1. Asst. Prof., Air Quality Engrg., Texas Agric. Experiment Station, 6500 Amarillo Blvd., W. Amarillo, TX 79106; formerly, Grad. Student, Civ. Engrg. Dept., Univ. of Texas at Austin, Austin, TX 78712.
2. Assoc. Prof., Civ. Engrg. Dept., Univ. of Texas at Austin, Center for Energy and Environmenal Resources, R7100, 10100 Burnet Rd., Austin, TX 78758. E-mail: corsi@mail.utexas.edu
3. Prof., Civ. Engrg. Dept., Univ. of Texas at Austin, ECJ 8.6, Austin, TX 78712.