1. Department of Mathematical Sciences, Delaware State University, Dover, DE 19901-2277, USA
2. Applied and Industrial Mathematics Research Group, School of Physical, Environmental and Mathematical Sciences, UNSW Canberra, ACT 2600, Australia
3. Department of Physics, Faculty of Sciences, Badji Mokhtar University, 23000 Annaba, Algeria
4. Department of Chemistry, Physics and Environment, University Dunarea de Jos Galati, 111 Domneasca Street, 800201 Galati, Romania
5. Department of Mathematics, Faculty of Sciences, King Abdulaziz University, Jeddah-80203, Saudi Arabia