1. Dept. of Civil Engineering, Urmia Univ., Urmia, Iran; Univ. of Tabriz, Tabriz, Iran.
2. Dept. of Civil Engineering, Urmia Univ., Urmia, Iran.
3. Dept. of Nanoscience and Nanoengineering, Istanbul Technical Univ., Istanbul, Turkey.
4. Senior Scientist, AON Benfield, Chicago, IL 60601.