CCR GmbH Coating Technology, Rheinbreitbach; Institut für Physik, Universität Augsburg, D-86135 Augsburg; stephan.maendl(at)physik.uni-augsburg.de
Received 26 July 2000, accepted 1 September 2000 by U. Eckern
(approx. 20 pages)
Received 28 April 2000, revised 16 August 2000,
accepted 8 September 2000 by G. Röpke
(approx. 30 pages)
II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, gudrun.pinter(at)desy.de
Received 8 November 1999, revised 8 August 2000, accepted
5 September 2000 by K. Fredenhagen
(approx. 33 pages)