1,809 research outputs found

    Digital Mapping and Environmental Characterization of National Wild and Scenic River Systems

    Get PDF
    Spatially accurate geospatial information is required to support decision-making regarding sustainable future hydropower development. Under a memorandum of understanding among several federal agencies, a pilot study was conducted to map a subset of National Wild and Scenic Rivers (WSRs) at a higher resolution and provide a consistent methodology for mapping WSRs across the United States and across agency jurisdictions. A subset of rivers (segments falling under the jurisdiction of the National Park Service) were mapped at a high resolution using the National Hydrography Dataset (NHD). The spatial extent and representation of river segments mapped at NHD scale were compared with the prevailing geospatial coverage mapped at a coarser scale. Accurately digitized river segments were linked to environmental attribution datasets housed within the Oak Ridge National Laboratory s National Hydropower Asset Assessment Program database to characterize the environmental context of WSR segments. The results suggest that both the spatial scale of hydrography datasets and the adherence to written policy descriptions are critical to accurately mapping WSRs. The environmental characterization provided information to deduce generalized trends in either the uniqueness or the commonness of environmental variables associated with WSRs. Although WSRs occur in a wide range of human-modified landscapes, environmental data layers suggest that they provide habitats important to terrestrial and aquatic organisms and recreation important to humans. Ultimately, the research findings herein suggest that there is a need for accurate, consistent, mapping of the National WSRs across the agencies responsible for administering each river. Geospatial applications examining potential landscape and energy development require accurate sources of information, such as data layers that portray realistic spatial representations

    A semi-mechanistic model of hydrocyclones - developed form industrial data and inputs from CFD.

    Get PDF
    The flow behavior in hydrocyclones is extremely complex, leading the designers to rely on empirical equations for predicting cyclone performance. A number of classifying cyclone models have been developed and used in mineral comminution circuit simulators in the past. The problem with these empirical cyclone models is that they cannot be used outside the range of conditions under which they were developed. A semi-mechanistic hydrocyclone model is developed using the dimensionless approach based on both the fluid mechanics concepts from Computational Fluid Dynamics (CFD) simulations and the wide range of industrial cyclone performance data. The improved model consist a set of equations for the water split to underflow (R), reduced cut-size (d), throughput (Q) and sharpness of the separation (α). The model for R, d, Q gives a very good fit to the data. The alpha model shows reasonable correlation for the cyclone design and operating conditions. Additional data sets were used to validate the new hydrocyclone model by comparing the predictions of the model equations with the experimental results

    Rescaling the Governance of Renewable Energy : Lessons from the UK Devolution Experience

    Get PDF
    An earlier version of this paper was presented at the symposium ‘Scale in environmental governance: power reconfiguration, democratic legitimacy and institutional (mis-)fit’, Berlin-Brandenburg Academy of Sciences and Humanities, Berlin 7-8 March 2013. We would like to thank the symposium participants, special issue editors and three anonymous referees for their comments and advice.Peer reviewedPublisher PD

    Examining the diversity of MRCS examiners

    Get PDF
    Acknowledgements The authors would like to acknowledge Gregory Ayre from the Intercollegiate Committee for Basic Surgical Examinations for his support during this project. Funding Royal College of Surgeons of Edinburgh, Royal College of Surgeons of Ireland. Royal College of Physicians and Surgeons of Glasgow and Royal College of Surgeons of England.Peer reviewedPublisher PD

    Once Daily Valacyclovir for Reducing Viral Shedding in Subjects Newly Diagnosed with Genital Herpes

