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We present maps of the artificial sky brightness in Europe in V band with a resolution of ~1 km. The aim is to understand the state of night sky pollution in Europe, to quantify the present situation and to allow future monitoring of trends. For each terrestrial site the artificial sky brightness in a given direction on the sky is obtained by integrating the contributions from each surface area in the surroundings, using detailed models of the propagation in the atmosphere of the upward light flux emitted by the area. The top-of-atmosphere light flux is measured by the Operational Linescan System of the Defence Meteorological Satellite Program (DMSP) satellites. The modelling technique, which was introduced and developed by Garstang, takes into account the extinction along light paths, double scattering of light from atmospheric molecules and aerosols, and Earth curvature. Use of this technique allows us to assess the aerosol content of the atmosphere.
Large surveys of the local Universe have shown that galaxies with different intrinsic properties such as colour, luminosity and morphological type display a range of clustering amplitudes. Galaxies are therefore not faithful tracers of the underlying matter distribution. This modulation of galaxy clustering, called bias, contains information about the physics behind galaxy formation. It is also a systematic to be overcome before the large-scale structure of the Universe can be used as a cosmological probe. Two types of approaches have been developed to model the clustering of galaxies. The first class is empirical and filters or weights the distribution of dark matter to reproduce the measured clustering. In the second approach, an attempt is made to model the physics which governs the fate of baryons in order to predict the number of galaxies in dark matter haloes. I will review the development of both approaches and summarise what we have learnt about galaxy bias.
The future of centimetre and metre-wave astronomy lies with the Square Kilometre Array (SKA), a telescope under development by a consortium of 17 countries that will be 50 times more sensitive than any existing radio facility. Most of the key science for the SKA will be addressed through large-area imaging of the Universe at frequencies from a few hundred MHz to a few GHz. The Australian SKA Pathfinder (ASKAP) is a technology demonstrator aimed in the mid-frequency range, and achieves instantaneous wide-area imaging through the development and deployment of phased-array feed systems on parabolic reflectors. The large field-of-view makes ASKAP an unprecedented synoptic telescope that will make substantial advances in SKA key science. ASKAP will be located at the Murchison Radio Observatory in inland Western Australia, one of the most radio-quiet locations on the Earth and one of two sites selected by the international community as a potential location for the SKA. In this paper, we outline an ambitious science program for ASKAP, examining key science such as understanding the evolution, formation and population of galaxies including our own, understanding the magnetic Universe, revealing the transient radio sky and searching for gravitational waves.
We have measured the angular two-point correlation function of EROs. The halo model is fitted to the observed clustering, and dark matter halo mass, bias and satellite fraction are estimated in three redshift bins. We also compare our results with the semi-analytical galaxy formation model. This work illustrates the power of clustering analysis in providing observational constraints on simulations.
Polycrystalline diamond thin films have been deposited on single crystal silicon substrates at low temperatures (<950° C) using a mixture of methane and hydrogen gases by high pressure microwave plasma assisted chemical vapor deposition. Low temperature deposition has been achieved by cooling the substrate holder with nitrogen gas. For deposition at reduced substrate temperature, it has been found that nucleation of diamond will not occur unless methane/hydrogen ratio is increased significantly from its value at higher substrate temperature. Selective deposition of polycrystalline diamond thin films has been achieved at 600° C using our technique previously used at 930° C. Decrease in the diamond particle size and growth rate, and an increase in surface smoothness have been observed with decreasing substrate temperature during the growth of thin films. The morphology is analyzed by scanning electron microscopy and the as-deposited films are identified by Raman spectroscopy.
Uniform arrays of nanopillars, nanospikes, nanorings and rings atop nanopillars were fabricated using modified nanosphere lithography on the Si(111) surface and observed using AFM and SEM. A self-assembled monolayer mask which utilized 450±10nm polystyrene spheres were used as an etch mask during a fabrication process of physical Ar+ ion bombardment followed by SF6 RIE to produce nanopillars with flat tops that could be as large as 210nm in height and 175nm in diameter. Nanospikes of approximately the same height were fabricated made with a FWHM of 250nm. The initial Ar+ ion bombardment step was varied to achieve up to 4 times faster etch rates and narrowed widths in the nanospikes. Both types nanostructures systems were “self-wired” which is an intrinsic result of this fabrication process. Self-wired nanorings and rings atop nanopillar structures were also fabricated using a two step etching process along with sonication. The nanorings had inner and outer diameters of 225±5nm and 175±5 nm, respectively and were up to 20nm in height and their nanowire connectivity could be made optional by a judicious choice of solvent for sonication. The self-wired Si nanostructures were also “dressed” with self-assembled Ge quantum dots. These Ge/Si nano-architectured structures possess the basic framework for fabricating novel nanoelectronic and nano-optoelectronic devices in the foreseeable future.
Polycrystalline diamond thin films have been deposited on single crystal silicon substrates at low temperatures (⋚ 600 °C) using a mixture of hydrogen and methane gases by high pressure microwave plasma-assisted chemical vapor deposition. Low temperature deposition has been achieved by cooling the substrate holder with nitrogen gas. For deposition at reduced substrate temperature, it has been found that nucleation of diamond will not occur unless the methane/hydrogen ratio is increased significantly from its value at higher substrate temperature. Selective deposition of polycrystalline diamond thin films has been achieved at 600 °C. Decrease in the diamond particle size and growth rate and an increase in surface smoothness have been observed with decreasing substrate temperature during the growth of thin films. As-deposited films are identified by Raman spectroscopy, and the morphology is analyzed by scanning electron microscopy.
It is concluded that Bearup's cercaria, described from Pyrazus australis in Australia, is different from Cercaria variglandis; the former develops into Austrobilharzia terrigalensis and the latter into A. variglandis (Syn. M. Chapini Price, 1929; M. variglandis Stunkard and Hinchliffe, 1952).
Bearup's cercaria should be henceforth treated as that of A. terrigalensis and not as C. variglandis.
Two specimens of this fluke were collected from the nictitating membrane of the Steppe Eagle, Aquila nipalensis Hudson, shot near the lake Chinhut, about 5 miles from Lucknow, U.P.
The body.(Fig. 1) is aspinose, flattened and clavate with a narrow anterior and a broadly rounded posterior end. It measures 4·5–5·9 mm. in length and 1·5–1·8 mm. in maximum width in the middle region. The oral sucker is terminal measuring 0·33–0·36 mm. X 0·47–0·49 mm. The ventral sucker is larger than the oral sucker, situated at the level of the division of. the anterior and middle-thirds of the body, and about 1·14 mm. from the anterior extremity. It measures 0·56–0·61 mm. X 0·52–0·54 mm.
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