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Digital Transformation of Hospitals: How to Collaborate with Start-Ups? The Case of Setting up a Telesurveillance Activity as an Organizational Dispositive
No full textInternational audienceEncouraged by healthcare policies, start-ups are developing digital tools to meet the needs of hospitals. These collaborations carry multiple issues as innovation, exploration, and organizational learning. Yet, few studies analyse the joint actions of hospital actors and start-ups. Drawing on a longitudinal case study, the objective of this article is to retrace the construction of a distributed collective action among actors with complementary roles aiming to both design a digital tool, foster its appropriation, and to strengthen its institutional recognition. We will particularly examine the progressive arrangement of heterogeneous elements leading to a process of “dispositive organizational setting up”. This approach highlights the interdependencies between institutionalization and appropriation process, as well as organizational learning related to collaborations between start-ups and hospital players
Métabolisme dans les eaux du bassin de la Seine au regard de la matière organique Sous la direction de: Fascicule #28 du PIREN Seine
No full textInternational audienceLe cycle du carbone est fondamentalement lié au vivant et il est au coeur de la notion d’Anthropocène. Cette ère incarne l’altération des grands cycles naturels par l’humanité jusqu’à avoir franchi des seuils d’irréversibilité par rapport à l’ère de relative stabilité géologique qu’est l’Holocène. Même si des frémissements se font sentir dès l’Antiquité, cet emballement n’a démarré qu’au début de la révolution industrielle. Deux cents ans auront ainsi suffi pour dévier de la stabilité d’une ère qui en comptabilise onze mille sept cents.Le carbone est, quant à lui, un élément constitutif du métabolisme des organismes, du métabolisme des rivières au sens d’équilibre entre production et consommation de matière organique, mais également du métabolisme territorial, qui désigne l’ensemble des flux d’énergie et de matières mis en jeu par le fonctionnement d’un territoire donné. Ces trois types de métabolismes ont notamment en commun de consommer de l’énergie pour produire, entre autres, de la matière organique, et de générer des émissions de gaz avec des effets radicalement opposés : oxygène versus gaz à effet de serre (GES) comme le dioxyde de carbone (CO2) ou le méthane (CH4).S'il existe depuis 2006 un bilan annuel du carbone émis à léchelle globale, cette évaluation n'intègre toujours pas le métabolisme des eaux de surface et des estuaires. Pour autant, il apparaît en outre que les systèmes fluvio-estuariens sont en fait beaucoup plus auto-alimentés en carbone atmosphérique par les processus de photosynthèse et d’échange air-eau que ne le prévoit le concept de « tuyau actif », qui ne s’appuie que sur les processus internes aux cours d’eau. Les grands axes des systèmes fluviaux sous un climat tempéré semblent sursaturés en CO2, avec un impact important des effluents des stations d’épuration sur les cours d’eau.Les changements globaux n’entraînent pas seulement des modifications de la quantité absolue de carbone sous forme de gaz à effet de serre, mais affectent également le carbone inorganique et organique, dissous et particulaire. En ce qui concerne le carbone organique, la composition chimique est également modifiée par les processus biogéochimiques qui la régissent et en particulier l’activité des microorganismes. En retour, ces changements dans la composition du carbone organique influencent également l’activité hétérotrophe, la libération de CO2, la biogéochimie des nutriments et des polluants, et la formation de sous-produits de désinfection (Zhuang et Yang, 2018).Au delà des aspects climatiques et malgré un rôle clé dans les processus environnementaux, la composition et la réactivité de la matière organique (MO) sont encore mal comprises. Il est notamment essentiel d’améliorer les connaissances sur les propriétés physico-chimiques des différentes formes de la MO. En effet, non seulement la quantité de carbone organique dissous , mais aussi et surtout sa qualité, reflètent l’interaction dynamique entre les sources de MO et les processus biogéochimiques et sont susceptibles d’avoir des répercussions écologiques. Comprendre ces dynamiques du carbone est indispensable pour la modélisation de la qualité de l’eau le long du continuum aquatique des cours d’eau incluant d’autres compartiments, tels que les lacs et réservoirs, les zones humides et les interfaces nappe-rivière.Le présent fascicule fait ainsi état des travaux menés par le PIREN-Seine sur ce lien étroit entre métabolisme des rivières et matière organique, structuré autour des deux axes de la démarche scientifique du programme : observations (Chapitres 1 et 2) et modélisations (Chapitres 3 et 4)
Élaboration d'une Méthode d'Évaluation du Potentiel Énergétique pour les Projets de Renouvellement deParcs Éoliens
