1. Zeller+Gmelin GmbH & Co. KG, Schlossstraße 20, 73054 Eislingen/Fils, Germany
2. National Centre for Advanced Tribology at Southampton (nCATS), Mechanical Engineering Department, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, UK
3. Technology Consultant, Sailegärten 2, 72351 Erlaheim, Germany