Department of Physics, Islamic University of Gaza, Gaza, Palestine; Department of Physics, Sudan University of Science and Technology, Khartoum, Khartoum, Sudan
Ubeid, Muin F., Department of Physics, Islamic University of Gaza, Gaza, Palestine; Shabat, Mohammed Musa, Department of Physics, Islamic University of Gaza, Gaza, Palestine; Sid-Ahmed, Mohammed Osman, Department of Physics, Sudan University of Science and Technology, Khartoum, Khartoum, Sudan