1. Department of Civil and Environmental Engineering, Swanson School of Engineering; University of Pittsburgh; Pittsburgh Pennsylvania 15260 U.S.A.
2. Department of Civil and Environmental Engineering, Cullen College of Engineering; University of Houston; Houston Texas 77204-4003 U.S.A.
3. Department of Chemical and Petroleum Engineering, Swanson School of Engineering; University of Pittsburgh; Pittsburgh Pennsylvania 15260 U.S.A.