1,883 research outputs found

    Estimation of hand and finger kinematics using inertial sensors

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    A new dataglove is developed and presented. Inertial sensors are placed on various hand and finger segments to estimate the hand pose

    Final results from the EU project AVATAR: aerodynamic modelling of 10 MW wind turbines

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    This paper presents final results from the EU project AVATAR in which aerodynamic models are improved and validated for wind turbines on a scale of 10 MW and more. Special attention is paid to the improvement of low fidelity engineering (BEM based) models with higher fidelity (CFD) models but also with intermediate fidelity free vortex wake (FVW) models. The latter methods were found to be a good basis for improvement of induction modelling in engineering methods amongst others for the prediction of yawed cases, which in AVATAR was found to be one of the most challenging subjects to model. FVW methods also helped to improve the prediction of tip losses. Aero-elastic calculations with BEM based and FVW based models showed that fatigue loads for normal production cases were over predicted with approximately 15% or even more. It should then be realised that the outcome of BEM based models does not only depend on the choice of engineering add-ons (as is often assumed) but it is also heavily dependent on the way the induced velocities are solved. To this end an annulus and element approach are discussed which are assessed with the aid of FVW methods. For the prediction of fatigue loads the so-called element approach is recommended but the derived yaw models rely on an annulus approach which pleads for a generalised solution method for the induced velocities

    Latest results from the EU project AVATAR: aerodynamic modelling of 10 MW wind turbines

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    This paper presents the most recent results from the EU project AVATAR in which aerodynamic models are improved and validated for wind turbines on a scale of 10 MW and more. Measurements on a DU 00-W-212 airfoil are presented which have been taken in the pressurized DNW-HDG wind tunnel up to a Reynolds number of 15 Million. These measurements are compared with measurements in the LM wind tunnel for Reynolds numbers of 3 and 6 Million and with calculational results. In the analysis of results special attention is paid to high Reynolds numbers effects. CFD calculations on airfoil performance showed an unexpected large scatter which eventually was reduced by paying even more attention to grid independency and domain size in relation to grid topology. Moreover calculations are presented on flow devices (leading and trailing edge flaps and vortex generators). Finally results are shown between results from 3D rotor models where a comparison is made between results from vortex wake methods and BEM methods at yawed conditions

    Analysis of factors relating to pet rabbits relinquished to two UK re-homing centres

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    Rabbits are a common companion animal in the UK and some reports suggest that large numbers are relinquished to re-homing centres each year. This study aimed to investigate the characteristics of rabbits relinquished to two UK re-homing centres and explore reasons given for relinquishment. The centres contributed data for all rabbits that entered their centre during 2013 (n=205). Most rabbits (59.5%) were relinquished by an owner. A similar number of males to females were relinquished and a larger number of rabbits were not neutered (72.4%) and adults (56%). Most rabbits were healthy on arrival (61.5%). The most common reasons for relinquishment were: too many rabbits / unplanned litters (30.3%) and housing problems (23.8%). Rabbit related reasons accounted for 12.2% of rabbits relinquished. Reasons for relinquishment were associated with one of the recorded rabbit characteristics. Further detailed studies are needed to explore the dynamics of pet rabbit ownership and factors that affect the breakdown of rabbit-owner relationships in the UK

    Near-Threshold eta Meson Production in Proton-Proton Collisions

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    The production of eta mesons has been measured in the proton-proton interaction close to the reaction threshold using the COSY-11 internal facility at the cooler synchrotron COSY. Total cross sections were determined for eight different excess energies in the range from 0.5 MeV to 5.4 MeV. The energy dependence of the total cross section is well described by the available phase-space volume weighted by FSI factors for the proton-proton and proton-eta pairs.Comment: 9 pages, 1 table, 5 figure

    Total and Differential Cross Sections for the pp-->pp eta-prime Reaction Near Threshold

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    The eta-prime meson production in the reaction pp-->pp eta-prime has been studied at excess energies of Q = 26.5, 32.5 and 46.6 MeV using the internal beam facility COSY-11 at the cooler synchrotron COSY. The total cross sections as well as one angular distribution for the highest Q-value are presented. The excitation function of the near threshold data can be described by a pure s-wave phase space distribution with the inclusion of the proton-proton final state interaction and Coulomb effects. The obtained angular distribution of the eta-prime mesons is also consistent with pure s-wave production.Comment: 6 pages, 5 figures, submitted to Eur. Phys. J.
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