1. Graduate Student, Univ. of Colorado, Denver, Dept. of Civil Engineering, Campus Box 113, PO Box 173364, Denver, CO 80217-3364.
2. Adjunct Professor, Dept. of Chemistry, Community College of Denver, Campus Box 201, PO Box 173363, Denver, CO 80217-3363; formerly, Graduate Student, Univ. of Colorado, Denver, Dept. of Geography and Environmental Sciences, Denver, CO 80217-3364.
3. Assistant Professor, Univ. of Colorado, Denver, Dept. of Civil Engineering, Campus Box 113, PO Box 173364, Denver, CO 80217-3364 (corresponding author).