1,055 research outputs found

    A novel topology of high-speed SRM for high-performance traction applications

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    A novel topology of high-speed Switched Reluctance Machine (SRM) for high-performance traction applications is presented in this article. The target application, a Hybrid Electric Vehicle (HEV) in the sport segment poses very demanding specifications on the power and torque density of the electric traction machine. After evaluating multiple alternatives, the topology proposed is a 2-phase axial flux machine featuring both segmented twin rotors and a segmented stator core. Electromagnetic, thermal and mechanical models of the proposed topology are developed and subsequently integrated in an overall optimisation algorithm in order to find the optimal geometry for the application. Special focus is laid on the thermal management of the machine, due to the tough thermal conditions resulting from the high frequency, high current and highly saturated operation. Some experimental results are also included in order to validate the modelling and simulation results

    Darcy's law without friction in active nematic rheology

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    Landfast ice controls on turbulence in Antarctic coastal seas

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    Knowledge of the ocean surface layer beneath Antarctic landfast ice is sparse. In this article surface layer turbulent and fine structure are quantified with and without landfast ice in the same West Antarctic Peninsula location. Landfast ice reduced turbulence levels locally to an order of magnitude less than ice-free values, and near-inertial energy and sub-inertial tidal energy levels to less than half their ice-free values. Vertical turbulent heat and nutrient fluxes were, respectively, 6 and 10 times greater than previously estimated. Under-ice tidal energy dissipation over the entire Antarctic continental shelf due to seasonal landfast ice cover is estimated at 788 MW. The total rate of wind-generated turbulence in the surface ocean is greatly reduced by the presence of seasonal landfast ice to an average of 14% of the ice-free value, but with large sectoral variations. Counter-intuitively, however, tides and wind contribute approximately equally to the turbulent kinetic energy budget of the upper ocean between the Antarctic coastline and the maximal landfast ice extent, with large sectoral variations, attributed to geographic variations in the strength of the barotropic tide

    Etiology, Immunopathogenesis and Biomarkers in Behçet’s disease

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    Behçet’s disease (BD) is a type of vasculitis with many distinctive clinical manifestations and multifactorial immunopathogenesis. The cause of BD remains unknown, but it has been postulated that in a genetically predisposed or susceptible population, exogenous agents trigger the dysregulation of both autoinflammatory and autoimmune responses resulting in multisystem vasculitis. There are robust ongoing efforts across the globe to elucidate and identify signature markers to improve and assist in rapid diagnosis of the disease and to tailor the best therapy accordingly. While association of human leukocyte antigen (HLA)-B*51 (B*51:01 subtype) allele is well recognized as the strongest genetic susceptibility gene so far among genetically predisposed BD patients, further investigations using the latest technology have led to the identification of several novel single nucleotide polymorphisms (SNPs) and other associated genes involved in the pathogenesis. There are several “established” cytokines known to be involved in the pathogenesis of BD, which have been further implicated in the genome-wide association studies (GWAS)-based cytokine/receptor gene loci studies, as well as numerous “novel” cytokines, which are currently being studied and identified. This chapter offers insights into current knowledge and thoughts regarding the future of biomarkers in BD

    Study of Mill Island ice core (East Antarctica): A sensitive site for high resolution ocean climate signals?

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    第2回極域科学シンポジウム 氷床コアセッション 11月16日(水) 国立極地研究所 2階大会議

    Polar maps of c-band backscatter parameters from the advanced scatterometer

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    Maps of backscatter anisotropy parameters from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Advanced Scatterometer (ASCAT), a C-band fan-beam scatterometer, contain unique and valuable data characterising the surface and subsurface of various cryospheric elements, including sea ice and ice sheets. The computational expense and considerable complexity required to produce parameter maps from the raw backscatter data inhibits the wider adoption of ASCAT data. Here, backscatter anisotropy parameter maps gridded at a resolution of 12.5 km per pixel are made available to the community in order to facilitate the exploitation of these parameters for cryospheric applications. These maps have been calculated from the EUMETSAT Level 1B Sigma0 product acquired from ASCAT on board MetOp-A, MetOp-B and MetOp-C. The dataset is unique in that it prioritises anisotropy characterisation over temporal resolution and combines ASCAT data from multiple platforms. The parameterisation chosen assumes a linear falloff of backscatter with incidence angle and a fourth-order Fourier series parameterisation of azimuth angle anisotropy. The product (Fraser and Cartwright, 2022) is available at https://doi.org/10.26179/91c9-4783 presented on three timescales depending on orbital platform availability: 5 d (2007 to 2020 – MetOp-A only – suitable for users requiring a long time series), 2 d (2013 to 2020 – MetOp-A and MetOp-B) and 1 d resolution (2019–2020 – MetOp -A, MetOp-B and MetOp-C – suitable for users needing both high temporal resolution and detailed anisotropy characterisation). Datasets will be updated annually
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