Functionally graded materials VIII : proceedings of the 8th International Symposium on Multifunctional and Functionally Graded Materials (FGM2004) : held in Leuven, Belgium, 11-14... by International Symposium on Multifunctional and Functionally Graded Materials (8th : 2004 : Leuven, Belgium), Biest, Omer Van der, Gasik, Michael, Vleugels, Jozef