Effects of Sweep and Thickness on the Static Longitudinal Aerodynamic Characteristics of a Series of Thin, Low-aspect-ratio, Highly Tapered Wings at Transonic Speeds : Transonic-bump Method

An investigation by the transonic-bump technique of the static longitudinal aerodynamic characteristics of a series of thin, low-aspect-ratio, highly tapered wings has been made in the Langley high-speed 7- by 10-foot tunnel. The Mach number range extended from about 0.60 to 1.18, with corresponding Reynolds numbers ranging from about 0.75 x 10(6) to 0.95 x 10(6). The angle of attack range was from -10 degrees to approximately 32 degrees.The effects on drag and lift-drag ratio of a variation in sweep angle from -14.03 degrees to 45 degrees with respect to the quarter-chord line for wings of 3-percent-chord thickness was found to be small in comparison to the effects of a variation in thickness from 2 percent chord to 4.5 percent chord for wings with 14.03 degree sweepback. For the range of variables considered, variations in plan form were considerably more important with regard to longitudinal stability characteristics than the variations in thickness. For the series of basic wings having an aspect ratio of 4, the most hearly linear pitching-moment characteristics were obtained with 26.57 degree of sweepback of the quarter-chord line. However, for the modified series of wings (obtained by clipping the tips of the original wings parallel to the plane of symmetry to give an aspect ratio of 3 and a taper ratio of 0.143), the most nearly linear pitching-moment characteristics were obtained with 36.87 degrees of sweepback. By decreasing the thickness-to-chord ratios from 0.03 to 0.02, a large increase in lift-curve slope was obtained for both the basic and modified wings. All of the wings of both series had fairly large inward shifts of the lateral center-of-pressure location (indicative of tip stalling) with increasing lift coefficient, except those wings having minimum sweepback angles

Take Care

''The exhibition series’ political proposition, kept in play throughout, pivots on care as a possible nodal point among actions, struggles, and visions that “re-place” care “as an arche of human existence and of social relations.” [4] In its organizing strategies, Take Care strives to take on the challenges posed by its program: to rethink affective dimensions of (curatorial) labour; decentre individual authorship; profile radical communities of care; reallocate cultural and institutional resources; cut through apathy and empathy; practice collective resiliency; respect existing initiatives and historical precedents; and generate new bonds. Take Care is, in short, a connective project.'' -- Publisher's websit

Percutaneous recanalization of occlusion of central and proximal veins in chronic hemodialysis: Technical Note

Percutaneous recanalization of occlusion of central and proximal veins in chronic hemodialysis. Occlusion of the central and proximal veins in chronic hemodialysis patients results in considerable edema of the arm of the vascular access that is unable to drain normally. This is a formidable problem because it is very often necessary to close the vascular access, which is sometimes the last available one. To avoid resorting to this disastrous solution, recanalization of the occluded vein by percutaneous recanalization followed by endoluminal angioplasty was successfully performed in five patients (4 innominate veins and one axillary vein). Immediate failure occurred in a sixth patient, and delayed failure after two months of patency (innominate vein) in another patient for whom there had been no systematic stent placement. Recanalization was still patent in four other patients at 3, 6, 12 and 26 months. These results are an encouragement to attempt percutaneous recanalization by angioplasty of occluded central veins because, when successful, this technique makes it possible to preserve the vascular access and to avoid onerous surgery. We believe that this technique should therefore become better known

Research in Medical Education: Balancing Service and Science*

Since the latter part of the 1990’s, the English-speaking medical education community has been engaged in a debate concerning the types of research that should have priority. To shed light on this debate and to better understand its implications for the practice of research, 23 semi-structured interviews were conducted with “influential figures” from the community. The results were analyzed using the concept of “field” developed by the sociologist Pierre Bourdieu. The results reveal that a large majority of these influential figures believe that research in medical education continues to be of insufficient quality despite the progress that has taken place over the past 2 decades. According to this group, studies tend to be both redundant and opportunistic, and researchers tend to have limited understanding of both theory and methodological practice from the social sciences. Three factors were identified by the participants to explain the current problems in research: the working conditions of researchers, budgetary restraints in financing research in medical education, and the conception of research in the medical environment. Two principal means for improving research are presented: intensifying collaboration between PhD’s and clinicians, and encouraging the diversification of perspectives brought to bear on research in medical education

The Association between 25-Hydroxyvitamin D and Hemoglobin A1c Levels in Patients with Type 2 Diabetes and Stage 1–5 Chronic Kidney Disease

Aim. To examine the relationship between plasma 25-hydroxyvitamin D (25(OH)D) levels and blood hemoglobin A1c (HbA1c) levels in diabetic patients at various stages of chronic kidney disease (CKD). Methods. We screened for data collected between 2003 and 2012. The correlation between 25(OH)D and HbA1c levels was studied in patients categorized according to the severity of CKD and their vitamin D status. A multivariate linear regression model was used to determine whether 25(OH)D and HbA1c levels were independently associated after adjustment for a number of covariates (including erythrocyte metformin levels). Results. We identified 542 reports from 245 patients. The mean HbA1c value was 6.7±1.0% in vitamin D sufficiency, 7.3±1.5% in insufficiency, and 8.4±2.0% in deficiency (P<0.0001). There was a negative correlation between 25(OH)D and HbA1c levels for the population as a whole (r=-0.387, P<0.0001) and in the CKD severity subgroups (r=-0.384, P<0.0001 and r=-0.333, P<0.0001 for CKD stages 1–3 and 4-5, resp.). In the multivariate analysis, the 25(OH)D level was the only factor associated with HbA1c (P<0.0001). Conclusion. 25(OH)D levels were negatively correlated with HbA1c levels independently of study covariates

Identity ambiguity and the promises and practices of hybrid e-HRM project teams

The role of IS project team identity work in the enactment of day-to-day relationships with their internal clients is under-researched. We address this gap by examining the identity work undertaken by an electronic human resource management (e-HRM) 'hybrid' project team engaged in an enterprise-wide IS implementation for their multi-national organisation. Utilising social identity theory, we identify three distinctive, interrelated dimensions of project team identity work (project team management, team 'value propositions' (promises) and the team's 'knowledge practice'). We reveal how dissonance between two perspectives of e-HRM project identity work (clients' expected norms of project team's service and project team's expected norms of themselves) results in identity ambiguity. Our research contributions are to identity studies in the IS project management, HR and hybrid literatures and to managerial practice by challenging the assumption that hybrid experts are the panacea for problems associated with IS projects