1. Dep. of Civil Engineering; 208 Harbert Engineering Center, Auburn Univ. Auburn AL 36849-5337 USA
2. Environ. Sci. Div.; Oak Ridge National Lab.; P.O. Box 2008 Oak Ridge TN 37831-6038 USA
3. Dep. of Agronomy; 104 Sturgis Hall, Louisiana State Univ. Baton Rouge LA 70803 USA