48 research outputs found

    Two images of Nantes as a ‘Green Model’ of Urban Planning and Governance: The ‘Collaborative City’ Versus the ‘Slow City’

    Get PDF
    This article examines how the city of Nantes, European Green Capital in 2013, came to promote plans for a new international airport at Notre-Dame-des-Landes. Deploying poststructuralist discourse theory, it analyses how the highly politicised struggle against the airport reveals the limits of the Nantes model of urban sustainability and collaboration, giving rise to a counter model, which we provisionally characterise as the ‘slow city’. While the struggle against the airport can be understood as a rural social movement, we show how its ideals and logics have been progressively displaced to Nantes itself, disclosing new images and possibilities of urban governance

    Formation of diblock copolymers at PP/PA6 interfaces and their role in local crystalline organization under fast heating and cooling conditions

    No full text
    International audienceMultilayer polypropylene/polyamide 6 (PP/PA(6)) films are commonly obtained by co-extrusion, with PP/PA(6) interfaces reinforced through diblock PP/PA(6) copolymers formed in situ by the reaction of maleic anhydride modified PP on the NH2 end-groups of PA(6) molecules at the contact between the two molten polymers. We present procedures allowing one to form PP/PA(6) thin films assemblies in thermal conditions (fast heating and cooling kinetics, short annealing times) representative of typical co-extrusion conditions. Selective dissolution of the PA(6) part of the assemblies permits to first dose the surface density of copolymer, and second to analyze by AFM imaging the incidence of the copolymer surface density on the crystalline morphology at the interface. These experiments are a first step toward the identification of the key parameters controlling the fracture toughness in these multilayer films

    Coating behaviour for materials of industrial waste incinerators and heat exchangers in high temperature corrosive atmospheres

    No full text
    A coating obtained by flame spraying (Ni-Al) and an aluminizing type (Sermaloy J) were tested in laboratory and in industrial waste incinerator (substrate : AISI 310S steel). In laboratory tests, the studied parameters were : HCl-content (1 and 3% vol. in air + 0.1% vol. SO2), temperature (600 and 800 °C) and thermal cycling between 800 and 400 °C. The increasing of the temperature and HCl-content, and also thermal cycling lead to a degradation of the non coated steel and Ni-Al coated specimen behaviours ; as for Sermaloy J, only temperature raising seems to have a detrimental effect (first batch). For the field tests, the specimens were exposed at about 600 °C in flue gases containing about 0.4% vol. HCl and flying ashes (sodium chloride and sulfate) ; the corrosion phenomena are more closed to molten salts interactions than to gaseous corrosion : Ni-Al behaves better compared with Sermaloy J and the non coated steel which are much more attacked than in laboratory. However, Sermaloy J and Ni-Al can lead to a real protection of a steel substrate but the manufacturing conditions have a great influence on the behaviour of the coated specimens
    corecore