Synchrotron x-ray measurement and finite element analysis of residual strain in TIG welded aluminium alloy 2024

Residual strains have been measured in a tungsten inert gas (TIG) butt-welded 2024 aluminum alloy plate using synchrotron X-ray diffraction. Novel two-dimensional strain maps spanning the entire plate reveal steep gradients in residual stress and provide detailed validation data for finite element (FE) analysis. Two variants of a FE model have been used to predict the residual strain distributions, incorporating different levels of plate constraint. The model uses decoupled thermal and elastic- plastic mechanical analyses and successfully predicts the longitudinal and transverse residual strain field over the entire weld. For butt weld geometries, the degree of transverse constraint is shown to be a significant boundary condition, compared to simpler bead-on-plate analyses. The importance of transverse residual strains for detailed model validation is highlighted, together with the need for care in selecting the location for line scans. The residual stress is largest in the heat-affected zone (HAZ), being equal to the local postweld yield stress, though the strength increases subsequently by natural aging. In addition, a halving of the diffraction line width has been observed local to the weld, and this correlates with the microstructural changes in the region

Goodbye wave: Trevor Nunn’s Twelfth Night – a maritime valediction

This article considers the importance of valediction to the autumnal tone of the film and attends to the maritime imagery as well as its centrality to Nunn's cinematic storytelling

Inaugurating the complete works (again): Shakespeare Nation, Doranism and literalism in the Royal Shakespeare Company’s 2014 summer season

Greg Doran, Artistic Director of the Royal Shakespeare Company, inaugurated his Shakespeare Nation project in 2014. This involves yet another staging of the complete works. This article examines his production of the two parts of Henry IV as well as The Witch of Edmonton. It also covers the production of The Two Gentlemen of Verona in the main house and three other shows in the Swan, labelled the ‘Roaring Girls’ season. The article exposes a tendency towards literalism in Doran’s own work (which it labels ‘Doranism’) and argues that this quality leads to an imaginative diminution of Shakespeare’s theatricality

Variability in the Anthropometric Status of Four South African Populations

Coefficients of variation (V) of 4 populations were compared for each of 11 parameters. Males differed significantly in cristal height and 3 skinfolds. It has been suggested that negroids vary more in relation to their means in cristal height because of the onset of differential growth of the lower limbs. Relatively large Vs in skinfold measurements of White and Indian boys, notably those of the trunk, arose because there were more obese individuals with extreme values in the White and Indian populations than in the Cape Coloured and negroid populations. In females, leg circumferences and subscapular skinfolds differed significantly. Leg circumference Vs of Indian females were probably enhanced as a result of variably high adiposity in the calf region. The presence of extreme values in obese girls of this group had been the cause of raised Vs in subscapular skinfold measurements. There appear to be three periods during which the Vs of males and females differed: males varied more than females at the ages of 6 and 7 years; then females varied more until between 13 and 15 years, when males again became more variable. White males, however, varied more than White females in skinfolds. This may be caused by the presence of extreme values at either end of the distribution graph of both 'over-optimal nutrition and undernutrition. It is shown that confidence limits based on a central value of the standard deviation (σ) do not take into account the increasing variability with age noted in most parameters in populations of growing individuals. In future studies, variability changes should be shown by placing polynomials into one of the categories described in this article.S. Afr. Med. J., 48, 643 (1974)

Application of electron multiplying CCD technology in space instrumentation

Electron multiplying CCD (EMCCD) technology has found important initial applications in low light surveillance and photon starved scientific instrumentation. This paper discusses the attributes of the EMCCD which make it useful for certain space instruments, particularly those which are photon starved, and explores likely risks from the radiation expected in such instruments

A comparison of sequential total and activated white cell count in patients undergoing coronary artery bypass grafting, using cardiopulmonary bypass, with and without a white cell filter

Introduction Cardiopulmonary bypass (CPB) has been shown to induce a systemic inflammatory response similar to the local reaction seen after tissue damage [1]. This leads to the release of toxic substances, such as elastase, which cause endothelial damage and may adversely affect outcome [2]. Use of a leucocyte depleting arterial line filter is one of many anti-inflammatory strategies that are undergoing evaluation. Leucocyte depleting filters may be capable of selectively removing activated white cells [3], but this has not been proved in vivo. The aim of the present study was to compare sequential total and activated white cells during CPB, using either a leucocyte depleting or standard arterial line filter. Materials and methods After local ethical committee approval, 20 patients undergoing coronary artery bypass grafting using CPB were prospectively randomly allocated to have either a Leukogard LG–6 (Pall Biomedical, Portsmouth, UK) or a nonleucocyte depleting filter inserted into the arterial line of the CPB circuit. Arterial limb blood samples were taken immediately after institution of CPB (0min) and at 10–min intervals throughout the bypass period. Activated white cells were identified using nitroblue tetrazolium, then both total and activated white cell numbers counted after staining with Leucoplate.Results Table 1 shows the number of white cells counted/1.25 ? l (volume of a single channel of Nageotte counting chamber) using light microscopy (× 25).Conclusion The LG6 leucocyte filter reduces the total white cell count and is capable of selectively removing activated white cells during CPB. The exact relationship between leucocyte depletion and improved patient outcome still remains unclear

Energy Performance Contracting - Is it time to check the small print?

Energy Performance Contracting has been suggested as a key strategy to increase energy efficiency retrofits of existing building stock: reducing the uncertainty of returns on the investment by guaranteeing the level of energy savings that will result and thus making energy efficiency investment significantly more attractive. However, in order for this potential to be realised, investors need to have confidence in the level of protection offered by the guarantee. This study explores the consequences of alternative approaches to measuring and verifying savings due to a lighting retrofit project in a hypothetical UK school. It finds that the hours of lighting use can significantly affect the final savings. In most cases a significant increase in gas consumption is seen which is ignored by several of the measurement options leading to the potential for a loss of confidence in the value of the savings guarantee if a more transparent approach is not taken by the contractor