3,494 research outputs found
Measurement of the derivative 'ZW' for an oscillating aerofoil
This report presents the results of experimental
measurements of the damping derivative coefficient zw for
constant chord rigid wings of various aspect ratios having
sweepback angles of zero and 450.
The results for the rectangular wings Flow substantial
agreement with the unsteady aerofoil theory developed
by TI.P. Jones $2) The dependence of Zvi upon frequency parameter
is as given by theory and is much less than for two dimensional
flow, but the numerical results are approximately
10 per cent below the theoretical. This is attributed to the
large trailing edge angle 22° of the N.A.C.A. 0020 section
used for the model aerofoils.
The effect of sweepback is to decrease the numerical
value of z , but this effect is much less pronounced, for low
than for high aspect ratios. For aspect ratios 5 and 3
the numerical value is greater than would be given by a factor
of proportionality equal to the cosine of the angle of
sweepback.
The measurements were corrected for tunnel interference
by a method based on the theoretical work of 7.P.Jones.(1
Predicting airborne coronavirus inactivation by far-UVC in populated rooms using a high-fidelity coupled radiation-CFD model
There are increased risks of contracting COVID-19 in hospitals and long-term care facilities, particularly
for vulnerable groups. In these environments aerosolised coronavirus released through breathing
increases the chance of spreading the disease. To reduce aerosol transmissions, the use of low dose
far-UVC lighting to disinfect in-room air has been proposed. Unlike typical UVC, which has been used to
kill microorganisms for decades but is carcinogenic and cataractogenic, recent evidence has shown that
far-UVC is safe to use around humans. A high-fidelity, fully-coupled radiation transport and fluid dynamics
model has been developed to quantify disinfection rates within a typical ventilated room. The model
shows that disinfection rates are increased by a further 50-85% when using far-UVC within currently
recommended exposure levels compared to the rooms’ ventilation alone. With these magnitudes of
reduction, far-UVC lighting could be employed to mitigate SARS-CoV-2 transmission before the onset of
future waves, or the start of winter when risks of infection are higher. This is particularly significant in
poorly-ventilated spaces where other means of reduction are not practical, in addition social distancing
can be decreased without increasing the risk
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The experiences and perspectives of overseas trained speech and language therapists working in the United Kingdom
There is a growing body of research which has investigated the experience of the migrant health worker. However, only one of these studies has included speech and language therapists thus far, and then only with extremely small numbers. The aim of this study was to explore the experiences and perspectives of migrant speech and language therapists living in the UK. Twenty-three overseas qualified speech and language therapists living in the UK completed an online survey consisting of 36 questions (31 closed question, 5 open-ended questions). The majority of participants came from Australia or the USA and moved to the UK early in their careers. Participants reported a range of benefits from working in another country and more specifically working in the UK. The findings were consistent with other research on migrant health workers regarding known pull factors of travel, finance, and career. This study suggests additional advantages to working in the UK were realised once participants had started working in the UK, such as the UK job lifestyle. Finally, the migrant speech and language therapists were similar in profile to other migrant health workers in terms of age and country of origin previously reported in the literature
Understanding Class-level Testability Through Dynamic Analysis
It is generally acknowledged that software testing is both challenging and time-consuming. Understanding the factors that may positively or negatively affect testing effort will point to possibilities for reducing this effort. Consequently there is a significant body of research that has investigated relationships between static code properties and testability. The work reported in this paper complements this body of research by providing an empirical evaluation of the degree of association between runtime properties and class-level testability in object-oriented (OO) systems. The motivation for the use of dynamic code properties comes from the success of such metrics in providing a more complete insight into the multiple dimensions of software quality. In particular, we investigate the potential relationships between the runtime characteristics of production code, represented by Dynamic Coupling and Key Classes, and internal class-level testability. Testability of a class is consider ed here at the level of unit tests and two different measures are used to characterise those unit tests. The selected measures relate to test scope and structure: one is intended to measure the unit test size, represented by test lines of code, and the other is designed to reflect the intended design, represented by the number of test cases. In this research we found that Dynamic Coupling and Key Classes have significant correlations with class-level testability measures. We therefore suggest that these properties could be used as indicators of class-level testability. These results enhance our current knowledge and should help researchers in the area to build on previous results regarding factors believed to be related to testability and testing. Our results should also benefit practitioners in future class testability planning and maintenance activities
A Sailor’s Disease Presenting in Urban America with Red Spots on the Legs
Sailors were often affected by nutritional deficiencies due to the absence of fresh foods on long voyages. One example is the development of scurvy from a lack of vitamin C ingestion. In modern society in which fresh food are available this disease is infrequently recognized. The following case describes a 62-year-old male who presented with “red spots” on his legs and a large area of ecchymosis on his thigh. After initial testing failed to elicit a cause, a dietary history revealed that the patient had a peculiar diet of only ice cream with a total avoidance of fruits and vegetables. This case highlights the importance of a good history and physical examination as the basis for medical diagnosis
What difference does ("good") HRM make?
The importance of human resources management (HRM) to the success or failure of health system performance has, until recently, been generally overlooked. In recent years it has been increasingly recognised that getting HR policy and management "right" has to be at the core of any sustainable solution to health system performance. In comparison to the evidence base on health care reform-related issues of health system finance and appropriate purchaser/provider incentive structures, there is very limited information on the HRM dimension or its impact. Despite the limited, but growing, evidence base on the impact of HRM on organisational performance in other sectors, there have been relatively few attempts to assess the implications of this evidence for the health sector. This paper examines this broader evidence base on HRM in other sectors and examines some of the underlying issues related to "good" HRM in the health sector. The paper considers how human resource management (HRM) has been defined and evaluated in other sectors. Essentially there are two sub-themes: how have HRM interventions been defined? and how have the effects of these interventions been measured in order to identify which interventions are most effective? In other words, what is "good" HRM? The paper argues that it is not only the organisational context that differentiates the health sector from many other sectors, in terms of HRM. Many of the measures of organisational performance are also unique. "Performance" in the health sector can be fully assessed only by means of indicators that are sector-specific. These can focus on measures of clinical activity or workload (e.g. staff per occupied bed, or patient acuity measures), on measures of output (e.g. number of patients treated) or, less frequently, on measures of outcome (e.g. mortality rates or rate of post-surgery complications). The paper also stresses the need for a "fit" between the HRM approach and the organisational characteristics, context and priorities, and for recognition that so-called "bundles" of linked and coordinated HRM interventions will be more likely to achieve sustained improvements in organisational performance than single or uncoordinated interventions
What are the priorities for improving cataract surgical outcomes in Africa? Results of a Delphi exercise.
PURPOSE: The quality of cataract surgery delivered in sub-Saharan Africa (SSA) is a significant constraint to achieving the elimination of avoidable blindness. No published reports from routine SSA cataract services attain the WHO benchmarks for visual outcomes; poor outcomes (<6/60) often comprise 20% in published case series. This Delphi exercise aimed to identify and prioritise potential interventions for improving the quality of cataract surgery in SSA to guide research and eye health programme development. METHODS: An initial email open-question survey created a ranked list of priorities for improving quality of surgical services. A second-round face-to-face discussion facilitated at a Vision 2020 Research Mentorship Workshop in Tanzania created a refined list for repeated ranking. RESULTS: Seventeen factors were agreed that might form target interventions to promote quality of cataract services. Improved training of surgeons was the top-ranked item, followed by utilisation of biometry, surgical equipment availability, effective monitoring of outcomes of cataract surgery by the surgeon, and well-trained support staff for the cataract pathway (including nurses seeing post-operative cases). CONCLUSION: Improving the quality of cataract surgery in SSA is a clinical, programmatic and public health priority. In the absence of other evidence, the collective expert opinion of those involved in ophthalmic services regarding the ranking of factors to promote quality improvement, refined through this Delphi exercise, provides us with candidate intervention areas to be evaluated
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Near-zero humidities on Ben Nevis, Scotland, revealed by pioneering 19th-century observers and modern volunteers
The weather on Ben Nevis – the highest mountain in the British Isles, 1345 m AMSL – sometimes shows episodes of remarkably low relative humidity (RH) with few precedents anywhere else in the British Isles. We are able to quantify this for the first time using a high-quality series of hourly dry- and wet-bulb observations, made on the summit. These observations were made between 1883 and 1904, but have only just become available to modern science, thanks to thousands of volunteers who worked to rescue this unique and exemplary dataset from published volumes. Careful examination and analysis of the original observations using modern psychrometric theory revealed several occasions where we are confident that the summit RH fell close to zero as a result of anticyclonic subsidence. Three case histories are examined in some detail. The nineteenth-century Ben Nevis humidity records are also compared with contemporary automatic weather station (AWS) data from two high-altitude Scottish mountain sites
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