1. Graduate Research Assistant, Dept. of Wood Science, Univ. of British Columbia, Vancouver BC, Canada V6T 1Z4.
2. Professor, Dept. of Wood Science, Univ. of British Columbia, Vancouver BC, Canada V6T 1Z4 (corresponding author).
3. Professor Emeritus, Dept. of Civil Engineering, Univ. of British Columbia, Vancouver, BC Canada V6T 1Z4.