Schraknepper, H. [P:(DE-HGF)0] ; Bäumer, C. [P:(DE-Juel1)159254] ; Gunkel, F. [P:(DE-Juel1)130677] ; Dittmann, R. [P:(DE-Juel1)130620] ; De Souza, R. A. [P:(DE-HGF)0]