1. Department of Mechanical Engineering and Materials Science University of Pittsburgh Pittsburgh PA 15261 USA
2. Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA 15213 USA
3. DWGreve Consulting Sedona AZ 86351 USA
4. Department of Electrical and Computer Engineering University of Pittsburgh Pittsburgh PA 15261 USA
5. Department of Physics and Astronomy University of Pittsburgh Pittsburgh PA 15261 USA