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Couplage de procédés assistés par CO2 supercritique pour le développement de solides auto-émulsionnables (S-SEDDS)
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DECADOM: solutions for monitoring manufacturing defects
No full texthttps://imtech.imt.fr/en/2022/06/28/decadom-solutions-for-monitoring-manufacturing-defects/IMT Mines Albi and its corporate partner Diota launched the “Inspection 4.0” joint laboratory in 2016 to detect and analyze part manufacturing defects. In 2020, the Decadom project was launched. This initiative has developed inspection solutions based on the use of a scanner hand-held by an operator or mounted on a robot to investigate defects on mechanical parts
DECADOM : des solutions pour contrôler les anomalies de fabrication
No full texthttps://imtech.imt.fr/2022/04/19/decadom-des-solutions-pour-controler-les-anomalies-de-fabrication/Pour analyser les problèmes de fabrication des pièces, IMT Mines Albi et l’entreprise Diota ont mis en place en 2016 le laboratoire commun de recherche « Inspection 4.0 ». Dans le cadre de ce laboratoire commun, ils ont lancé en 2020 le projet Decadom. Cette initiative a permis le développement de solutions d’inspection basées sur l’utilisation d’un scanner porté à la main par un opérateur ou porté par un robot pour étudier les défauts des pièces
Characterisation of recovered carbon black and dispersibility evaluation for eventual valorisation in rubber formulations
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No full textThe co-utilization of biomass and coal in existing coal-based conversion technologies has received increasing interest for its ability to reduce the dependence on fossil fuels and produce high quality products. However, the fuel properties of biomass as a feedstock (high moisture content, low energy density and high O/C ratio) lead to various operational challenges. Torrefaction is considered to be one of the most promising pre-treatment methods for upgrading biomass fuel properties to become more similar to coal. During this process, the physical and chemical properties of biomass as fuel are improved by increasing its energy density, lowering O/C and H/C ratios and inverting its hydrophilic nature. Co-pyrolysis of torrefied biomass and coal has the potential to be an efficient route for converting biomass to bio-energy and bio-refinery products. For example, as a first step in the gasifiers of coal-to-liquid (CTL) industrial plants for the production of Fischer Tropsch fuels. However, to stimulate the transition to bioenergy-based technologies, a reduction in process costs is required. This may be achieved by improving the efficiency of these technologies through a better understanding of the chemistry and physics of this process. While the practical aspects of the pyrolysis process with the successful design, optimization and operation are the principal economic drivers, the control of fundamental chemistry and physics rationalized by effective and accurate reaction modelling is critical. Due to the course of primary and secondary pyrolysis reactions being interwoven, clear limitations of knowledge still exist in the field of modelling, specifically for torrefied biomass. The aim of this thesis was to investigate the yields and composition of products derived during co-pyrolysis of torrefied biomass and coal in order to develop a mechanistic lumped kinetic model (including primary and secondary reactions) applicable to a wide range of operating conditions. To achieve this aim, torrefied biomass was produced at 280 °C in a pilot rotary kiln and subsequently co-pyrolysis was conducted in a fixed bed reactor at variable mix ratios (25-75 wt.%), temperatures (400-600 °C) and pressures (1-30 bar) to investigate the extent of secondary- and synergistic reactions. The results showed that during co-pyrolysis, condensation and dehydration reactions of depolymerized fractions were inhibited in favour of synergistic reactions between the fragments. Furthermore, the presence of coal vapours lead to the significant enhancement of methoxyphenols (guaiacols) and furanics yields, whilst phenol yields were inhibited, suggesting the inhibition of demethoxylation reactions in the presence of coal fragments. These synergistic reactions occurred predominantly in the molten/liquid-phase and the reactor pressure significantly affected these reaction pathways by controlling the evaporation rate of the molten-phase (limiting it at high pressures), thereby favouring molten-phase recombination reactions. The amount of inherent inorganics in the blends also significantly affected