This U.S.-Yugoslav cooperative research project in physical chemistry between Dusan Bratko of the University of Ljubljana and Lesser Blum of the University of Puerto Rico addresses statistical and mechanical problems of solvation phenomena in simple solvent systems and in ionic colloid systems. The investigators will emphasize the thermodynamic and transport properties. The research consists in three parts: study of hard sphere fluid in a confined system, solvation pehomena in a waterlike liquid and colloidal interactions. The co-investigators have published jointly and are well recognized for contributions in this field. This project was approved by the U.S.-Yugoslav Joint Board on Cooperation in Science and Technology and is supported through a joint fund consisting of matching contributions from the U.S. and Yugoslav governments. The U.S. contribution is provided annually by the Department of State. No NSF funds are involved. The grants are composed principally of Yugoslav dinars and made to the principal Yugoslav institute. Grants include travel for U.S. scientists to Yugoslavia and a modest dollar allowance for Yugoslav scientists' living expenses in the U.S.