1. Laboratório Nacional de Energia e Geologia, 1649-038 Lisboa, Lisboa e Vale
do Tejo, Portugal
2. RWTH University, Templergraben
55, 52062 Aachen, North Rhine-Westphalia, Germany
3. ABB Corporate Research, Wallstadter
Strasse 59, 68526 Ladenburg, Baden-Württemberg, Germany