3,871 research outputs found
Non-Gaussianity detections in the Bianchi VIIh corrected WMAP 1-year data made with directional spherical wavelets
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
Design of thermal control system for cryogenic fluid storage tank
Task 3 space storable propellant module environmental control technology Summary report
Thermal control system for space storable propellant modul
Exploring educators’ understanding of developing learners’ reading skills and their readiness to implement CAPS
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
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
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
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
Thermal control concepts for space storable fluorine hydrazine propulsion modul
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