L'imaginaire urbain dans les régions ouvrières en reconversion: Le bassin stéphanois et le bassin minier du Nord Pas de Calais

Cette recherche est une recherche sociologique et anthropologique coordonnée par Michel Rautenberg rassemblant le Centre Max Weber de Saint-Étienne, le Centre Lillois d'études et de recherches sociologiques et économiques (sous la responsabilité du professeur Licia Valladarès) et l' Université de Sofia (sous la responsabilité du professeur Ivaylo Ditchev). Démarrée en décembre 2007 elle s'est terminée en avril 2011 et a bénéficié d'une aide de l'ANR de 180 k€ pour un montant global de 250 k€ de subventions publiques (non comprise une allocation de recherche).The general hypothesis at the origin of this research is that urban transformations do not go without social representations and the field of the imagination. It is essential for each image, word or story to be related to concrete situations that the researcher can describe. The choice of cities is thus not negligible. In this research programme, it has focussed on cities which have a had a difficult economic history characterised by brutal de-industrialization - more in people's minds than by its suddenness. This has left a traumatic effect on individual and collective memories, an urban landscape of industrial wasteland and 3 decades later it continues to strongly influence urban renovation policies. The first issue of this research, which in its second phase was extended to include Bulgarian cities thanks to the support of the Ministry for Foreign Affairs, was to establish a method making it possible to describe this imagination. So researchers agreed to work on imagination "operators", that is to say means (administrative, artistic or social) used by socially identified actors : artists, associations, inhabitants, former miners, municipal authorities. The second issue was to favour the imagination of cites which cannot be measured against communication strategies but which considers the "popular" social imagination which is sufficiently autonomous to exist outside municipal institutions - without asserting that it is completely independent. The third issue was to find common features in the comparison between situations close enough in their history to justify a pertinent comparison.L'hypothèse générale à l'origine de cette recherche est que les transformations urbaines ne font pas l'économie des représentations et des imaginaires sociaux. Il est donc nécessaire que chaque image, parole ou récit recueilli soit rapporté à des situations concrètes que le chercheur peut décrire. Le choix des villes n'est alors pas anodin. Dans ce programme de recherche, il s'est porté sur des villes qui ont eu une histoire économique difficile caractérisée par une désindustrialisation brutale -dans les esprits peut-être plus que par sa soudaineté. Celle ci a laissé des traumatismes dans les mémoires individuelles et collectives, un paysage urbain de friches industrielles, et continue après 3 décennies d'influencer fortement sur les politiques de rénovation urbaine

Structure et réactivité de poudres d’aluminium nanostructurées

Les poudres d'aluminium sont depuis longtemps utilisées comme additifs dans de nombreuses formulations pour la pyrotechnie ou les propergols. Introduites en quantité relativement faible dans les propergols des fusées, elles permettent d'accroître significativement les vitesses de combustion. Cependant, les mécanismes à l'origine de cette meilleure réactivité restent encore mal compris et vont bien au-delà d'une simple explication en terme d'augmentation de l'état de division. Au cours de cette thèse nous avons élaboré des poudres d'aluminium par broyage à haute énergie, technique mécanique peu couteuse qui pourrait être une alternative aux procédés de fabrication actuels. Nous montrons que cette méthode permet l'obtention de particules micrométriques ou nanométriques suivant les conditions de broyage. Les particules sont polycristallines et présentent une morphologie en plaquette. Les poudres nanométriques obtenues présentent une réactivité comparable voire même supérieure aux nanopoudres sphériques actuellement élaborées par électro-explosion de fil ou voie plasma. Nous montrons que cette bonne réactivité est lié à la morphologie des particules ainsi qu'à la microstructure de la couche d'alumine native qui passive l'aluminium.Aluminium nanopowders have been using for a long time as additives in many formulations for propergol or in pyrotechnics. Introduced in small quantity in rocket propergol they allow to increase the combustion rate. However, the reactivity of aluminium particles is not really understood and not just linked to the size reduction effect. All along this study, we have elaborated aluminium powders using high energy mechanical milling, a mechanical technique with a low cost which could be an alternative process of powders fabrication. We prove that this method allows elaboration of micro and nano-particles as a function of the mechanical parameters. The particles are polycristallines with flake morphology. The obtained nanopowders have a similar reactivity, or better than spherical nanopowders obtained by wire electrical explosion or plasma. We proove that this good reactivity is linked to the particles morphology, as well as also to the microstructure of the native alumina core shell

High-energy ball milling to enhance the reactivity of aluminum nanopowders

International audienceHigh-energy ball-milling is proven to be an effective technique for manufacturing reactive aluminum nanopowders. The procedure of milling presented in this work allows the elaboration of aluminum powders with specific surface areas around 20 m 2 /g. The particles have platelet morphology and are constituted by a nanocrystalline aluminum core surrounded by a thick amorphous alumina layer of 4.57 0.5 nm. The reactivity of the powders is enhanced as compared to nanopowders elaborated with techniques involving vapor phase condensation. The morphology, the microstructure and the initial thickness of the alumina layer are shown to be important parameters that influence the reactivity. The method could be extended to any other ductile metal, provided a hard surface layer is continuously formed during milling

Effect of doping on global and local order in crystalline GeTe

International audienceEffect of nitrogen and carbon doping on the structure of GeTe has been investigated using x-ray diffraction and extended x-ray absorption fine structure (EXAFS) spectroscopies. While Bragg diffraction which probes the global structure exhibits a clear transition upon doping from the rhombohedral phase to the cubic (rocksalt) phase, the local structure probed by EXAFS remains rhombohedrally distorted across the compositions studied. The apparent inconsistency between the results of the two techniques used is attributed to disordering upon doping and the resulting order-disorder transition that is “seen” by site-averaging diffraction as a displacive rhombohedral-to-cubic transition

SLAM-associated protein favors the development of iNKT2 over iNKT17 cells.

International audienceInvariant NKT (iNKT) cells differentiate in the thymus into three distinct lineages defined by their cytokine and transcription factor expression. Signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) is essential for early stages of iNKT cell development, but its role during terminal differentiation of iNKT1, iNKT2, or iNKT17 cells remains unclear. Taking advantage of SAP-deficient mice expressing a Vα14-Jα18 TCRα transgene, we found that SAP is critical not only for IL-4 production but also for the terminal differentiation of IL-4-producing iNKT2 cells. Furthermore, without SAP, the IL-17 producing subset is expanded, while IFN-γ-producing iNKT1 differentiation is only moderately compromised. Lack of SAP reduced the expression of the transcription factors GATA-3 and promyelocytic leukemia zinc finger, but enhanced the levels of retinoic acid receptor-related orphan receptor γt. In the absence of SAP, lineage commitment was actually shifted toward the emergence of iNKT17 over iNKT2 cells. Collectively, our data unveil a new critical regulatory function for SAP in thymic iNKT cell fate decisions

A functional mini-GDE transgene corrects impairment in models of glycogen storage disease type III

International audienc

StarPU

StarPU is a runtime system that offers support for heterogeneous multicore machines