1. Department
of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
2. Department
of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
3. Center for Nanophase
Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37381, United States
4. Charles
M. Bowden
Research Laboratory, National Research Council−AMRDEC, Redstone Arsenal, Huntsville, Alabama 35898, United States