sentences:  In 1929, he was appointed the U.S. delegate to the First International Conference on the Properties of Steam; he served as delegate in all successive conferences on this subject through the eighth in 1974.In 1965, he published the classic textbook "Principles of General Thermodynamics" with George Hatsopoulos which was major turning point in thermodynamics since Gilbert N. Lewis and Merle Randall with their 1923 "Thermodynamics" textbook.Their now famous version of the second law of thermodynamics is