1. Associates III, Materials Engineering, Wiss, Janney, Elstner Associates, Inc., 330 Pfingsten Rd., Northbrook, IL 60062.
2. Product Development Manager, Cemex Trademarks Worldwide Ltd., Römerstrasse 13, 2555 Bruegg b. Biel, Switzerland.
3. Professor, Dept. of Civil Engineering, Northwestern Univ., 2145 N. Sheridan Rd., Evanston, IL 60208.