1. Division of Materials Science and Engineering; Hanyang University; Seoul 133-791 South Korea
2. Departments of Aerospace & Mechanical Engineering and Materials Science; University of Southern California; Los Angeles CA 90089-1453 U.S.A.
3. Department of Materials Engineering and Civil Construction; Universidade Federal de Minas Gerais; Belo Horizonte MG 31270-901 Brazil
4. Materials Research Group; Faculty of Engineering and the Environment; University of Southampton; Southampton SO17 1BJ U.K.