1. Joint Institute for High Temperature RAS, Izhorskaya 13 Bd. 2, 125412 Moscow, Russia
2. Technische Universitat Ilmenau, PF 100565, 98684 Ilmenau, Germany
3. University of Michigan—Dearborn, Dearborn, Michigan 48128-1491, USA
4. Moscow Power Engineering Institute, Krasnokazarmennaya 14, 111250 Moscow, Russia