1. Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
2. Oak Ridge Associated Universities, Oak Ridge, TN 37830, USA.
3. Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
4. Institute of Mechanics of Ufa–Bashkortostan Branch of the Russian Academy of Sciences, 6 Karl Marx Street, Ufa, 450 000, Russia.