223 research outputs found

    Numerical investigation of unsteady laminar incompressible co-axial boundary layer flows

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    Finite difference method for analysis of laminar incompressible boundary layer flows at jet exi

    Turbulent kinetic energy equation and free mixing

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    Calculation of free shear flows was carried out to investigate the usefulness of several concepts which were previously successfully applied to wall flows. The method belongs to the class of differential approaches. The turbulence is taken into account by the introduction of one additional partial differential equation, the transport equation for the turbulent shear stress. The structure of turbulence is modeled after Bradshaw et al. This model was used successfully in boundary layers and its applicability to other flows is demonstrated. The work reported differs substantially from that of an earlier attempt to use this approach for calculation of free flows. The most important difference is that the region around the center line is treated by invoking the interaction hypothesis (concerning the structure of turbulence in the regions separated by the velocity extrema). The compressibility effects on shear layer spreading at low and moderate Mach numbers were investigated. In the absence of detailed experiments in free flows, the evidence from boundary layers that at low Mach numbers the structure of turbulence is unaffected by the compressibility was relied on. The present model was tested over a range of self-preserving and developing flows including pressure gradients using identical empirical input. The dependence of the structure of turbulence on the spreading rate of the shear layer was established

    Laminar mixing of heterogeneous axisymmetric coaxial confined jets Final report

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    Laminar mixing of heterogeneous axisymmetrical coaxial confined jets for application to nuclear rocket propulsio

    Liquid droplet evaporation in stagnant high pressure and high temperature environment Final report

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    Experimental evaporation histories of liquid droplets in stagnant high pressure and high temperature environmen

    VRI: 3D QSAR at variable resolution

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    VRI (Variable Resolution Invariants) is a new approach to quantitative structure–activity relations that makes use of three-dimensional features of molecules at different levels of spatial resolution as well as levels of resolution in atomic properties. These descriptors are independent of any numbering of the atoms of a molecule. They are also independent of rigid translation and rotation of a given conformer, which avoids problems with aligning different molecules or docking them with a receptor site model. Steric effects, stereospecificity, substituent effects, lipophilicity, and conformational flexibility are all dealt with in a single, natural formalism. Simple datasets can be fitted using a small number of descriptors corresponding to low-resolution descriptions of the molecules. More complicated data can require additional descriptors that recognize finer details of three-dimensional structure and physico-chemical properties. Overfitting due to the large number of descriptors is handled by partial least-squares analysis with crossvalidation. Performance in fitting and predicting is demonstrated on some simple illustrative cases, and on three standard sets of real data: steroids binding to human corticosteroid binding globulin and testosterone binding globulin, and inhibitors of dihydrofolate reductase. ©1999 John Wiley & Sons, Inc. J Comput Chem 20: 1577–1585, 1999Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34692/1/11_ftp.pd

    Use of Malaria Rapid Diagnostic Test to Identify Plasmodium knowlesi Infection

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    Reports of human infection with Plasmodium knowlesi, a monkey malaria, suggest that it and other nonhuman malaria species may be an emerging health problem. We report the use of a rapid test to supplement microscopic analysis in distinguishing the 5 malaria species that infect humans

    Clinical characteristics, etiology, and initial management strategy of newly diagnosed periprosthetic joint infection: A multicenter, prospective observational cohort study of 783 patients

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    Background Periprosthetic joint infection (PJI) is a devastating complication of joint replacement surgery. Most observational studies of PJI are retrospective or single-center, and reported management approaches and outcomes vary widely. We hypothesized that there would be substantial heterogeneity in PJI management and that most PJIs would present as late acute infections occurring as a consequence of bloodstream infections. Methods The Prosthetic joint Infection in Australia and New Zealand, Observational (PIANO) study is a prospective study at 27 hospitals. From July 2014 through December 2017, we enrolled all adults with a newly diagnosed PJI of a large joint. We collected data on demographics, microbiology, and surgical and antibiotic management over the first 3 months postpresentation. Results We enrolled 783 patients (427 knee, 323 hip, 25 shoulder, 6 elbow, and 2 ankle). The mode of presentation was late acute (>30 days postimplantation and 30 days postimplantation with ≥30 days of symptoms; 148, 19%). Debridement, antibiotics, irrigation, and implant retention constituted the commonest initial management approach (565, 72%), but debridement was moderate or less in 142 (25%) and the polyethylene liner was not exchanged in 104 (23%). Conclusions In contrast to most studies, late acute infection was the most common mode of presentation, likely reflecting hematogenous seeding. Management was heterogeneous, reflecting the poor evidence base and the need for randomized controlled trials

    11th German Conference on Chemoinformatics (GCC 2015) : Fulda, Germany. 8-10 November 2015.

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    Incidence and effects of Varicella Zoster Virus infection on academic activities of medical undergraduates - a five-year follow-up study from Sri Lanka

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    <p>Abstract</p> <p>Background</p> <p>The adult population in Sri Lanka is having high level of susceptibility for Varicella Zoster Virus (VZV) infection. Among medical undergraduates, 47% are VZV seronegative. The purpose of the present study was to determine the incidence of VZV infection in medical undergraduates in Sri Lanka, and to describe the effects of VZV infection on their academic activities.</p> <p>Methods</p> <p>A retrospective cohort of medical undergraduates' susceptible for VZV infection was selected from the University of Peradeniya, Sri Lanka. Data on the incidence of VZV infection (Chickenpox) during their undergraduate period was collected using a self-administered structured questionnaire. A second questionnaire was administered to collect data on the details of VZV infection and the impact of it on their academic activities. VZV incidence rate was calculated as the number of infections per 1,000 person years of exposure. Descriptive statistics were used to describe the impact of VZV infection on academic activities.</p> <p>Results</p> <p>Out of the 172 susceptible cohort, 153 medical undergraduates were followed up. 47 students reported VZV infection during the follow up period and 43 of them participated in the study. The cumulative incidence of VZV infection during the period of five and half years of medical training was 30.7%. Incidence density of VZV infection among medical undergraduates in this cohort was 65.1 per 1,000 person years of follow-up. A total of 377 working days were lost by 43 students due to the VZV infection, averaging 8.8 days per undergraduate. Total academic losses for the study cohort were; 205 lectures, 17 practicals, 13 dissection sessions, 11 tutorials, 124 days of clinical training and 107 days of professorial clinical appointments. According to their perception they lost 1,927 study hours due to the illness (Median 50 hours per undergraduate).</p> <p>Conclusions</p> <p>The incidence of VZV infection among Sri Lankan medical undergraduates is very high and the impact of this infection on academic activities causes severe disruption of their undergraduate life. VZV immunization for susceptible new entrant medical undergraduates is recommended.</p
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