1. Senior Lecturer, Dept. of Mechanical Engineering, Univ. of North Texas, Denton, TX 76203-5017 (corresponding author).
2. Professor Emeritus, Dept. of Civil Engineering, Univ. of New Mexico, Albuquerque, NM 87131.
3. Professor, Dept. of Civil Engineering, Univ. of New Mexico, Albuquerque, NM 87131.