1. Faculty of Materials Science and Engineering, Bahir Dar Institute of Technology, Bahir Dar University, P. O. Box 26, Bahir Dar, Ethiopia
2. Department of Materials Science and Engineering, National Taiwan University of Science and Technology 43, Sec. 4 Keelung Road, Taipei 10607, Taiwan
3. Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan