Equation of state studies of nitrogen, neon, and hydrogen-deuteride near their liquid-gas critical points

Thesis/Dissertation · Sat Jan 01 00:00:00 EST 1983

OSTI ID:5494715

Pestak, M W

Five stacked parallel plates forming four capacitors were used to measure the density at four different heights in a temperature range -5 x 10/sup -2/ < t < +2 x 10/sup -3/ where t is the reduced temperature (T-T/sub c/)/T/sub c/ for Nitrogen, Neon, and Hydrogen Deuteride. These measurements allowed simultaneous determination of (1) the order parameter, (2) isothermal compressibility (both above and below the critical temperature T/sub c/), and (3) the chemical potential versus density on the critical isotherm for the three fluids near their liquid-vapor critical points. For data outside the gravitationally rounded region, power law analysis, which includes correction to scaling terms for the order parameter and the isothermal compressibility, is described in detail. The results agree with Renormalization Group predictions for the leading critical exponents as well as the first correction exponent and the leading amplitude ratios. Analysis of data in the gravitationally rounded region using the restricted cubic model compliments the power law analysis. A consistent determination of certain amplitude ratios for all three fluids is discussed. Special care has been taken to correctly account for the effect of gravity, to eliminate temperature gradients, and to restrict the free choice of T/sub c/.

• Research Organization: Pennsylvania State Univ., University Park (USA)
• OSTI ID: 5494715
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HYDROGEN DEUTERIDE
COMPRESSIBILITY
CRITICAL TEMPERATURE
ORDER PARAMETERS
THERMODYNAMIC ACTIVITY
NEON
NITROGEN
EQUATIONS OF STATE
EXPERIMENTAL DATA
DATA
DEUTERIDES
DEUTERIUM COMPOUNDS
ELEMENTS
EQUATIONS
FLUIDS
GASES
HYDROGEN COMPOUNDS
INFORMATION
MECHANICAL PROPERTIES
NONMETALS
NUMERICAL DATA
PHYSICAL PROPERTIES
RARE GASES
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
360603* - Materials- Properties