COMPARISON OF THREE EQUATIONS OF STATE FOR TRANSITION METALS

2011 ◽  
Vol 25 (21) ◽  
pp. 2813-2821 ◽  
Author(s):  
RONGGANG TIAN ◽  
JIUXUN SUN ◽  
FEI YU ◽  
WEI YANG ◽  
XINYING XUE
Keyword(s):  
Equation Of State ◽  
Transition Metals ◽  
Compression Ratio ◽  
Cohesive Energy ◽  
Equations Of State ◽  
Energy Data ◽  
Practical Applications ◽  
Best Fitting ◽  
Compression Data

A modified generalized Morse (mGM) equation of state (EOS) is proposed that can incorporate the cohesive energy data correctly. It is compared with a four-parameter modified Rose EOS (MR EOS) which is proposed by following the Rose's approach and the Vinet EOS. The MR, mGM and Vinet EOSs are applied to five transition metals to fit all experimental compression data available. The results show that for all pressure ranges the mGM EOS gives the best fitting results. From the comparison of variation of pressure and energy versus compression ratio between MR and mGM EOS, it is clear that the pressure and energy of the MR EOS oscillate both in the neighborhood of (V/V0) ≈ 0.005 and in the range (V/V0) > 1. Such oscillations are physically incorrect, and the tendency of the mGM EOS are physically correct both in the neighborhood of (V/V0) ≈ 0.005 and in the range (V/V0) > 1. Generally speaking, the mGM EOS has evident advantage among the three EOSs, and the MR EOS's practical applications are seriously limited because of the physically incorrect oscillations.

Two Universal Equations of State for Solids

2010 ◽  
Vol 65 (1-2) ◽  
pp. 34-44
Author(s):  
Jiu-Xun Sun ◽  
Qiang Wu ◽  
Yang Guo ◽  
Ling-Cang Cai
Keyword(s):  
Cohesive Energy ◽  
Equations Of State ◽  
Second Best ◽  
Practical Applications ◽  
The Third ◽  
Lennard Jones ◽  
Compression Data ◽  
Two Parameters

AbstractIn this paper, two equations of state (EOSs) (Sun Jiu-Xun-Morse with parameters n = 3 and 4, designated by SMS3 and SMS4) with two parameters are proposed to satisfy four merits proposed previously and give improved results for the cohesive energy. By applying ten typical EOSs to fit experimental compression data of 50 materials, it is shown that the SMS4 EOS gives the best results; the Baonza and Morse EOSs give the second best results; the SMS3 and modified generalized Lennard-Jones (mGLJ) EOSs give the third best results. However, the Baonza and mGLJ EOSs cannot give physically reasonable values of cohesive energy and P-V curves in the expansion region; the SMS3 and SMS4 EOS give fairly good results, and have some advantages over the Baonza and mGLJ EOSs in practical applications.

SITE-SPECIFIC EQUATIONS OF STATE FOR COASTAL SEA AREAS AND INLAND WATER BODIES

2017 ◽  
Author(s):  
Natalia Andrulionis ◽  
Natalia Andrulionis ◽  
Ivan Zavialov ◽  
Ivan Zavialov ◽  
Elena Kovaleva ◽  
...  
Keyword(s):  
Equation Of State ◽  
Black Sea ◽  
Water Samples ◽  
Equations Of State ◽  
Sea Water ◽  
Ionic Composition ◽  
Water Bodies ◽  
Aral Sea ◽  
The Black Sea ◽  
Coastal Sea

This article presents a new method of laboratory density determination and construction equations of state for marine waters with various ionic compositions and salinities was developed. The validation of the method was performed using the Ocean Standard Seawater and the UNESCO thermodynamic equation of state (EOS-80). Density measurements of water samples from the Aral Sea, the Black Sea and the Issyk-Kul Lake were performed using a high-precision laboratory density meter. The obtained results were compared with the density values calculated for the considered water samples by the EOS-80 equation. It was shown that difference in ionic composition between Standard Seawater and the considered water bodies results in significant inaccuracies in determination of water density using the EOS-80 equation. Basing on the laboratory measurements of density under various salinity and temperature values we constructed a new equation of state for the Aral Sea and the Black Sea water samples and estimated errors for their coefficients.

