25 research outputs found

    Un symbole à bout de souffle ? Le maintien de la paix dans la culture stratégique canadienne

    Get PDF
    L’objectif de cet article est d’examiner comment les opĂ©rations de maintien de la paix sont parvenues Ă  façonner de maniĂšre aussi marquante la culture stratĂ©gique canadienne depuis plus de cinquante ans. Il s’agit plus prĂ©cisĂ©ment d’en analyser une dimension particuliĂšre, soit le processus de lĂ©gitimation de l’usage de la force militaire par les Ă©lites politiques canadiennes, grĂące Ă  l’utilisation du symbole que reprĂ©sente le maintien de la paix pour les Canadiens. L’un des impacts de ce processus, vis-Ă -vis de pratiques militaires qui correspondent de moins en moins au symbole du maintien de la paix, est le dĂ©veloppement d’un Ă©cart significatif entre la rhĂ©torique et les faits. Il en rĂ©sulte une crise de lĂ©gitimation de l’usage de la force militaire au Canada, qui s’exprime par une ambiguĂŻtĂ© croissante quant au rĂŽle des Forces canadiennes sur la scĂšne internationale, et dont l’actuel engagement militaire en Afghanistan reprĂ©sente le point culminant.This article examines how peacekeeping operations became a cornerstone of Canada’s strategic culture since 1956. It analyzes the process through which the symbol of peacekeeping has been used by Canadian political leaders, thus creating an increasingly important gap between rhetoric and the true actions of Canadian Forces abroad. Canadian political decision-makers have contributed to creating a legitimization crisis by preserving ambiguity as for the role of the Canadian Forces, ambiguity which currently culminates with the deployment of thousands of Canadian soldiers in Afghanistan

    L'influence canadienne à travers les opérations de paix, 1956 à 2005

    Get PDF
    Un des mythes de la politique Ă©trangĂšre canadienne veut que plus le pays dĂ©ploie de Casques bleus dans le cadre d'opĂ©rations de paix, plus il jouit d'une influence tangible auprĂšs des autres États. Cette rhĂ©torique, pratiquement calquĂ©e de l'approche fonctionnaliste, persiste depuis la crĂ©ation des Nations unies, en dĂ©pit des multiples changements de gouvernements. L'objectif de ce mĂ©moire est donc de vĂ©rifier si ce raisonnement est justifiĂ©, et que le pays se voit vĂ©ritablement octroyer une influence quelconque Ă©manant de sa participation aux missions multilatĂ©rales. Trois cas sont Ă©tudiĂ©s, soit la Force d'urgence des Nations Unies (FUNU), la Force de protection des Nations Unies dans les Balkans (FORPRONU) et la Force internationale d'assistance et de sĂ©curitĂ© (FIAS). L'analyse des trois opĂ©rations sĂ©lectionnĂ©es ne permet pas de corroborer la thĂšse des Ă©lites politiques canadiennes, ni de l'infirmer catĂ©goriquement. Elle permet nĂ©anmoins de douter de l'efficacitĂ© de l'argumentaire ; plusieurs Ă©lĂ©ments le remettent d'ailleurs en question

    Heat transfer in a swirling fluidized bed with Geldart type-D particles

    Get PDF
    A relatively new variant in fluidized bed technology, designated as the swirling fluidized bed (SFB), was investigated for its heat transfer characteristics when operating with Geldart type D particles. Unlike conventional fluidized beds, the SFB imparts secondary swirling motion to the bed to enhance lateral mixing. Despite its excellent hydrodynamics, its heat transfer characteristics have not been reported in the published literature. Hence, two different sizes of spherical PVC particles (2.61mm and 3.65mm) with the presence of a center body in the bed have been studied at different velocities of the fluidizing gas. The wall-to-bed heat transfer coefficients were measured by affixing a thin constant foil heater on the bed wall. Thermocouples located at different heights on the foil show a decrease in the wall heat transfer coefficient with bed height. It was seen that only a discrete particle model which accounts for the conduction between the particle and the heat transfer surface and the gas-convective augmentation can adequately represent the mechanism of heat transfer in the swirling fluidized bed

    IL-2/anti-IL-2 antibody complexes show strong biological activity by avoiding interaction with IL-2 receptor α subunit CD25

    No full text
    IL-2 is crucial to T cell homeostasis, especially of CD4+ T regulatory cells and memory CD8+ cells, as evidenced by vigorous proliferation of these cells in vivo following injections of superagonist IL-2/anti-IL-2 antibody complexes. The mechanism of IL-2/anti-IL-2 antibody complexes is unknown owing to a lack of understanding of IL-2 homeostasis. We show that IL-2 receptor α (CD25) plays a crucial role in IL-2 homeostasis. Thus, prolongation of IL-2 half-life and blocking of CD25 using antibodies or CD25-deficient mice led in combination, but not alone, to vigorous IL-2–mediated T cell proliferation, similar to IL-2/anti-IL-2 antibody complexes. These data suggest an unpredicted role for CD25 in IL-2 homeostasis
    corecore