    Get PDF
    Objective. Genital herpes (GH) recurrences and viral shedding are more frequent in the first year after initial HSV-2 infection. The objective of this study was to provide the first evaluation of valacyclovir 1 g once daily compared to placebo in reducing viral shedding in subjects newly diagnosed with GH. Methods. 70 subjects were randomized to receive valacyclovir 1 g daily or placebo in a crossover design for 60 days with a 7-day washout period. A daily swab of the genital/anal-rectal area was self-collected for HSV-2 detection by PCR. Subjects attended the clinic for routine study visits and GH recurrence visits. Treatment differences were assessed using a nonparametric crossover analysis. Results. 52 subjects had at least one PCR measurement in both treatment periods and comprised the primary efficacy population. Valacyclovir significantly reduced HSV-2 shedding during all days compared to placebo (mean 2.9% versus 13.5% of all days (P < .01), a 78% reduction). Valacyclovir significantly reduced subclinical HSV-2 shedding during all days compared to placebo (mean 2.4% versus 11.0% of all days (P < .01), a 78% reduction). However, 79% of subjects had no GH recurrences while receiving valacyclovir compared to 52% of subjects receiving placebo (P < .01). Conclusion. In this study, the frequency of total and subclinical HSV-2 shedding was greater than reported in earlier studies involving subjects with a history of symptomatic genital recurrences. Our study is the first to demonstrate a significant reduction in viral shedding with valacyclovir 1 g daily compared to placebo in a population of subjects newly diagnosed with HSV-2 infection

    Does performance at medical school predict success at the Intercollegiate Membership of the Royal College of Surgeons (MRCS) examination? : A retrospective cohort study

    Get PDF
    Funding Information: Royal College of Surgeons of England, Royal College of Surgeons of Edinburgh, Royal College of Surgeons of Ireland and Royal College of Physicians and Surgeons of Glasgow (award/grant number is not applicable). Acknowledgements: The authors would like to acknowledge Iain Targett at the Royal College of Surgeons of England, for his help with data collection and Gregory Ayre from the Intercollegiate Committee for Basic Surgical Examinations for their support during this project. Our thanks to members of the UKMED Research Group who provided useful feedback on an earlier version of this manuscript, and whose comments helped refine the paper. The authors would also like to acknowledge Daniel Smith for his help with the UKMED database. Data Source: UK Medical Education Database (‘UKMED’). UKMEDP043 extract generated on 25 July 2018. We are grateful to UKMED for the use of these data. However, UKMED bears no responsibility for their analysis or interpretation. The data include information derived from that collected by the Higher Education Statistics Agency Limited (‘HESA’) and provided to the GMC (‘HESA Data’). Source: HESA Student Records 2007/2008 to 2015/2016. Copyright Higher Education Statistics Agency. The Higher Education Statistics Agency makes no warranty as to the accuracy of the HESA Data, cannot accept responsibility for any inferences or conclusions derived by third parties from data or other information supplied by it.Peer reviewedPublisher PD

    Does performance at the intercollegiate Membership of the Royal Colleges of Surgeons (MRCS) examination vary according to UK medical school and course type? A retrospective cohort study

    Get PDF
    Acknowledgments The authors would like to acknowledge Iain Targett at the Royal College of Surgeons of England, for his help with data collection and John Hines and Gregory Ayre from the Intercollegiate Committee for Basic Surgical Examinations for their support during this project. Our thanks to members of the UKMED Research Group who provided useful feedback on an earlier version of this manuscript, and whose comments helped refine the paper. The authors would also like to acknowledge Daniel Smith for his help with the UKMED database. Data source: UK Medical Education Database ('UKMED'). UKMEDP043 extract generated on 25/07/2018. We are grateful to UKMED for the use of these data. However, UKMED bears no responsibility for their analysis or interpretation the data includes information derived from that collected by the Higher Education Statistics Agency Limited ('HESA') and provided to the GMC ('HESA Data'). Source: HESA Student Records 2002/2003 to 2015/2016. Copyright Higher Education Statistics Agency Limited. The Higher Education Statistics Agency Limited makes no warranty as to the accuracy of the HESA Data, cannot accept responsibility for any inferences or conclusions derived by third parties from data or other Information supplied by it.Peer reviewedPublisher PD
    corecore