353 research outputs found

    Peyronie's disease - a perspective on the disease and the long-term results of radiotherapy

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    From 1966 to 1988, 98 of 108 patients with symptomatic Peyronie's disease received radiotherapy at our institution. In 11 of 61 patients (18%) who attended the clinic regularly for follow-up for longer than a year, new lesions distinct from the original lesions developed. This confirms that there is progression of the disease in a substantial number of cases after treatment. Long-term follow-up over an average of 111,5 months was achieved by means of a questionnaire in 47 of the 98 cases (48%). Forty-one of these patients (87,2%) had sexual intercourse after radiation. Twenty-eight of the 41 (68,3%) still have intercourse. Their average age at present is 59,6 years while the average age of the 13 patients (31,7%) not having intercourse is 70,9 years. The decline in sexual activity is thus age-related. Twenty-one of 25 patients (84%) experienced relief from pain, and angulation of the penis improved in 17 of 44 patients (38,6%) after radiotherapy. Radiotherapy may therefore be of benefit to patients with active Peyronie's disease and should be investigated in a randoIIlised controlled study

    Development and initial application of a blade design methodology for overspeed power-regulated tidal turbines

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    The range and variability of flow velocities in which horizontal axis tidal stream turbines operate introduces the requirement for a power regulation method in the system. Overspeed power regulation (OSPR) has the potential to improve the structural robustness and decrease the complexity associated with active pitch power regulation methods, while removing the difficulties of operating in stalled flow. This paper presents the development of a methodology for the design of blades to be used in such systems. The method requires a site depth, maximum flow velocity and rated power or flow speed as input parameters. The pitch setting, twist and chord distribution were set as input parameters, variable through the use of alteration functions. Rotor performance has been broken down into OSPR performance metrics which consider coefficients of power and thrust, and cavitation inception. Three visual-numerical tools have been developed: the OSPR performance metrics were used in conjunction with a one-at-a-time sensitivity analysis approach to develop a design space; cavitation inception analyses gave plots of converging cavitation and pressure terms for each blade section; the local angle of attack and torque distribution across the blade designs were plotted at key turbine operation states. Alterations to pitch setting and twist distribution are shown to have most impact upon the design requirement of increased gradient in the rotor speed-efficiency relationship in the overspeed region; coupled with such alterations, targeted changes to the chord distribution have been shown to increase the maximum efficiency. The prevention of cavitation has been highlighted as a driver for speed-limiting design alterations. While facilitating blade design, the methodology also produces experiential knowledge which can be stored, and shared in graphical format

    Congenital bipartite lunate presenting as a misdiagnosed lunate fracture: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>A rare case of congenital bipartite lunate in a child is reported. Carpal variants are very uncommon as independent entities, with only three previous reports of this condition in the English literature.</p> <p>Case presentation</p> <p>An 11-year-old Caucasian boy presented with pain in the left wrist after a fall. Radiographs in the emergency department demonstrated a lunate that was divided into palmar and dorsal parts, causing a misdiagnosis of fractured lunate. Magnetic resonance imaging was then used to differentiate between the two diagnoses.</p> <p>Conclusion</p> <p>Very few cases of bipartite lunate have been reported in the literature, and unless awareness is raised about congenital anomalies such as this variant, confusion may arise.</p

    Tow-tank testing of a 1/20th scale horizontal axis tidal turbine with uncertainty analysis

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    Tidal turbine developers and researchers use small scale testing (i.e. tow tank and flume testing) as a cost effective and low risk way to conduct proof-of-concept studies and evaluate early stage device performance. This paper presents experimental performance data for a three-bladed 1/20th scale NREL S814 tidal turbine rotor, produced at the 4.6 Ă— 2.5 m and 76 m long Kelvin Hydrodynamics Laboratory tow tank at Strathclyde University. The rotor performance was characterised from very low tip speed ratios to runaway for four carriage speeds. A maximum CP of 0.285 and a maximum CT of 0.452 were recorded at tip speed ratios of 3.53 and 4.45 for a carriage speed of 1 m/s. The uncertainty in the instrument calibration and experimental measurements was quantified, allowing accurate representation of the experiments in numerical models. The methodology behind the uncertainty calculations is described in this paper. The uncertainty in the experimental measurements was found to be less than 5% for over 87% of the tests. Reynolds number scaling effects were found to be influential on the rotor performance in the range of velocities tested

    Do Plans and Execution Agree in a Humanitarian Medical Mission?

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    There is a significant need for orthopaedic care in developing countries. Fo

    Dynamic linkages between stock markets : the effects of crises and globalization

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    This paper investigates changes in the dynamics of linkages between selected national stock markets during the period 1995–2009. The analysis focuses on the possible effects of globalization and differences between crisis and non-crisis periods. We model the dynamics of dependencies between the series of daily returns on selected stock indices over different time periods, and compare strength of the linkages. Our tools are dynamic copula models and a formal sequential testing procedure based on the model confidence set methodology. We consider two types of dependencies: regular dependence measured by means of the conditional Spearman’s rho, and dependencies in extremes quantified by the conditional tail dependence coefficients. The main result consists of a collection of rankings created for the considered subperiods, which show how the mean level of strength of the dependencies have been changing in time. The rankings obtained for Spearman’s rho and tail dependencies differ, which allows us to distinguish between the results of crises and the effect of globalization.info:eu-repo/semantics/publishedVersio
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