1. Asst.-Doctor Prof. Dept. of Hydr. and Sanitation, School of Engrg. of Sao Carlos, Univ. of Sao Paulo, Sao Carlos, Brazil; formerly, Post-Doctoral Fellow, Dept. of Civ. Engrg, Iowa State Univ., Ames, Iowa
2. Prof. Dept. of Civ. Engrg., Iowa State Univ., Ames, Iowa