1. School of Environment and Natural Resources, The Ohio State Univ.; The Ohio Agricultural Research and Development Center; 1680 Madison Ave. Wooster OH 44691
2. Key Lab. of Advanced Civil Engineering Materials; Tongji Univ., Ministry of Education; 1239 Siping Rd. Shanghai 200092 China
3. Dep. of Vegetable Science; College of Agronomy and Biotechnology, China Agricultural Univ.; 2 Yuanmingyuan Xilu Beijing 100193 PR China
4. Electric Power Research Institute (EPRI); New Berlin WI 53151