1. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996-2010.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996-2010.
3. Professor and Distinguished Scientist, Dept. of Chemistry, Univ. of Tennessee, Knoxville, TN 37996-1600; and, Division of Chemical Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6120.