COEXISTENCE PHENOMENA IN THE CRITICAL REGION: II. INFLUENCE OF GRAVITY ON THE COEXISTENCE CURVES OF ETHANE, ETHYLENE, AND XENON

1953 ◽  
Vol 31 (6) ◽  
pp. 569-584 ◽  
Author(s):  
S. G. Whiteway ◽  
S. G. Mason
Keyword(s):  
Critical Point ◽  
Critical Region ◽  
Major Part ◽  
Region Ii ◽  
Gravitational Compression ◽  
Good Agreement ◽  
Liquid Vapor ◽  
Observed Behavior

Liquid–vapor coexistence curves of ethane, ethylene, and xenon have been measured in the region of the critical point. Impurities present in the ethane and ethylene gave retrograde systems; reduction of the impurities yielded coexistence curves which were flat along the temperature axis to 0.001 °C. When the height of the ethylene system was decreased the range of densities over which the curve was flat was diminished. Stirring of the system caused the curve to be rounded. Similar results, confirming those of Weinberger and Schneider, were obtained with xenon. The observed behavior is in good agreement with the hypothesis that the major part of the flat top effect is due to gravitational compression.

A Rational Equation of State for Water and Water Vapor in the Critical Region

1964 ◽  
Vol 86 (3) ◽  
pp. 320-326 ◽  
Author(s):  
E. S. Nowak
Keyword(s):  
Water Vapor ◽  
Equation Of State ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Critical Point ◽  
Critical Region ◽  
Constant Pressure ◽  
Parametric Equation ◽  
Enthalpy And Entropy ◽  
Specific Volumes

A parametric equation of state was derived for water and water vapor in the critical region from experimental P-V-T data. It is valid in that part of the critical region encompassed by pressures from 3000 to 4000 psia, specific volumes from 0.0400 to 0.1100 ft3/lb, and temperatures from 698 to 752 deg F. The equation of state satisfies all of the known conditions at the critical point. It also satisfies the conditions along certain of the boundaries which probably separate “supercritical liquid” from “supercritical vapor.” The equation of state, though quite simple in form, is probably superior to any equation heretofore derived for water and water vapor in the critical region. Specifically, the deviations between the measured and computed values of pressure in the large majority of the cases were within three parts in one thousand. This coincides approximately with the overall uncertainty in P-V-T measurements. In view of these factors, the author recommends that the equation be used to derive values for such thermodynamic properties as specific heat at constant pressure, enthalpy, and entropy in the critical region.

Liquid-vapor critical point of physisorbed films

1984 ◽  
Vol 148 (1) ◽  
pp. 200-211 ◽  
Author(s):  
James R. Klein ◽  
M.H.W. Chan ◽  
Milton W. Cole
Keyword(s):  
Critical Point ◽  
Liquid Vapor

Liquid-vapor critical point of physisorbed films

1984 ◽  
Vol 148 (1) ◽  
pp. A484
Author(s):  
James R. Klein ◽  
M.H.W. Chan ◽  
Milton W. Cole
Keyword(s):  
Critical Point ◽  
Liquid Vapor

scholarly journals The molecular scattering of light in vapours and in liquids and its relation to the opalescence observed in the critical state

1922 ◽  
Vol 102 (715) ◽  
pp. 151-161 ◽  
Keyword(s):  
Critical Point ◽  
Critical State ◽  
Incident Light ◽  
Wave Length ◽  
Molecular Scattering ◽  
Avogadro’S Number ◽  
Quantitative Manner ◽  
The Mean ◽  
Good Agreement ◽  
Molecular Scattering Of Light

It has long been known that in the immediate vicinity of the critical state, many substances exhibit a strong and characteristic opalescence. In recent years, the phenomenon has been studied by Travers and Usher in the case of carefully purified CS 2 , SO 2 , and ether, by S. Young, by F. B. Young in the case of ether, and in a quantitative manner by Kammerlingh Onnes and Keesom in the case of ethylene. An explanation of the phenomenon on thermodynamic principles as due to the accidental deviations of density arising in the substance was put forward by Smoluchowski. He obtained an expression for the mean fluctuation of density in terms of the compressibility of the substance, and later, Einstein applied Maxwell’s equations of the electromagnetic field to obtain an expression for the intensity of the light scattered in consequence of such deviations of density. He showed that the fraction α of the incident energy scattered in the substance per unit volume is 8 π 3 /27 RT β ( μ 2 – 1) 2 ( μ 2 + 2) 2 /N λ 4 (1) In this, R and N are the gas constant and Avogadro’s number per grammolecule, β is the isothermal compressibility of the substance, μ is the refractive index and λ is the wave-length of the incident light. Keesom tested this formula over a range of 2·35° above the critical point of ethylene and found good agreement except very close to the critical point.

Transport properties of helium near the liquid-vapor critical point. IV. The shear viscosity of3He and4He

1987 ◽  
Vol 67 (3-4) ◽  
pp. 237-289 ◽  
Author(s):  
Charles C. Agosta ◽  
Suwen Wang ◽  
L. H. Cohen ◽  
H. Meyer
Keyword(s):  
Transport Properties ◽  
Critical Point ◽  
Shear Viscosity ◽  
Liquid Vapor
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