Search

The potential of low-voltage, high-resolution scanning and scanning transmission electron microscopy (SEM/STEM) for morphological characterization of various surface insulating films on aluminium and its alloys has been assessed by examination of porous anodic films, barrier anodic films and corrosion product layers. The characterization shows clearly the value of the approaches, particularly the ability to image directly fine details of appropriately-prepared aluminium surfaces that have usually required examination by transmission electron microscopy (TEM). Such ready characterization assists mechanistic understanding of the contributions of the macroscopic surface and flaws or second phase to the filming and corrosion processes. Further, the approaches are applicable to other materials where such understanding was limited by the sample preparation routes available for TEM. [Copyright &y& Elsevier]

Magneto–rheological fluid dampers (MR dampers) have recently been designed to control the response of civil engineering and building structures because of their large force capacity and controllable force characteristics. To enable them to control structural responses, the dynamic characteristics of structures need to be clarified. This paper discusses the design of MR dampers with a bypass orifice mechanism and verifies their performance by means of dynamic tests and dynamic analytical models. Their dynamic characteristics are investigated experimentally to compare the performance of two different magneto–rheological fluids. One is developed by the Lord Corporation and the other is newly developed in Japan. The effectiveness and validity of MR dampers with a bypass are discussed on the basis of these results. [ABSTRACT FROM AUTHOR]

We have performed extensive ab initio modelling of alumina, calculating energy differences between various possible structures and highlighting the reasons why alumina forms in the corundum structure. We have also performed Harris-Foulkes calculations for these structures and demonstrate the remarkably accurate results that this method gives for these very complex structures. [ABSTRACT FROM AUTHOR]