3,018 research outputs found

    Non-Newtonian and flow pulsatility effects in simulation models of a stented intracranial aneurysm

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    Permission to redistribute provided by publishers.Three models of different stent designs implanted in a cerebral aneurysm, originating from the Virtual Intracranial Stenting Challenge'07, are meshed and the flow characteristics simulated using commercial computational fluid dynamics (CFD) software in order to investigate the effects of non-Newtonian viscosity and pulsatile flow. Conventional mass inflow and wall shear stress (WSS) output are used as a means of comparing the cfd simulations. In addition, a WSS distribution is presented, which clearly discriminates in favour of the stent design identified by other groups. It is concluded that non-Newtonian and pulsatile effects are important to include in order to avoid underestimating wss, to understand dynamic flow effects, and to discriminate more effectively between stent designs. © Authors 2011

    Enhanced visualisation of complex thermofluid data: Vertical and horizontal combined convection and microscale heat transfer cases

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    Copyright @ 2000 UITIn general, convective heat transfer is an 'n-dimensional' problem where n is well in excess of 3 for steady flows. Traditionally, the method of dimensional analysis results in a small number of dimensionless groups. In the case of steady forced convection these can reduce to three, namely the Nusselt (Nu), Reynolds (Re) and Prandtl (Pr) numbers, for heat transfer, fluid flow regime and fluid properties respectively. Again, traditionally, data are presented on log-log graphs, say of Nu versus Re, with Pr being a possible third parameter. For natural convection, the Grashof number (Gr) expresses buoyancy effects in place of Re, while for combined (natural and forced) convection Gr becomes additional to, rather than replacing, Re. Using sets of data for: (a) vertical combined convection in nuclear safety, (b) horizontal combined convection review material, and (c) microchannel heat transfer, in the first part of this paper we survey this problem. We reach the following conclusions: that heat transfer data are presented in either 'holistic' or 'reductive' modes, and that other thermodynamic performance data are related to the generic scientific cases of (a) 3-dimensional space and (b) multi-dimensional space. In the second part of the paper we present a first attempt at applying design-type procedures to specifying this problem. Visualisation priorities are suggested from which particular solutions will be developed in future

    Canadian Literature: European Perspective

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    Unexpected Au Alloying in Tailoring In-Doped SnTe Nanostructures with Gold Nanoparticles

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    Materials with strong spin-orbit interaction and superconductivity are candidates for topological superconductors that may host Majorana fermions (MFs) at the edges/surfaces/vortex cores. Bulk-superconducting carrier-doped topological crystalline insulator, indium-doped tin telluride (In-SnTe) is one of the promising materials. Robust superconductivity of In-SnTe nanostructures has been demonstrated recently. }Intriguingly, not only 3-dimensional (3D) nanostructures but also ultra-thin quasi-2D and quasi-1D systems can be grown by the vapor transport method. In particular, nanostructures with a controlled dimension will give us a chance to understand the dimensionality and the quantum confinement effects on the superconductivity of the In-SnTe and may help us work on braiding MFs in various dimensional systems for future topological quantum computation technology. With this in mind, we employed gold nanoparticles (GNPs) with well-identified sizes to tailor In-SnTe nanostructures grown by vapor transport. However, we could not see clear evidence that the presence of the GNPs is necessary or sufficient to control the size of the nanostructures. Nevertheless, it should be noted that a weak correlation between the diameter of GNPs and the dimensions of the smallest nanostructures has been found so far. To our surprise, the ones grown under the vapor--liquid--solid mechanism, with the use of the GNPs, contained gold that is widely and inhomogeneously distributed over the whole body

    What do we need to consider when planning, implementing and researching the use of alternatives to face-to-face consultations in primary healthcare?

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    Objectives: Communications technologies are variably utilised in healthcare. Policymakers globally have espoused the potential benefits of alternatives to face-to-face consultations, but research is in its infancy. The aim of this essay is to provide thinking tools for policymakers, practitioners and researchers who are involved in planning, implementing and evaluating alternative forms of consultation in primary care. Methods: We draw on preparations for a focussed ethnographic study being conducted in eight general practice settings in the UK, knowledge of the literature, qualitative social science and Cochrane reviews. In this essay we consider different types of patients, and also reflect on how the work, practice and professional identities of different members of staff in primary care might be affected. Results: Elements of practice are inevitably lost when consultations are no longer face-to-face, and we know little about the impact on core aspects of the primary care relationship. Resistance to change is normal and concerns about the introduction of alternative methods of consultation are often expressed using proxy reasons; for example, concerns about patient safety. Any planning or research in the field of new technologies should be attuned to the potential for unintended consequences. Conclusions: Implementation of alternatives to the face-to-face consultation is more likely to succeed if approached as co-designed initiatives that start with the least controversial and most promising changes for the practice. Researchers and evaluators should explore actual experiences of the different consultation types amongst patients and the primary care team rather than hypothetical perspectives

    Fiduciary Principles: Corporate Responsibilities to Stakeholders

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    The recent corporate scandals and financial crisis has increased demand for accountability in business decisions. Corporate governance reform initiatives designed to increase financial disclosure and responsibility are insufficient to rebuild public trust in business. Corporate boards and officers must comply with the legal norms to which they are already subject; as fiduciaries they have duties of care, loyalty and good faith. This article examines modern fiduciary duties that currently govern corporate conduct and thus severely limit corporate responsibility. Revisiting the historical and religious origins of fiduciaries that shaped the ethical and moral duties gives insight into the true role of a fiduciary. We propose a new, well-defined definition of fiduciary duties that could offer corporate managers guidance in developing new stakeholder relationships

    1.5 °C pathways for the Global Industry Classification (GICS) sectors chemicals, aluminium, and steel.

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    To achieve the goals of the Paris Climate Agreement, decarbonization targets and benchmarks for specific industry sectors are required. This opens up a whole new research area for energy modelling because although decarbonization pathways have been developed for countries, regions, or communities, few have been developed for industry sectors. In this research, we document the development of energy scenarios for industry sectors classified under the Global Industry Classification Standard (GICS). A bottom-up energy demand analysis based on market projections for the chemical, aluminium, and steel industries forms the basis for scenario development, with the aim of completely decarbonizing the electricity and process heat supplies for these industries by 2050. We document the individual steps in the energy demand analyses based on industry-specific market projections and energy intensities. In the last step, the carbon budget is calculated. The complete decarbonization of the industries analysed seems possible based on the available technology. Supplementary Information: The online version contains supplementary material available at 10.1007/s42452-022-05004-0
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