performance than NHS in all the studied cases.Also,it can be concluded that the best hydrothermal performance for PHS belongs toφ=1%and V=0.5 m·s^-1,while for NHS,these values are 1%and 2 m·s^-1.

The Second Law of Thermodynamics in a Quantum Heat Engine Model

The second law of thermodynamics has been proven by many facts in classical world. Is there any new property of it in quantum world？ In this paper, we calculate the change of entropy in T.D. Kieu＇s model for quantum heat engine （QHE） and prove the broad validity of the second law of thermodynamics. It is shown that the entropy of the quantum heat engine neither decreases in a whole cycle, nor decreases in either stage of the cycle. The second law of thermodynamics still holds in this QHE model. Moreover, although the modified quantum heat engine is capable of extracting more work, its efficiency does not improve at all. It is neither beyond the efficiency of T.D. Kieu＇s initial model,nor greater than the reversible Carnot efficiency.

A new discipline: ［Non-Classic(N-C) State-field Theory of Thermodynamics (S-F.TOT)a new second law(2nd-law) of thermodynamics(OT),the Law of Coupling (LOC)］［(N-C).(S-F.TOT)New (2nd-law)OT, (LOC)］,expressed as a theoretical flow sheet

In this paper, the mistakes in the traditional first law are pointed out. A new second law of thermodynamics, the law of coupling is mentioned. The Liu's Principle of Free Energy Conservation is stated. And finally a New Discipline is expressed as A THEORETICAL FLOW SHEET.

Calculating the Refrigeration Coefficient by Using the Second Law of Thermodynamics

Refrigeration coefficient, ε, is usually calculated by using the First Law of Thermodynamics. In this paper, a new derivation process is introduced through the combination of the Second Law of Thermodynamics with the First Law of Thermodynamics. As a result, two new calculation equations for refrigeration coefficient are proposed. One equation is equivalent to the common method, but its form is a little complicated for real calculation. Another equation is the further simplification, and can be used to calculate the refrigeration coefficient instead of common method with a oermit error.

Entropy Analysis of Vapor-Compression Refrigeration System by Using the Second Law of Thermodynamics

By means of the Second Law of Thermodynamics,thispaper gives out the entropy analysis method for vapor-comperession refrigeration system.The thermal irrevers-ibility of the system charged with R12 and its hopeful al-ternative refrlgerant R134a have been studied respective-ly.On the basis of all the research results of this paper,the measure used to save energy for vapor-compressionrefrigeration system has been put out.

Quantum Gravitational Effects on Tunneling Rate of Reissner-Nordstroum Black Hole Emission and Generalized Second Law

The semi-classical black hole tunneling radiation (Parikh-Wilczek tunneling proposal) is calculated undera minimal length uncertainty analysis.It is shown that,the generalized second law of thermodynamics may bound thetunneling probability radiation of a Reissner-Nordstrom black hole radiation.

Second Law Analysis of the Optimal Fin by Minimum Entropy Generation

Based on the entropy generation concept of thermodynamics, this paper estabfished a general theoretical model for the analysis of entropy generation to optimize fins, in which the minimum entropy generation was selected as the object to be studied. The irreversibility due to heat transfer and friction was taken into account so that the minimum entropy generation number has been analyzed with respect to second law of thermodynamics in the forced cross-flow. The optimum dimensions of cylinder pins were discussed. It＇s found that the minimum entropy generation number depends on parameters related to the fluid and fin physical parameters. Varlatioms of the minimum entropy generation number with different parameters were analyzed.

A Reformulation of Newton Second Law for Charged Particles and Its Application to Quantum Dynamics

We propose a reformulation of Newton’s second law of motion for charged particles and possible applications of the reformulation to quantum dynamics. We show that the negative energy states arising from the Dirac equation in relativistic quantum mechanics can be verified using the reformulating framework. We also discuss possible hidden dynamics underlying the concept of quantum jumps in quantum mechanics as outlined in Schrödinger’s article: ARE THERE QUANTUM JUMPS? In this case, we show that the hidden dynamics of quantum jumps are also determined by the Coulomb interaction between charged particles.

The SLA （Second Law Analysis） in Convective Heat Transfer Processes

In all convective heat transfer situations, losses occur in the flow field （by dissipation） as well as in the temperature field （by conduction）. Typically these losses are more or less quantified by the friction factorfwith respect to losses in the flow field, and the Nusselt number Nu for the heat transfer quality. Assessing the process of convective heat transfer as a whole, then becomes problematic because two different non-dimensional quantities, f and Nu, have to be combined somehow. From a thermodynamics point of view, there is a reasonable alternative： Since all losses become manifest in corresponding entropy generation rates, these rates are determined in the velocity as well as in the temperature field. Based on the integration of the entropy generation fields, an energy devaluation number is introduced. It basically determines how much oftbe so-called entropic potential of the energy involved in a convective heat transfer process is used within it. This approach is called SLA （second law analysis）.

