The reactions of Pb(N0 ) and Pb(SCN)2 with 2-(aminomethy1)pyridine (C H N = L) yielded colourless crystals of L Pb(N0 ) ( I ) and L Pb(SCN) , (2), respectively. Their structures were determined by X-ray crystallography. Crystal data: 1, monoclinic, P2 /c, a = 9.263 (4) ?, b = 7.783 (2) ?, c = 6.692 (3) ?, ? = 101.26 (2)?, Z = 2, Mo K?, 1540 observed (I > 2.5 ?(I) data (22 ? C), R = 0...

STATEMENT OF PROBLEM Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging h...

+*Clarke, I C, Brown, S, Pezzotti, G, Green, D D, T. Donaldson, T D +Loma Linda University, Loma Linda, CA [email protected] INTRODUCTION The feature that makes yttria-stabilized, tetragonal zirconia polycrystalline (Y-TZP) ceramic both strong and fatigue resistant is its ability to partially transform under stress from tetragonal phase to its monoclinic phase, i.e. an inherent metastability [1]....