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Thermodynamics

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Full-Text Articles in Physics

Thermodynamic Properties Of V, Cr, Mo, And Fe Metals And Their Binary Alloys, Taiwo Akande, Fadeke Matthew-Ojelabi, Gbenga Agunbiade, Ebenezer Babatope Faweya Jan 2019

Thermodynamic Properties Of V, Cr, Mo, And Fe Metals And Their Binary Alloys, Taiwo Akande, Fadeke Matthew-Ojelabi, Gbenga Agunbiade, Ebenezer Babatope Faweya

Turkish Journal of Physics

The interactions between distinctive alloying elements have been scrutinized through atomistic investigation for essential material selection. The tight-binding model was applied to compute the thermodynamic properties of V, Cr, Mo, and Fe metals and their binary alloys. The calculated results agree with the accessible experiment in some cases, while some are closer in agreement with the experiment. The minimum formation enthalpies observed are -17.80, -15.20, -13.10, -11.50, and -0.90 eV for Cr-Mo, Cr-V, Fe-V, V-Fe, and Mo-Cr, respectively. The Cr-Mo alloy is the most stable of all the selected alloys with the least formation enthalpy. For the alloy structure, bcc …


Super Inflation Mechanism And Dark Energy From A Cosmological Entropy Perspective, Ali̇ İhsan Keski̇n Jan 2018

Super Inflation Mechanism And Dark Energy From A Cosmological Entropy Perspective, Ali̇ İhsan Keski̇n

Turkish Journal of Physics

Various approaches are developed that provide a unification of the early inflationary epoch of the universe and dark energy (cosmic accelerating expansion case). In one respect, we express this unification in a universal thermodynamic framework within the context of $F\left( T,T_{G} \right)$ gravity, where $T$ represents the torsion invariant and $T_{G}$ is the teleparallel equivalent of the Gauss--Bonnet term. For a Friedmann-Robertson-Walker universe model bounded by the dynamical apparent horizon, we explore the generalized second law of gravitational thermodynamics (GSLT). Finally, we discuss the super inflation mechanism, the deceleration case (radiation and dust regions), and the late time cosmic acceleration …


Thermodynamics Of Cosmological Models With Generalized $G$ And $\Lambda $, M Saratchandra Singh, Sanasam Surendra Singh Jan 2018

Thermodynamics Of Cosmological Models With Generalized $G$ And $\Lambda $, M Saratchandra Singh, Sanasam Surendra Singh

Turkish Journal of Physics

Here we investigate spatially flat Friedmann-Robertson-Walker space-time models of the universe to study the thermodynamic behaviors in light of variables $G$ and $\Lambda $. A particular method to find the solutions of Einstein's field equations and mathematical expressions for temperature and entropy of the perfect fluid cosmological models is introduced by using both the equation of state and the assumption $G=G_{0} \,a^{n}$. It is observed that the phantom field of ($\omega


Nature Of Entropy In A Scalar-Tensor Theory Of Gravity, Onur Siğinç, Mustafa Salti, Hi̇lmi̇ Yanar, Oktay Aydoğdu Jan 2018

Nature Of Entropy In A Scalar-Tensor Theory Of Gravity, Onur Siğinç, Mustafa Salti, Hi̇lmi̇ Yanar, Oktay Aydoğdu

Turkish Journal of Physics

This work is devoted to studying the generalized nature of the entropy function in a specific form of the scalar-tensor-vector (STeVe) theory of gravity for the Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime in the state of thermal equilibrium. For this purpose, we define an equilibrium picture of thermodynamics by making use of a suitable set of the dark energy density and dark pressure descriptions, which defines an energy-momentum tensor obeying the local energy conservation law. Furthermore, we also discuss our results numerically in order to get additional implications.


Second Law Of Gravitational Thermodynamics In The Locally Rotationally Symmetric Bianchi Type-Ii Universe, Murat Korunur Jan 2017

Second Law Of Gravitational Thermodynamics In The Locally Rotationally Symmetric Bianchi Type-Ii Universe, Murat Korunur

Turkish Journal of Physics

In this work, under the assumption that the universe is locally rotationally symmetric (LRS) Bianchi type-II and filled with anisotropic dark fluid (dark energy and dark radiation), we investigate whether the generalized second law of thermodynamics (GSLT) is still valid. We also consider another important condition for LRS Bianchi type-II spacetimes whereby the model expansion $\theta $ is proportional to the shear $\sigma $, which leads to $B=A^{n}$ (where n is a constant and A and B are the metric potentials). Based on this, we derive a general circumstance for the GSLT and find that its validity depends on the …


Symmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Masssymmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Mass, Randy Wayne Jan 2015

Symmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Masssymmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Mass, Randy Wayne

Turkish Journal of Physics

I have previously proposed a discrete symmetry called CPM (charge-parity-mass) symmetry that defines matter as having positive mass and antimatter as having negative mass-both being involved in processes that proceed forward in time. I have generalized the second law of thermodynamics to describe and predict the order of events in time that take place in reversible thermodynamic systems composed of positive or negative mass. Here I extend the CPM symmetry to irreversible thermo-optical radiation systems characterized by the Stefan-Boltzmann law, Planck's blackbody radiation law, and Einstein's law of specific heat. The laws of radiation analyzed in terms of CPM symmetry …


Thermodynamics Of Liquid Alkali Metals Using Pseudopotential Perturbation Scheme, Jagendra Kamalsinh Baria, Ashvinkumar Ramaniklal Jani Jan 2012

Thermodynamics Of Liquid Alkali Metals Using Pseudopotential Perturbation Scheme, Jagendra Kamalsinh Baria, Ashvinkumar Ramaniklal Jani

Turkish Journal of Physics

Recently proposed model potential of Baria and Jani is used with the exchange and correlation effect of Sarkar et al. to calculate internal energy (Enthalpy), Entropy and Helmholtz free energy of liquid Na, K, Rb and Cs at various temperatures with the variational approach. The parameter of the potential is determined with the standard zero pressure condition. The structure factor derived by Percus-Yevick solution for hard sphere fluids which is characterized by hard sphere diameter \sigma is used. A good agreement between theoretical investigations and experimental findings has confirmed the ability of the model potential to the liquid alkali metals.