1. Research Chemist, Biological Laboratory Technician and Research Nutritionist, respectively, Carbohydrate Nutrition Laboratory, Nutrition Institute, Science and Education Administration, United States Department of Agriculture, Agricultural Research Center - East, Beltsville.
2. Adjunct Professor, Department of Food, Nutrition and Institution Administration, University of Maryland, College Park.
3. Research Assistant, Department of Food, Nutrition and Institution Administration, University of Maryland College Park.
4. Research Associate, Department of Chemistry, University of Maryland, College Park.
5. Professor and Chairman, Department of Food, Nutrition and Institution Administration, University of Maryland, College Park.