1. Department of Mechanical, Materials and Aerospace Engineering, Indian Institute of Technology Dharwad, Dharwad 580011, Karnataka, India
2. Department of Mathematics, North Carolina State University , Raleigh, NC 27695
3. Department of Mathematics, Indian Institute of Technology Dharwad, Dharwad 580011, Karnataka, India
4. Department of Mathematics, Vivekananda Mahavidyalaya (The University of Burdwan) , West Bengal 713103, India