1. BioPlasma Research group, Dublin Institute of Technology, Sackville Place, Dublin 1, Ireland
2. Biosystems Engineering, University College, Dublin, Dublin 4, Ireland
3. NCPST, Dublin City University, Dublin, Ireland
4. Faculty of Physics, University of Belgrade, P.O.B. 368, Belgrade, Serbia
5. School of Mechanical and Materials Engineering, University College Dublin, Belfield, Dublin 4, Ireland