No full textFor new wind farm investments, including repowering, two key metrics are crucial: the estimated annual energy production and its associated uncertainty. Investors seek low uncertainty, which hinges on accurately estimating the uncertainty itself. This creates two research goals: 1) reducing uncertainty through improved climate and wind farm modeling—current methods still range from 6% to 12% uncertainty, and 2) refining the reliability of uncertainty models with better and faster propagation techniques. State-of-the-art EYA methods are well-accepted in the industry, but reducing uncertainty offers significant financial advantages. Repowering offers a new opportunity for EYA since it benefits from extensive historical data from the existing site, including 10-minute energy production records. This thesis aims to incorporate this data into the EYA process while to improve both accuracy and reliability. Most studies overlook uncertainty or fail to quantify improvements. This thesis proposes a method that achieves reliable AEP estimates with better uncertainty predictions.Pour tout investissement dans un parc éolien, y compris dans le cadre du renouvellement, deux indicateurs clés sont essentiels : l'estimation de la production annuelle d’énergie et l'incertitude qui y est associée. Les investisseurs favorisent les projets à faible incertitude, ce qui dépend de la fiabilité de son estimation. Cela crée deux objectifs de recherche : 1) réduire l'incertitude grâce à une meilleure modélisation du climat et des parcs éoliens — les méthodes actuelles affichent encore des incertitudes de l'ordre de 6 % à 12 %, et 2) affiner la fiabilité des modèles d'incertitude avec des techniques de propagation plus rapides et plus précises. Les méthodes actuelles sont bien acceptées dans l'industrie, mais réduire l'incertitude offre des avantages financiers importants. Le renouvellement représente un nouveau défi car il bénéficie de nombreuses données historiques du site existant, y compris des enregistrements de production énergétique toutes les 10 minutes. Cette thèse vise à intégrer ces données dans le processus d’estimation du productible. La plupart des études existantes négligent l'incertitude ou ne parviennent pas à en quantifier les améliorations. Cette thèse propose une méthode qui fournit des estimations fiables de la production annuelle avec des prédictions d'incertitude améliorées
Experimental VLE Data and Thermodynamic Modeling of the Ethane + Hexafluoropropylene Oxide (HFPO) System
No full textInternational audienceThis study presents experimental vapor-liquid equilibrium (VLE) data for two fluorinated-based systems. Experimental VLE data for the R116 + propane system at 292.22 and 296.93 K were initially undertaken to validate the experimental setup and procedure. Subsequently, VLE data for the ethane + HFPO system were measured at five isotherms (283.39, 290.32, 298.67, 308.42, and 318.45 K), encompassing three below and two above the critical temperature of ethane, the more volatile component. The measurements were conducted using a static-analytical setup, with equilibrium-phase sampling performed via a capillary sampler and composition analysis carried out using gas chromatography. The uncertainties in the measurements were estimated to be within 0.07 K for temperature, 11 kPa for pressure, and 0.009 and 0.008 mole fractions for the liquid- and vapor-phase compositions, respectively. Thermodynamic modeling of VLE data for the two systems was undertaken using the homogeneous "Phi-Phi" approach, employing the Peng-Robinson equation of state with the Mathias-Copeman alpha function. A combination of the Wong-Sandler mixing rule with the nonrandom two-liquid activity coefficient model was utilized to account for fluid mixture behavior. This modeling approach yielded satisfactory results, as shown by AAD xy and bias xy values of less than 3%
Optimisation factorielle à plusieurs niveaux du rapport acide/minerai et de la concentration des solides dans la récupération hydrométallurgique du nickel à partir de minerais latéritiques
No full textInternational audienceThis study applies a multilevel factorial design to optimise nickel (Ni) extraction in a High-Pressure Acid Leaching (HPAL) autoclave, examining the influence of slurry solid content and acid-to-ore (A/O) ratio on Ni yield, selectivity (Ni/(Al+Fe)), and scale formation. A regression model was established to predict these responses across varying A/O ratios and solid contents. Using Minitab® statistical software, response surface methodology (RSM) was employed to identify process conditions that balance maximised Ni yield, enhanced selectivity and reduced scale formation. To predict outputs beyond the experimental range, the complex models generated in Minitab® were simplified into ‘linear + quadratic + interaction terms’ using the least squares method in Matlab®. Results indicate that higher Ni yield (> 95 wt.%) is achieved at a lower slurry solid content (< 27 wt.%) and higher A/O ratios (> 0.35), whereas higher solution purity (selectivity > 3) is favoured at lower A/O ratios with preferably lower solid content (∼22 wt.%). Scale formation increases significantly with higher solid content and A/O ratios exceeding 0.35. Optimisation revealed that a compromise between Ni yield, selectivity, and scale minimisation is necessary, with the highest composite desirability (0.68) obtained at 22 wt.% solid content and an A/O ratio of 0.35. The findings provide valuable insights for industrial leaching process optimisation, highlighting the trade-offs between maximising Ni recovery, limiting impurity dissolution and minimising scale formation
