413 research outputs found

    Sulfate and Phosphate Speleothems at Jenolan Caves, New South Wales, Australia

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    Sulfate and phosphate deposits at Jenolan Caves occur in a variety of forms and compositions including crusts, ‘flowers’ and fibrous masses of gypsum (selenite), and clusters of boss-like speleothems (potatoes) of ardealite (calcium sulphate, phosphate hydrate) with associated gypsum. This boss-like morphology of ardealite does not appear to have been previously described in the literature and this is the first report of ardealite in New South Wales. Gypsum var. selenite occurs in close association with pyrite-bearing palaeokarst, while the ardealite gypsum association appears to relate to deposits of mineralised bat guano. Isotope studies confirm that the two gypsum suites have separate sources of sulfur, one from the weathering of pyrite (-1.4 to +4.9 δ34S) for gypsum (selenite) and the other from alteration of bat guano (+11.4 to +12.9 δ34S) for the ardealite and gypsum crusts

    Adaptive optics for the LEP 2 synchrotron light monitors

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    The image obtained with the LEP synchrotron radiation telescopes deteriorates, giving multiple and deformed images, when the beam energy goes beyond 80 GeV at beam currents above 2 mA. This problem is due to the deformation of the light extracting beryllium mirror, by as little as 1 mm, and had been predicted at the design stage. To overcome this problem, several changes together with an adaptive optics set-up have been introduced. These essentially consist of a cylindrically deformable mirror to compensate the cylindrical deformation of the beryllium mirror and a movable detector to compensate the spherical deformation. Both components are continuously adjusted as a function of beam current and energy

    The OTR screen betatron matching monitor of the CERN SPS

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    In order to satisfy the stringent emittance requirements of LHC, betatron matching monitors, based on multiturn beam profile measurements, have been proposed for the SPS and LHC. A test monitor has been installed for evaluation in the CERN SPS first in 1996 and improved in 1997. It is based on an OTR screen and a fast beam profile acquisition system. It has been used with proton beams to assess the quality of the betatron matching from the PS to the SPS in 1998. Experience and results are presented

    Minerals of Jenolan Caves, New South Wales, Australia: Geological and Biological Interactions

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    Geological and biological processes in the Jenolan Caves have formed a range of mineral species spanning several chemical groups. So far 25 mineral species have been either confirmed, or identified for the first time at Jenolan. Their chemical groups include carbonates: (calcite, aragonite, hydromagnesite, huntite, dolomite, ankerite); silicates: (kaolinite, K-deficient muscovite (‘illite’), montmorillonite clays); phosphates, (ardealite, hydroxylapatite, taranakite, leucophosphite, variscite, crandallite, montgomeryite, kingsmountite); sulfate: (gypsum); oxides: (quartz, cristobalite, amorphous silica, hematite, romanèchite); hydroxide: (goethite); nitrate: (niter); and chloride: (sylvite). Dolomitised limestone bedrock and ankerite veins can be recognised as a magnesium source of some magnesium carbonate minerals, as well as supplying a calcite inhibitor favouring aragonite formation. The cave clays have diverse origins. Some are recent sedimentary detritus. Older clays of Carboniferous age contain components of reworked altered volcaniclastics washed or blown into the caves, so these clays may represent argillic alteration of volcanic products. Some of the clays may have formed as alteration products of ascending hydrothermal fluids. The phosphates and some gypsum formed when bat guano reacted chemically with limestone and cave clays. Gypsum has also been formed from the breakdown of pyrite in altered bedrock or dolomitic palaeokarst. The niter and sylvite have crystalized from breakdown products of mainly wallaby guano

    Environmental and ecological citizenship in civil society

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    Drawing from the work of Andrew Dobson, two notions of citizenship in civil society can be distinguished: environmental citizenship, which focuses on environmental rights and seeks to redefine the relationship between the state and the citizen; and ecological citizenship, which goes beyond a rights-based notion of citizenship to advocate the fair usage of ecological space across international borders. Using civil society initiatives to conserve forests, this article argues that these two notions of citizenship should be seen as overlapping in that civil society groups seek to work through national and international law to reduce the ecological footprint of some countries on others. The article concludes by drawing a distinction between the environmental state and the ecological state

    Measurement of Liver Blood Flow: A Review

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    The study of hepatic haemodynamics is of importance in understanding both hepatic physiology and disease processes as well as assessing the effects of portosystemic shunting and liver transplantation. The liver has the most complicated circulation of any organ and many physiological and pathological processes can affect it1,2. This review surveys the methods available for assessing liver blood flow, examines the different parameters being measured and outlines problems of applicability and interpretation for each technique

    First Results from Betatron Matching Monitors Installed in the CERN PSB and SPS

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    In order to satisfy the tight emittance requirements of LHC, betatron matching monitors, based on multiturn beam profile measurements, have been proposed and installed in the CERN SPS and PSB. The SPS monitor is based on a OTR beam profile acquisition system and was installed two years ago and has since been tested. It helped to uncover a mismatch between PS and SPS. Experience and more results wil l be presented. The PSB monitor is based on a wire SEM and has been installed at the beginning of 1998. The first results presented here are very promising

    Counterparts: Clothing, value and the sites of otherness in Panapompom ethnographic encounters

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    This is an Author's Accepted Manuscript of an article published in Anthropological Forum, 18(1), 17-35, 2008 [copyright Taylor & Francis], available online at: http://www.tandfonline.com/10.1080/00664670701858927.Panapompom people living in the western Louisiade Archipelago of Milne Bay Province, Papua New Guinea, see their clothes as indices of their perceived poverty. ‘Development’ as a valued form of social life appears as images that attach only loosely to the people employing them. They nevertheless hold Panapompom people to account as subjects to a voice and gaze that is located in the imagery they strive to present: their clothes. This predicament strains anthropological approaches to the study of Melanesia that subsist on strict alterity, because native self‐judgments are located ‘at home’ for the ethnographer. In this article, I develop the notion of the counterpart as a means to explore these forms of postcolonial oppression and their implications for the ethnographic encounter

    The effect of playground and nature-based interventions on physical activity and self-esteem in UK school children

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    School playtime provides opportunities for children to engage in physical activity (PA). Playground playtime interventions designed to increase PA have produced differing results. However, nature can also promote PA, through the provision of large open spaces for activity. The purpose of this study is to determine which playtime interventions are most effective at increasing moderate-to-vigorous physical activity (MVPA) and if this varies by school location. Fifty-two children from an urban and rural school participated in a playground sports (PS) and nature-based orienteering intervention during playtime for one week. MVPA was assessed the day before and on the final day of the interventions using accelerometers. Intervention type (p  0.05). The provision of PS influences PA the most; however, a variety of interventions are required to engage less fit children in PA
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