1. LTP (Laboratory for Thermophysical Properties) GmbH, Associated Institute at the University of Oldenburg, Marie-Curie-Strasse 10, D-26129 Oldenburg, Germany, Dow Haltermann Custom Processing, Dow Chemical Company, B-9130 Kallo (Kieldrecht), Belgium, and Department of Industrial Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany