1. Department of Engineering and Mathematics, Sheffield Hallam University, Sheffield S11WB, U.K.
2. Department of Mechanical & Construction Engineering, Northumbria University, Newcastle-upon-Tyne NE1 8ST, U.K.
3. SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4FS, U.K.
4. Sellafield Ltd., Cumbria CA20 1PG, U.K.
5. Hitachi High-Technologies Europe, Daresbury WA4 4AB, U.K.
6. Department of Engineering, Newcastle University, Newcastle NE1 7RU, U.K.