1. Mechanical Engineering, Marquette University, Milwaukee, Wisconsin 53233, USA
2. Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
3. Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
4. Earth and Planetary Sciences, University of California, Davis, California 95616, USA
5. Air Force Research Laboratory, Eglin AFB, Florida 32542, USA