1. Graduate Engineer, The Morton Partnership Ltd., The Old Cavalier, 89 Dunbridge St., Bethnel Green, London, E2 6JJ, U.K.
2. PhD Student, School of Chemical, Environmental, and Mining Engineering, Univ. of Nottingham, University Park, Nottingham, NG7 2RD, U.K.
3. Dept. of Architecture and Civil Engineering, Univ. of Bath, Bath, BA2 7AY, U.K.
4. Dept. of Architecture and Civil Engineering, Univ. of Bath, Bath BA2 7AY, U.K.