A comparison between able-bodied and wheelchair dependent individuals during manual wheelchair propulsion using a dynamometer

http://www.worldcat.org/oclc/3242761

The Hunt for the Rest of the Higgs Bosons

We assess the current state of searches at the LHC for additional Higgs bosons in light of both direct limits and indirect bounds coming from coupling measurements of the Standard Model-like Higgs boson. Given current constraints, we identify and study three LHC searches that are critical components of a comprehensive program to investigate extended electroweak symmetry breaking sectors: production of a heavy scalar or pseudoscalar with decay to $t \bar t$; $b \bar b$ and $t \bar t$ associated production of a heavy scalar or pseudoscalar with decay to invisible final states; and $t \bar b$ associated production of a charged Higgs with decay to $\bar t b$. Systematic experimental searches in these channels would contribute to robust coverage of the possible single production modes of additional heavy Higgs bosons.Comment: 44 pp., 23 fi

Flow through a very porous obstacle in a shallow channel

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence

Local blockage effect for wind turbines

This paper presents a combined theoretical and CFD study on the fluid-mechanical limit of power extraction by a closely-spaced lateral array of wind turbines. The idea of this study originates in recent studies on the array optimisation of tidal/marine turbines, for which the power coefficient of each turbine is known to increase significantly if the lateral spacing between turbines, or the local blockage, is optimised. The present study, using 3D Reynolds- averaged Navier-Stokes (RANS) simulations of a boundary-layer flow over a closely-spaced lateral array of up to 9 actuator discs, suggests that a similar—albeit less significant—power increase due to the effect of local blockage can be achieved even for wind turbines. A possible theoretical approach to estimating this power increase is also discussed

Quantitation of amino acids in diverse mammalian cell culture media types with the REBEL at-line analyzer

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Change Point Problem for Censored Data

Department of Probability and Mathematical StatisticsKatedra pravděpodobnosti a matematické statistikyMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

Observations of pumping and vortex dynamics due to a cylinder oscillating normal to a plane wall

Understanding the fluid dynamics associated with a circular cylinder oscillating normal to a plane wall is important for safe design of offshore infrastructure, such as power cables and pipeline risers. This paper investigates the fluid dynamics of an oscillating cylinder with no imposed incident current experimentally using flow visualisation and force measurements where the ratio of the cylinder Reynolds number (Re) to Keulegan–Carpenter number (KC) is β = 500 and KC varies between 2 and 12. The minimum distance between the cylinder and wall was between 12.5 % and 50 % of the diameter. Across this parameter space three primary vortex flow regimes were observed: (i) for KC ≤ 5, the flow field is approximately symmetric about the cylinder centreline and the velocity field between the cylinder and the wall resembled a pumping flow in phase with cylinder motion, which is well predicted by potential theory for most of the cycle; (ii) for 5 < KC < 8, the flow field is increasingly asymmetric but with frequent switching of the side associated with vortex shedding; and (iii) for KC ≥ 8, the flow field is consistently asymmetric due to vortex shedding. The in-line force increases when the cylinder is near the wall due to dynamic pressures associated with pumping. This increase can be estimated using potential theory superimposed onto the force time history for an isolated cylinder at the same KC and Re. This study complements recent numerical modelling focused on low Reynolds number conditions and provides important insights into the fluid mechanics associated with trenching beneath cable and pipeline risers