139 research outputs found
Experimental effects of wing location on wing-body pressures at supersonic speeds
An experimental study was performed at supersonic speeds to measure wing and body spanwise pressure distributions on an axisymmetric-body delta wing model on which the wing vertical location on the body was systematically varied from low- to high-mounted positions. In addition, for two of these positions both horizontal and radial wing angular orientations relative to the body were tested, and roll angle effects were investigated for one of the positions. Seven different wing-body configurations and a body-alone configuration were studied. The test was conducted at Mach numbers from 1.70 to 2.86 at angles of attack from about -4 deg to 24 deg. Pressure orifices were located at three longitudinal stations on each wing-body model, and at each station the orifices were located completely around the body, along the lower surface of the right wing (looking upstream), and along the upper surface of the left wing. All pressure coefficient data are tabulated and selected samples are shown graphically to illustrate the effects of the test variables. The effects of angle of attack, roll angle, Mach number, longitudinal station, wing vertical location, wing angular orientation, and wing-body juncture are analyzed. The vertical location of the wing on the body had a very strong effect on the body pressures. For a given angle of attack at a roll angle of 0 deg, the pressures were virtually constant in the spanwise direction across the windward surfaces of the wing-body combination. Pressure-relieving, channeling, and vortex effects were noted in the data
Study of lee-side flows over conically cambered delta wings at supersonic speeds, part 1
An experimental investigation was performed in which surface pressure data, flow visualization data, and force and moment data were obtained on four conical delta wing models which differed in leading-edge camber only. Wing leading-edge camber was achieved through a deflection of the outboard 30% of the local wind semispan of a reference 75 degrees swept flat delta wing. The four wing models have leading-edge deflection angles delta sub F of 0, 5, 10, and 15 degrees measured streamwise. Data for the wings with delta sub F = 10 and 15 degrees showed that hinge-line separation dominated the lee-side wing loading and prohibited the develpment of leading-edge separation on the deflected portion of wing leading edge. However, data for the wing with delta sub F = 5 degrees, a vortex was positioned on the deflected leading edge with reattachment at the hinge line. Flow visualization results were presented which detail the influence of Mach number, angle of attack, and camber on the lee-side flow characteristics of conically cambered delta wings. Analysis of photgraphic data identified the existence of 12 distinctive lee-side flow types. In general, the aerodynamic force and moment data correlated well with the pressure and flow visualization data
Women\u27s experience of academic collaboration.
This study examines the experience of collaboration for women academics in adult education. While the women describe a range of collaborative experiences, they place the greatest value on more complex forms of collaboration in which the self, the partner(s), and the work exist in a highly dynamic and interactive relationship. This study suggests that collaboration provides one way in which women are creating life-giving spaces for themselves within the masculinist culture of the academy
Experimental study at low supersonic speeds of a missile concept having opposing wraparound tails
A wind-tunnel investigation has been performed at low supersonic speeds (at Mach numbers of 1.60, and 2.16) to evaluate the aerodynamic characteristics of a missile concept capable of being tube launched and controlled with a simple one-axis canard controller. This concept, which features an axisymmetric body with two planar canards and four wraparound tail fins arranged in opposing pairs, must be in rolling motion to be controllable in any radial plane with the planar canards. Thus, producing a constant rolling moment that is invariant with speed and attitude to provide the motion is desirable. Two tail-fin shaping designs, one shaved and one beveled, were evaluated for their efficiency in producing the needed rolling moments, and the results showed that the shaved fins were much more desirable for this task than the beveled fins
Depression predicts future emergency hospital admissions in primary care patients with chronic physical illness
PublishedObjective
More than 15 million people currently suffer from a chronic physical illness in England. The
objective of this study was to determine whether depression is independently associated with
prospective emergency hospital admission in patients with chronic physical illness.
Method
1860 primary care patients in socially deprived areas of Manchester with at least one of four
exemplar chronic physical conditions completed a questionnaire about physical and mental
health, including a measure of depression. Emergency hospital admissions were recorded using
GP records for the year before and the year following completion of the questionnaire.
Results
The number of patients who had at least one emergency admission in the year before and the
year after completion of the questionnaire were 221/1411 (15.7%) and 234/1398 (16.7%)
respectively. The following factors were independently associated with an increased risk of
prospective emergency admission to hospital; having no partner OR 1.49 (95% CI 1.04 to 2.15);
having ischaemic heart disease OR 1.60 (95% CI 1.04 to 2.46); having a threatening experience
OR 1.16 (95% CI 1.04 to 1.29) per experience; depression OR 1.58 (95% CI 1.04 to 2.40);
emergency hospital admission in year prior to questionnaire completion OR 3.41 (95% CI (1.98
to 5.86).
