356 research outputs found

    Preliminary test of a luminescence profile monitor in the CERN SPS

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    In order to satisfy the tight emittance requirements of LHC, a non-intercepting beam profile monitor is needed in the SPS to follow the beam emittance evolution during the acceleration cycle from 26 to 450 GeV. Beyond 300 GeV, the synchrotron light monitor can be used. To cover the energy range from injection at 26 GeV to 300 GeV, a monitor based on the luminescence of gas injected in the vacuum chamber has been tested and has given interesting results. This monitor could also be used in LHC, where the same problem arises. Design and results are presented for the SPS monitor

    Can we improve children's spelling ability by teaching morphemes through text reading :an intervention study exploring the relationship between morphological awareness and literacy

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    Background: The need to improve children's spelling ability remains a\ud key government agenda and is an issue encountered frequently by\ud Educational Psychologists (EPs) in their practice. Recent research has\ud suggested that there is a strong connection between awareness of\ud morphemes and understanding and accurate use of the English spelling\ud system, but relatively little is taught on this subject in school. The aim of\ud the present study was to investigate whether a 5-week intervention can\ud promote the development of 6- to 8-year-olds' morphological awareness\ud and spelling ability.\ud Method: Through the medium of guided group reading, an Intervention\ud group were taught about the morphological rules that govern the spelling\ud of plural `-s' and past tense `-ecf, whilst a Control group were taught about\ud two phonologically-based spelling patterns. The intervention was\ud compatible with current curriculum demands and was delivered to whole\ud classes by their teachers. Pseudoword spelling tasks were administered\ud at pre-, immediate post-, and delayed post-intervention points to assess\ud the children's learning of the morphological rules in question.\ud Results: Quantitative analyses suggested that the intervention did not\ud have a significant impact on morphological awareness in spelling.\ud However, a third of participating children showed clear gains, and reasons\ud for variation in response to intervention were explored. The overall picture\ud indicated that those with better literacy skills have better baseline\ud morphological awareness and that they also responded best to the\ud intervention.\ud Conclusions: The implications of the results are discussed with reference\ud to theories of literacy development and individual differences therein; and\ud in the context of teaching and the profession of Educational Psychology. It\ud is hoped that the study will increase the evidence-base of EP work, and\ud raise awareness that the system of morphemes could be a powerful\ud resource for children learning literacy

    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

    Real-time and Freehand Multimodal Imaging: Combining White Light Endoscopy with All-Optical Ultrasound

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    Minimally invasive surgery offers significant benefits over open surgery in terms of patient recovery, complication rates, and cost. Accurate visualisation is key for successful interventions; however, no single imaging modality offers sufficient resolution, penetration, and soft-tissue contrast to adequately monitor interventional treatment. Consequently, multimodal interventional imaging is intensively investigated. All-optical ultrasound (AOUS) imaging is an emerging modality where light is used to both generate and detect ultrasound. Using fibre-optics, highly miniaturised imaging probes can be fabricated that yield high-quality pulse-echo images and are readily integrated into minimally invasive interventional instruments. In this work, we present the integration of a miniature (diameter: 800 µm), highly directional AOUS imaging probe into a commercially available white light urethroscope, and demonstrate the first real-time, 3D multimodal imaging combining AOUS and white light endoscopy. Through the addition of an electromagnetic tracker, the position and pose of the instrument could be continuously recorded. This facilitated accurate real-time registration of the imaging modalities, as well as freehand operation of the instrument. In addition, the freehand imaging paradigm allowed for “piece-wise” scanning where the instrument was retracted and repositioned without recalibration. The presented imaging probe and system could significantly improve the quality of image guidance during interventional surgery

    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

    Optical fiber laser ultrasound transmitter with electrospun composite for minimally invasive medical imaging

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    We report an optical fiber ultrasound transmitter with electrospun MWCNT-polymer composite, generating high-amplitude broadband ultrasound. They produced pressures in the range of conventional intravascular imaging transducers, and can be incorporated into catheters/needles for keyhole surgery

    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

    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
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