Technical Narrative: This U.S.-Turkey collaborative research project involving physicists from Catholic University and Erciyes University in Kayseri, Turkey will investigate the global properties of a number of equations of state for binary mixtures. Project funding will enable Dr. Mustafa Keskin of Erciyes University to spend two months in the laboratory of Dr. Paul Meijer at Catholic University. Additionally, Dr. Meijer will travel to Kayseri and spend three weeks in Dr. Keskin's laboratory. This cooperative research project will elucidate global features of binary fluid critical phase line behavior in relation to classes of equations of state and parameter ranges. This project is useful from the standpoint of providing an overall perspective on phase behavior and strategies for representing or interpreting it in terms of categories of equations of state. This project in thermophysical properties fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Turkey to combine complementary talents and pool research resources in areas of strong mutual interest and competence.