1. Assoc. Prof., Div. of Materials Engrg., Coll. of Engrg., The Univ. of Iowa, Iowa City, Iowa.
2. Grad. Research Asst., Div. of Materials Engrg., Coll. of Engrg., The Univ. of Iowa, Iowa City, Iowa; on leave as Reader, Dept. of Applied Mechanics, MNR Engrg. Coll., Allahabad, India