Boundary stabilization of a Bresse‐type system

In this paper, we are concerned with asymptotic stability of a class of Bresse‐type system with three boundary dissipations. The beam has a rigid body attached to its free end. We show that exponential stabilization can be achieved by applying force and moment feedback boundary controls on the shear, longitudinal, and transverse displacement velocities at the point of contact between the mass and the beam. Our method is based on the operator semigroup technique, the multiplier technique, and the contradiction argument of the frequency domain method. Copyright © 2015 John Wiley & Sons, Ltd.     

A microstructural study of the structure of plasma electrolytically oxidized titanium foils

The structure and distribution of TiO₂ rutile and anatase phases of anodized titanium foil, subjected to a special high-voltage electrochemical preparation technique, are reported. We applied X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy on samples that were oxidized for various times. Combining data from the different techniques led to a model in which the initially formed porous, micrometer-thick TiO₂ layer, consisting in a large part of anatase, is transformed into rutile. The result is a porous rutile layer on top of anatase, which is in direct contact with the Ti metal. The first structural model is derived from the evaluated data and the phenomena that occurred during preparation are clarified.