101 research outputs found

    POD\u2013Galerkin reduced order methods for combined Navier\u2013Stokes transport equations based on a hybrid FV-FE solver

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    The purpose of this work is to introduce a novel POD\u2013Galerkin strategy for the semi-implicit hybrid high order finite volume/finite element solver introduced in Berm\ufadez et al. (2014) and Busto et al. (2018). The interest is into the incompressible Navier\u2013Stokes equations coupled with an additional transport equation. The full order model employed in this article makes use of staggered meshes. This feature will be conveyed to the reduced order model leading to the definition of reduced basis spaces in both meshes. The reduced order model presented herein accounts for velocity, pressure, and a transport-related variable. The pressure term at both the full order and the reduced order level is reconstructed making use of a projection method. More precisely, a Poisson equation for pressure is considered within the reduced order model. Results are verified against three-dimensional manufactured test cases. Moreover a modified version of the classical cavity test benchmark including the transport of a species is analysed

    Scale issues in soil moisture modelling: problems and prospects

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    Soil moisture storage is an important component of the hydrological cycle and plays a key role in land-surface-atmosphere interaction. The soil-moisture storage equation in this study considers precipitation as an input and soil moisture as a residual term for runoff and evapotranspiration. A number of models have been developed to estimate soil moisture storage and the components of the soil-moisture storage equation. A detailed discussion of the impli cation of the scale of application of these models reports that it is not possible to extrapolate processes and their estimates from the small to the large scale. It is also noted that physically based models for small-scale applications are sufficiently detailed to reproduce land-surface- atmosphere interactions. On the other hand, models for large-scale applications oversimplify the processes. Recently developed physically based models for large-scale applications can only be applied to limited uses because of data restrictions and the problems associated with land surface characterization. It is reported that remote sensing can play an important role in over coming the problems related to the unavailability of data and the land surface characterization of large-scale applications of these physically based models when estimating soil moisture storage.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Disease burden and costs from excess alcohol consumption, obesity, and viral hepatitis: fourth report of the Lancet Standing Commission on Liver Disease in the UK

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    © 2017 Elsevier Ltd. This report contains new and follow-up metric data relating to the eight main recommendations of the Lancet Standing Commission on Liver Disease in the UK, which aim to reduce the unacceptable harmful consequences of excess alcohol consumption, obesity, and viral hepatitis. For alcohol, we provide data on alcohol dependence, damage to families, and the documented increase in alcohol consumption since removal of the above-inflation alcohol duty escalator. Alcoholic liver disease will shortly overtake ischaemic heart disease with regard to years of working life lost. The rising prevalence of overweight and obesity, affecting more than 60% of adults in the UK, is leading to an increasing liver disease burden. Favourable responses by industry to the UK Government's soft drinks industry levy have been seen, but the government cannot continue to ignore the number of adults being affected by diabetes, hypertension, and liver disease. New direct-acting antiviral drugs for the treatment of chronic hepatitis C virus infection have reduced mortality and the number of patients requiring liver transplantation, but more screening campaigns are needed for identification of infected people in high-risk migrant communities, prisons, and addiction centres. Provision of care continues to be worst in regions with the greatest socioeconomic deprivation, and deficiencies exist in training programmes in hepatology for specialist registrars. Firm guidance is needed for primary care on the use of liver blood tests in detection of early disease and the need for specialist referral. This report also brings together all the evidence on costs to the National Health Service and wider society, in addition to the loss of tax revenue, with alcohol misuse in England and Wales costing £21 billion a year (possibly up to £52 billion) and obesity costing £27 billion a year (treasury estimates are as high as £46 billion). Voluntary restraints by the food and drinks industry have had little effect on disease burden, and concerted regulatory and fiscal action by the UK Government is essential if the scale of the medical problem, with an estimated 63 000 preventable deaths over the next 5 years, is to be addressed
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