1. Department of Bioproducts and Biosystems, Aalto University School of Chemical Engineering, P.O.
Box 16300, FI-00076 Aalto, Finland
2. Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina S/S, 47005 Valladolid, Spain
3. Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland