THE INFLUENCE OF DOMAIN AND DIFFUSIVITY PERTURBATIONS ON THE DECAY OFEND EFFECTS IN HEAT-CONDUCTION

For a standard heat conduction problem in a semi-infinite cylinder the authors investigate the influence of domain perturbation and of the v ariation of the diffusivity coefficient on the decay of Saint Venant e nd effects. The particular problem investigated is one in which the la teral surface of the cylinder is maintained at zero temperature and a nonzero temperature is prescribed on the near end. Energy methods are used to assess,the influence of the perturbations. A Phragmen-Lindelof type alternative and explicit decay bounds are derived.