4,723 research outputs found

    Resistive Magnetohydrodynamic Equilibria in a Torus

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    It was recently demonstrated that static, resistive, magnetohydrodynamic equilibria, in the presence of spatially-uniform electrical conductivity, do not exist in a torus under a standard set of assumed symmetries and boundary conditions. The difficulty, which goes away in the ``periodic straight cylinder approximation,'' is associated with the necessarily non-vanishing character of the curl of the Lorentz force, j x B. Here, we ask if there exists a spatial profile of electrical conductivity that permits the existence of zero-flow, axisymmetric r esistive equilibria in a torus, and answer the question in the affirmative. However, the physical properties of the conductivity profile are unusual (the conductivity cannot be constant on a magnetic surface, for example) and whether such equilibria are to be considered physically possible remains an open question.Comment: 17 pages, 4 figure

    Toroidal Vortices in Resistive Magnetohydrodynamic Equilibria

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    Resistive steady states in toroidal magnetohydrodynamics (MHD), where Ohm's law must be taken into account, differ considerably from ideal ones. Only for special (and probably unphysical) resistivity profiles can the Lorentz force, in the static force-balance equation, be expressed as the gradient of a scalar and thus cancel the gradient of a scalar pressure. In general, the Lorentz force has a curl directed so as to generate toroidal vorticity. Here, we calculate, for a collisional, highly viscous magnetofluid, the flows that are required for an axisymmetric toroidal steady state, assuming uniform scalar resistivity and viscosity. The flows originate from paired toroidal vortices (in what might be called a ``double smoke ring'' configuration), and are thought likely to be ubiquitous in the interior of toroidally driven magnetofluids of this type. The existence of such vortices is conjectured to characterize magnetofluids beyond the high-viscosity limit in which they are readily calculable.Comment: 17 pages, 4 figure

    Critical factors in the information management process: the analysis of hospital-based patient safety incident reports

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    The purpose of this study is to describe the nature of patient safety incidents relating to information management and to identify critical factors for a safe information management process in a university hospital. A total of 813 information management incidents in hospital-based adverse event reports were analyzed using directed content analysis. Descriptive statistics and cross tabulations were used to quantify the results. The results of this study showed that the majority of incidents occurred during the information distribution phase. The most frequent incidents fell into the category of written information transfer and communication; furthermore, many of these incidents concerned medication data. There was a high amount of inaccurate data and omissions in the different phases of the information management process. Information organization and storage, information distribution, and information use phases are critical in terms of patient safety, and a high proportion of the problems in this area are potentially preventable. It is thus essential to develop more effective strategies to ensure safe information management. The data from this study also suggest that while incident reports can help to identify breakdowns in the information management process, the quality of reporting needs to be improved

    Comparison of external evaluation policies and regulations for quality improvement and safety of health services in Norway and the United States

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    Purpose The authors compare perspectives on external evaluation of health service provision between Norway and the USA. External inspection and accreditation are examples of internationally wide-spread external evaluation methods used to assess the quality of care given to patients. Different countries have different national policy strategies and arrangements set up to do these evaluations. Although there is growing attention to the impact and effects on quality and safety from external evaluation, there is still a gap in knowledge to how structures and processes influence these outcomes. Accordingly, the purpose of this article is to describe the structures and processes in external evaluation designed to promote quality improvement in Norway and the USA with attention to comparison of enablers and barriers in external evaluation systems. Design/methodology/approach Data collection consisted of documentary evidence retrieved from governmental policies, and reviews of the Joint Commission (the US), international guidelines, recommendations and reports from the International Society for Quality in Health Care, and the World Health Organization, and policies and regulations related to Norwegian governmental bodies such as the Ministry of Health and Care Services, the Norwegian Directorate of Health, and the Norwegian Board of Health Supervision . Data were analyzed inspired by a deductive, direct content analytical framework. Findings The authors found that both accreditation and inspection are strategies put in place to ensure that healthcare providers have adequate quality systems as well as contributing to the wider risk and safety enhancing management and implementation processes in the organizations subjected to evaluation. The US and the Norwegian external regulatory landscapes are complex and include several policymaking and governing institutions. The Norwegian regulatory framework for inspection has replaced an individual blame logic with a model which “blames” the system for inadequate quality and patient harm. This contrasts with the US accreditation system, which focuses on accreditation visits. Although findings indicate an ongoing turning point in accreditation, findings also demonstrate that involving patients and next of kin directly in adverse event inspections is a bigger part of a change in external inspection culture and methods than in processes of accreditation. Research limitations/implications The message of this paper is important for policymakers, and bodies of inspection and accreditation because knowledge retrieved from the comparative document study may contribute to better understanding of the implications from the different system designs and in turn contribute to improving external evaluations. Originality/value Although there is a growing attention to the impact and effects on quality and safety from external evaluation, the implications of different regulatory strategies and arrangements for evaluation on quality and safety remain unclear.acceptedVersio

    The Value of Information Technology-Enabled Diabetes Management

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    Reviews different technologies used in diabetes disease management, as well as the costs, benefits, and quality implications of technology-enabled diabetes management programs in the United States
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