Temperature equations of state

Zwanzig R 1954 High temperature equation of state by a perturbation method I. Nonpolar Gases J. Chem. Phys. 22 1420... 

Zwanzig R W 1954. High-temperature Equation of State by a Perturbation Method. 1. Nonpolar Gases. Journal of Chemical Physics 22 1420-1426. 

The pressure is to be identified as the component of stress in the direction of wave propagation if the stress tensor is anisotropic (nonhydrostatic). Through application of Eqs. (2.1) for various experiments, high pressure stress-volume states are directly determined, and, with assumptions on thermal properties and temperature, equations of state can be determined from data analysis. As shown in Fig. 2.3, determination of individual stress-volume states for shock-compressed solids results in a set of single end state points characterized by a line connecting the shock state to the unshocked state. Thus, the observed stress-volume points, the Hugoniot, determined do not represent a stress-volume path for a continuous loading. 

In the above subsection it was demonstrated that the inclusion of electrostatic interactions into the pressure-area-temperature equation of state provides a better fit to the observed equilibrium behavior than the model with two-dimensional neutral gas. Considering this fact, we would like to devote our attention now to the character of the lipid film under the dynamical, nonequilibrium conditions. In the following we shall describe the dynamical behavior of the phospholipid(l,2-dipalmitoyl-3-sn-phosphatidylethanolamines DPPE) thin films in the course of the compression and expansion cycles at air/water interface. 

Bottinga Y. E. and Richet P. (1981). High pressure and temperature equation of state and calculation of the therodynamic properties of gaseous carbon dioxide. Amer. Jour. Set, 281 615-660. 

Angel RJ (1993) The high-pressure, high-temperature equation of state of calcium fluoride, Cap2. J Phys Cond Matter 5 L141-L144... 

GordiUo, M.C., Boronat, J., and CasuUeras, J. (2000). Zero-temperature equation of state of quasi-one-dimensional H2. Phys. Rev. Lett., 85, 2348-51. 

A methanol model was previously implemented in the Cheetah code. The model is based on a combination of shock Hugoniot data and sound speeds determined via ISLS. High-pressure and temperature equation of state data on pure ethanol was not available, so Impulsive Stimulated Light Scattering measurements were made of the sound speed of ethanol at 250° C. Results are shown in Figure 5. A Cheetah exponential-6 potential model was fit to the ISLS measurements. The 3% difference between data sets shows the utility of Cheetah and the consistency between static and dynamic equation of state measurements. High precision ISLS measurements easily resolve ethanol velocities from 2-3% lower methanol velocities. 

The problem of finding effectively the equation of state of a mixture of hard spheres of different diameters, incidentally, is of considerable interest in a number of applications, e.g., for finding the high temperature equation of state of mixtures of real gases and the surface tension of mixtures, amoi other things. While a number of the theories of fluids mentioned in Section IV of this chapter can also be reformulated " formally for mixtures,... 

For low or moderately high fluid densities one can take for g (r) the virial equation (34). Using this and Eq, (80) for

high temperature equation of state from (89) to be... 

The isotherms of this perturbation high-temperature equation of state lead surprisingly to a critical point and a van der Waals loop in a gas-liquid phase equilibrium. While this occurs wdl beyond the range of validity of the derivation, the critical point data are astonishingly good ... 

Fig. 13. The experimental high temperature equation of state for argon the figures associated with the lines refer to the various volumes of the fluid in cc.

R. W. Zwanzig,/. Chem. Phys., 22,1420 (1954). High-Temperature Equation of State by a... 

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