THE SECOND LAW ANALYSIS OF GLOBAL IRRADIANCE BASED ON OBSERVED SPECTRAL DISTRIBUTIONS

There have emerged ample literature about the Second Law analysis of extraterrestrial and terrestrial solar radiation consequent to the pioneer works by R. Petela and D. C. Spanner, of which most are irrelevant to the frequency distribution of solar radiation. Since the Second Law analysis was introduced to the fields like photovoltaic and photosynthesis, rendering a need for a method closely related to solar radiation spectrum, some authors created wavelength dependent dilute factots to take the various influence of atmosphere on the frequency distribution into consideration. Because of the complexity of the influence on different frequency, it is not convenient and accurate enough to practically apply the present exergy theories of diluted solar radiation to real solar exergy systems at the surface of the earth. This paper shows a numerical method of Second Law analysis in dealing with the cases of diluted solar irradiance on the earth, based on the observed spectra of global direct and diffuse

Chloride Diffusivity Analysis of Existing Concrete Based on Fick's Second Law

According to the existing concrete core samples obtained in site, chloride concentration and porosity of existing normal hydraulic concrete were measured, and chloride diffusivity in existing hydraulic concrete was studied. By Fick’s second law, the chloride diffusion coefficients in the steady diffusion area were calculated. The chloride diffusion of different mix proportion concrete was tested, and chloride diffusion coefficients and porosities of freshly concrete were measured, moreover, the relationship between diffusion coefficient and porosity was analyzed. The results show that the varying law of chloride diffusion coefficient with exposure time of existing concrete can be predicted in a better way by Fick’s second law and water-cement ratios or porosity of concrete and chloride concentration in existing concrete.

Loschmidt’s Paradox, Extended to CPT Symmetry, Bypasses Second Law

Loschmidt’s paradox is extended by replacing its assumption of time reversibility with full CPT symmetry. Mobility is identified as a means for expressing collisions or dissipation, and the cross product of its gradient with the magnetic field, for expressing parity. Three phenomena incorporating such cross products are identified. The first is the cross product of the mobility gradient with the magnetic field. The second combines this cross product with the E cross B drift. The third is the reciprocal of the Nernst effect expressed as a cross product of the temperature gradient and the magnetic field. Simulations are conducted for testing Loschmidt’s extended paradox. Onsager’s exclusion of magnetic fields and rotation from reciprocals violates CPT symmetry and is unjustified. All three cross-product phenomena skew statistics in a fashion unanticipated by Boltzmann’s assumptions in his H-Theorem. CPT symmetric systems fall outside the assumptions of the theorem which is not rendered invalid but simply limited to its domain of applicability. Therefore, these systems do not violate the second law as Boltzmann defines it. They bypass it.

The Faraday Isolator, Detailed Balance and the Second Law

A Faraday isolator is shown to develop a temperature difference between its input and output, but still complies with the second law when all the heat carriers, in this case, photons are homogeneous and indistinguishable. This result is a consequence of the H-theorem which assumes homogeneity and indistinguishability of particles. However, when a thermal feedback path is added, in which heat carriers have physical properties different from the photons in the isolator, then a heterogeneous system is formed not covered by the H-theorem, and the second law is violated.

Erratum to “The Faraday Isolator, Detailed Balance and the Second Law” [Journal of Applied Mathematics and Physics, Vol. 5, No. 4, April 2017 PP. 889-899]

A Faraday isolator is shown to develop a temperature difference between its input and output, but still complies with the second law when all the heat carriers, in this case, photons are homogeneous and indistinguishable. This result is a consequence of the H-theorem which assumes homogeneity and indistinguishability of particles. However, when a thermal feedback path is added, in which heat carriers have physical properties different from the photons in the isolator, then a heterogeneous system is formed not covered by the H-theorem, and the second law is violated.

The Generalized Thermodynamic Temperature and the New Expressions of the First and the Second Law of Thermodynamics

The classical thermodynamics reflects the significant relationship between the heat and the temperature. On the basis of the relationships, according to the mathematical derivation, this paper structures the conceptions of generalized heat, generalized thermodynamic temperature, generalized entropy and so on. The series of conceptions in the classical thermodynamics is merely a special case of the generalized thermodynamics. Based on these conceptions of generalized thermodynamics, this paper presents the new expressions of the first law and the second law of thermodynamics. In other words, these expressions are endued with new explanations. The Eq. LZ = kTS given by this paper provides theoretical basis for these new expressions.

