Limpieza y restauración con láser

Los primeros trabajos referidos a la limpieza y restauración con láser de objetos de valor patrimonial datan de mediados de la década del 70. Sin embargo es recién en los últimos años que se observa una evolución sistemática tanto en las investigaciones relacionadas con el tema, como en el desarrollo de equipos láser versátiles y compactos para este tipo de aplicaciones. Simultáneamente en este período se asiste a una consolidación de los conocimientos vinculados a los procesos de interacción lásermateria involucrados en estos tratamientos. (Párrafo extraído del texto a modo de resumen)</i

Optimal design for active damping in sandwich structures using the Direct MultiSearch method

This paper addresses the problem of optimal positioning of surface bonded piezoelectric patches in sandwich plates with viscoelastic core and laminated face layers. The objective is to maximize a set of modal loss factors for a given frequency range using multiobjective topology optimization. Active damping is introduced through co-located negative velocity feedback control. The multiobjective topology optimization problem is solved using the Direct MultiSearch Method. An application to a simply supported sandwich plate is presented with results for the maximization of the first six modal loss factors. The influence of the finite element mesh is analyzed and the results are, to some extent, compared with those obtained using alternative single objective optimization

Semiclassical thermodynamics of scalar fields

We present a systematic semiclassical procedure to compute the partition function for scalar field theories at finite temperature. The central objects in our scheme are the solutions of the classical equations of motion in imaginary time, with spatially independent boundary conditions. Field fluctuations -- both field deviations around these classical solutions, and fluctuations of the boundary value of the fields -- are resummed in a Gaussian approximation. In our final expression for the partition function, this resummation is reduced to solving certain ordinary differential equations. Moreover, we show that it is renormalizable with the usual 1-loop counterterms.Comment: 24 pages, 5 postscript figure