31 research outputs found
Une dĂ©marche participative de recherche-intervention au service dâune « gouvernance Ă©mancipatrice »
International audienceCe projet de recherche inscrit en Sciences de lâEducation, a pour objectif de mettre en place une dĂ©marche de recherche collaborative avec les membres du directoire de la plus grande entreprise sociale dâEurope, dans le but de conduire et dâaccompagner le changement de sa gouvernance, vers une « gouvernance Ă©mancipatrice ». ConsidĂ©rĂ©e comme le « cap » Ă©thique et praxĂ©ologique du projet, la « gouvernance Ă©mancipatrice » est une tentative de relever le dĂ©fi dâune Ă©mancipation des contraintes organisationnelles entravant le potentiel crĂ©ateur des acteurs, tout en maintenant une structuration indispensable Ă la rĂ©alisation dâun travail collectif. Lâorganisation sur laquelle porte le projet est une entreprise de 15000 salariĂ©s, dont les secteurs dâactivitĂ© recouvrent la plupart des champs de lâintervention sociale (jeunesse, emploi, handicap, santĂ©, sĂ©niors) et de la nouvelle Ă©conomie (start up, finance solidaire), a en effet toujours Ă©tĂ© dirigĂ©e par son fondateur qui anticipe actuellement la transition de pouvoir. Lâenjeu de ce projet de thĂšse CIFRE est donc, par la mise en place dâune dĂ©marche de recherche-intervention (dĂ©sormais R-I), dĂ©veloppĂ©e au sein de l'UMR EFTS de lâUniversitĂ© de Toulouse Jean JaurĂšs et thĂ©orisĂ©e par Bedin (2013) et Marcel (2015), de rĂ©pondre au double enjeu heuristique de production de connaissances sur cette gouvernance, et praxĂ©ologique de les utiliser pour la transformer en relation avec les professionnels de lâentreprise. Pour cela, la dĂ©marche de R-I a Ă©tĂ© pensĂ©e autour des orientations mĂ©thodologiques suivantes : lâanalyse du fonctionnement de cette gouvernance par une grille dâanalyse multiniveaux (juridique, structurel, stratĂ©gique, anthropologique, hermĂ©neutique et Ă©co-politique), suivie de sa restitution auprĂšs des membres du directoire, qui doit permettre la crĂ©ation de savoirs-hybrides destinĂ©s Ă engendrer un processus de « conscientisation » (Freire, 2001) de leurs pratiques de gouvernance. Cette premiĂšre Ă©tape aboutira ensuite Ă la co-construction de scenarii prospectifs dâĂ©volution de la gouvernance, afin dâenvisager les diffĂ©rentes possibilitĂ©s de parvenir Ă une « gouvernance-Ă©mancipatrice ». Lâaccompagnement du changement vers une « gouvernance Ă©mancipatrice » doit ainsi sâinscrire dans une dĂ©marche de coopĂ©ration du chercheur-intervenant avec les diffĂ©rents groupes dâacteurs, afin dâinitier un changement de regard sur la rĂ©alitĂ© socioculturelle de lâorganisation, puis de co-Ă©laborer avec les acteurs les moyens de sa transformation. Le projet dâune « gouvernance Ă©mancipatrice » sâinscrirait donc dans une dynamique de « rĂ©enchanter le travail » par une reconnaissance de « la force propositionnelle et dĂ©ontique de ceux qui tiennent avec talent le rapport entre travail et Ă©mancipation, pour relayer leur praxis jusquâaux institutions et traduire leur expĂ©rience du monde en art de vivre » (Dejours, 2009)
Treatment of Boiler Condensate by Ultrafiltration for Reuse
The generation of water vapor is crucial for the petrochemical industry. In order to protect the boiler from damage, the re-injected water must not contain any suspended matter, especially hydrocarbons. Moreover, it is condensed steam with a temperature close to 100 °C and the unintentional creation or chronic generation of pollution, respectively, that can more or less produce the concentrated pollution. In this context, membrane processes appear promising in order to achieve this reuse and more especially crossflow ceramic membranes. The novelty of this paper is to study the retention of hydrocarbons and suspended solids contained in the condensate hot water of a high-capacity boiler using ceramic ultrafiltration membranes. In total, two ultrafiltration molecular weight cut-offs were used: 50–150 kDa. Several operating parameters were studied such as effluent type (accidental or chronic pollution), temperature, transmembrane pressure, initial volume, and pilot plant size. In all cases, retention of suspended matter was above 90% and residual hydrocarbon concentrations were under 0.1 ppm even for high-volume concentrations. Control of the transmembrane pressure and the molecular weight cut-off of the membrane are key to optimizing the process. Despite the high-volume concentration obtained, the membranes were perfectly regenerated with conventional cleaning procedures
