1. Department of Mechanical Engineering, University of Houston, Houston, Texas 77204-4006, USA
2. Materials Science and Engineering Program, University of Houston, Houston, Texas 77204, USA
3. STR Group, Inc., Engels av. 27, P.O. Box 89, 194156, St. Petersburg, Russia
4. Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, Texas 77204, USA