All-day radiative cooling with superhydrophobic, fluorine-free polydimethylsiloxane-embedded porous polyethylene coating
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Comparative analysis of thermal management systems in electric vehicles at extreme weather conditions: Case study on Nissan Leaf 2019 Plus, Chevrolet Bolt 2020 and Tesla Model 3 2020
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Evidence for the stabilization of FeN sites by Pt particles during acidic oxygen reduction
No full textInternational audienceWhile Fe–N–C materials have shown promising initial oxygen reduction reaction (ORR) activity, they lack durability in acidic medium. Key degradation mechanisms include FeN site demetallation and deactivation by reactive oxygen species. Here we show for mainstream Fe–N–Cs that adding 1 wt.% Pt nanoparticles via a soft polyol method results in well-defined and stable Pt/Fe–N–C hybrids. The Pt addition strongly reduces the H2O2 production and Fe leaching rate during ORR, while post mortem Mössbauer spectroscopy reveals that the highly active but unstable Fe(III)N4 site is partially stabilized. The similar HO electroreduction activity of Pt/Fe–N–C and Fe–N–C and other analyses point toward a long-distance electronic effect of Pt nanoparticles in stabilizing FeN sites. Computational chemistry reveals that spin polarization of distant Pt atoms mitigates the structural changes of FeN sites upon adsorption of oxygenated species atop Fe, especially in high-spin state
Incremental global asymptotic stability equals incremental global exponential stability - but at equilibria.
No full textInternational audienceIncremental stability has become increasingly common in the context of nonlinear control. However, there is a lack of understanding of the difference between several notions of incremental stability. The objective of this paper is to show that the notion of incremental global asymptotic stability is very similar to that of incremental global exponential stability. In particular, nonexponential relaxation of the convergence rate appears only "locally" but not "globally." Some examples are provided to justify our theoretical arguments
Enhancing Safety Performance through Cultural Maturity: A Comprehensive Framework for Multinational Oil and Gas Operations
No full textInternational audienceThis article presents the results of a major HSE Review conducted through four subsidiaries of an oil & gas company to provide insights and recommendations to enhance the current HSE system. The analysis was carried out for subsidiaries in North America, Middle East and Western Europe. It has required about 600 documents reviewed, more than 100 interviews conducted, about 130 hours of Field visits to evaluate HSE system implementation effectiveness, and more than 1500 Safety climate survey participants. The methodology relies on one hand, on a Safety Culture Maturity framework to analyze perceptions at different levels of the organization, and on the other hand, on expert judgment following field observations and interactions with workforce and management across all subsidiaries. The overall results highlight perceived strengths and gaps in the current different elements of Safety culture at each subsidiary and highlight specific perceived strengths and shortcoming in Safety Culture. A second section of the article discusses how maturity models can be a legitimate tool despite some inherent limitations underlined by part of the safety science research community, alongside a consideration of some common critique of the safety culture construct. The article gives an illustration of how practitioners can use maturity models and how the results support the setting of improvement plans that integrate key risk themes to drive effective & sustainable enhancement. We also a gue f om a safety p a t t one 's po nt of v ew that us ng matu ty mo els g ve the oppo tun ty to ve owne sh p an commitment processes that may be eventually more important that the deliverables. The paper provides elements for a better understanding of how underpinnings of maturity models articulate with assessment of safety culture and explore their methodological properties to show how some theoretical weaknesses can paradoxically become competitive advantages in the practical implementation of safety improvement approaches