245 research outputs found

    Recruitment, use, and satisfaction with a web platform supporting families of children with suspected or diagnosed developmental coordination disorder: A randomized feasibility trial

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    Objectives. To determine the feasibility of recruiting families of children with suspected or diagnosed developmental coordination disorder (sdDCD) and explore their satisfaction with a web-based intervention Design. A feasibility randomized trial was conducted. Participants were the parents of 5-12-year-old children with sdDCD. The intervention group had access to online resources, group and private forums, and videoconferencing with a therapist. Main outcomes were recruitement and retention rates. Satisfaction was documented through a post-intervention survey and interview. Results. The recruitment rate was seven participants per month (n = 28 participants) and retention rate was 68%. Satisfaction was moderate. No differences in use and satisfaction were observed between groups. Participants formulated recommendations for improving the intervention, including targeting families earlier in the diagnosis process, and pre-scheduling meetings with therapists. Conclusions. This study demonstrated the feasibility of future trials, and highlighted avenues for improvement. Parent involvement during the development of the intervention is discussed at length. Abbreviations: DCD: Developmental Coordination Disorder; sdDCD: suspected or diagnosed Developmental Coordination Disorder; RCT: randomized-controled trial

    Mixing in Circular and Non-circular Jets in Crossflow

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    Coherent structures and mixing in the flow field of a jet in crossflow have been studied using computational (large eddy simulation) and experimental (particle image velocimetry and laser-induced fluorescence) techniques. The mean scalar fields and turbulence statistics as determined by both are compared for circular, elliptic, and square nozzles. For the latter configurations, effects of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane can be single- or double-peaked, depending on the nozzle shape and orientation. A proper orthogonal decomposition of the transverse velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the case for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which implies failure of the gradient diffusion hypothesis

    Characterization of an Ionization Readout Tile for nEXO

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    A new design for the anode of a time projection chamber, consisting of a charge-detecting "tile", is investigated for use in large scale liquid xenon detectors. The tile is produced by depositing 60 orthogonal metal charge-collecting strips, 3~mm wide, on a 10~\si{\cm} ×\times 10~\si{\cm} fused-silica wafer. These charge tiles may be employed by large detectors, such as the proposed tonne-scale nEXO experiment to search for neutrinoless double-beta decay. Modular by design, an array of tiles can cover a sizable area. The width of each strip is small compared to the size of the tile, so a Frisch grid is not required. A grid-less, tiled anode design is beneficial for an experiment such as nEXO, where a wire tensioning support structure and Frisch grid might contribute radioactive backgrounds and would have to be designed to accommodate cycling to cryogenic temperatures. The segmented anode also reduces some degeneracies in signal reconstruction that arise in large-area crossed-wire time projection chambers. A prototype tile was tested in a cell containing liquid xenon. Very good agreement is achieved between the measured ionization spectrum of a 207^{207}Bi source and simulations that include the microphysics of recombination in xenon and a detailed modeling of the electrostatic field of the detector. An energy resolution σ/E\sigma/E=5.5\% is observed at 570~\si{keV}, comparable to the best intrinsic ionization-only resolution reported in literature for liquid xenon at 936~V/\si{cm}.Comment: 18 pages, 13 figures, as publishe
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