Anna, the Tale Bearer

Cover title.Originally published in 1807, as number 4 in a series entitled The Magic Lantern (Welch 1153). 12 pages, [1] leave of plates: illustrations; 17 cmhttps://digitalcommons.georgefox.edu/quakerbooks/1035/thumbnail.jp

The design, implementation and evaluation of mass conferencing

There have been attempts to classify and analyse the approaches and techniques of using videoconferencing for teaching and learning. Most classifications include the use of videoconferencing techniques to support lecture‐style delivery to large audiences, or what might be referred to as ‘mass conferencing’. This is often dismissed by sceptics as another gimmick: the real thing is better, or it may be viewed as simply just another didactic approach with little to commend it either in the form of communication or in pedagogical terms. However, the key element in its use is the context within which the mass conferencing is being applied Whatever videoconferencing approaches are employed, it is our view that their successful implementation implies both a clearly defined structure and an operational template. Thus, this paper underlines some of the processes which we have used in mass conferencing. We then evaluate the outcomes, and identify, some themes to be incorporated in successful mass conferencing, including the key factors involved in successful delivery, namely in the preparation, activity, and evaluation stages. In operational terms, the introduction of an external element, beyond the control of course tutors, has highlighted many organizational, pedagogical and technical questions, some of which we address

Effect of Mach number on the structure of turbulent spots

Direct numerical simulations have been performed to study the dynamics of isolated turbulent spots in compressible isothermal-wall boundary layers. Results of a bypass transition scenario at Mach 2, 4 and 6 are presented. At all Mach numbers the evolved spots have a leading-edge overhang, followed by a turbulent core and a calmed region at the rear interface. The spots have an upstream-pointing arrowhead shape when visualized by near-wall slices, but a downstream-pointing arrowhead in slices away front the wall. The lateral spreading of the spot decreases substantially with the Mach number, consistent with a growth mechanism based on the instability of lateral shear layers. Evidence for a supersonic (Mach) mode substructure is found in the Mach 6 case, where coherent spanwise structures are observed under the spot overhang region

Direct numerical simulation of 'short' laminar separation bubbles with turbulent reattachment

Direct numerical simulation of the incompressible Navier–Stokes equations is used to study flows where laminar boundary-layer separation is followed by turbulent reattachment forming a closed region known as a laminar separation bubble. In the simulations a laminar boundary layer is forced to separate by the action of a suction profile applied as the upper boundary condition. The separated shear layer undergoes transition via oblique modes and [Lambda]-vortex-induced breakdown and reattaches as turbulent flow, slowly recovering to an equilibrium turbulent boundary layer. Compared with classical experiments the computed bubbles may be classified as ‘short’, as the external potential flow is only affected in the immediate vicinity of the bubble. Near reattachment budgets of turbulence kinetic energy are dominated by turbulence events away from the wall. Characteristics of near-wall turbulence only develop several bubble lengths downstream of reattachment. Comparisons are made with two-dimensional simulations which fail to capture many of the detailed features of the full three-dimensional simulations. Stability characteristics of mean flow profiles are computed in the separated flow region for a family of velocity profiles generated using simulation data. Absolute instability is shown to require reverse flows of the order of 15–20%. The three-dimensional bubbles with turbulent reattachment have maximum reverse flows of less than 8% and it is concluded that for these bubbles the basic instability is convective in nature

Achieving a model for improving medical devices management policy

Hospitals have always faced fundamental questions of patient safety, care, and budgetary concerns. There has been increasing recognition recently of the serious issue of medical devices management, covering the areas of procurement, training, maintenance, and governance. This issue, documented by the National Audit Office, National Patient Safety Agency, Medicines and Healthcare Products Regulatory Agency, National Health Service Litigation Authority, and World Health Organisation, impacts on healthcare costs and patient safety. It has led to new Health and Social Care Act Regulations, enforced by the Care Quality Commission. As a result of my work as a consultant in the field of medical devices management, I constructed a policy model based on my own specialist experience and knowledge. This research sought to improve that model through participatory research conducted at an NHS Hospital in London. It took the form of a case study that specifically explored the core policy areas, but this time in collaboration with participants with expertise in one or more of the four interrelated policy areas of procurement, training, maintenance, and governance. This collaboration involved researching and analysing the external demands from regulatory agencies and internal demands from the organisation, centred on procurement, budgetary, and policy issues. The action research informed changes in policy, especially around procurement, leading to improvements in practice. The challenge of keeping policy up to date, and consistent with the external regulations and internal operational demands, is discussed in the case study. The Hospital’s internal politics and culture were found to be a help when starting up the case study, but a hindrance when it came to getting agreement and approvals to change the policy content, because of multiple committees and competing interests. The overall outcome of the project was an organisationally approved best practice policy model for medical devices management within a governance framework that meets the needs of the external regulators, and the management of the organisation. More specifically it was discovered that the use, maintenance, and governance of medical equipment were all reliant on a central issue, namely procurement practice. Procurement conduct for the organisation was redefined within the Hospital policy, and is making training, maintenance, and governance easier to achieve, thereby reducing risk and cost. A major consequence is that all budget holders need to be trained in procurement itself. Moreover, it is anticipated that the model could be used at similar healthcare organisations, ultimately leading to a contribution to knowledge and practice which assists in patient safety and meeting budgets

Embedded direct numerical simulation for aeronautical CFD

AbstractA method is proposed by which a direct numerical simulation of the compressible Navier-Stokes equations may be embedded within a more general aeronautical CFD code. The method may be applied to any code which solves the Euler equations or the Favre-averaged Navier-Stokes equations. A formal decomposition of the flowfield is used to derive modified equations for use with direct numerical simulation solvers. Some preliminary applications for model flows with transitional separation bubbles are given.</jats:p

Viscous instability of a compressible round jet

The compressible linear stability equations are derived from the Navier Stokes equations in cylindrical polar coordinates. Numerical solutions for locally parallel flow are found using a direct matrix method. Discretization with compact finite difference is found to have better convergence properties than a Chebyshev spectral method for a round jet test case. The method is validated against previous results and convergence is tested for a range of jet profiles. Finally and en method is used to determine the dominant frequency of a Mach 0.9 jet

A modification of Amiet's classical trailing edge noise theory for strictly two dimensional flows

The aim of this report is to derive theoretical expressions for the far-field pressure generated by disturbances convecting over a trailing edge. First, a general calculation of thefar-field pressure is discussed. Then the classical theory of Amiet (1976b) is reviewed,listing the most relevant assumptions. Amiet's theory is then revised for two-dimensional flows