Ingénierie de la connaissance pour la prévention des risques en santé, sécurité au travail et environnement

Ce rapport de recherche dresse le bilan de cinq années (2009/2013) de collaboration de recherche entre la société Preventeo et le Centre de recherche sur les risques et les Crises (CRC) de MINES ParisTech. A cette fin, il présente les résultats de cinq thèses conduites sur la période. Deux d'entre elles portent sur la démarche de conception de modèles afin de caractériser la maîtrise des conformités en santé, sécurité au travail et environnement. Une troisième thèse traite du concept de culture de sécurité. Enfin, deux thèses ont permis de transformer les modèles en ingénierie, l'une sous la forme d'une ontologie, préalable indispensable à la création de bases de connaissances, l'autre sous la forme d'un tableau de bord pour le management de la santé et de la sécurité au travail

Combined in situ mechanical testing and scale-bridging 3D analysis of nanoporous gold

In this work we present results on in situ small scale testing of nanoporous gold (npg) in scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By combining nano- and micromechanical testing of pillar structures with advanced tomographic imaging, a 3D characterization of the plastic deformation process in different states of deformation is achieved. For small strut sizes 360° electron tomography (ET) is applied enabling high quality reconstructions of the 3D morphology of npg without missing-wedge artefacts. Combining the geometric information with mechanical data from in situ testing in SEM and TEM the yield strength is precisely determined. Furthermore, the experimentally derived 3D data are used as input for large-scale molecular dynamics (MD) simulations in order to understand the role of strain localization and identify predominant defect processes. Please click Additional Files below to see the full abstract

Les centres en France : idéologie et incarnations contemporaines du centre

First, we prove the existence of a specific centrist political thought that goes from Aristotle to French centrist President Valery Giscard d'Estaing. To do so, considering each great age of political thought, we build a syndox (Ancient greek, « common thought ») of thinkers who stood for the virtue of moderation on the field of political thought. Thus we can identify a paradigm of centrist political thought. We then prove this paradigm is an ideology. Secund, we prove contemporary centrist voters (1999-2012) approve this ideology. We also deduct from their preferences among political parties and famous politicians that there are four families embodying Centre: centre-right, centre-left, green-centre, extreme-centre. We also identify parties and politicians that embodied these four families from 1999 to 2012. Third, we identify these four families from French Revolution to nowadays. We also prove, thanks to tools coming from economic science, that financing of political parties is a competitive market, whereas access to seats at National Assembly is a duopoly. We then build a model that allows us to explain and predict tactical choices made by parties: the « GRADD model. » It explains that centre is divided into four families because of divergent tactical preferences when considering both sides of the duopoly. Interviews with major politicians also make it possible to confirm our conclusions.Dans un premier temps, cette thèse démontre l'existence d'une pensée politique spécifique du centre sur le temps long de l'histoire des idées, d'Aristote à Valéry Giscard d'Estaing. Elle établit dans ce but, pour chaque grande époque de l'histoire des idées, un syndoxe (du grec « pensée commune ») des penseurs ayant transposé la vertu de mesure dans la pensée politique. Elle en déduit un paradigme de la pensée politique du centre, et établit que cette pensée politique constitue une idéologie. Dans un deuxième temps, cette thèse démontre que l'électorat contemporain du centre (1999-2012) se reconnaît dans cette idéologie. Elle déduit en outre des préférences partisanes et personnelles de cet électorat l'existence de quatre familles du centre : le centre-droit, le centre-gauche, le centre-vert, et l'extrême centre. Elle identifie par ailleurs les personnalités et partis ayant incarné ces familles du centre de 1999 à 2012. Dans un troisième temps, cette thèse identifie les quatre familles du centre de la Révolution française à nos jours. Elle démontre par ailleurs, en utilisant des instruments de la science économique, que le financement des partis politiques est en concurrence ouverte et que la répartition des sièges à l'Assemblée nationale est en duopole : elle en déduit un modèle explicatif et prédictif des choix tactiques des partis, le modèle GRADD, qui explique l'éclatement du centre en quatre familles par leurs divergences de préférence d'alliances dans le duopole. Des entretiens avec des personnalités politiques emblématiques permettent en outre de valider les conclusions de la thèse

