3,871 research outputs found

    Editorial: Throwing Shoes

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    Non-Gaussianity detections in the Bianchi VIIh corrected WMAP 1-year data made with directional spherical wavelets

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    Many of the current anomalies reported in the Wilkinson Microwave Anisotropy Probe (WMAP) 1-year data disappear after `correcting' for the best-fit embedded Bianchi type VII_h component (Jaffe et al. 2005), albeit assuming no dark energy component. We investigate the effect of this Bianchi correction on the detections of non-Gaussianity in the WMAP data that we previously made using directional spherical wavelets (McEwen et al. 2005a). As previously discovered by Jaffe et al. (2005), the deviations from Gaussianity in the kurtosis of spherical Mexican hat wavelet coefficients are eliminated once the data is corrected for the Bianchi component. This is due to the reduction of the cold spot at Galactic coordinates (l,b)=(209^\circ,-57\circ), which Cruz et al. (2005) claim to be the source of non-Gaussianity introduced in the kurtosis. Our previous detections of non-Gaussianity observed in the skewness of spherical wavelet coefficients are not reduced by the Bianchi correction. Indeed, the most significant detection of non-Gaussianity made with the spherical real Morlet wavelet at a significant level of 98.4% remains (using a very conservative method to estimate the significance). We make our code to simulate Bianchi induced temperature fluctuations publicly available.Comment: 11 pages, 8 figures, replaced to match version accepted by MNRA

    Task 7 space storable propellant module environmental control technology

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    Design of thermal control system for cryogenic fluid storage tank

    Task 3 space storable propellant module environmental control technology Summary report

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    Thermal control system for space storable propellant modul

    Exploring educators’ understanding of developing learners’ reading skills and their readiness to implement CAPS

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    This study explored what three Intermediate Phase English First Additional Language teachers understood about reading and teaching reading, and the strategies they used to develop learners’ reading skills. Data gathered through interviews and observations of classroom practice were used to consider the extent of their readiness to achieve the aims implicit in the Curriculum and Assessment Policy Statement (CAPS). It was found that these educators understand reading primarily as the oral performance of decoding text to speech, and view comprehension as a separate and restricted entity; also, limitations in their understanding of comprehension processes involved in reading impeded their readiness to implement CAPS. Shortcomings in educators’ schooling experiences, training and professional development were considered with a view to informing future teacher training and workshops. This study formed part of a university led research project which investigated well-documented indications of poor development of literacy skills in South African schools.Keywords: Curriculum and Assessment Policy Statement (CAPS), Decoding, Interactive models of reading, Intermediate Phase (IP), Reading skills, Annual National Assessment (ANA)

    Space storable propellant module thermal control technology. Volume 2 - F2/N2H4 propulsion module Summary report

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    Space storable fluorine/hydrazine tank module thermal control design for Jupiter missio

    Genus Topology of the Cosmic Microwave Background from the WMAP 3-Year Data

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    We have independently measured the genus topology of the temperature fluctuations in the cosmic microwave background seen in the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data. A genus analysis of the WMAP data indicates consistency with Gaussian random-phase initial conditions, as predicted by standard inflation. We set 95% confidence limits on non-linearities of -101 < f_{nl} < 107. We also find that the observed low l (l <= 8) modes show a slight anti-correlation with the Galactic foreground, but not exceeding 95% confidence, and that the topology defined by these modes is consistent with that of a Gaussian random-phase distribution (within 95% confidence).Comment: MNRAS LaTeX style (mn2e.cls), EPS and JPEG figure

    The effect of thermophoresis on the discharge parameters in complex plasma experiments

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    Thermophoresis is a tool often applied in complex plasma experiments. One of the usual stated benefits over other experimental tools is that changes induced by thermophoresis neither directly depend on, nor directly influence, the plasma parameters. From electronic data, plasma emission profiles in the sheath, and Langmuir probe data in the plasma bulk, we conclude that this assumption does not hold. An important effect on the levitation of dust particles in argon plasma is observed as well. The reason behind the changes in plasma parameters seems to be the change in neutral atom density accompanying the increased gas temperature while running at constant pressure.Comment: 14 pages, 12 figure

    Task 6 storable propellant module environmental control technology Summary report

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    Thermal control concepts for space storable fluorine hydrazine propulsion modul
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