Two innovative equivalent statements of the third law of thermodynamics

It is found from textbooks and literature that there are three different statements for the third law of thermodynamics,i.e., the Nernst theorem, the unattainability statement of absolute zero temperature, and the heat capacity statement. It is pointed out that such three statements correspond to three thermodynamic parameters, which are, respectively, the entropy,temperature, and heat capacity, and can be obtained by extrapolating the experimental results of different parameters at ultralow temperatures to absolute zero. It is expounded that because there is no need for additional assumptions in the derivation of the Nernst equation, the Nernst theorem should be renamed as the Nernst statement. Moreover, it is proved that both the Nernst statement and the heat capacity statement are mutually deducible and equivalent, while the unattainability of absolute zero temperature is only a corollary of the Nernst statement or the heat capacity statement so that it is unsuitably referred to as one statement of the third law of thermodynamics. The conclusion is that the Nernst statement and the heat capacity statement are two equivalent statements of the third law of thermodynamics.

Energy and first law of thermodynamics for Born-Infeld-anti-de-Sitter black hole

We calculate the local energy and the energy density of the Reisner-Norstrom-anti-de-Sitter black hole, study the first law of thermodynamics and show the Smarr formula for the Born-Infeld-anti-de-Sitter black hole. Applying the first law of thermodynamics to the black hole region, we analyse the three energy exchange processes between the black hole region and the outer and the inner regions.

Effective first law of thermodynamics of black holes with two horizons

For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Bekenstein-Smarr formula and the effective first law of thermodynamics are derived.

Confirmation of the First Law of Thermodynamics in Theory and Extended Bernoulli Equation

The internal energy change of ideal gas does not depend on the volume and pressure. The internal energy change of real gas has not any relation with the volume and pressure, which had been proved. If the internal energy change had not any relation with the volume and pressure, we could confirm the first law of thermodynamics in theory. Simultaneously, the internal energy change is the state function that shall be able to be proved in theory. If the internal energy change depended on the volume and pressure, we could not prove that the internal energy change is the state function and the chemical thermodynamics theory is right. The extended or modified Bernoulli equation can be derived from the energy conservation law, and the internal energy change, heat, and friction are all considered in the derivation procedure. The extended Bernoulli equation could be applied to the flying aircraft and mechanical motion on the gravitational field, for instance, the rocket and airplane and so on. This paper also revises some wrong ideas, viewpoints, or concepts about the thermodynamics theory and Bernoulli equation.

The Application of the Generalized Differential Formulation of the First Law of Thermodynamics for Evidence of the Tidal Mechanism of Maintenance of the Energy and Viscous-Thermal Dissipative Turbulent Structure of the Mesoscale Oceanic Eddies

The practical significance of the established generalized differential formula-tion of the first law of thermodynamics (formulated for the rotational coor-dinate system) is evaluated (for the first time and for the mesoscale oceanic eddies) by deriving the general (viscous-compressible-thermal) and partial (incompressible, viscous-thermal) local conditions of the tidal maintenance of the quasi-stationary energy and dissipative turbulent structure of the mesoscale eddy located inside of the individual fluid region of the ther-mally heterogeneous viscous (compressible and incompressible, respective-ly) heat-conducting stratified fluid over the two-dimensional bottom topog-raphy characterized by the horizontal coordinate x along a horizon-tal axis X. Based on the derived partial (incompressible) local condition (of the tidal maintenance of the quasi-stationary energy and viscous-thermal dis-sipative turbulent structure of the mesoscale eddy) and using the calculated vertical distributions of the mean viscous dissipation rate per unit mass and the mean thermal dissipation rate per unit mass in four regions near the observed mesoscale (periodically topographically trapped by nearly two-dimensional bottom topography h(x) eddy located near the northern region of the Yamato Rise in the Japan Sea, the combined analysis of the energy structure of the eddy and the viscous-thermal dissipative structure of turbulence is presented. The convincing evidence is presented of the tidal mechanism of maintenance of the eddy energy and viscous-thermal dissipa-tive structure of turbulence (produced by the breaking internal gravity waves generated by the eddy) in three regions near the Yamato Rise subjected to the observed mesoscale eddy near the northern region of the Yamato Rise of the Japan Sea.