1. Department of Electrical, IT and Cybernetics, University of South − Eastern Norway, Kjølnes ring 56, 3918 Porsgrunn, Norway
2. Department of Process, Energy and Environmental Technology, University of South − Eastern Norway, Kjølnes ring 56, 3918 Porsgrunn, Norway
3. SINTEF Materials and Chemistry, Forskningveien 1, 0314 Oslo, Norway