1. Postdoctoral Research Associate, Dept. of Biological and Agricultural Engineering, North Carolina State Univ., 127 Weaver Lab, Campus Box 7625, Raleigh, NC 27695-7625 (corresponding author).
2. Professor and Department Head, Dept. of Biological and Agricultural Engineering, North Carolina State Univ., 104 Weaver Administration Bldg., Campus Box 7625, Raleigh, NC 27695-7625.