Stress Analysis of Three Marginal Configurations of Full Posterior Crowns by Three-Dimensional Photoelasticity

A simplified method was developed by which three-dimensional composite photoelastic models were constructed. The optimum marginal configuration for the stress distribution was determined and was found to be of the chamfer type.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66544/2/10.1177_00220345740530052501.pd

Spin tunnelling in mesoscopic systems

We study spin tunnelling in molecular magnets as an instance of a mesoscopic phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel splitting between various pairs of Zeeman levels in this molecule oscillates as a function of applied magnetic field, vanishing completely at special points in the space of magnetic fields, known as diabolical points. This phenomena is explained in terms of two approaches, one based on spin-coherent-state path integrals, and the other on a generalization of the phase integral (or WKB) method to difference equations. Explicit formulas for the diabolical points are obtained for a model Hamiltonian.Comment: 13 pages, 5 figures, uses Pramana style files; conference proceedings articl