1. Advanced Devices & Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
2. National Renewable Energy Laboratory, Golden, Colorado 80401, USA
3. Physics Department, Indian Institute of Technology Bombay, Mumbai 400076, India
4. Fluids Research Laboratory, Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, USA