1. Faculty of Mechanical Engineering, Thermodynamics, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum,
Germany
2. Fluid Science and Resources Division, The University of Western Australia, Crawley, Western Australia 6009,
Australia
3. Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305,
USA