Visual narratives of desired mobilites

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Flood hazard mapping techniques with LiDAR in the absence of river bathymetry data

In many areas of the world, flood risk assessment is either out of date or completely lacking. In Quebec (Canada), one of the challenges to map flood risk is the very large territory combined with very few datasets on river bathymetry, which are required to run hydraulic models. The objective of this study is to assess the precision and accuracy of 2D flood hydraulic modelling exclusively based on LiDAR elevation data which do not include information on in-channel river bathymetry. Hydraulic simulations (HEC-RAS 5.0) are carried out, for discharges of 20-, 100- and 500-year recurrence intervals, using two techniques that do not require bathymetry data, either subtracting discharge of the LiDAR survey from the flood discharge or estimating flow depth from the water surface slope. These techniques are compared to a traditional approach using bed topography obtained from detailed field surveys, on two long reaches (several kilometers). Sensitivity tests were conducted to assess the impacts of the main sources of error on simulated flood levels. Results show that both techniques can be applied with limited introduction of error in the modelled flood stages, and that errors are greatly reduced if calibration data are available

Flood hazard mapping techniques with LiDAR in the absence of river bathymetry data

In many areas of the world, flood risk assessment is either out of date or completely lacking. In Quebec (Canada), one of the challenges to map flood risk is the very large territory combined with very few datasets on river bathymetry, which are required to run hydraulic models. The objective of this study is to assess the precision and accuracy of 2D flood hydraulic modelling exclusively based on LiDAR elevation data which do not include information on in-channel river bathymetry. Hydraulic simulations (HEC-RAS 5.0) are carried out, for discharges of 20-, 100- and 500-year recurrence intervals, using two techniques that do not require bathymetry data, either subtracting discharge of the LiDAR survey from the flood discharge or estimating flow depth from the water surface slope. These techniques are compared to a traditional approach using bed topography obtained from detailed field surveys, on two long reaches (several kilometers). Sensitivity tests were conducted to assess the impacts of the main sources of error on simulated flood levels. Results show that both techniques can be applied with limited introduction of error in the modelled flood stages, and that errors are greatly reduced if calibration data are available

Dynamique photo-induite ultra-rapide de matériaux moléculaire sous pression.

International audienceRecently, material science has moved from observing and understanding electronic and structuralorders to control physical properties of materials on command by using external stimuli such as light.From this point of view, a crucial aspect is the understanding of the fundamental interactions withinthe system (electron-electron and electron-phonon) to control the emergent cooperative effects.Here, we combine ultrafast optical spectroscopy and high-pressure setup to monitor the out-of-equilibirum dynamics of the material under well-defined controlled thermodynamical environnement.The obtained results demonstrate the use of spectroscopy of coherent phonon as a thermodynamicalphase marker of the Metal to Insulator Transition in (EDO-TTF)SbF6

Super-resolved live-cell imaging using Random Illumination Microscopy

International audienceSuper-resolution fluorescence microscopy has been instrumental to progress in biology. Yet, the photo-induced toxicity, the loss of resolution into scattering samples or the complexity of the experimental setups curtail its general use for functional cell imaging. Here, we describe a new technology for tissue imaging reaching a 114nm/8Hz resolution at 30 µm depth. Random Illumination Microscopy (RIM) consists in shining the sample with uncontrolled speckles and extracting a high-fidelity super-resolved image from the variance of the data using a reconstruction scheme accounting for the spatial correlation of the illuminations. Super-resolution unaffected by optical aberrations, undetectable phototoxicity, fast image acquisition rate and ease of use, altogether, make RIM ideally suited for functional live cell imaging in situ . RIM ability to image molecular and cellular processes in three dimensions and at high resolution is demonstrated in a wide range of biological situations such as the motion of Myosin II minifilaments in Drosophila