5,005 research outputs found

    Arc/gas electrode

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    A gas/arc electrode is disclosed for use under vacuum conditions where a first housing encloses a second housing, with an end of the second housing extending through an opening in the first housing and having an outlet orifice. Provisions are made for circulating a coolant through the first housing to surround and cool the second housing. An electrical current and a gas, such as argon, as passed through the second housing, with the current flowing through a narrow stream of the ionized gas flowing through the outlet orifice to a workpiece to be treated. The second housing forms a chamber which has a cross sectional area, in a plane perpendicular to the direction of gas flow, of at least ten times the cross sectional area of the outlet orifice such that a gas pressure can be maintained in the chamber to reduce erosion of the chamber walls

    Investigation of weld joint detection capabilities of a coaxial weld vision system

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    This report describes the second phase of a series of evaluations of a vision-based welding control sensor for the Space shuttle Main Engine Robotic Welding System. The robotic welding system is presently under development at the Marshall Space Flight Center. This evaluation determines the factors influencing the minimum joint gap required for consistent detection of the weld joint

    Implications for welfare, productivity and sustainability of the variation in reported levels of mortality for laying hen flocks kept in different housing systems: A meta-analysis of ten studies

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    Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM) was higher in flocks with intact beaks (χ2 = 6.03; df 1; p = 0.014) than in those with trimmed beaks. Most data were available for free-range systems (2,823 flocks), where producer recorded CM at 60–80 weeks of age averaged 10% but with a range from 0% to 69.3%. Life cycle assessment showed that the main effect of increased levels of hen mortality is to increase the relative contribution of breeding overheads, so increasing environmental burdens per unit of production. Reducing CM to levels currently achieved by the 1st quartile could reduce flock greenhouse gas emissions by as much as 25%. Concurrently this would enhance hen welfare and better meet the expectation of egg consumers. More research to understand the genetic x environment interaction and detailed records of the causes of mortality is required so that improved genotypes can be developed for different systems and different breeds can be better managed within systems

    Sequential simulation model development

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    Sequential simulation (SqS) is a physical form of simulation that recreates care pathway trajectories rather than single episodes of care. Current physical simulation in health care focuses on specific tasks or particular teams and settings. However, the patient perspective is a journey through the care system and not an isolated component. To date, SqS has been used for a range of applications, including training multidisciplinary teams on end-of-life care, developing integrated care approaches, quality improvement projects, designing new models of care, evaluating new interventions, and improving care of the deteriorating patient in an acute setting, to name but a few. Many applications are possible, and therefore the design process can be lengthy and complex. This article outlines an approach the author took over a 3-year period to generate a usable SqS model through empirical and theoretical data. The model draws on process, observational, survey, and evaluative data to generate an understanding of the key components that constitute the design process of an SqS. This approach resulted in an empirically and theoretically driven model that can be used and refined by others in the field of health-care simulation

    Investigation of the D and E region during the IQSY Final report, 1964 - 1965

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    Nike-Apache rocket measurements of lower ionosphere during International Quiet Sun Yea

    Mixed tenure orthodoxy: practitioner reflections on policy effects

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    This article examines mixed tenure as a policy orthodoxy. It first sets out how mixed tenure may be considered to constitute an orthodoxy within planning, being generally accepted as a theory and practice even in the absence of supporting evidence. Five elements of this orthodoxy are identified, relating to (1) housing and the environment, (2) social change, (3) economic impacts, (4) sustainable communities, (5) and sociospatial integration. Interviews with practitioners involved with three social housing estates that have experienced mixed-tenure policy interventions are reported to consider why the implementation and effects of mixed tenure might not correspond with the orthodox understanding. It is argued that policy ambiguity and weaknesses in policy theory and specification, alongside practical constraints, lie behind incomplete and counterproductive policy implementation, but a belief in pursuing the policy orthodoxy persists nevertheless
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