REGULARITY AND UPPER SEMICONTINUITY OF PULLBACK ATTRACTORS FOR A CLASS OF NONAUTONOMOUS THERMOELASTIC PLATE SYSTEMS

We study the long-time dynamics, in the sense of pullback attractors, of solutions for semilinear nonautonomous thermoelastic plate systems in a bounded smooth domain in R-N , N >= 2. Using the theory of uniform sectorial operators, in the sense of P. Sobolevskii (1961), we will prove existence, uniform boundedness, regularity and upper semicontinuity of pullback attractors for the evolution system {u(tt) + Delta(2)u + a Delta theta = f(u), t > tau, x is an element of Omega, theta(t) - kappa(t) Delta theta - a Delta u(t) = 0, t > tau, x is an element of Omega, subject to boundary conditions u = Delta u = theta =0, t > tau, x is an element of partial derivative Omega, with respect to the functional parameter kappa.