1,303 research outputs found

    Regards renouvelés sur la transition entre le secondaire et le collégial - Avis à la Ministre de l'éducation, du loisir et du sport - Version Abrégée

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    Version abrégéeÉgalement disponible en version papier, cote : 787594Également disponible en anglais sous le titre: New perspectives on the transition from secondary school to college - Abridged versio

    Détection des unités d’utilisation et de couverture du sol urbain au moyen d’une simulation SPOT

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    La méthode utilisée consiste à classifier l'utilisation et la couverture du sol de l'agglomération urbaine de Sherbrooke avec l'aide d'images numériques acquises par un capteur aéroporté. Un survol de simulation du futur satellite SPOT a été effectué sur la région de Sherbrooke à l'aide du balayeur Daedalus multibande (DS1260) du Centre canadien de télédétection. Ce survol nous a permis d'estimer les possibilités du futur satellite SPOT pour la détection des phénomènes urbains. La télédétection des zones urbaines permettra la cartographie de ces unités d'utilisation et de couverture du sol ainsi qu'une remise à jour régulière des documents.The purpose was to evaluate the capacity of the future satellite SPOT to detect land use/cover in an urban milieu. A SPOT simulation over the Sherbrooke area was flown during the summer of 1982. After spectral and spatial resampling of the data, we obtained results which are comparable to SPOT characteristics. Remote sensing is thus both useful for land use/cover classification as well as updating data bases in urban milieu

    Développement d’une spatio-carte orientée vers la planification urbaine : résultats préliminaires

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    L'administration municipale nécessite le développement d'outils adaptés à la gestion de l'information urbaine. Dans un tel contexte, la télédétection est une nouvelle source d'information appelée à faciliter la planification urbaine. Le satellite SPOT avec une résolution spatiale de 10 m en mode panchromatique et de 20 m en mode multibande répond aux spécifications spatiales des études en aménagement urbain. Le but de cette recherche est de produire une spatio-carte en combinant des informations cartographiques aux données SPOT. La base du document est une image satellitaire améliorée radiométriquement et corrigée géométriquement à laquelle on superpose des informations géocodées. La démarche méthodologique utilisée pour la production d'une spatio-carte est présentée. On discute également de la pertinence d'un tel document dans la gestion municipale. La zone test est l'agglomération de Sherbrooke (Québec).Municipal administration requires the development of tools adapted to the management of urban information. In this context, remote sensing constitutes a new source of information useful in urban planning. The SPOT satellite, with a spatial resolution of 10 m in panchromatic mode and 20 m in multiband mode, meets the spatial specifications required in the context of urban planning studies. The objective of this research is to produce a spatial map by integrating cartographic information and SPOT data. The base of the document is a radiometrically and geometrically corrected satellite image to which geocoded data is integrated. The methodology used for the production of the spatial map is outlined. The relevance of such a document in the field of municipal management is discussed. The test site chosen for the study is the city of Sherbrooke (Québec)

    Santé mentale, alcool/drogues et violence : adaptation du modèle tripartite de Goldstein

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    Plusieurs recherches démontrent que le fait de présenter un trouble mental sévère et un trouble concomitant lié à une substance serait associé à un risque plus élevé de comportements violents. Toutefois, il n’existe aucun modèle conceptuel expliquant la relation entre ce type de comorbidité psychiatrique et la violence. Cet article propose une première explication du phénomène basée sur une adaptation des volets psychopharmacologique et économicocompulsif du modèle tripartite de Goldstein, à la population atteinte d’un trouble mental sévère et persistant (la schizophrénie ou la maladie bipolaire) et d’un trouble concomitant lié à une substance

    Hydrophobically directed aldol reactions: polystyrene-supported L-proline as a recyclable catalyst for direct asymmetric aldol reactions in the presence of water

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    A simple synthetic methodology for the preparation of a polystyrene- supported L-proline material is reported, and this material has been used as catalyst in direct asymmetric aldol reactions between several ketones and arylaldehydes to furnish aldol products in high yields and stereoselectivities. Screening of solvents showed that these reactions take place only in the presence of water or methanol, at lower levels of conversion in the latter case. This solvent effect, coupled with the observed high stereoselectivities, has been ex- Introduction In the last decade organocatalysis has became a field of great interest.[1] Organocatalysts are metal-free small organic molecules that are able to function as efficient and selective catalysts for a large variety of enantioselective transformations. In this context, -proline and its derivatives have emerged as powerful organocatalysts.[2] -Proline can be regarded as the simplest “enzyme” and it has been successfully applied in many reactions, such as Robinson annulations,[3] aldol reactions,[4] Mannich reactions,[5] Michael reactions,[6] direct electrophilic α-aminations,[7] Diels– Alder reactions,[8] Baylis–Hillman reactions,[9] aza-Morita- Baylis–Hillman reactions,[10] α-selenenylation,[11] oxidation,[ 12] chlorination,[13] and others.[14] Among all these processes, -proline-mediated aldol reactions affording β-hydroxy ketones have been investigated in great depth. Indeed, the aldol reaction is one of the most important C–C bond-formation methods in organic synthesis.[ 15] Proline and its derivatives operate by bifunctional catalysis and play the role of a simplified version of the type I [a] Dipartimento di Chimica Organica “E.Paternò”, Università di Palermo, Viale delle Scienze, Pad. 17, 90128 Palermo, Italy Fax: +39-091-596825 E-mail: [email protected] © 2007 Wiley-VCH Verlag GmbH 4688 & Co. KGaA, Weinheim Eur. J. Org. Chem. 2007, 4688–4698 plained in terms of the formation of a hydrophobic core in the inner surface of the resin, whereas the hydrophilic proline moiety lies at the resin/water interface. Such a microenvironment both promotes the aldol reaction and increases the stereoselectivity. Recycling investigations have shown that this material can be reused, without loss in levels of conversion and stereoselectivity, for at least five cycles

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured
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