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Amélioration de la cinétique de dissolution de la nifédipine cristallisée par procédé anti-solvant de CO2 supercritique
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Conception et évaluation d'environnements virtuels dédiés à la gestion de crise
No full textDuring a crisis, the efficiency and quickness of the response might mean life or death for the victims. Strong knowledge of the situation and an effective decision-making process are crucial to ensure that the crisis will be solved with the minimum damage to people and goods. Two phases of the crisis are then important to consider: the preparation phase and the response phase. They are crucial, but they currently present many drawbacks that limit their effectiveness. The work presented in this manuscript first identifies some drawbacks and limits of crisis preparation and proposes to use virtual reality (VR) to overcome them. To be prepared, crisis responders must regularly organize training exercises to simulate a crisis and rehearse the plans and procedures to solve it. In this work, we propose VR training environments reproducing sensible sites, in which crisis scenarios can be implemented. The objective is to propose several features: (i) a realistic and adaptable environment with multiple training conditions, (ii) a safe environment so users can test different responses without any risks, (iii) the possibility to train as many times as needed with no further costs, (iv) the possibility to record training sessions to analyze and learn from them, and (v) a multi-player environment in which users from different locations can join. Recent advances in technology have made VR and virtual environments (VE) more and more present in our lives. They can be found in various domains and for multiple purposes (medicine, military, teaching, entertaining...). The question of evaluating the maturity of these VEs then arises, to assess whether VEs are effective for their given purpose. This work thus reviews the existing evaluation systems and uses them to build a new evaluation framework that aims to provide two features: (i) a complete and objective evaluation system to assess the maturity of VEs, and (ii) a guide to help VE designers and developers build performant VEs. Regarding the crisis response phase, the difficulty is to get relevant and faithful knowledge of the situation. Gathering and understanding data is crucial but can be complicated, especially in large-scale crises. Decision-support systems are valuable tools to help analyze this multitude of information. VR can also help with the visualization and understanding of that data. In this context, this work uses the proposed maturity framework to design and implement a VR crisis cell, to improve situational awareness and decision-making. The objectives of such a VE are the following: (i) provide a faithful and updated representation of the crisis, (ii) offer multiple points of view on what is happening on-site, (iii) provide a link with a decision-support system to identify the best response to the crisis, and (iv) offer new visualization and analysis tools to understand voluminous data.Pendant une crise, l'efficacité et la rapidité de la réponse peuvent être synonymes de vie ou de mort pour les victimes. Une connaissance approfondie de la situation et un processus décisionnel efficace sont essentiels pour garantir que la crise sera résolue avec un minimum de dommages pour les personnes et les biens. Deux phases de la crise sont alors importantes à considérer : la phase de préparation et la phase de réponse. Bien que cruciales, elles présentent actuellement de nombreux inconvénients qui limitent leur efficacité. Les travaux présentés dans ce manuscrit identifient tout d'abord les inconvénients et les limites de la préparation à la crise et proposent d'utiliser la réalité virtuelle (VR) pour les surmonter. Pour être préparés, les intervenants de la crise doivent régulièrement organiser des exercices d'entraînement pour simuler une crise et répéter les plans et procédures pour la résoudre. Dans ces travaux, nous proposons des environnements de formation en VR reproduisant des sites sensibles, dans lesquels des scénarios de crise peuvent être mis en oeuvre. L'objectif est de proposer plusieurs modules : (i) un environnement réaliste et adaptable avec de multiples conditions d'entraînement, (ii) un environnement sûr pour que les utilisateurs puissent tester différentes réponses sans risque, (iii) la possibilité de s'entraîner autant de fois que nécessaire sans coûts supplémentaires, (iv) la possibilité d'enregistrer les sessions d'entraînement pour les analyser et en tirer des enseignements, et (v) un environnement multi-joueurs dans lequel des utilisateurs peuvent se rejoindre même s'ils sont physiquement distants. Les progrès technologiques récents ont rendu la VR et les environnements virtuels (EV) de plus en plus présents. On les trouve dans divers domaines et à des fins multiples. La question de l'évaluation de la maturité de ces EV se pose alors, afin de déterminer si les EV sont efficaces pour l'objectif qu'ils poursuivent. Ces travaux passent donc en revue les systèmes d'évaluation existants sur lesquels ils se basent pour construire un nouveau cadre d'évaluation qui vise à fournir : (i) un système d'évaluation complet et objectif pour évaluer la maturité des EV, et (ii) un guide pour aider les concepteurs et les développeurs de EV à construire des EV. En ce qui concerne la phase de réponse à la crise, la difficulté est d'obtenir une connaissance pertinente et fidèle de la situation. La collecte et la compréhension des données sont cruciales mais peuvent être compliquées, en particulier dans les crises de grande ampleur. Les systèmes d'aide à la décision sont des outils précieux pour aider à analyser cette multitude d'informations. La VR peut également aider à la visualisation et à la compréhension de ces données. Dans ce contexte, ces travaux utilisent le cadre de maturité proposé pour concevoir et mettre en œuvre une cellule de crise en VR, afin d'améliorer la connaissance de la situation et la prise de décision. Les objectifs d'une telle cellule de crise sont les suivants : (i) fournir une représentation fidèle et actualisée de la crise, (ii) offrir plusieurs points de vue sur ce qui se passe sur place, (iii) fournir un lien avec un système d'aide à la décision pour identifier la meilleure réponse à la crise, et (iv) offrir de nouveaux outils de visualisation et d'analyse pour comprendre des données volumineuses
Automatisation du traitement des media sociaux: opportunités et obstacles identifiés
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Characterization and physical properties of a lunar regolith analog for powder bed fusion-based additive manufacturing processes
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High cycle fatigue behavior of 316L steel fabricated by laser powder bed fusion: effects of surface defect and loading mode
