1. Scientist, Environment Program, Pulp and Paper Research Institute of Canada, 570 Blvd. St-Jean, Pointe-Claire, Montreal, Canada, QC H9R 3J9.
2. Professor, Dept. of Civil Engineering, 6250 Applied Science Ln., Univ. of British Columbia, Vancouver, Canada, BC V6T 1Z4.
3. Professor, Dept. of Civil Engineering, 6250 Applied Science Ln., Univ. of British Columbia, Vancouver, Canada BC V6T 1Z4.