%0 Journal Article %A Arrieta Algarra, José María %A Carvalho, Alexandre N. %A Rodríguez Bernal, Aníbal %T Perturbation of the diffusion and upper semicontinuity of attractors %D 1999 %@ 0893-9659 %U https://hdl.handle.net/20.500.14352/57844 %X We obtain uniform bounds for attractors of parabolic problems with nonlinear boundary conditions with respect to perturbations in the diffusion coefficients. These bounds are the main tool to obtain continuity properties of the attractors relatively to perturbations of the diffusion coefficient. We study two examples where the diffusion is perturbed: one related to homogenization theory and the other taken from composite materials where the diffusion goes to infinity in some subdomain. %~