Abstract: Using a modified version of the nonanalytic equation of state, thermophysical properties of isobutane are derived from physical properties data and are tabulated at integral temperatures over the entire range of fluid states from 114 to 700 K along isobars at pressures to 70 MPa. Results include dielectric constants, densities, enthalpies, entropies, equation of state, internal energies, isobars, isochores, isotherms, Joule-Thomson inversion, heats of vaporization, melting line, orthobaric densities, specific heats, sound velocities, vapor pressures, and virial coefficients. In addition to the equation of state, equations are given for vapor pressures, orthobaric vapor and liquid densities, ideal gas properties, second virial coefficients, dielectric constants, heats of vaporization, melting pressures, and orthobaric liquid specific heats, enthalpies, and entropies. Several new sets of data have been used in this correlation; comparisons between experimental and calculated values are given.

From introduction: The accurate prediction of phase equilibria plays an important. role in the chemical process industries. A grief overview of final phase equilibria predictive techniques is presented with special emphasis on methods in current use in industry. Areas were better fundamental understanding will lead to improved models are discussed whenever possible.

Summarizes progress to date on the formulation and numerical integration of systems of equations modeling general two-phase flows in a pipe.

Integrated tables of pressure, volume, and temperature for the saturated liquid, from the triple point to the critical point, for oxygen, nitrogen, argon, and parahydrogen.

Technique for varying the coupling of power from far-infrared gas lasers and the design and construction of these lasers.

Review of the progress in research, instrumentation, and service activities of the Spectrochemical Analysis Section from July 1970 to June 1971.