A new model has been developed for calculation of fluid-phase equilibria of asymmetric mixtures. This local-composition model extends the quasi-chemical theory of Guggenheim (known to correlate well liquid-state activity coefficients) to fluids of all densities. The model can be applied to any equation of state, contains only one new adjustable parameter per binary pair, and can be extended to multicomponent mixtures of large and small molecules by use of the surface areas of the molecules. Although the local-composition model is a nonrandomness approach, all randomness boundary conditions are met. Significant improvement over the random-mixing model is shown for the prediction of vapor-liquid equilibria of methane/water and ethane/water systems.

Masters Theses in the Pure and Applied Sciences was first conceived, published, SIld disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna and broader dissemination. tional publishing house to assure improved service Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 30 (thesis year 1985) a total of 12,400 theses titles from 26 Canadian and 186 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work.

Reviews the latest developments in a subject relevant to professionals involved in the simulation and design of chemical processes - includes disk of computer programs.