Portail HAL UHA (Université de Haute-Alsace)
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Machinability analysis of UD-GFRP composites in edge trimming with diamond-coated burr tools at various fiber orientations
No full textInternational audienceMachining operations that are usually required during the manufacturing process of fiber-reinforced polymers (FRPs) are likely to generate numerous specific defects on the machined parts. Cutting tools with specific geometries, such as burr tools with many pyramidal teeth, help to reduce this type of defect. Previous studies in milling with this kind of tool focused mainly on multidirectional (MD) FRP composites. However, it is well known that fiber orientation is a critical parameter in FRP machining. Accordingly, this paper presents a machinability analysis of unidirectional (UD) FRP composites in edge trimming at various fiber orientations, for the specific case of burr tools. Edge trimming experiments are conducted using glass fiber reinforced polymer (GFRP) composites and diamond-coated burr tools. For each machining test, cutting forces, machined surface temperature and surface quality are quantified, as well as defects on external plies, which are characterized with a device specifically developed for this purpose. The results demonstrate that all the parameters are affected greatly by fiber orientation. The maximum temperature rise and the resultant force generally move in the same direction. The surface irregularities, and the maximum rise in temperature, move globally in opposite directions. Uncut fibers on the lower face of the workpiece are related to axial forces and may be facilitated by high temperatures. Moreover, the effect of fiber orientation on cutting forces in the workpiece plane, machined surface temperature and surface quality is analogous to previous literature on orthogonal cutting
« Réunir tous les castors dans une seule main » : les modalités de contrôle de la traite des fourrures au Canada 1674‑1759
No full textInternational audienceDepuis les premiers temps de la colonie, la traite du castor est sujette à un monopole d’exportation, une situation qui ne changera pas jusqu’à la fin du Régime français en dépit des désaccords, voire des conflits que le principe suscite. Jusqu’en 1674, ces droits et l’ensemble de la gestion de la colonie sont cédés à des compagnies de commerce. Comment, après cette date, le monopole de la traite s’est-il articulé avec la politique royale de développement du territoire ? À des échelles différentes, l’emprise du Domaine d’Occident sur ce commerce s’est incarnée dans l’espace et a contribué à le structurer, en lien avec d’autres protagonistes. Au fil des ans et des affermages, des cessions de bail, des transferts de monopole, le contrôle des fourrures s’est régulièrement réorganisé entre les acteurs du commerce canadien. En s’appuyant sur un travail de mise en cartes, le chapitre montre qu’à différentes échelles, le développement de la traite des fourrures, conjugué à sa dimension monopoliste, ont suscité des tensions et créé des incompatibilités politiques et territoriales – à commencer par la place qu’elle doit occuper dans l’économie de la colonie –, mais qu’ils ont aussi contribué de façon plus large au contrôle de la Nouvelle‑France
Continuous production of gold nanoparticles: towards an industrial production
No full textInternational audienceGold nanoparticles (AuNPs) have gained significant attention for their applications in catalysis, sensing, electronics, diagnostics and therapeutics, necessitating scalable and reproducible production methods. Currently established protocols of AuNPs synthesis restrict up-scalability, and thus prevent its industrialization into biomedical fields that could otherwise exploit their ground-breaking assets. This study explores a continuous hydrothermal process for the synthesis of AuNPs using gold trihydroxide (Au(OH)₃) as a chloride-free precursor, compatible with a lab-made industrial-grade equipment. Batch synthesis was first used to determine optimal reaction conditions based on the Turkevich-Frens method, employing trisodium citrate as a reducing agent. These conditions were adapted to a continuous setup operating at high pressure (250 bar) and variable temperatures (100°C-400°C). Under high pressure, well-dispersed AuNPs with different sizes and morphologies were successfully synthesized. Characterizations of sizes, shapes and localized surface plasmon resonance confirmed successful particle formation, and provided information about dispersion state and optical properties. The system enabled steady AuNPs production with minimal loss, demonstrating a promising route for scalable and controlled AuNPs synthesis suitable for biomedical applications
Persulfate activation by Fe-rich biochar from sewage sludge digestate for organic pollutants removal: performance and superoxide radical role
No full textInternational audienceHerein, an innovative methodology aimed at the valorization of sewage sludge through advanced treatment and utilization strategies, thereby fostering a circular economy while attaining both ecological and economic advantages. The research involved a two-step process: an initial Fenton-like chemical pretreatment to enhance sludge biodegradability, followed by anaerobic digestion (AD) to yield methane as an energy source. Subsequently, the iron-rich digestate generated from this process was subjected to pyrolysis, resulting in iron-rich biochar (FBC-600). As a catalyst, FBC-600 accelerated the degradation of Orange G (OG) via persulfate (PS) activation. Under optimized conditions (0.5 g/L FBC-600, 10 mM PS, 50 mg/L OG), 100 % of OG removal was achieved within 60 min. Notably, FBC-600/PS system exhibited remarkable stability and robustness against variations in pH (from 3 to 11), coexisting anions, tap water, and using other common organic pollutants. The FBC-600/PS system exhibited an activation energy of 14.88 kJ/mol and retained 88.9 % OG removal efficiency after five reuse cycles. ensuring consistent performance. Furthermore, mechanistic investigations revealed that the synergistic interaction of oxygen-containing groups (OFGs), iron and nitrogen species, and structural defects synergistically promoted PS activation and enhanced reactive oxygen species (ROS) production. Quenching experiments and electron paramagnetic resonance (EPR) confirmed the predominant role of radical species, particularly O, in the degradation of OG. In the context of the circular economy, the as-developed FBC-600, estimated at 3210 US$/t. Hence, this work highlights a sustainable “waste-to-resource” approach for water treatment, offering both ecological and economic benefits
