Equations of state for liquids from the zero‐temperature isotherm: Quantum corrections for hydrogen

1980 ◽  
Vol 73 (11) ◽  
pp. 5760-5765 ◽  
Author(s):  
Yaakov Rosenfeld
Keyword(s):  
Equations Of State ◽  
Quantum Corrections ◽  
Zero Temperature ◽  
Temperature Isotherm

ON THE THERMODYNAMICS OF AN ANHARMONIC CRYSTAL WITH HIGH ANISOTROPY

1995 ◽  
Vol 09 (04n05) ◽  
pp. 585-597 ◽  
Author(s):  
V.I. ZUBOV ◽  
M.P. LOBO ◽  
J.N.T. RABELO
Keyword(s):  
Equations Of State ◽  
Quantum Corrections ◽  
Anharmonic Crystal ◽  
Cubic Crystal ◽  
Specific Heats ◽  
Atomic Displacements ◽  
High Anisotropy ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Strong Anharmonicity

The correlative method of the unsymmetrized self-consistent field is used to study the atomic properties of a simple model of an anharmonic crystal with strong anisotropy, namely, a crystal with primitive hexagonal (PH) lattice. The self-consistent potential, Helmholtz free energy and mean-square atomic displacements are obtained in the case of weak anharmonicity. Equations of state are derived and solved. The internal energy and specific heats are calculated. The first quantum corrections are expressed in terms of the de Boer parameter included. An influence of anharmonicity is analyzed. The thermal expansion of the model considered is very anisotropic but the quantum corrections to the lattice parameters are isotropic. The results of calculations are compared with those for one- and two-dimensional models and for the isotropic crystal with the same coordination number as in the PH lattice, i.e. a body-centered cubic crystal. Other things being equal, the coefficient of volume expansion and specific heats of anisotropic crystals are greater than those of isotropic ones. A possibility of studying the strong anharmonicity in anisotropic crystals is discussed.

scholarly journals Relativistic Neutron Stars: Rheological Type Extensions of the Equations of State

Symmetry ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 189
Author(s):  
Alexander Balakin ◽  
Alexei Ilin ◽  
Anna Kotanjyan ◽  
Levon Grigoryan
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Equations Of State ◽  
Pressure Profile ◽  
Spherically Symmetric ◽  
Zero Temperature ◽  
New Approach ◽  
Modified Equations

Based on the Rheological Paradigm, we extend the equations of state for relativistic spherically symmetric static neutron stars, taking into consideration the derivative of the matter pressure along the so-called director four-vector. The modified equations of state are applied to the model of a zero-temperature neutron condensate. This model includes one new parameter with the dimensionality of length, which describes the rheological type screening inside the neutron star. As an illustration of the new approach, we consider the rheological type generalization of the non-relativistic Lane–Emden theory and find numerically the profiles of the pressure for a number of values of the new guiding parameter. We have found that the rheological type self-interaction makes the neutron star more compact, since the radius of the star, related to the first null of the pressure profile, decreases when the modulus of the rheological type guiding parameter grows.

TWO EQUATIONS OF STATE CONSIDERING THE THERMAL EFFECT FOR α, β AND ω PHASES OF ZIRCONIUM

2008 ◽  
Vol 22 (03) ◽  
pp. 167-180
Author(s):  
RONGGANG TIAN ◽  
JIUXUN SUN ◽  
CHAO ZHANG ◽  
FULONG WANG
Keyword(s):  
Experimental Data ◽  
Thermal Effect ◽  
Equations Of State ◽  
Zero Point ◽  
Hexagonal Structure ◽  
Zero Temperature ◽  
Β Phase ◽  
Ω Phase ◽  
Α Phase ◽  
Einstein Model

The Baonza and mGLJ equations of state (EOS) modified previously to consider the thermal effect are applied to study the thermodynamic properties of Zirconium (Zr) . It is proposed that the zero-point vibration term should be deleted in a thermal EOS, and the parameters cannot be directly taken as experimental data at a reference temperature, [Formula: see text] and [Formula: see text], but their values at absolute zero temperature, [Formula: see text] and [Formula: see text]. Based on the Einstein model, an approach is proposed to solve [Formula: see text] and [Formula: see text] from [Formula: see text] and [Formula: see text]. For the hcp (α phase), bcc (β phase) and hexagonal structure (ω phase) of Zr , the molar volume (V), isothermal bulk modulus (B) and thermal expansion coefficient (α) was calculated as a function of pressure and temperature. The predictive capabilities of the complete EOS are discussed and compared with experimental data.

WARM STELLAR MATTER: APPLICATION TO SLOWLY ROTATING COMPACT OBJECTS

2008 ◽  
Vol 23 (05) ◽  
pp. 729-740
Author(s):  
M. D. ALLOY ◽  
D. P. MENEZES
Keyword(s):  
Equations Of State ◽  
Compact Objects ◽  
Zero Temperature ◽  
Stellar Matter

In the present paper we investigate one possible variation on the usual static pulsars: the inclusion of rotation. We use a formalism proposed by Hartle and Thorne to calculate the properties of rotating pulsars with all possible compositions. The calculations were performed for both zero temperature and for fixed entropy equations of state.

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