Application of the Redlich-Kwong-Soave equation of state to the solubility of water in compressed gases

1984 ◽  
Vol 49 (5) ◽  
pp. 1116-1121
Author(s):  
Josef P. Novák ◽  
Jaroslav Matouš ◽  
Petr Pick ◽  
Jiří Pick
Keyword(s):  
Equation Of State ◽  
Binary Systems ◽  
Equations Of State ◽  
Published Data ◽  
Interaction Coefficients

Published data on the solubility of water in compressed gases were employed for calculating the interaction coefficients kij in the Redlich-Kwong-Soave equations of state for binary systems of water with argon, nitrogen, CO2, N2O, CH4, C2H6, or C2H4. With these coefficients, the estimate of the solubility of water in these gases has been improved by more than one order.

scholarly journals Global Well-Posedness of the Ocean Primitive Equations with Nonlinear Thermodynamics

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Peter Korn
Keyword(s):  
Equation Of State ◽  
Equations Of State ◽  
Boussinesq Equations ◽  
Climate Science ◽  
Rational Functions ◽  
Ocean Dynamics ◽  
Global Ocean ◽  
Primitive Equations ◽  
Well Posedness ◽  
Nonlinear Thermodynamics

AbstractWe consider the hydrostatic Boussinesq equations of global ocean dynamics, also known as the “primitive equations”, coupled to advection–diffusion equations for temperature and salt. The system of equations is closed by an equation of state that expresses density as a function of temperature, salinity and pressure. The equation of state TEOS-10, the official description of seawater and ice properties in marine science of the Intergovernmental Oceanographic Commission, is the most accurate equations of state with respect to ocean observation and rests on the firm theoretical foundation of the Gibbs formalism of thermodynamics. We study several specifications of the TEOS-10 equation of state that comply with the assumption underlying the primitive equations. These equations of state take the form of high-order polynomials or rational functions of temperature, salinity and pressure. The ocean primitive equations with a nonlinear equation of state describe richer dynamical phenomena than the system with a linear equation of state. We prove well-posedness for the ocean primitive equations with nonlinear thermodynamics in the Sobolev space $${{\mathcal {H}}^{1}}$$ H 1 . The proof rests upon the fundamental work of Cao and Titi (Ann. Math. 166:245–267, 2007) and also on the results of Kukavica and Ziane (Nonlinearity 20:2739–2753, 2007). Alternative and older nonlinear equations of state are also considered. Our results narrow the gap between the mathematical analysis of the ocean primitive equations and the equations underlying numerical ocean models used in ocean and climate science.

scholarly journals Measuring the structure and equation of state of polyethylene terephthalate at megabar pressures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Lütgert ◽  
J. Vorberger ◽  
N. J. Hartley ◽  
K. Voigt ◽  
M. Rödel ◽  
...  
Keyword(s):  
Equation Of State ◽  
Polyethylene Terephthalate ◽  
Density Functional ◽  
Equations Of State ◽  
Md Simulations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Shock Hugoniot ◽  
Highly Correlated

AbstractWe present structure and equation of state (EOS) measurements of biaxially orientated polyethylene terephthalate (PET, $$({\hbox {C}}_{10} {\hbox {H}}_8 {\hbox {O}}_4)_n$$ ( C 10 H 8 O 4 ) n , also called mylar) shock-compressed to ($$155 \pm 20$$ 155 ± 20 ) GPa and ($$6000 \pm 1000$$ 6000 ± 1000 ) K using in situ X-ray diffraction, Doppler velocimetry, and optical pyrometry. Comparing to density functional theory molecular dynamics (DFT-MD) simulations, we find a highly correlated liquid at conditions differing from predictions by some equations of state tables, which underlines the influence of complex chemical interactions in this regime. EOS calculations from ab initio DFT-MD simulations and shock Hugoniot measurements of density, pressure and temperature confirm the discrepancy to these tables and present an experimentally benchmarked correction to the description of PET as an exemplary material to represent the mixture of light elements at planetary interior conditions.

Equation of state for the detonation products of energetic materials

2021 ◽  
Vol 11 (8) ◽  
pp. 1269-1287
Author(s):  
Xiangyu Huo ◽  
Li Zhang ◽  
Mingli Yang
Keyword(s):  
Artificial Intelligence ◽  
High Pressure ◽  
Computer Simulations ◽  
Energetic Materials ◽  
Equations Of State ◽  
Experiment Study ◽  
Detonation Products ◽  
Main Approach ◽  
Practical Applications ◽  
Integrated Theory

Energetic materials (EMs) are one of the necessities in many military and civilian applications. Measuring the thermodynamic behaviors of detonation products of EMs at high temperature and high pressure, their equations of state (EOSs) not only serve as a basis in the design of novel materials, but also provide valuable information for their practical applications. The EOS study has a long history, but keeps moving all the time. Various EMs have been developed, the EOS of detonation products provides abundant information in the thermochemistry, hydromechanics and detonation physics, which in turn feedbacks the development of novel EMs and their EOSs. With the development of experimental techniques and computer simulations, many EOSs have been proposed for various explosives in recent years. While experiments keep their fundamental roles, integrated theory-experiment study has become the main approach to the EOS establishment for novel EMs. Moreover, computer simulations based on interatomic and/or intermolecular interaction will have great potential in the future when big data and artificial intelligence are introduced into the field.

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