No full textInternational audienceThe mechanical performances of additive manufactured (AM) material are highly dependent on the fabrication process which inevitably results in surface imperfection as well as porosity. In the present study, the high cycle fatigue (HCF) behavior of an AM stainless steel 316L is experimentally investigated to characterize and evaluate the effect of the inherent surface defects. Profilometry and Computed Tomography are used. A series of fatigue experiments is carried out under different loading modes including tension, bending, and torsion fatigue tests. For each loading condition, different surface preparations are used to investigate the effect of surface state. Fatigue tests reveal that surface treatment can improve fatigue performances, the improvements observed being higher under tension/bending loading than under torsion loading. The fractographic analysis is performed for all the available tested specimens to reveal the mechanism of fatigue crack initiation. Lack-of-fusion (LoF) defects play the predominant role in the fatigue performance of SS 316L fabricated by laser powder bed fusion (LPBF). The presence of multiple LoF defects at the surface or subsurface is detrimental to the endurance under cyclic loading. By using Murakami approach modeling the relationship between fatigue strength and defect size, it is found that the multiple clustering defects act synergistically as one large virtual crack to initiate the fatigue crack
Isothermal P, x, y Data for the Nitrogen + Carbon Monoxide System at five Temperatures from 100 to 130 K and Pressures up to 3.4 MPa
No full textInternational audienceIsothermal vapor-liquid equilibrium (VLE) data have been measured for the nitrogen + carbon monoxide binary system at 5 temperatures from 100.01 to 130.07 K, and at pressures from 0.37 to 3.35 MPa. This system had already been studied by different authors. Nevertheless, the existing literature data generally indicate high vapor pressure for pure CO and for the highest CO composition in the N 2-CO binary VLE measurements. Our new VLE data have been measured using the "static-analytic" method, taking advantage of two pneumatic capillary samplers (Rolsi®, Armines' patent) coupled to an adapted apparatus able to work at cryogenic temperatures. The new data were compared with the predictions of the GERG equation of state and their consistency was checked by a Van Ness type test. We have observed that the isothermal P, x, y data were well represented with the Peng-Robinson equation of state, especially in the CO rich region
Addressing the gas kinetics Boltzmann equation with branching-path statistics
No full textInternational audienceThis article proposes a statistical numerical method to address gas kinetics problems obeying the Boltzmann equation. This method is inspired by Monte Carlo algorithms used in linear transport physics, where virtual particles are followed backwards in time along their paths. The nonlinear character of gas kinetics translates, in the numerical simulations presented here, into branchings of the virtual particle paths. The obtained algorithms have displayed in the few tests presented here two noticeable qualities: (1) they involve no mesh and (2) they allow one to easily compute the gas density at rarefied places of the phase space, for example, at high kinetic energy
Dimensionnement optimal d’une armoire de dispensation sous contraintes d’adjacence
No full textInternational audienceThis book is centered around the development of agile, high-performing healthcare institutions that are well integrated into their environment. The aim is to take advantage of artificial intelligence, optimization and simulation methods to provide solutions to prevent, anticipate, monitor and follow public health developments in order to intervene at the right time, using tools and resources that are both appropriate and effective. The focus is on the people involved – the patients, as well as medical, technical and administrative staff – in an effort to provide an efficient healthcare and working environment that meets safety, quality and productivity requirements.Healthcare Systems has been written by healthcare professionals, researchers in science and technology as well as in the social sciences and humanities from various French-speaking countries. It explores the challenges and opportunities presented by digital technology in our practices, organizations and management techniques
Supported Metal Single Atom Catalysis
No full textInternational audienceCovers all key aspects of supported metal single atom catalysts, an invaluable resource for academic researchers and industry professionals alikeSingle atom catalysis is one of the most innovative and dynamic research areas in catalysis science. Supported metal catalysts are used extensively across the chemical industry, ranging from fine and bulk chemical production to petrochemicals. Single atom catalysts (SACs) combine the advantages of both homogeneous and heterogeneous catalysts such as catalyst stability, activity, and high dispersion of the active phase.Supported Metal Single Atom Catalysis provides an authoritative and up-to-date overview of the emerging field, covering the synthesis, preparation, characterization, modeling, and applications of SACs. This comprehensive volume introduces the basic principles of single atom catalysis, describes metal oxide and carbon support materials for SAC preparation, presents characterization techniques and theoretical calculations, and discusses SACs in areas including selective hydrogenation, oxidation reactions, activation of small molecules, C-C bond formation, and biomedical applications. Highlights the activity, selectivity, and stability advantages of supported metal SACs compared to other heterogeneous catalysts Covers applications of SACs in thermal catalysis, electrocatalysis, and photocatalysis Includes chapters on single atom alloys and supported double and triple metal atom catalysts Discusses the prospects, challenges, and potential industrial applications of SACsSupported Metal Single Atom Catalysis is an indispensable reference for all those working in the fields of catalysis, solid-state chemistry, materials science, and spectroscopy, including catalytic chemists, organic chemists, electrochemists, theoretical chemists, and industrial chemists
Instability is the norm! A physics-based theory to navigate among risks and opportunities
No full textInternational audienceMost decision-supports methods are dedicated to the identification and characterization of risks and opportunities. The concrete exploitation of these risks and opportunities is generally depending on the ability of users to analyze multi-dimensional situations, to mobilize their experience and to foresee consequences. In this article, a new and original data science-based vision of risk and opportunity management for decision-making purpose is introduced. The main expected benefit of this vision is to enable decision makers to manage the performance trajectory of a considered system by visualizing and combining the impact of risks and opportunity