[1] Kim Il Sung Univ, Dept Phys, Pyongyang, North Korea
[2] Univ Nevada, Mech Engn Dept, Reno, NV 89557 USA
[3] MIT, Chem Engn Dept, Cambridge, MA 02139 USA
[4] Okinawa Inst Sci & Technol, Onna, Okinawa 9040495, Japan
[5] Peking Univ, Inst Condensed Matter & Mat Phys, Sch Phys, Beijing 100871, Peoples R China
[6] Univ Naples Federico II, Chem Mat & Ind Prod Engn DICMaPI Dept, I-80125 Naples, Italy