the extent of the synergistic reactions by catalysing solid/gas and solid/liquid free radical reactions. Moreover, the pressure promoted the adsorption of volatiles onto the surface of these catalytic sites (primary inorganics) and favoured the production of secondary light oxygenates/char. From these experimental observations, new reaction pathways for the molten-phase reactions were proposed. After concluding on the significant effect of molten-phase synergistic and secondary reactions under slow pyrolysis conditions, an analytical Py-GC-MS/FID study was performed to obtain further insight into the composition of hot pyrolytic volatiles from raw and torrefied biomass, allowing the development of a lumped kinetic model to describe primary reactions of three reference biopolymers (cellulose, hemicelluloses and lignin) in a total of 13 consecutive primary first order reactions. The primary reaction scheme was validated by comparing the model outputs of the reaction scheme to the results of the Py-GC-MS/FID analysis as well as to comprehensive experimental data of bio-oil derived from raw pine sawdust in a fast pyrolysis micropyrolyzer. The model accurately predicted the yields of major pyrolysis products (volatiles and char) as well as the yields of various chemical condensate groups in the bio-oil (maximum deviation < 4 wt.%). The reaction scheme was then further extended to include secondary reactions, which were described in 6 consecutive first order reactions. These reactions included 3 liquid/molten-phase secondary reactions for conversion of high molecular weight depolymerized fragments and 3 gas-phase secondary reactions for conversion of primary volatiles. The secondary scheme was validated by comparing the model outputs to the experimental results derived in the fixed bed reactor at various temperatures and pressures. The comparison of the model outputs and the experimental results were satisfactory and the model predicted the correct trends in product distribution for an increase in pressure: bio-oil yields significantly decreased, whereas gas yields increased. Moreover, the composition of the bio-oil and gas was changed: sugar groups were absent at higher pressures, whereas CO2 and H2 yields increased. The proposed kinetic model was therefore shown to provide adequate descriptions of the yields and composition of pyrolysis products derived from raw/torrefied biomass in different reactor systems (μg- and mg-scale micropyrolyzers and a g-scale fixed bed reactor) for a wide range of process conditions (heating rate, temperature, volatile residence time and pressure) and could easily be incorporated into reactor models during co-pyrolysis reactor design.Non renseign
Modélisation des espèces volatiles produites lors de la torréfaction de la biomasse par apprentissage automatique
No full textNational audienceLa torréfaction est un traitement thermique sous une atmosphère pauvre en oxygène, adapté à la biomasse sèche. Les produits obtenus sont un solide torréfié et des espèces gazeuses : gaz permanents, espèces volatiles et eau. Certaines espèces volatiles peuvent être récupérées comme source de produits à haute valeur ajoutée. Il reste cependant difficile de récupérer les espèces volatiles en raison de leur production hétérogène selon la nature de la biomasse et le niveau de température. Une première tentative de modélisation par une approche additive, où les fractions extraites sont pondérées selon la composition macromoléculaire de la biomasse brute, a été réalisée récemment (González Martínez, 2022). Le travail présenté ici s’inscrit dans la continuité pour développer un modèle prédictif de production des principales espèces volatiles libérées lors de la torréfaction selon une approche statistique basée uniquement sur les données expérimentales
Démarche outillée d'analyse du déroulement du programme au bloc opératoire : application à la régulation
No full textISBN : 9781784058678Leah Rifi, Franck Fontanili, Michel Jeanney. A Tool-based Approach to Analyze Operating Room Schedule Execution: Application to Online Management. Sondes Chaabane; Étienne Cousein; Philippe Wieser. Healthcare Systems : Challenges and Opportunities, Wiley-ISTE, p. 179-193 (chap. 12), 2022, 978-1-78630-799-
Contrôle des interactions interfaciales verre/matrice appliqué à la synthèse in situ du PA6 anionique pour la fabrication des composites
