1. Fiber and Particle Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland
2. NMR Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland
3. Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, P.O. Box 50, 90029 Oulu, Finland
4. Chemical Process Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland
5. VTT Technical Research Centre of Finland, Vuorimiehentie 3, 02150 Espoo, Finland