1. Graduate Research Assistant, Dept. of Agricultural and Biological Engineering, Purdue Univ., 225 South University Street, West Lafayette, IN 47907.
2. Professor, Dept. of Agricultural and Biological Engineering, Purdue Univ., 225 South University Street, West Lafayette, IN 47907..
3. Associate Professor, Dept. of Agricultural and Biological Engineering, and Dept. of Earth and Atmospheric Sciences, Purdue Univ., 225 South University Street, West Lafayette, IN 47907 (corresponding author).