1. Graduate Student, St. Anthony Falls Laboratory, Dept. of Civil, Environmental and Geo-Engineering, Univ. of Minnesota, Minneapolis, MN 55414 (corresponding author).
2. Professor, Dept. of Civil, Environmental and Geo-Engineering, Univ. of Minnesota, Minneapolis, MN 55414.
3. Professor, Dept. of Bioproducts and Biosystems Engineering, Univ. of Minnesota, 1390 Eckles Ave., St. Paul, MN 55108.