[1] Uttarakhand Tech Univ, Dept Math, Dehra Dun 248007, Uttar Pradesh, India
[2] Shoolini Univ, Sch Mech & Civil Engn, Solan 173229, India
[3] BFIT Dehradun, Dept Math, Uttarakhand 248007, India
[4] Govind Ballabh Pant Engn Coll, Dept Math, Uttarakhand 246194, India
[5] Shoolini Univ, Himalayan Ctr Excellence Nanotechnol, Solan 173229, India