22,443 research outputs found

    Search for Contact Interactions in the Dimuon Final State at ATLAS

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    The Standard Model has been successful in describing many fundamental aspects of particle physics. However, there are some remaining puzzles that are not explained within the context of its present framework. We discuss the possibility to discover new physics in the ATLAS Detector via a four-fermion contact interaction, much in the same way Fermi first described Weak interactions. Using a simple ratio method on dimuon events, we can set a 95% C.L. lower limit on the effective scale Lambda = 7.5 TeV (8.7 TeV) for the constructive Left-left Isoscalar Model of quark compositeness with 100 pb^-1 (200 pb^-1) of data at sqrt{s} = 10 TeV.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

    Float-polishing process and analysis of float-polished quartz

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    A fluid-mechanical model is developed for the float-polishing process. In this model laminar flow between the sample and the lap results in pressure gradients at the grooves that support the sample on a fluid layer. The laminar fluid motion also produces supersmooth, damage-free surfaces. Quartz substrates for applications in high-stress environments were float polished, and their surfaces were analyzed by optical scatterometry, photoacoustic spectroscopy, and atomic force microscopy. The removal of 100 µm of material by a lapping-polishing process, with final float polishing, left low levels of subsurface damage, with a surface roughness of approximately 0.2-nm rms

    X-ray polarimetry with an active-matrix pixel proportional counter

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    We report the first results from an X-ray polarimeter with a micropattern gas proportional counter using an amorphous silicon active matrix readout. With 100% polarized X-rays at 4.5 keV, we obtain a modulation factor of 0.33 +/- 0.03, confirming previous reports of the high polarization sensitivity of a finely segmented pixel proportional counter. The detector described here has a geometry suitable for the focal plane of an astronomical X-ray telescope. Amorphous silicon readout technology will enable additional extensions and improvements.Comment: 4 pages, 4 figures, 1 tabl

    Structure, bonding and morphology of hydrothermally synthesised xonotlite

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    The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies

    The struggle for legitimacy: language provision in two ‘residual’ comprehensive high schools in Australia

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    © 2016, © 2016 Informa UK Limited, trading as Taylor & Francis Group. Despite the contemporary policy rhetoric of global citizenry and the importance of languages and intercultural capabilities, language learning in Australian schools struggles for recognition and support. The curriculum marginalisation of languages, however, is uneven, affecting some school sectors more than others. In this article, we examine the provision of languages in two government comprehensive high schools, both low socio-economic status, located in urban areas in New South Wales, Australia’s largest state. They are termed ‘residual’ high schools because they cater for the students remaining in the local schools while others attend either private or selective government high schools. We provide a qualitative picture of language provision in these two schools from the perspectives of key stakeholders–school principals, teachers, students and parents. We also draw on observational data of language classes. The aim is to provide, within a largely social class framework, an understanding of the state of language provision in these schools. We argue that currently students in these schools are experiencing unequal access to the linguistic and cultural capital associated with language learning relative to students in more privileged communities and schools

    The literacy and numeracy ‘crisis’ in Australian workplaces: discursive rhetoric vs. production floor realities

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    © 2013 Taylor & Francis. The dominant discourse on adult literacy and numeracy in Australia sees the federal government, industry, workforce skills agencies and the media speaking with one voice on the ‘crisis’ involving workers’ low literacy and numeracy skills. Underpinning this discourse are the Australian results of the international Adult Literacy and Life Skills Survey (ALLS) which are used to model correlations between low literacy/numeracy levels and productivity. In turn, these correlations are deemed to have implications for the competitiveness of individual enterprises and the prosperity of the nation. In the ALLS, approximately half of manufacturing workers are found at the lowest two levels. Adopting an ethnographic perspective, and viewing literacy and numeracy as social practices, this paper investigates this ‘crisis’ from the situated perspectives of managers, trainers and workers in three manufacturing companies. Multiple observations of production work and semi-structured interviews with over 50 company personnel reveal a contradiction between the crisis discourse rhetoric on workplace literacy and numeracy and the realities of production work. Literacy and numeracy are found not to have a negative influence on production work in the three companies. This raises questions about the basis for the crisis discourse, and government policy and programmes that flow from it
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