1 Department of Mathematics, Nandalal Ghosh B.T. College, Panpur, P.O.-Narayanpur, District –North 24 4 Parganas, Pin code-743126, West Bengal, India; sura_pati@yahoo.co.in 5 2 Department of Mathematics, Indian Institute of Engineering Science and Technology, Shibpur, P.O.-Botanic 6 Garden, Howrah-711103, West Bengal, India; salam50in@yahoo.co.in (S.A.); roy_t_k@yahoo.co.in (T.K.R.) 7 * Corresp...