557 research outputs found

    Development of a computer code for calculating the steady super/hypersonic inviscid flow around real configurations. Volume 1: Computational technique

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    A numerical procedure has been developed to compute the inviscid super/hypersonic flow field about complex vehicle geometries accurately and efficiently. A second order accurate finite difference scheme is used to integrate the three dimensional Euler equations in regions of continuous flow, while all shock waves are computed as discontinuities via the Rankine Hugoniot jump conditions. Conformal mappings are used to develop a computational grid. The effects of blunt nose entropy layers are computed in detail. Real gas effects for equilibrium air are included using curve fits of Mollier charts. Typical calculated results for shuttle orbiter, hypersonic transport, and supersonic aircraft configurations are included to demonstrate the usefulness of this tool

    Analyzing liquids

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    Exploring the physical controls of regional patterns of flow duration curves – Part 2: Role of seasonality, the regime curve, and associated process controls

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    The goal of this paper is to explore the process controls underpinning regional patterns of variations of streamflow regime behavior, i.e., the mean seasonal variation of streamflow within the year, across the continental United States. The ultimate motivation is to use the resulting process understanding to generate insights into the physical controls of another signature of streamflow variability, namely the flow duration curve (FDC). The construction of the FDC removes the time dependence of flows. Thus in order to better understand the physical controls in regions that exhibit strong seasonal dependence, the regime curve (RC), which is closely connected to the FDC, is studied in this paper and later linked back to the FDC. To achieve these aims a top-down modeling approach is adopted; we start with a simple two-stage bucket model, which is systematically enhanced through addition of new processes on the basis of model performance assessment in relation to observations, using rainfall-runoff data from 197 United States catchments belonging to the MOPEX dataset. Exploration of dominant processes and the determination of required model complexity are carried out through model-based sensitivity analyses, guided by a performance metric. Results indicated systematic regional trends in dominant processes: snowmelt was a key process control in cold mountainous catchments in the north and north-west, whereas snowmelt and vegetation cover dynamics were key controls in the north-east; seasonal vegetation cover dynamics (phenology and interception) were important along the Appalachian mountain range in the east. A simple two-bucket model (with no other additions) was found to be adequate in warm humid catchments along the west coast and in the south-east, with both regions exhibiting strong seasonality, whereas much more complex models are needed in the dry south and south-west. Agricultural catchments in the mid-west were found to be difficult to predict with the use of simple lumped models, due to the strong influence of human activities. Overall, these process controls arose from general east-west (seasonality) and north-south (aridity, temperature) trends in climate (with some exceptions), compounded by complex dynamics of vegetation cover and to a less extent by landscape factors (soils, geology and topography)

    Quantitative Study of Clostridium difficile Incidence Related to Influenza and Antimicrobial Use

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    In the United States, influenza causes approximately 36,000 deaths and over 200,000 hospitalizations each year with elderly most often affected. Clostridium difficile infection (CDI) is another major health care challenge and pressing public health issue associated with 14,000 deaths and over 335,000 hospitalizations annually. The use of antibiotics has been implicated in the development of CDI. This study\u27s purpose was to test the relationship of seasonal influenza incidence and antiviral/antibiotic use in CDI development among hospitalized patients. Grounded in the epidemiologic wheel model of man-environment interactions, this retrospective observational study described and analyzed data from a proprietary, laboratory, and pharmacy-based system from a cohort of hospitals. The association between 147 patients with a diagnosis and/or positive test for influenza, the independent variables of delivery of antivirals/antibiotics (n = 130) during the patient\u27s hospitalization, and the dependent variable of positive test or diagnosis of CDI (n = 17) was tested using multiple logistic regressions. The study results did not prove to be significant for the 3 research questions, suggesting no impact of antiviral use (R2 = .05, p = .336), antibiotic use (R2 = .05, p = .290), or antiviral and/or antibiotic use (R2 = .04, p = .382) on development of CDI within 60 days of discharge. However, findings indicated that recommended antiviral medication was inconsistently administered to influenza positive patients and that inappropriate prescribing patterns for antimicrobial agents coincided with seasonal influenza. Implications for positive social change include confirming the importance of antibiotic stewardship as an essential aspect of quality healthcare

    A Strategic Planning Intervention Employing Large Group Change: A Scholar/Practitioner Application

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    We present a scholar-practitioner collaboration applying a large group positive change project, representing the first such application methodology involving first responders. Positive change intervention is based on a multistage process involving Appreciative Inquiry and S.O.A.R. (Strengths, Opportunities, Aspirations and Results), designed to engage the community in inclusion, transparency, and mutual commitment in developing a strategic plan. Part of this plans objective is acquiring national accreditation, which has only been obtained by 217 of 30,052 fire department in the country. The project included 30 interns and 64 interviews with employees, trustees, and community residents, in preparation for the SOAR strategic planning sessio

