Volume 8, Issue 2, September 2014, Pages 159–171




Tassew Alemayehu1 and ASSEFA SERGAWIE2
1 Department of Biology, Adigrat University, Adigrat, Tigray, P.Box. 50, Ethiopia
2 College of natural and computational sciences, department of chemistry, Adis Abeba Inistitute Technology University, Adis Abeba, Ethiopia