Impact of Graphite Properties and Electrode Formulation on Potassium-Ion Battery Performance and Storage Mechanisms
No full textInternational audienc
Automated Coding of French Emergency Calls Using BERT
No full textEmergency Medical Dispatch Centres (EMDC) in France are facing a growing number of calls, each requiring a rapid and efficient response, leaving no time for emergency medical dispatchers to code case files. However, this coding is essential for improving patient care through epidemiological analysis and, ultimately, for developing a decision support system. This study explores the use and deployment of natural language processing (NLP) models to automatically code records in French, based on the notes taken by call takers during emergency calls. Our work investigates fine-tuned biomedical pre-trained encoder models models for classifying highly noisy medical records, demonstrating that these models can successfully accomplish this task with a high F1 score (94%) without requiring more computationally expensive language models. To ensure the longterm reliability of the models, validation methods specifically addressing the challenges posed by EMDC data were developed. NLP can automate the coding of EMDC call records with a high degree of accuracy. However, the models currently rely solely on the written notes in the files. Future work incorporating call transcripts could further enhance their accuracy
La relation à la marque du Z consommateur : une étude exploratoire des causes de détachement
No full textNational audienceThe objective of this qualitative research, conducted with 130 GenZers, and using consumer narratives, is to explore the reasons of brand attachment and brand detachment of this specific group. The analysis of the data collected,analyzed through the prism of the functional attitude theories, highlights different factors according to the product category to which the mentioned brands relate (ready-to-wear vs. food) and underlines that the reasons which anchored attachment are not always those that explain detachment. More specifically, if the utilitarian function is the most prominent in justifying attachment, the expression of values, not only ethical but also related to identity, becomes more significant in explaining detachment from fashion brands, while it is the ego-defensive function that dominates when it comes to food. Recommendations for brand managers are provided in order to meet consumer expectations and anticipate brand detachment.L’objectif de cette recherche qualitative, menée auprès de 130 consommateurs de la génération Z par l’approche des récits de consommation, est d’explorer les raisons de l’attachement à la marque et du détachement pour ces consommateurs. L’analyse des données, via le prisme des théories fonctionnelles des attitudes, permet de préciser les types de facteurs en fonction de la catégorie de produit à laquelle se rattachent les marques citées (prêt-à-porter vs alimentaire) et de montrer que les raisons qui fondent l’attachement ne sont pas toujours celles qui expliquent le détachement. En particulier, si la fonction utilitaire est la plus saillante pour justifier l’attachement, l’expression de valeurs éthiques mais surtout identitaires, devient plus prégnante pour expliquer le détachement des marques de vêtements, tandis que c’est la défense de l’égo qui domine pour l’alimentaire. Un ensemble de recommandations est proposé pour répondre aux attentes des consommateurs et d’anticiper le détachement de la marque
Combining client-based anomaly detection and federated learning for energy forecasting in smart buildings
No full textInternational audienc
The football model, stochastic ordering and martingale transport
No full textTournaments are competitions between a number of teams, the outcome of which determines the relative strength or rank of each team. In many cases, the strength of a team in the tournament is given by a score. Perhaps, the most striking mathematical result on the tournament is Moon's theorem, which provides a necessary and sufficient condition for a feasible score sequence via majorization. To give a probabilistic interpretation of Moon's result, Aldous and Kolesnik introduced the football model,the existence of which gives a short proof of Moon's theorem. However, the existence proof of Aldous and Kolesnik is nonconstructive, leading to the question of a ``canonical" construction of the football model. The purpose of this paper is to provide explicit constructions of the football model with an additional stochastic ordering constraint, which can be formulated by martingale transport. Two solutions are given: one is by solving an entropy optimization problem via Sinkhorn's algorithm, and the other relies on the idea of shadow couplings. It turns out that both constructions yield the property of strong stochastic transitivity. The nontransitive situations of the football model are also considered
Influence du mouvement du doigt sur les vibrations induites et sur la perception du toucher de surfaces texturées
No full textInternational audienceInfluence du mouvement du doigt sur les vibrations induites et sur la perception du toucher de surfaces texturée