    Exploring the physical controls of regional patterns of flow duration curves – Part 1: Insights from statistical analyses

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    The flow duration curve (FDC) is a classical method used to graphically represent the relationship between the frequency and magnitude of streamflow. In this sense it represents a compact signature of temporal runoff variability that can also be used to diagnose catchment rainfall-runoff responses, including similarity and differences between catchments. This paper is aimed at extracting regional patterns of the FDCs from observed daily flow data and elucidating the physical controls underlying these patterns, as a way to aid towards their regionalization and predictions in ungauged basins. The FDCs of total runoff (TFDC) using multi-decadal streamflow records for 197 catchments across the continental United States are separated into the FDCs of two runoff components, i.e., fast flow (FFDC) and slow flow (SFDC). In order to compactly display these regional patterns, the 3-parameter mixed gamma distribution is employed to characterize the shapes of the normalized FDCs (i.e., TFDC, FFDC and SFDC) over the entire data record. This is repeated to also characterize the between-year variability of "annual" FDCs for 8 representative catchments chosen across a climate gradient. Results show that the mixed gamma distribution can adequately capture the shapes of the FDCs and their variation between catchments and also between years. Comparison between the between-catchment and between-year variability of the FDCs revealed significant space-time symmetry. Possible relationships between the parameters of the fitted mixed gamma distribution and catchment climatic and physiographic characteristics are explored in order to decipher and point to the underlying physical controls. The baseflow index (a surrogate for the collective impact of geology, soils, topography and vegetation, as well as climate) is found to be the dominant control on the shapes of the normalized TFDC and SFDC, whereas the product of maximum daily precipitation and the fraction of non-rainy days was found to control the shape of the FFDC. These relationships, arising from the separation of total runoff into its two components, provide a potential physical basis for regionalization of FDCs, as well as providing a conceptual framework for developing deeper process-based understanding of the FDCs

    Camel Digital Necropsy Guide

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    Jaundice / Icterus Jaundice / icterus is yellowing of tissue due to elevated bilirubin levels. The tissue under the skin and on the surfaces of the stomachs and intestines is normally white to cream colored. If it is yellow, the animal is jaundiced/icteric. Three processes can lead to jaundice: 1. Over-production of bilirubin due to increased red blood cell destruction, 2. Liver disease, and 3. Bile duct obstruction. In a jaundiced animal, carefully assess the liver. If the liver appears normal, the jaundice may be due to increased red blood cell (erythrocyte) destruction, which can occur with certain blood parasites, such as anaplasmosis. Note that the dromedaries do not have a gall bladder

    Modeling Iron and Light Controls on the Summer \u3ci\u3ePhaeocystis antarctica\u3c/i\u3e Bloom in the Amundsen Sea Polynya

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    Of all the Antarctic coastal polynyas, the Amundsen Sea Polynya is the most productive per unit area. Observations from the 2010-2011 Amundsen Sea Polynya International Research Expedition (ASPIRE) revealed that both light and iron can limit the growth of phytoplankton (Phaeocystis antarctica), but how these controls manifest over the bloom season is poorly understood, especially with respect to their climate sensitivity. Using a 1-D biogeochemical model, we examine the influence of light and iron limitation on the phytoplankton bloom and vertical carbon flux at 12 stations representing different bloom stages within the polynya. Model parameters are determined by Bayesian optimization and assimilation of ASPIRE observations. The model-data fit is most sensitive to phytoplankton physiological parameters, which among all model parameters are best constrained by the optimization. We find that the 1-D model captures the basic elements of the bloom observed during ASPIRE, despite some discrepancies between modeled and observed dissolved iron distributions. With this model, we explore the way iron availability, in combination with light availability, controlled the rise, peak, and decline of the bloom at the 12 stations. Modeled light limitation by self-shading is very strong, but iron is drawn down as the bloom rises, becoming limiting in combination with light as the bloom declines. These model results mechanistically confirm the importance of climate-sensitive controls like stratification and meltwater on phytoplankton bloom development and carbon export in this region

    Nurses\u27 Alumnae Association Bulletin - Volume 17 Number 1

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    Alumnae Notes Committee Reports Digest of Alumnae Association Meetings Greetings from Miss Childs Greetings from the Educational Director Greetings from the President Graduation Awards - 1951 Jefferson\u27s New Hospital Addition Marriages Necrology Neurosurgery Department New Arrivals New Drugs Notes on the Cause of Leukemia Nursing Staff Saul Among the Prophets Staff Activities, 1951-1952 Students\u27 Corner The Hospital Pharmacy The Student Nurse Association of Pennsylvania White Haven and Barton Memorial Division
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