99 research outputs found

    Relations entre le leadership des directions d'Ă©cole primaire et l'empowerment des enseignants

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    ThÚse numérisée par la Direction des bibliothÚques de l'Université de Montréal

    Guide pédagogique du Portfolio D.E.S.S. en administration de l'éducation

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    Dans le contexte du DESS en administration de l’éducation, le portfolio est un outil d’apprentissage qui amĂšne l’étudiant Ă  vivre un processus rĂ©flexif supervisĂ© et Ă  organiser une collection de productions significatives s’accumulant progressivement Ă  l’intĂ©rieur du dĂ©roulement des cours. Le guide pĂ©dagogique explique les choix qui ont donnĂ© lieu au Portfolio pour les Ă©tudiants. Le portfolio suppose une rĂ©flexion en deux temps, le premier en a priori et portant sur le profil de sortie, le glossaire, le guide de choix de cours et le choix des compĂ©tences Ă  dĂ©velopper par l’étudiant selon les cours et le second, a posteriori, et portant essentiellement sur l’écart existant entre les intentions d’apprentissage exprimĂ©es au dĂ©part et le niveau atteint Ă  la fin du programme.Document produit dans le cadre d'un projet CLI

    Detecting topological edge states with the dynamics of a qubit

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    We consider the Su-Schrieffer-Heeger (SSH) chain, which has 0, 1, or 2 topological edge states depending on the ratio of the hopping parameters and the parity of the chain length. We couple a qubit to one edge of the SSH chain and a semi-infinite undimerized chain to the other, and evaluate the dynamics of the qubit. By evaluating the decoherence rate of the qubit we can probe the edge states of the SSH chain. The rate shows strong even-odd oscillations with the number of sites reflecting the presence or absence of edge states. Hence, the qubit acts as an efficient detector of the topological edge states of the SSH model. This can be generalized to other topological systems.Comment: 10 pages, 9 figure

    Cartes conceptuelles du Glossaire

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    Ce guide pĂ©dagogique fait suite au Glossaire du DESS en administration de l'Ă©ducation. Il explique comment les mots du vocabulaire reliĂ© au travail des directions d'Ă©tablissement scolaire et Ă  leur formation peuvent ĂȘtre regroupĂ©s dans des cartes conceptuelles pour mieux en saisir la portĂ©e. Il explicite aussi la conception et la construction de cartes conceptuelles et prĂ©sente des exemples issus de la concertation entre les formateurs

    Concepts «fondamentaux» en administration de l’éducation

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    Glossaire Ă©laborĂ© par des membres de la cellule "administration scolaire" au DĂ©partement d'administration et fondements de l'Ă©ducation. DĂ©finitions retenues qui s’appliquent toutes au domaine de l’éducation. Document complĂ©mentaire aux notions vĂ©hiculĂ©es dans le cours ETA6900 : Introduction Ă  l’administration de l’éducation

    A review on mathematical modeling of microbial and plant induced permafrost carbon feedback

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    ABSTRACT: This review paper analyses the significance of microbial activity in permafrost carbon feedback (PCF) and emphasizes the necessity for enhanced modeling tools to appropriately predict carbon fluxes associated with permafrost thaw. Beginning with an overview of experimental findings, both in situ and laboratory, it stresses the key role of microbes and plants in PCF. The research investigates several modeling techniques, starting with current models of soil respiration and plant-microorganism interactions built outside of the context of permafrost, and then moving on to specific models dedicated to PCF. The review of the current literature reveals the complex nature of permafrost ecosystems, where various geophysical factors have considerable effects on greenhouse gas emissions. Soil properties, plant types, and time scales all contribute to carbon dynamics. Process-based models are widely used for simulating greenhouse gas production, transport, and emissions. While these models are beneficial at capturing soil respiration complexity, adjusting them to the unique constraints of permafrost environments often calls for novel process descriptions for proper representation. Understanding the temporal coherence and time delays between surface soil respiration and subsurface carbon production, which are controlled by numerous parameters such as soil texture, water content, and temperature, remains a challenge. This review highlights the need for comprehensive models that integrate thermo-hydro-biogeochemical processes to understand permafrost system dynamics in the context of changing climatic circumstances. Furthermore, it emphasizes the need for rigorous validation procedures to reduce model complexity biases

    Experimental and theoretical assessment of water sorbent kinetics

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    ABSTRACT: The kinetics of water adsorption in powder sorbent layers are important to design a scaled-up atmospheric water capture device. Herein, the adsorption kinetics of three sorbents, a chromium (Cr)-based metal–organic framework (Cr-MIL-101), a carbon-based material (nanoporous sponges/NPS), and silica gel, have been tested experimentally, using powder layers ranging from ∌0 to 7.5 mm in thickness, in a custom-made calibrated environmental chamber cycling from 5 to 95% RH at 30 °C. A mass and energy transfer model was applied onto the experimental curves to better understand the contribution of key parameters (maximum water uptake, kinetics of single particles, layer open porosity, and particle size distribution). Open porosity (i.e., the void-to-particle ratio in the sorbent layer) shows the highest influence to improve the kinetics. Converting the sorbent kinetics data into a daily yield of captured water demonstrated (i) the existence of an optimal open porosity for each sorbent, (ii) that thinner layers with moderate open porosity performed respectively better than thicker layers with high open porosity, and (iii) that high maximum water uptake and fast single-particle kinetics are not necessarily predictive of high daily water yield

    Improving atmospheric water harvesting in carbon-based sorbents through CO₂ activation

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    ABSTRACT: Atmospheric water harvesting (AWH) can serve as an alternative fresh water source in regions with scarce access to drinking water. While many techniques are geographically or seasonally limited, sorbent-based AWH shows the potential for wider application. Low-cost, carbon-based sorbents named nanoporous sponges (NPS) are recently developed, exhibiting fast and repeatable water uptake of 0.14 g g⁻Âč at 90% relative pressure. While useful from a cost and daily water yield point of view, there is room for improvement. This article presents an improved production process combining pyrolysis and activation under CO₂ in a single step, yielding improved NPS capable of reproducibly reaching a water uptake of 0.47 g g⁻Âč at 95% relative pressure while maintaining fast sorption rates. The NPS show significant endurance and are able to maintain stable performance over numerous humidity cycles. An unexpected time-dependant sorption behavior is also identified for NPS produced with a modified synthesis formulation, due to an increase in sodium carbonate residual content

    Nanoporous sponges as carbon-based sorbents for atmospheric water generation

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    Water scarcity threatens more and more people in the world. Moisture adsorption from the atmosphere represents a promising avenue to provide fresh water. Nanoporous sponges (“NPSs” ), new carbon-based sorbents synthesized from the pyrolysis of resorcinol-formaldehyde resin, can achieve comparable performance to metal organic framework-based systems, but at a significantly lower cost. Oxygen and nitrogen functionalities can be added to the NPS surface, through oxidation and addition of phenanthroline to the initial reagent mixture, respectively. The resulting NPS sorbents have high specific surface areas of 347 to 527 m2·g–1 and an average capillary-condensation-compatible pore size of 1.5 nm. When oxidized, the NPS can capture up to 0.28 g of water per gram of adsorbent at a relative pressure of 0.90 (0.14 g·g–1 at P/Psat = 0.40) and maintain this adsorption capacity over multiple adsorption/desorption cycles. Scaled-up synthesis of the NPS was performed and tested in an experimental water capture setup, showing good agreement between small- and larger-scale adsorption properties. Water adsorption isotherms fitted with the theoretical model proposed by Do and Do demonstrate that hydroxyl functionalities are of key importance to NPS behavior
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