1. Professor, Toxcon Health Sciences Research Centre Inc., 9607 41 Ave., Edmonton AB, Canada T6E 5X7. E-mail: cjeng@toxcon.com
2. Associate Professor, Dept. of Civil and Environmental Engineering, Markin/CNRL Natural Resources Engineering Facility, Univ. of Alberta, Edmonton AB, Canada T6G 2W2 (corresponding author). E-mail: warrenk@ualberta.ca
3. Research Scientist, Dept. of Civil and Environmental Engineering, Markin/CNRL Natural Resources Engineering Facility, Univ. of Alberta, Edmonton AB, Canada T6G 2W2. E-mail: dwsmith@ualberta.ca