 He returned to the United States in 1974 as a Visiting Associate Professor in 1974, thereafter as a visiting professor at Minnesota in 1975 before joining Purdue University as a Professor of Chemical Engineering in 1976.Professor Ramkrishna’s research interests lie in the application of mathematics to chemical and biochemical reaction engineering.He has published nearly 200 papers and two books, one entitled Linear Operator Methods in Chemical Engineering (Prentice-Hall) coauthored with Neal Amundson, and the other on Population Balances.