1. Dipl.-Ing., Senior Scientist, Institute for Materials Research and Testing (MFPA Weimar) at Bauhaus-University Weimar, Amalienstrasse 13, D-99423 Weimar, Germany.
2. Dr. rer. nat, Head of Project Group, Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany.
3. Dipl.-Phys., Senior Scientist, Fraunhofer-Institute for Non-Destructive Testing (IZfP), University, Building 37, D-66123 Saarbrücken, Germany.