Treatment of Boiler Condensate by Ultrafiltration for Reuse
The generation of water vapor is crucial for the petrochemical industry. In order to protect the boiler from damage, the re-injected water must not contain any suspended matter, especially hydrocarbons. Moreover, it is condensed steam with a temperature close to 100 °C and the unintentional creation or chronic generation of pollution, respectively, that can more or less produce the concentrated pollution. In this context, membrane processes appear promising in order to achieve this reuse and more especially crossflow ceramic membranes. The novelty of this paper is to study the retention of hydrocarbons and suspended solids contained in the condensate hot water of a high-capacity boiler using ceramic ultrafiltration membranes. In total, two ultrafiltration molecular weight cut-offs were used: 50â150 kDa. Several operating parameters were studied such as effluent type (accidental or chronic pollution), temperature, transmembrane pressure, initial volume, and pilot plant size. In all cases, retention of suspended matter was above 90% and residual hydrocarbon concentrations were under 0.1 ppm even for high-volume concentrations. Control of the transmembrane pressure and the molecular weight cut-off of the membrane are key to optimizing the process. Despite the high-volume concentration obtained, the membranes were perfectly regenerated with conventional cleaning procedures
Remote operated aspiration device for waste lying on the floor of casemates of the STEL installation in Marcoule
International audienceThis article describes the study project and the implementation of the aspiration remote operated device called GOBIE. This robot is being used as part of a project for waste recovery and conditioning. After a presentation of the project context, the missions and objectives of this system, together with the core features shall be detailed hereafter. This includes interesting and innovative subsystems like aspiration, communication, transport and control
Comparison of LPCVD and sputter-etched ZnO layers applied as front electrodes in tandem thin-film silicon solar cells
Aluminum-doped zinc oxide (ZnO:Al) layers deposited by sputtering and boron-doped zinc oxide (ZnO:B) layers deposited by low-pressure chemical vapor deposition (LPCVD) are well-established materials for front electrodes in thin-film silicon solar cells. In this study, both types of front electrodes are evaluated with respect to their inherent properties and their surface textures in micromorph tandem solar cells in the superstrate configuration. The silicon layer stack investigated here consists of a 220-nm-thick amorphous silicon top cell, a 40-nm-thick intermediate reflector and a 1.1-”m-thick microcrystalline silicon bottom cell; for this specific silicon layer stack, the LPCVD ZnO:B provides higher power conversion efficiency than its sputtered ZnO:Al counterpart. The growth-friendly surface topography of ZnO:Al yields better electrical performance. However, tandem cells on ZnO:Al suffer from a fundamental optical limitation in terms of light trapping in the top cell. They also show a higher parasitic absorption linked to the relatively high doping concentration of the ZnO:Al layers used here. Detailed analysis of the experimental results allows us to clearly understand the opto-electrical behavior of both types of cells and envisage several possible upgrades to further improve their performance
Un modÚle autorégressif robuste aux valeurs aberrantes pour le débruitage de données censurées avec application à la surveillance du SARS-CoV-2 par Obépine
16 pages, 13 figuresThis work is motivated by the ObĂ©pine French system for SARS-CoV-2 viral load monitoring in wastewater. The objective of this work is to identify, from time-series of noisy measurements, the underlying auto-regressive signals, in a context where the measurements present numerous missing data, censoring and outliers. We propose a method based on an auto-regressive model adapted to censored data with outliers. Inference and prediction are produced via a discretised smoother. This method is both validated on simulations and on real data from ObĂ©pine. The proposed method is used to denoise measurements from the quantification of the SARS-CoV-2 