1. Centre of Computational Engineering and Integrated Design (CEID) , Lappeenranta University of Technology , PO Box 20 , FI-53851 Lappeenranta , Finland
2. LUT Savo Sustainable Technologies , Lappeenranta University of Technology , Varkaus unit, Opiskelijankatu 3 , FI-78210 Varkaus , Finland
3. Savon Sellu Ltd. , PO Box 57 , FI-70101 Kuopio , Finland