1. Department of Mathematics, COMSATS University Islamabad 1 , Islamabad Campus, Park Road, Tarlai Kalan, Islamabad 45550, Pakistan
2. Department of Science and Humanities, Sir Syed CASE Institute of Technology 3 , Islamabad 44000, Pakistan
3. School of Energy and Power Engineering, Jiangsu University 4 , Zhenjiang 212013, China