1. Researcher, Metal Industries Research and Development Centre, 1001 KaoNan Highway, Kaohsiung 811, Taiwan.
2. Engineer, Dept. of Environmental Resources Management, Chia Nan Univ. of Pharmacy and Science Tainan, No. 60, Sec. 1, Erren Rd., Rende District, Tainan City 71710, Taiwan.
3. Professor, Dept. of Environmental Resources Management, Chia Nan Univ. of Pharmacy and Science Tainan, No. 60, Sec. 1, Erren Rd., Rende District, Tainan City 71710, Taiwan (corresponding author).
4. Director, Center for Research in Energy Systems and Technologies, School of Engineering, Univ. of San Carlos, Cebu City 6000, Philippines.