Investigating the microstructure of as-sprayed high-crystalline Yb2Si2O7 environmental barrier coating (EBC) deposited by atmospheric plasma spray (APS)

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Investigating the microstructure of as-sprayed high-crystalline Yb2Si2O7 environmental barrier coating (EBC) deposited by atmospheric plasma spray (APS)

Please click Additional Files below to see the full abstract

Study and Comparison of Surface Roughness Measurements

National audienceThis survey paper focus on recent researches whose goal is to optimize treatments on 3D meshes, thanks to a study of their surface features, and more precisely their roughness and saliency. Applications like watermarking or lossy compression can benefit from a precise roughness detection, to better hide the watermarks or quantize coarsely these areas, without altering visually the shape. Despite investigations on scale dependence leading to multi-scale approaches, an accurate roughness or pattern characterization is still lacking, but challenging for those treatments. We think there is still room for investigations that could benefit from the power of the wavelet analysis or the fractal models. Furthermore only few works are now able to differentiate roughness from saliency, though it is essential for faithfully simplifying or denoising a 3D mesh. Hence we have investigated roughness quantification methods for analog surfaces, in several domains of physics. Some roughness parameters used in these fields and the additionnal information they bring are finally studied, since we think an adaptation for 3D meshes could be beneficial

Quand la recherche-action au doctorat devient possible place à l’artisan-chercheur

Le cheminement prévu pour le doctorat réseau amène certaines contraintes à l’étudiant-chercheur qui souhaiterait opter pour une recherche participative, notamment la recherche-action. Cet article fait état de la réflexion amorcée lors de mon cheminement doctoral concernant la méthodologie et m’ayant mené vers la création d’un modèle hybride. Ce modèle hybride s’inspire en partie du « proactive model research » proposé par Schmuck (2006) ainsi que du modèle proposé par Guay et Prud’homme (2011)

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells

International audienceA methodology is proposed for finding structures that are, optically speaking, locally optimal : a physical analysis of much simpler structures is used to constrain the optimization process. The obtained designs are based on a flat amorphous silicon layer (to minimize recombination) with a patterned anti-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers

Early defect in branching morphogenesis of the ureteric bud in induced nephron deficit

Early defect in branching morphogenesis of the ureteric bud in induced nephron deficit. Development of the metanephric kidney during embryogenesis can be altered both in vivo and in vitro by exposure to gentamicin, which may lead to oligonephronia. To study the role of the ureteric bud in nephron deficit genesis, we used metanephros organ cultures exposed to gentamicin as a model of impaired nephrogenesis. Ultrastructural localization of the antibiotic showed that by eight hours it was already present within the epithelial cells of the ureteric bud and in its growing ends, and also trapped in the adjacent blastema. Using confocal microscopy and image analysis, we devised a quantitative approach to analyze the branching pattern of the ureteric bud, and showed that by 24 hours of culture, despite no change of explants growth, gentamicin had significantly decreased the number of branching points. This effect involved the early branching events and was limited to end buds that had no nephron anlagen nearby. Our findings indicate that impaired branching morphogenesis of the ureteric bud is the likely event of gentamicin-induced nephron deficit

The Late Palaeozoic glaciation subsurface record, Chaco Basin (Bolivia)

Late Palaeozoic glaciation is the longest of the Phanerozoic era. It is recorded in numerous Gondwanian basins, some having a high petroleum potential like the Chaco Basin. In this basin, the quality of the available seismic, well and outcrop data permits to characterise the Late Palaeozoic glacial record. Palaeovalleys >500 m deep and ~7 km wide have here been analysed. Focusing on the glaciogenic Carboniferous deposits, the seismic data with well-ties and their outcrop analogues provide new sedimentological insights. The palaeovalley infill is imaged as a chaotic seismic facies overlain by an aggrading-prograding prism, interpreted as tillites covered by a fluvio-deltaic system respectively. Tillites form both under the ice and during rapid ice recession whereas fluvio-deltaic systems can only originate from a stable ice margin and last until the ice sheets withdraw inland. These two depositional modes are repeated several times generating the progressive burial of the Carboniferous palaeovalleys. This succession of erosions and fills records major glacial stages containing a series of glacial and interglacial phases from the Late Devonian to the Early Permian. Depicting the Late Palaeozoic glacial history of the Chaco Basin seems crucial for the localisation of potential good reservoirs