2000 - 2006

• Professor, Department of Chemical Engineering, The Pennsylvania State University

1983 - 2000

• Head, Department of Chemical Engineering, The Pennsylvania State University

1975 - 2006

• Professor, Department of Chemical Engineering, The Pennsylvania State University

1971 - 1975

• Associate Professor, Department of Chemical Engineering, The Pennsylvania State University

1969 - 1971

• Senior Research Engineer, Dow Chemical Company, Engineering Section of Dow's Interdiscipline Group

1963 - 1969

• Research Engineer, Dow Chemical Company, Process Fundamentals Laboratory