E gene in wastewater by RT-qPCR. The resulting smoothed signal shows a good correlation with other epidemiological indicators and an estimate of the whole system noise is produced.Ce travail est motivĂ© par le systĂšme français de surveillance de la charge virale SARS-CoV-2 dans les eaux usĂ©es ObĂ©pine. L'objectif de ce travail est d'identifier, Ă partir de sĂ©ries temporelles de mesures bruitĂ©es, les signaux auto-rĂ©gressifs sous-jacents, dans un contexte oĂč les mesures prĂ©sentent de nombreuses donnĂ©es manquantes, censurĂ©es et aberrantes. Nous proposons une mĂ©thode fondĂ©e sur un modĂšle auto-rĂ©gressif adaptĂ© aux donnĂ©es censurĂ©es et aux valeurs aberrantes. L'infĂ©rence et la prĂ©diction sont rĂ©alisĂ©es via un lisseur discrĂ©tisĂ©. Cette mĂ©thode est validĂ©e Ă la fois sur des simulations numĂ©riques et sur des donnĂ©es rĂ©elles d'ObĂ©pine. La mĂ©thode proposĂ©e est utilisĂ©e pour dĂ©bruiter les mesures issues de la quantification du gĂšne E de SARS-CoV-2 dans les eaux usĂ©es par RT-qPCR. Le signal lissĂ© rĂ©sultant montre une bonne corrĂ©lation avec d'autres indicateurs Ă©pidĂ©miologiques et une estimation du bruit de l'ensemble du systĂšme est produite
A Flexible Smoother Adapted to Censored Data With Outliers and Its Application to SARS-CoV-2 Monitoring in Wastewater
A sentinel network, Obépine , has been designed to monitor SARS-CoV-2 viral load in wastewaters arriving at wastewater treatment plants (WWTPs) in France as an indirect macro-epidemiological parameter. The sources of uncertainty in such a monitoring system are numerous, and the concentration measurements it provides are left-censored and contain outliers, which biases the results of usual smoothing methods. Hence, the need for an adapted pre-processing in order to evaluate the real daily amount of viruses arriving at each WWTP. We propose a method based on an auto-regressive model adapted to censored data with outliers. Inference and prediction are produced via a discretized smoother which makes it a very flexible tool. This method is both validated on simulations and real data from Obépine . The resulting smoothed signal shows a good correlation with other epidemiological indicators and is currently used by Obépine to provide an estimate of virus circulation over the watersheds corresponding to about 200 WWTPs
Un modÚle autorégressif robuste aux valeurs aberrantes pour le débruitage de données censurées avec application à la surveillance du SARS-CoV-2 par Obépine
16 pages, 13 figuresThis work is motivated by the ObĂ©pine French system for SARS-CoV-2 viral load monitoring in wastewater. The objective of this work is to identify, from time-series of noisy measurements, the underlying auto-regressive signals, in a context where the measurements present numerous missing data, censoring and outliers. We propose a method based on an auto-regressive model adapted to censored data with outliers. Inference and prediction are produced via a discretised smoother. This method is both validated on simulations and on real data from ObĂ©pine. The proposed method is used to denoise measurements from the quantification of the SARS-CoV-2 E gene in wastewater by RT-qPCR. The resulting smoothed signal shows a good correlation with other epidemiological indicators and an estimate of the whole system noise is produced.Ce travail est motivĂ© par le systĂšme français de surveillance de la charge virale SARS-CoV-2 dans les eaux usĂ©es ObĂ©pine. L'objectif de ce travail est d'identifier, Ă partir de sĂ©ries temporelles de mesures bruitĂ©es, les signaux auto-rĂ©gressifs sous-jacents, dans un contexte oĂč les mesures prĂ©sentent de nombreuses donnĂ©es manquantes, censurĂ©es et aberrantes. Nous proposons une mĂ©thode fondĂ©e sur un modĂšle auto-rĂ©gressif adaptĂ© aux donnĂ©es censurĂ©es et aux valeurs aberrantes. L'infĂ©rence et la prĂ©diction sont rĂ©alisĂ©es via un lisseur discrĂ©tisĂ©. Cette mĂ©thode est validĂ©e Ă la fois sur des simulations numĂ©riques et sur des donnĂ©es rĂ©elles d'ObĂ©pine. La mĂ©thode proposĂ©e est utilisĂ©e pour dĂ©bruiter les mesures issues de la quantification du gĂšne E de SARS-CoV-2 dans les eaux usĂ©es par RT-qPCR. Le signal lissĂ© rĂ©sultant montre une bonne corrĂ©lation avec d'autres indicateurs Ă©pidĂ©miologiques et une estimation du bruit de l'ensemble du systĂšme est produite
Stationary Wave Integrated Fourier Transform Spectrometer (SWIFTS)
International audienc