5502document3795O'Callaghan11PhD.pdfapplication/pdffff3cdc2731d168a31382d2dba25442bMD555339382011-07-19 16:39:59http://etheses.bham.ac.uk//id/eprint/1663/1/O%27Callaghan11PhD.pdf22651document3795O=0027Callaghan11PhD.pdfapplication/pdf55339382011-07-21 10:57:52http://etheses.bham.ac.uk//id/eprint/1663/1/O%3D0027Callaghan11PhD.pdf