1. Department of Physics; School of Natural Sciences; Adama Science and Technology University; PO Box 1888 Adama Ethiopia
2. BK21 Plus Nanoconvergence Technology Division; Pusan National University; Miryang 627-706 Korea
3. Oromia Coffee Farmers Cooperative Union; Department of coffee quality inspection; PO Box, 1394 Gelan Ethiopia
4. Department of Nanomaterials Engineering; Pusan National University; Miryang 627-706 Korea