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1

Dynamic Tsallis Entropy for Simple Model Systems

100%

Khusnutdinov N., Yulmetyev R., Emelyanova N.

Acta Physica Polonica A

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2006

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vol. 109

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issue 2

199-217

EN

In this paper we consider the dynamic Tsallis entropy and employ it for four model systems: (i) the motion of Brownian oscillator, (ii) the motion of Brownian oscillator with noise, (iii) the fluctuation of particle density in hydrodynamics limit as well as in (iv) ideal gas. We show that the small value of parameter non-extensivity 0 < q < 1 acts as a non-linear magnifier for small values of the entropy. The frequency spectra become more sharp and it is possible to extract useful information in the case of noise. We show that the ideal gas remains non-Markovian for arbitrary values of q.

2

Singular Pretransitional Behavior of the Electric Field-Dependent Part of the Thermodynamic Quantities of Strongly Polar Mesogenic Liquids in the Isotropic Phase

51%

Jadżyn J., Déjardin J., Czechowski G.

Acta Physica Polonica A

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2007

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vol. 111

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issue 6

877-884

EN

A new interpretation of the pretransitional temperature behavior of the static dielectric permittivity and its derivative in terms of the basic thermodynamic quantities: the internal energy, the entropy, and the Helmholtz free energy is presented. It was shown that in the case of strongly polar mesogenic compounds (as the homologous series of alkylcyanobiphenyls) the electric field-induced increments of both the internal energy and the entropy exhibit a critical-like temperature dependence in the vicinity of transition from the isotropic liquid to the nematic phase. As a most important pretransitional effect, it is shown that at a temperature of about 10 degrees before the phase transition, an electric field applied to the isotropic liquids induces an increase in the entropy (Δ S>0) instead of its decrease, as observed far from the phase transition or for the non-mesogenic dipolar liquids.

3

New Kinetic Theory for Absorption and Emission Rates of Radiation and New Equations for Lattice and Electronic Heat Capacities, Enthalpies and Entropies of Solids: Application to Copper

51%

Bozdoğan A.

Acta Physica Polonica A

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2017

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vol. 131

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issue 3

519-526

EN

New equations, which have analytical solutions, for lattice and electronic heat capacities, entropies and enthalpies at constant volume and constant pressure were derived by using kinetic theory, Kirchhoff and Stefan-Boltzmann laws and Wien radiation density equation. These equations were applied to the experimental constant volume heat capacity data of copper. The temperature Θ_{V} corresponding to 3R/2 was found to be 78.4 K for copper. Copper shows the dimensionality crossover from 3 to 2 at about 80 K. The Θ_{V}(T) is proportional to Debye temperature. The relationship between dimension and Θ_{V} was given. Temperature dependence of Debye temperature and non-monotonic behavior were discussed. The heat capacity and entropy values, predicted by the proposed models were compared with the values predicted by the Debye models. The results have shown that the proposed models fit the data better than the Debye models. Enthalpy equations derived in this study were compared with the polynomial model and a good fitting was obtained. The equation for the photon absorption equilibrium constant of copper was derived.

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1 Khusnutdinov N.

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Dynamic Tsallis Entropy for Simple Model Systems

Singular Pretransitional Behavior of the Electric Field-Dependent Part of the Thermodynamic Quantities of Strongly Polar Mesogenic Liquids in the Isotropic Phase

New Kinetic Theory for Absorption and Emission Rates of Radiation and New Equations for Lattice and Electronic Heat Capacities, Enthalpies and Entropies of Solids: Application to Copper