Journal of Pure and Applied Ultrasonics

A. K. George ¹, R. N. Singh ¹, S. Arafin ¹

Affiliations
1 Department of Physics, College of Science, Sultan Qaboos University, P.O. Box 36, Al Khodh 123, Muscat, OM

Abstract

Temperature dependent physical properties such as ultrasound velocity, density, compressibility and the molar volume are measured for different compositions of water-glycerol mixture. These data are further used to investigate the excess velocity (C^xs), excess adiabatic compressibility (κ_S^xs) and the excess molar volume (V^xs). C^xs at room temperature is found to be positive and exhibits maximum around the concentration of glycerol, x_g≈0.65. C^xs depends strongly on temperature and even becomes negative in the dilute limit of concentration at a temperature, 60°C. κ_S^xs is negative exhibiting maxima at room temperature. The excess volume is found to be positive. These results have been used to analyze the surface properties as well as the nature of interaction between molecules in the mixture.

Keywords

Ultrasonic Velocity, Adiabatic Compressibility, Excess Velocity, Excess Compressibility, Excess Molar Volume.

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Ryan T. Abraham ¹, A. K. George ²

Affiliations
1 Department of Chemical Engineering, Box 400741, University of Virginia, Charlottesville, Virginia VA22904-4741, US
2 Department of Physics, College of Science, Sultan Qaboos University, P.O. Box 36, Al Khodh 123, Muscat, OM

Abstract

The density, ultrasound velocity and specific heat capacity at constant pressure of three crude oil samples were measured between temperatures of 20°C to 60°C. The experimental tools used were, densitometry, ultrasonic interferometry and differential scanning calorimetry to evaluate the density, ultrasound velocity and the specific heat capacity, respectively. These measurements are further used to evaluate the adiabatic compressibility, coefficient of volume expansion and acoustic impedance of these three samples. To determine other important properties for the samples, a fundamental relationship between thermodynamic and thermo-elastic properties was determined. Using this relationship, the specific heat at constant volume, the ratio of specific heats and the isothermal compressibility was ascertained. Finally, to show the potential of the laboratory data, the temperature dependence of pressure, a relatively difficult measurement to make under reservoir conditions, was calculated using the isothermal compressibility and the coefficient of volume expansion.

Keywords

Thermo-Elastic Properties, Crude Oil, Specific Heat, Compressibility.

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