1. Department of General and Solid State PhysicsNational Technical University of UkraineIgor Sikorsky Kyiv Polytechnic Institute 37 Prospect Peremogy Kiev 03056 Ukraine
2. School of EngineeringUniversity of Liverpool London Campus, 33 Finsbury Square London EC2A 1AG UK
3. Department of Mechanical, Aerospace and Civil EngineeringBrunel University London Middlesex UB8 3PH UK