Affiliation: | (1) Atominstitut der Österreichischen Universitäten, Schüttelstrasse 115, A-1020 Vienna, Austria;(2) Coal Research Centre, Academy of Science, 51 Ulaanbaatar, Mongolia;(3) Present address: Universidad Simon Bolivar, Apartado 89000, 1080A Caracas, Venezuela;(4) IAEA Laboratories, A-2444 Seibersdorf, Austria |