9,734 research outputs found

    Computational Modelling of Wing Downwash Profile with Reynolds-Averaged and Delayed Detached-Eddy Simulations

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    This paper describes the computational model to predict downwash for a conventional fixed wing configuration at flight scales (ReMAC = 2.26 × 107 ). The lack of resolution in the downwash wake region resulted in an over-dissipation of the turbulent behaviour of airflow in the wing’s wake. This artificially inflates the effectiveness of the horizontal stabilizer where an over-prediction of pitch stiffness was observed. To resolve this over-dissipation, both the Reynolds-Averaged and Delayed Detached-Eddy Simulation methodology were adopted to accurately capture the downwash profile leaving the wing. Comparisons between the estimation of wall shear stresses and viscous wall unit against a ‘first-cut’ simulation are made and discussed. Fundamental features of the downwash profile including the spatial and temporal scales used for the mesh are also presented and detailed in this paper

    Improving access to health services – Challenges in Lean application

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    Purpose: Healthcare organisations face significant productivity pressures and are undergoing major service transformation. This paper serves to disseminate findings from a Lean healthcare project using a NHS Single Point of Access environment as the case study. It demonstrates the relevance and extent that Lean can be applied to this type of healthcare service setting. Design/methodology/approach: Action research was applied and Lean tools used to establish current state processes, identify wastes and develop service improvement opportunities based upon defined customer values. Findings: The quality of referral information was found to be the root cause of a number of process wastes and causes of failure for the service. Understanding the relationship and the nature of interaction between the service‟s customer/supplier led to more effective and sustainable service improvement opportunities and the co-creation of value. It was also recognised that not all the Lean principles could be applied to this type of healthcare setting. Practical implications: The study is useful to organisations using Lean to undertake service improvement activities. The paper outlines how extending the value stream beyond the organisation to include suppliers can lead to improved co-production and generation of service value. Originality/value: The study contributes to service productivity research by demonstrating the relevance and limitations of Lean application in a new healthcare service setting. The case study demonstrates the practical challenges of implementing Lean in reciprocal service design models and adds validity to existing contextual models

    An Asymptotic Preserving Maxwell Solver Resulting in the Darwin Limit of Electrodynamics

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    In plasma simulations, where the speed of light divided by a characteristic length is at a much higher frequency than other relevant parameters in the underlying system, such as the plasma frequency, implicit methods begin to play an important role in generating efficient solutions in these multi-scale problems. Under conditions of scale separation, one can rescale Maxwell's equations in such a way as to give a magneto static limit known as the Darwin approximation of electromagnetics. In this work, we present a new approach to solve Maxwell's equations based on a Method of Lines Transpose (MOLT^T) formulation, combined with a fast summation method with computational complexity O(Nlog⁥N)O(N\log{N}), where NN is the number of grid points (particles). Under appropriate scaling, we show that the proposed schemes result in asymptotic preserving methods that can recover the Darwin limit of electrodynamics

    Lean Thinking: Theory, Application and Dissemination

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    This book was written and compiled by the University of Huddersfield to share the learnings and experiences of seven years of Knowledge Transfer Partnership (KTP) and Economic and Social Research Council (ESRC) funded projects with the National Health Service (NHS). The focus of these projects was the implementation of Lean thinking and optimising strategic decision making processes. Each of these projects led to major local improvements and this book explains how they were achieved and compiles the lessons learnt. The book is split into three chapters; Lean Thinking Theory, Lean Thinking Applied and Lean Thinking Dissemination

    Translational aspects of cardiac cell therapy.

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    Cell therapy has been intensely studied for over a decade as a potential treatment for ischaemic heart disease. While initial trials using skeletal myoblasts, bone marrow cells and peripheral blood stem cells showed promise in improving cardiac function, benefits were found to be short-lived likely related to limited survival and engraftment of the delivered cells. The discovery of putative cardiac 'progenitor' cells as well as the creation of induced pluripotent stem cells has led to the delivery of cells potentially capable of electromechanical integration into existing tissue. An alternative strategy involving either direct reprogramming of endogenous cardiac fibroblasts or stimulation of resident cardiomyocytes to regenerate new myocytes can potentially overcome the limitations of exogenous cell delivery. Complimentary approaches utilizing combination cell therapy and bioengineering techniques may be necessary to provide the proper milieu for clinically significant regeneration. Clinical trials employing bone marrow cells, mesenchymal stem cells and cardiac progenitor cells have demonstrated safety of catheter based cell delivery, with suggestion of limited improvement in ventricular function and reduction in infarct size. Ongoing trials are investigating potential benefits to outcome such as morbidity and mortality. These and future trials will clarify the optimal cell types and delivery conditions for therapeutic effect

    The effects of devaluation on the balance of trade :

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    Elliptic Genera and 3d Gravity

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    We describe general constraints on the elliptic genus of a 2d supersymmetric conformal field theory which has a gravity dual with large radius in Planck units. We give examples of theories which do and do not satisfy the bounds we derive, by describing the elliptic genera of symmetric product orbifolds of K3K3, product manifolds, certain simple families of Calabi-Yau hypersurfaces, and symmetric products of the "Monster CFT." We discuss the distinction between theories with supergravity duals and those whose duals have strings at the scale set by the AdS curvature. Under natural assumptions we attempt to quantify the fraction of (2,2) supersymmetric conformal theories which admit a weakly curved gravity description, at large central charge.Comment: 50 pages, 9 figures, v2: minor corrections to section
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