Conclusion
To prevent potentially avoidable emergency hospital admissions, greater efforts should be made
to detect and treat co-morbid depression in people with chronic physical illness in primary care,
with a particular focus on patients who have no partner, have experienced threatening life
events, and who have had a recent emergency hospital admission.National Institute for Health Research (NIHR
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Donor-Transmitted Cancer in Orthotopic Solid Organ Transplant Recipients: A Systematic Review
Donor-transmitted cancer (DTC) has major implications for the affected patient as well as other recipients of organs from the same donor. Unlike heterotopic transplant recipients, there may be limited treatment options for orthotopic transplant recipients with DTC. We systematically reviewed the evidence on DTC in orthotopic solid organ transplant recipients (SOTRs). We searched MEDLINE, EMBASE, PubMed, Scopus, and Web of Science in January 2020. We included cases where the outcome was reported and excluded donor-derived cancers. We assessed study quality using published checklists. Our domains of interest were presentation, time to diagnosis, cancer extent, management, and survival. There were 73 DTC cases in liver (n = 51), heart (n = 10), lung (n = 10) and multi-organ (n = 2) recipients from 58 publications. Study quality was variable. Median time to diagnosis was 8 months; 42% were widespread at diagnosis. Of 13 cases that underwent re-transplantation, three tumours recurred. Mortality was 75%; median survival 7 months. Survival was worst in transmitted melanoma and central nervous system tumours. The prognosis of DTC in orthotopic SOTRs is poor. Although re-transplantation offers the best chance of cure, some tumours still recur. Publication bias and clinical heterogeneity limit the available evidence. From our findings, we suggest refinements to clinical practice. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020165001, Prospero Registration Number: CRD42020165001
The Deep Propagating Gravity Wave Experiment (DEEPWAVE): An airborne and ground-based exploration of gravity wave propagation and effects from their sources throughout the lower and middle atmosphere
The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic and other sources to regions of dissipation at high altitudes. The core DEEPWAVE field phase took place from May through July 2014 using a comprehensive suite of airborne and ground-based instruments providing measurements from Earth’s surface to ∼100 km. Austral winter was chosen to observe deep GW propagation to high altitudes. DEEPWAVE was based on South Island, New Zealand, to provide access to the New Zealand and Tasmanian “hotspots” of GW activity and additional GW sources over the Southern Ocean and Tasman Sea. To observe GWs up to ∼100 km, DEEPWAVE utilized three new instruments built specifically for the National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) Gulfstream V (GV): a Rayleigh lidar, a sodium resonance lidar, and an advanced mesosphere temperature mapper. These measurements were supplemented by in situ probes, dropsondes, and a microwave temperature profiler on the GV and by in situ probes and a Doppler lidar aboard the German DLR Falcon. Extensive ground-based instrumentation and radiosondes were deployed on South Island, Tasmania, and Southern Ocean islands. Deep orographic GWs were a primary target but multiple flights also observed deep GWs arising from deep convection, jet streams, and frontal systems. Highlights include the following: 1) strong orographic GW forcing accompanying strong cross-mountain flows, 2) strong high-altitude responses even when orographic forcing was weak, 3) large-scale GWs at high altitudes arising from jet stream sources, and 4) significant flight-level energy fluxes and often very large momentum fluxes at high altitudes
Gene Expression Profiles of Colonic Mucosa in Healthy Young Adult and Senior Dogs
Background: We have previously reported the effects of age and diet on nutrient digestibility, intestinal morphology, and large intestinal fermentation patterns in healthy young adult and senior dogs. However, a genome-wide molecular analysis of colonic mucosa as a function of age and diet has not yet been performed in dogs. Methodology/Principal Findings: Colonic mucosa samples were collected from six senior (12-year old) and six young adult (1-year old) female beagles fed one of two diets (animal protein-based vs. plant protein-based) for 12 months. Total RNA in colonic mucosa was extracted and hybridized to Affymetrix GeneChipH Canine Genome Arrays. Results indicated that the majority of gene expression changes were due to age (212 genes) rather than diet (66 genes). In particular, the colonic mucosa of senior dogs had increased expression of genes associated with cell proliferation, inflammation, stress response, and cellular metabolism, whereas the expression of genes associated with apoptosis and defensive mechanisms were decreased in senior vs. young adult dogs. No consistent diet-induced alterations in gene expression existed in both age groups, with the effects of diet being more pronounced in senior dogs than in young adult dogs. Conclusion: Our results provide molecular insight pertaining to the aged canine colon and its predisposition to dysfunction and disease. Therefore, our data may aid in future research pertaining to age-associated gastrointestinal physiologica
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