Studies on the promotion of nickel—alumina coprecipitated catalysts: I. Titanium oxide

A series of TiO2-promoted nickel—alumina catalysts has been prepared and characterized. The promoter was added in various proportions to a calcined coprecipitated nickel—alumina material by adsorption of the acetylacetonate complex of titanium, followed by further calcination and reduction. The structure of the resultant materials was similar to that of the unpromoted coprecipitated nickel—alumina. The chemisorption properties of the catalyst and its behaviour in the CO/H2 reaction were characteristic of a strong metal-support interaction (SMSI) reported in the literature for Ni/TiO2. The strong adsorption of both carbon monoxide and hydrogen were suppressed while the activity for carbon monoxide hydrogenation was increased, the activation energy being lowered. The higher activity, however, was relatively unstable under reaction conditions

Moiré interferometry applied to fracture in titanium tubes

Despite there being a substantial body of evidence to the contrary, moiré interferometry is often regarded - even by some adherents - as a curiosity of the optics lab. The present work seeks to demonstrate still further that the method can be an effective tool for practical materials research and assessment, in this case, in a novel and challenging experimental application involving fracture testing of heat exchanger tube material, the work being conducted in a conventional materials test laboratory setting. The key to the utility of the present setup lies with the priority given to its optical efficiency. In standard fracture toughness tests, it is axiomatic that standard specimen geometries be used. A dilemma arises when a material's properties are transformed to a substantial degree by the final stages of its process of manufacture, and when the very nature of the finished form dictates that standard geometries cannot be produced. The focus of this investigation was to measure crack-tip opening displacements (CTODs) in thin-walled titanium tubes. Fringe patterns corresponding to in-plane displacement contours were obtained interferometrically and the method for extracting CTODs from these is described. Significant differences in yield, ultimate strength, elongation, and fracture behaviour were observed for different material orientations

Corporate Social Responsibility at African mines: Linking the past to the present

This paper traces the origins of the 'brand' of Corporate Social Responsibility (CSR)employed at large-scale mines across sub-Saharan Africa. Conceived within fortified resource enclaves, the policies adopted and actions taken in the area of CSR at many of the region's large-scale mines today have had had minimal effect on community wellbeing. Further examination reveals that contemporary CSR strategy in the region's mining sector is often a 'repackaging' and 'rebranding' of moves made by major operators during the colonial period and early years of country independence to pacify and engage local communities. Today, this work is being championed as CSR but failing to deliver much change, its impact minimized by the economic and political forces at work in an era of globalization, during which extractive industry enclaves that are disconnected from local economies have been able to flourish. As case study of Ghana, long one of the largest gold mining economies in sub-Saharan Africa, is used to illustrate these points. © 201