D. Faraji
Department of Mechanical Engineering University of British Columbia Vancouver, Canada V6T 1Z4
Y. Barnea
sabbatical leave from NRCN, P.O.Box 9001, Beer-Sheva 84190, ISRAEL.
Martha Eva Salcudean
Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, V6T1Z4, BC, Canada