51 research outputs found

    Le territoire syrien entre intégration nationale et métropolisation renforcée

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    L'article présente la structuration du territoire syrien depuis la révolution ba`thiste de 1963 et les politiques d'aménagement du territoire conduites par les régimes successifs, selon les trois impératifs de contrôle politique, d'intégration nationale et d'autosuffisance, énergétique et alimentaire. Il décrit les formes de métropolisation et de fragmentation territoriale qui accompagnent la libéralisation économique depuis 2000, avant de tracer une typologie régionale détaillée

    Smart Localization Using a New Sensor Association Framework for Outdoor Augmented Reality Systems

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    Augmented Reality (AR) aims at enhancing our the real world, by adding fictitious elements that are not perceptible naturally such as: computer-generated images, virtual objects, texts, symbols, graphics, sounds, and smells. The quality of the real/virtual registration depends mainly on the accuracy of the 3D camera pose estimation. In this paper, we present an original real-time localization system for outdoor AR which combines three heterogeneous sensors: a camera, a GPS, and an inertial sensor. The proposed system is subdivided into two modules: the main module is vision based; it estimates the user’s location using a markerless tracking method. When the visual tracking fails, the system switches automatically to the secondary localization module composed of the GPS and the inertial sensor

    Impact of earthworm activity on the chemical fertility of irrigated soil with urban effluents

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    The reuse of urban effluents to irrigate the soils of peri-urban grasslands in the vicinity of the town of Setif (northeastern Algeria) is an old and widespread practice. In this context, the present study was conducted to evaluate the effect of the irrigation with urban effluents on the biological and chemical behavior of soils. Effluents analysis showed significant organic and particulate pollution, the latter contributed to earthworm abundance and increased the richness of irrigated soils with nutrients. The analysis of turricules revealed the role of earthworms through the activity of bioturbation in the increase of the rate of organic matter as well as in the bioavailability of the nutrients of the irrigated soils. In space, permanent vegetation cover has played an important role as a biofilter. This was confirmed by the inter-site differences recorded through the measured variables particularly organic ones.Keywords: Natural grasslands, urban effluents, earthworm activity, turricles, organic matte

    Deprotonative Cadmation of Functionalized Aromatics

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    International audienceThis communication describes the deproto-metalation of a large range of aromatics including heterocycles using a newly developed lithium-cadmium base. The reaction proceeds at room temperature with an excellent chemoselectivity and efficiency, and proved to be regioselective in most cases

    REPARTITION DES OISEAUX DANS QUELQUES OASIS DE LA PARTIE SEPTENTRIONALE DU SAHARA

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    In some oases of the northern part of the Sahara, those of the basin of Ouargla, Biskra and that of Oued Souf, the birds are studied. In the palm groves of the Ouargla basin 43 species belonging to 4 orders, 13 families and 21 genera are listed. Further north, in a Ziban (Biskra) palm grove, 49species are mentioned, representing 11% of the total Algerian species which correspond to 21 families of which the best represented are Turdidae, Columbidae and Sylviidae. In Oued Souf, 32 species are inventoried belonging to 17 families, in particular the Sylviidae. In Ghardaïa, among the 38 species, the Turdidae ranked first with 8 species (21.1%). Within these species, three appear to have settled as Streptopelia decaocto, even in a state of expansion, such as Passer domesticus x P. hispaniolensis.Dans quelques oasis du Sahara, celles de la cuvette d’Ouargla, de Biskra, d’Oued Souf et de Ghardaïa, les oiseaux sont étudiés. Dans les palmeraies de la cuvette d’Ouargla 43 espèces appartenant à 4 ordres, 13 familles et 21 genres sont recensées. Plus au nord, dans une palmeraie des Ziban (Biskra) 49 espèces sont mentionnées, ce qui représente 11 % du total des espèces algériennes qui correspondent à 21 familles dont les mieux représentées sont celles des Turdidae, des Columbidae et des Sylviidae. A Oued Souf, 32 espèces sont inventoriées appartenant à 17 familles, notamment les Sylviidae qui sont les mieux représentées. A Ghardaïa, parmi les 38 espèces ce sont les Turdidae qui occupent le premier rang avec 8 espèces (21,1 %). Au sein de ces espèces, trois semble avoir sédentarisées comme Streptopelia decaocto, même en état d’expansion, telle que Passer domesticus x P. hispaniolensis

    Synthesis of an alkylmagnesium amide and interception of a ring-opened isomer of the important utility amide 2,2,6,6-tetramethylpiperidide (TMP)

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    Two new magnesium complexes containing the important utility amide 2,2,6,6-tetramethylpiperidide (TMP) have been synthesised. Treating the magnesium bis(alkyl) reagent (Me3SiCH2)2Mg with a molar equivalent of TMP(H) in hydrocarbon medium produces the dimeric alkylmagnesium amide complex [(Me3SiCH2)Mg(μ-TMP)]22, which was isolated in high yield. X-ray crystallography revealed that 2 was an unsymmetrical dimer as unusually the two TMP ligands adopt different conformations – one a chair, the other a twisted boat. Solution studies (multinuclear NMR and DOSY NMR spectroscopies) show that 2 undergoes a monomerisation and Schlenk equilibrium in d8-THF. When (Me3SiCH2)2Mg was reacted with two molar equivalents of TMP(H) in hydrocarbon medium [in an effort to prepare Mg(TMP)2] a crystalline sample of a surprising product, a tetranuclear triheteroanionic amide-alkoxide-amidoalkene [(TMP)Mg(μ-TMP){μ-N(H)C(Me)2CH2CH2CH2C(Me) = CH2}Mg(μ-OCH2SiMe3)]23 was obtained. Complex 3 contains two unexpected anions, namely the alkoxide produced via oxygen insertion into a Mg–C bond, and the primary amidoalkene which is produced via ring opening of the TMP anion

    Le territoire syrien entre intégration nationale et métropolisation renforcée

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    L'article présente la structuration du territoire syrien depuis la révolution ba`thiste de 1963 et les politiques d'aménagement du territoire conduites par les régimes successifs, selon les trois impératifs de contrôle politique, d'intégration nationale et d'autosuffisance, énergétique et alimentaire. Il décrit les formes de métropolisation et de fragmentation territoriale qui accompagnent la libéralisation économique depuis 2000, avant de tracer une typologie régionale détaillée

    DOES EARTHWORMS DENSITY REALLY MODIFY SOIL'S HYDRODYNAMIC PROPERTIES IN IRRIGATED SYSTEMS WITH RECYCLED WATER?

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    <p>Our study has the general objective to understand the impact of the valuation of treated water on earthworm abundance and total porosity of the soil and the effect of the interaction between these two physical-biological components of the hydrological functioning of soils. It was carried out on the meadows soils of the valley of Wadi Bousselam.</p><p>Although the treated water has high organic and particulate filler, it improved the earthworm abundance, total porosity and hydraulic conductivity of the soil.</p

    High-Temperature Magnetic Characterization Using an Adapted Epstein Frame

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    International audienc

    On the Hybrid Aid-Localization for Outdoor Augmented Reality Applications

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    In mobile outdoor augmented reality applications, accurate localization is critical to register virtual augmentations over a real scene. Vision-based approaches provide accurate localization estimates but are still too sensitive to outdoor conditions (brightness changes, occlusions, etc.). This drawback can be overcome by adding other types of sensors. In this work, we combine a GPS and an inertial sensor with a camera to provide accurate localization. We will present the calibration process and we will discuss how to quantify the 3D localization accuracy. Experimental results on real data are presented
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