23,186 research outputs found
The ₅C₅ Survey of Radio Sources
The ₅C₅ survey, made with the Cambridge One-Mile telescope, covers an area about 4° in diameter at 408 MHz centred at α = 09ʰ40ᵐ,δ = 47∘00′ to a limiting flux density of 8⋅7 × 10⁻²⁹ Wm⁻² Hz⁻¹ at the centre, and a concentric area of diameter about 1° at 1407 MHz to a limiting flux density of 1⋅8×10−29Wm−2Hz−1. The positions and flux densities of 230 sources observed at 408 MHz, and of 52 observed at I407 MHz, are listed in Table I, with suggested optical identifications for some of the sources. The flux density and spectral index distributions are similar to those of the earlier ₅C surveys and there is no evidence for significant anisotropy in either distribution. New observations of some ₅C I sources included in the ₅C₅ survey show that the flux densities measured in ₅C I were in error
The 5C 6 and 5C 7 surveys of radio sources
5C 6 and 5C 7 continue the series of deep surveys made at 408 and 1407 MHz with the One-Mile telescope at Cambridge. They were intended (1) to provide a sample of faint radio sources suitable for further study; (2) to improve the statistics of source counts N(S) and spectral-index distributions at low flux densities; (3) to study the isotropy of the distribution of faint sources. Each observed field is about 4° in diameter at 408 MHz and 1° in diameter at 1407 MHz, and the field-centres are a α = 02ʰ14ᵐ, δ = 32° (5C 6) and α = 08ᵏ17ᵐ, δ = 27° (5C 7). The synthesized beamwidths (FWHM) are 80 arcsec (408 MHz) and 23 arcsec (1407 MHz). The techniques of observation and data-analysis followed closely those used for 5C 5 (Pearson, T. J., 1975. Mon. Not. R. astr. Soc., 171, 475), with some minor variations which are noted in Section 2
A finite element modelling methodology for the non-linear stiffness evaluation of adhesively bonded single lap-joints. Part 2, Novel shell mesh to minimise analysis time
A new modelling methodology is presented that enables the stiffness of adhesively bonded single lap-joints to be included in the finite element analysis of whole vehicle bodies. This work was driven by the need to significantly reduce computing resources for vehicle analysis. To achieve this goal the adhesive bond line and adherends are modelled by a relatively ‘small’ number of shell elements to replace the usual solid element mesh for a reliable analysis. Previous work in Part 1 has provided the necessary background information to develop and verify the new finite element analysis that reduces the solution runtime by a factor of 1000. Although a joint’s non-linear stiffness is reliably simulated to failure load, it is recognised by the authors that the coarse shell mesh cannot provide accurate peak stresses or peak strains for the successful application of a numerical failure criterion. Given that the new modelling methodology is very quick to apply to existing shell models of vehicle bodies, it is recommended for use by the stress analyst who requires, say at the preliminary design stage, whole vehicle stiffness performance in a significantly reduced timeframe
SPAR improved structure/fluid dynamic analysis capability
The capability of analyzing a coupled dynamic system of flowing fluid and elastic structure was added to the SPAR computer code. A method, developed and adopted for use in SPAR utilizes the existing assumed stress hybrid plan element in SPAR. An operational mode was incorporated in SPAR which provides the capability for analyzing the flaw of a two dimensional, incompressible, viscous fluid within rigid boundaries. Equations were developed to provide for the eventual analysis of the interaction of such fluids with an elastic solid
Variation of Radio Source Counts with Direction, for the 3CR and 4C Surveys
In an investigation of variations with direction of the radio source counts N(S) for the 3CR and 4C surveys, no anisotropy has been found which is not explicable in terms of random statistical differences between limited samples of sources; in particular, there is no significant difference between the slopes of the source counts in the northern and southern galactic hemispheres
The ₅C₅ Survey of Radio Sources
The ₅C₅ survey, made with the Cambridge One-Mile telescope, covers an area about 4° in diameter at 408 MHz centred at α = 09ʰ40ᵐ,δ = 47∘00′ to a limiting flux density of 8⋅7 × 10⁻²⁹ Wm⁻² Hz⁻¹ at the centre, and a concentric area of diameter about 1° at 1407 MHz to a limiting flux density of 1⋅8×10−29Wm−2Hz−1. The positions and flux densities of 230 sources observed at 408 MHz, and of 52 observed at I407 MHz, are listed in Table I, with suggested optical identifications for some of the sources. The flux density and spectral index distributions are similar to those of the earlier ₅C surveys and there is no evidence for significant anisotropy in either distribution. New observations of some ₅C I sources included in the ₅C₅ survey show that the flux densities measured in ₅C I were in error
Variation of Radio Source Counts with Direction, for the 3CR and 4C Surveys
In an investigation of variations with direction of the radio source counts N(S) for the 3CR and 4C surveys, no anisotropy has been found which is not explicable in terms of random statistical differences between limited samples of sources; in particular, there is no significant difference between the slopes of the source counts in the northern and southern galactic hemispheres
The role of physical activity during pregnancy in determining maternal and foetal outcomes
Background. A woman’s health status prior to, and during, pregnancy has been shown to influence maternal and foetal health outcomes, and therefore healthy behaviours should be encouraged to optimise weight gain during pregnancy. Discussion. Pre-gravid overweight and obesity, and excessive weight gain during pregnancy, are associated with several adverse pregnancy outcomes for the mother and the foetus. Despite the fact that physical activity during pregnancy reduces the risk of excessive gestational weight gain, physical activity levels typically decline during pregnancy. Several factors have been shown to influence physical activity during pregnancy, and preliminary data is available on identifying these factors in South African women. Conclusion. Very little is known about physical activity patterns in pregnant South African women in whom overweight and obesity is prevalent. Examining these patterns, as well as the barriers and facilitators of physical activity in this population will assist in informing future interventions. Keywords. South Africa, obesity, barriers, intervention
A New Component in the Radio Continua of PNe
A byproduct of experiments designed to map the CMB is the recent detection of a new component of foreground galactic emission. The anomalous foreground at 10–30 GHz, unexplained by traditional emission mechanisms, correlates with 100 mum dust emission, and is thus presumably due to dust.Is the anomalous foreground ubiquitous in the Galaxy? I will present evidence obtained with the CBI and SIMBA+SEST supporting the existence of the new component in the ISM at large, and in specific objects, in the form of a 31 GHz excess over free-free emission in PNe
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