[1] Univ Sains Malaysia, Sch Med Sci, Dept Phys, Kubang Kerian 16150, Kelantan, Malaysia
[2] Akanu Ibiam Fed Polytech, Dept Sci Lab Technol, POB 1007, Unwana 1007, Ebonyi, Nigeria
[3] Univ Sains Malaysia, Sch Med Sci, Unit Integrat Med, Kubang Kerian 16150, Kelantan, Malaysia
[4] Univ Sultan Zainal Abidin, Fac Med, Unit Phys, Kuala Terengganu 20400, Terengganu, Malaysia
[5] Univ Calabar, Coll Med Sci, Fac Basic Med Sci, Dept Phys, POB 1115, Calabar, Cross River Sta, Nigeria