14,958 research outputs found

    Identification of problems in nursing conferences

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    Thesis (M.S.)--Boston Universit

    Leakage predictions for Rayleigh-step, helium-purge seals

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    Rayleigh-step, helium purge, annular shaft seals, studied for use in liquid oxygen turbopumps, generate a hydrodynamic force that enables the seal to follow shaft perturbations. Hence, smaller clearances can be used to reduce seal leakage. FLOWCAL, a computer code developed by Mechanical Technology Incorporated, predicts gas flow rate through an annular seal with an axial pressure gradient. Analysis of a 50-mm Rayleigh-step, helium-purge, annular seal showed the flow rate increased axial pressure gradient, downstream pressure, and eccentricity ratio. Increased inlet temperature reduced leakage. Predictions made at maximum and minimum clearances (due to centrifugal and thermal growths, machining tolerances and + or - 2 percent uncertainty in the clearance measurement) placed wide boundaries on expected flow rates. The widest boundaries were set by thermal growth conditions. Predicted flow rates for a 50-mm Rayleigh-step, helium-purge, annular seal underestimated measured flow rates by three to seven times. However, the analysis did accurately predict flow rates for choked gas flow through annular seals when compared to flow rates measured in two other independent studies

    Metformin reverses development of pulmonary hypertension via aromatase inhibition

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    Females are more susceptible to pulmonary arterial hypertension than males, although the reasons remain unclear. The hypoglycemic drug, metformin, is reported to have multiple actions, including the inhibition of aromatase and stimulation of AMP-activated protein kinase. Inhibition of aromatase using anastrazole is protective in experimental pulmonary hypertension but whether metformin attenuates pulmonary hypertension through this mechanism remains unknown. We investigated whether metformin affected aromatase activity and if it could reduce the development of pulmonary hypertension in the sugen 5416/hypoxic rat model. We also investigated its influence on proliferation in human pulmonary arterial smooth muscle cells. Metformin reversed right ventricular systolic pressure, right ventricular hypertrophy, and decreased pulmonary vascular remodeling in the rat. Furthermore, metformin increased rat lung AMP-activated protein kinase signaling, decreased lung and circulating estrogen levels, levels of aromatase, the estrogen metabolizing enzyme; cytochrome P450 1B1 and its transcription factor; the aryl hydrocarbon receptor. In human pulmonary arterial smooth muscle cells, metformin decreased proliferation and decreased estrogen synthesis by decreasing aromatase activity through the PII promoter site of Cyp19a1. Thus, we report for the first time that metformin can reverse pulmonary hypertension through inhibition of aromatase and estrogen synthesis in a manner likely to be mediated by AMP-activated protein kinase

    A community of teachers: Using Activity Theory to investigate the implementation of ICTE in a remote Indigenous school

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    In 2001-2002, an innovative project entitled Reach In-Reach Out has been conducted in Far North Queensland. Its aim was to use telecommunications and Internet tools to facilitate communication between the children of Lockhart River who attend secondary school in such centres as Cairns, Townsville and Herberton and their families. This study was the first (of three) to investigate the impact of this project. Its focus is on the teachers of Lockart River State School and the changes made to their practice by the implementation of the project. The study described in this paper was conducted in Lockhart River which is situated on Kanthanumpu (Southern Kuuku Ya'u) land in Far North Queensland. The current population is estimated between 650 (Education Queensland, 2001a) and 800 (Lockhart River Land and Sea Management Agency, 2001) residents. The student population of Lockhart River State School in 2001was 26 (Kindy), 105 (Primary) and 30 (Alternate secondary/VET) programs) (Education Queensland, 2001a). At the end of 1999, the secondary school of Lockhart River was closed following a community decision to do so. This necessitated the majority of post-primary students having to leave Lockhart River to continue their education at boarding school. At the beginning of 2002, 38 students left the Lockhart River Community to attend boarding schools (and 8 remained to take part in the Alternate Secondary/VET program offered at the school). Table 1 details the secondary enrolments of Lockhart River students from 1998 to 2001, including the period covered by this study (2001)

    The dynamics and evolution of clusters of galaxies

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    Research was undertaken to produce a coherent picture of the formation and evolution of large-scale structures in the universe. The program is divided into projects which examine four areas: the relationship between individual galaxies and their environment; the structure and evolution of individual rich clusters of galaxies; the nature of superclusters; and the large-scale distribution of individual galaxies. A brief review of results in each area is provided

    Monitoring and Analysis of Frozen Debris Lobes, Phase I

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    INE/AUTC 12.2

    Resource efficiency: creating a route to logistics and the circular economy

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    Resource productivity needs to increase by 30% toward 2030, delivering a purported increase in employment while delivering a net benefit to GDP of 1% (European Commission, 2014). The Europe 2020 strategy will necessitate changes in product and service delivery (lightweighting) and a requirement for systems to support the flows of materials at end of life for collection, separation and re-use. There is a demand for resource efficiency improvements across a range of industrial sectors and a need for whole supply chain cooperation to ensure maximum impact of the circular economy concept. However with current challenges over quality and quantity of products moving through reverse logistics networks (Niknejad & Petrovic, 2014), this will undoubtedly place a need on current infrastructure [logistics] to review working practices. Innovative solutions will be required by industry to deliver sustainable networks that support aligned flows of manufacturing processes delivering supply chain surplus (Zhong, 2009)

    Targeting outcomes redux

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    "...There are sharply divergent views as to how much narrowly targeted interventions actually benefit the poor. These result from differing assessments of three issues: whether better targeting outcomes are likely to be achieved, whether such methods are cost-effective, and whether the living standards of the poor are improved by such targeted interventions. This paper focuses on the first issue. Using a newly constructed database of targeted interventions, it addresses three questions: (1) What targeting outcomes are observed? (2) Are there systematic differences in targeting performance by targeting methods and other factors? (3) What are the implications for such systematic differences for the design and implementation of targeted interventions?" from Authors' Abstract.Developing countries ,Poverty ,
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