This volume features the proceedings of the NATO AR Workshop held in Kishinev, the capital of Moldova, a fom1er Soviet Republic in the South- Eastern Europe. OUiing 3 working days 26 reports were presented, 8 of them by, or in collaboration with, speakers from Kishinev. The reports arc presented in the order they were given at the Workshop. As the topic was rather wide-ranged, all the sittings were plenmy. The opening communication was made by the...