No full textIn situ polymerization is a relevant option for manufacturing thermoplastic composites to overcome the difficulties associated with the high viscosity of their matrices. Therefore, liquid processes such as infusion or RTM, usually used for thermosetting resins, could be applied to thermoplastics. In the case of polyamide 6 (PA6) synthesized by Anionic Ring-Opening Polymerization (AROP), the system composed of monomers, catalyst and activator reacts in contact with the fibers. The surface chemistry is a crucial factor because it not only influences the polymerization and crystallization processes, but it also controls the fiber-matrix adhesion and thus the final properties of the composites. This PhD thesis aims at tailoring the surface chemistry of glass reinforcements to control the interfacial interactions and promote the polymerization of PA6. Glass microparticles with representative size of fiber were chosen. First, it was shown that the hydroxyl groups density on the glass surface affects the polymerization kinetics of PA6. A methodology was developed to carefully control this -OH groups density during the complete surface modification sequence. Then, the particles were treated with various silanes to create different types of interactions. A new route consisting in grafting the monomer onto the glass was proposed. Combining the results of the surface characterization and the properties of the composites, we conclude on the effect of the surface treatment on the polymerization and crystallization of PA6. A manufacturing process was developed to upscale specimen preparation. Finally, the mechanical characterization of the composites highlighted the dominating interfacial phenomena. The optimum grafting and surface treatment type were determined from the resulting macroscopic properties.La polymérisation in situ est une option pertinente pour la fabrication de composites thermoplastiques pour contourner les difficultés engendrées par la forte viscosité de leurs matrices. Ainsi, les procédés liquides de type infusion ou RTM utilisés habituellement pour les résines thermodurcissables pourraient être appliqués aux thermoplastiques. Dans le cas du polyamide 6 (PA6) synthétisé par polymérisation anionique par ouverture de cycle, le système composé de monomères, de catalyseur et d’activateur réagit au contact des fibres. La chimie de surface des renforts est un paramètre crucial car elle influence non seulement les processus de polymérisation et de cristallisation, mais elle contrôle également l’adhésion fibre-matrice et donc les propriétés finales des composites. Cette thèse vise à adapter la chimie de surface du verre afin de maîtriser les interactions à l’interface renfort/matrice pour favoriser la polymérisation du PA6. Des microparticules de verre de taille représentative des renforts fibreux ont été choisies. Tout d’abord, il a été montré que la densité des groupes hydroxyles présents à la surface du verre influence la cinétique de polymérisation et de cristallisation du PA6. Une méthodologie a été développée pour contrôler précisément cette densité des groupes -OH tout au long du processus de modification de surface. Ensuite, les particules ont été traitées avec des agents silanes pour créer différents types d’interactions. Une nouvelle approche qui consiste à greffer le monomère sur le verre a été développée. Les résultats de la synthèse in situ, combinés à la caractérisation de surface des particules, ont permis de déterminer l’effet des traitements sur la polymérisation et la cristallisation du PA6. Un procédé de fabrication a été mis au point pour élaborer des éprouvettes composites. Enfin, la caractérisation mécanique a mis en évidence les phénomènes aux interfaces, permettant ainsi de mesurer l’influence du greffage et du type de traitement de surface sur les propriétés macroscopiques
Predicting Patient’s Waiting Times in Emergency Department: A Retrospective Study in the CHIC Hospital Since 2019
No full textInternational audiencePredicting patient waiting times in public emergency department rooms (EDs) has relied on inaccurate rolling average or median estimators. This inefficiency negatively affects EDs resources and staff management and causes patient dissatisfaction and adverse outcomes. This paper proposes a data science-oriented method to analyze real retrospective data. Using different error metrics, we applied various Machine Learning (ML) and Deep learning (DL) techniques to predict patient waiting times, including RF, Lasso, Huber regressor, SVR, and DNN. We examined data on 88,166 patients’ arrivals at the ED of the Intercommunal Hospital Center of Castres-Mazamet (CHIC). The results show that the DNN algorithm has the best predictive capability among other models. By precise and real-time prediction of patient waiting times, EDs can optimize their activities and improve the quality of services offered to patients
