1. George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332;
2. Department of Mechanical Engineering, University of Engineering and Technology, Lahore, Lahore 54890, Punjab, Pakistan e-mail:
3. George W. Woodruff School of Mechanical Engineering, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 e-mail: