Volume 38, Issue 1, March 2009
Index of content:
38(2009); http://dx.doi.org/10.1063/1.3025886View Description Hide Description
Cross section data are collected and reviewed for electron collisions with oxygen molecules. Included are the cross sections for total and elasticscatterings, momentum transfer, excitations of rotational, vibrational, and electronic states, dissociation,ionization, electron attachment, and emission of radiations. For each process, the recommended values of the cross sections are presented, when possible. The literature has been surveyed through the end of 2007.
38(2009); http://dx.doi.org/10.1063/1.3043575View Description Hide Description
Simple but highly accurate correlations have been developed for the thermodynamic properties (including density, heat capacity, and speed of sound), viscosity,thermal conductivity, and static dielectric constant of liquidwater as a function of temperature at a pressure of . The calculations may be simply extended to a pressure range from the saturation pressure to . The temperature range covered in most cases is from ; this includes some temperatures where liquidwater is metastable. These correlations are designed to reproduce the best available data, which in most cases are described by formulations issued by the International Association for the Properties of Water and Steam (IAPWS). The equations presented here are simple enough to be used in applications such as spreadsheets. They provide a convenient alternative to the more complicated IAPWS formulations in cases where only liquidproperties at near-atmospheric pressure are of interest without increasing the uncertainty beyond that of the more complex formulations.
A Reference Equation of State for the Thermodynamic Properties of Sulfur Hexafluoride for Temperatures from the Melting Line to and Pressures up to38(2009); http://dx.doi.org/10.1063/1.3037344View Description Hide Description
A new equation of state for the thermodynamic properties of the fluid phase of sulfur hexafluoride in the form of a fundamental equation explicit in the Helmholtz energy is presented. The functional form consists of a part describing the ideal-gas state and the residual part as the difference between the real-fluid and the ideal-gas behavior. The residual part was developed using state-of-the-art linear and nonlinear optimization algorithms. It contains 36 coefficients, which were fitted to selected data for the thermal and caloric properties of sulfur hexafluoride in the single-phase region and on the vapor-liquid phase boundary. Especially for the thermal properties in the critical region, a very extensive and high-precision data set was available. In this work, information on the experimental data for the thermodynamic properties and all details of the new equation are presented. The new equation of state describes the surface of sulfur hexafluoride with an uncertainty in density of less than 0.02%–0.03% from the melting line up to temperatures of and pressures of . In the critical region, including the immediate vicinity of the critical point, the uncertainty in pressure is less than 0.01%. Reliable data sets of other thermodynamic properties are reproduced within their experimental uncertainties. The primary data, to which the equation was fitted, cover the fluid region from the melting line to temperatures of and pressures up to . Beyond this range, the equation can be extrapolated with a physically reasonable behavior up to very high temperatures and pressures. In addition to the equation of state, independent equations for the vapor pressure, the saturated-liquid and saturated-vapor densities, the melting pressure, and the sublimation pressure are given. Tables of thermodynamic properties calculated from the new equation of state are listed in the Appendix.