[1] Pondicherry Univ, Dept Phys, Pondicherry 605014, India
[2] Univ Yaounde I, Fac Sci, Dept Phys, Lab Mech, Yaounde, Cameroon
[3] Univ Bamenda, Higher Teachers Training Coll, Dept Phys, Bamenda, Cameroon
[4] Indian Inst Technol, Dept Mech Engn, Kanpur 208016, Uttar Pradesh, India
[5] Univ Yaounde I, Ctr Excellence Africain Technol Informat & Commun, Yaounde, Cameroon