HAL Université de Toulouse, et Toulouse INP
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Challenges in the direct lithiation of spent LFP cathodes: the crucial role of reducing agents
No full textInternational audienceRecycling spent lithium-ion batteries (LIBs) has become essential for mitigating resource shortages and reducing the environmental impact. Especially with the wide use of LiFePO4 cathodes, LIBs have become one of the most attractive batteries owing to their excellent electrochemical performance, long life cycle, safety and abundant availability of component elements. This article reviews the most advanced recycling technology for spent LFP cathodes: direct chemical regeneration. The literature review presented here focuses on the role of reducing agents. The direct recycling methods aim at repairing degraded LFP cathode materials and thereby reducing energy and chemical needs compared with traditional recycling methods, which are hindered by high energy consumption and secondary pollution. These innovations improve battery cycle life, lower energy consumption and production costs and support sustainable resource management. Direct regeneration technologies offer new opportunities to minimise resource waste and environmental pollution, promoting sustainable management of spent LIBs and advancing renewable energy technologies
Biasing from galaxy trough and peak profiles with the DES Y3 redMaGiC galaxies and the weak lensing mass map
No full textInternational audienceWe measure the correspondence between the distribution of galaxies and matter around troughs and peaks in the projected galaxy density, by comparing \texttt{redMaGiC} galaxies () to weak lensing mass maps from the Dark Energy Survey (DES) Y3 data release. We obtain stacked profiles, as a function of angle , of the galaxy density contrast and the weak lensing convergence , in the vicinity of these identified troughs and peaks, referred to as `void' and `cluster' superstructures. The ratio of the profiles depend mildly on , indicating good consistency between the profile shapes. We model the amplitude of this ratio using a function that depends on cosmological parameters , scaled by the galaxy bias. We construct templates of using a suite of -body (`Gower Street') simulations forward-modelled with DES Y3-like noise and systematics. We discuss and quantify the caveats of using a linear bias model to create galaxy maps from the simulation dark matter shells. We measure the galaxy bias in three lens tomographic bins (near to far): for voids, and for clusters, assuming the best-fit \textit{Planck} cosmology. Similar values with shifts are obtained assuming the mean DES Y3 cosmology. The biases from troughs and peaks are broadly consistent, although a larger bias is derived for peaks, which is also larger than those measured from the DES Y3 -point analysis. This method shows an interesting avenue for measuring field-level bias that can be applied to future lensing surveys
Obsolescence and Availability: The Hidden Challenges of Complex Systems
No full textInternational audienceThe obsolescence challenges associated with rapid technological advances have a significant impact on the overall performance of complex, longlife systems, particularly in sectors such as transportation and heavy industry. This paper addresses these challenges by modeling how obsolescence impacts system availability, reliability, and maintainability considering different categories of item: Make/Buy Repairable and Make/Buy Consumable. Each category encompasses distinct failure, fault and replacement scenarios, which are analysed using flow diagrams. The proposed models provide a systematic understanding of obsolescence mechanisms, including inventory management strategies, repair or replacement paths, and supplier interactions. They also address the progressive decline in availability caused by the obsolescence of components, tools, documentation and technical soft skills. The paper contributes a structured modeling approach based on flow diagrams that links obsolescence scenarios to maintenance decisions, helping anticipate and mitigate performance degradation. By clarifying the decision-making processes inherent in each scenario, the study improves the understanding of the impact of obsolescence on system performance. The article ends with findings and research on predicting system availability under obsolescence
Algèbre homotopique des feuilletages
No full textThere are two natural analogues of algebraic foliations in derived algebraic geometry, called partition Lie algebroids and infinitesimal derived foliations, and both make sense in general characteristics. We construct an equivalence between these two notions under some finiteness conditions. Our method is refining the PD Koszul duality by Brantner--Mathew, Brantner--Campos--Nuiten using the (completed) Hodge filtration.Il existe deux analogues naturels des feuilletages algébriques en géométrie algébrique dérivée, appelés algebroïdes de Lie à partition et feuilletages dérivés infinitésimaux, qui sont tous deux définis en caractéristique générale. Nous construisons une équivalence entre ces deux notions sous certaines conditions de finitude. Notre méthode consiste à raffiner la dualité de Koszul à puissances divisées de Brantner--Mathew, Brantner--Campos--Nuiten en utilisant la filtration de Hodge (complétée)
Design of an Energy Aware Data Replication Strategy for Cloud Systems Using Reinforcement Learning (BDA'2025)
No full textInternational audienceThe rapid growth of global data volumes has created a demand for scalable distributed systems that can maintain a high quality of service. Data replication is a widely used technique that provides fault tolerance, improved performance and higher availability. Traditional implementations often rely on threshold-based activation mechanisms, which can vary depending on workload changes and system architecture. System administrators typically bear the responsibility of adjusting these thresholds. To address this challenge, reinforcement learning can be used to dynamically adapt to workload changes and different architectures. Numerous reinforcement learning based data replication strategies have been proposed in the literature. However, few of them tackle the profitability, a crucial aspect in cloud systems. With the growing interest in the carbon footprint of cloud systems, the previous strategies also fail to study the environmental aspect. In this paper, we propose a novel data replication strategy for cloud systems that employs reinforcement learning to automatically learn system characteristics and adapt to workload changes. The strategy's aim is to provide satisfactory Quality of Service while optimizing a trade-off between provider profit and environmental impact. We present the architecture behind our solution and describe the reinforcement learning model by defining the states, actions and rewards.</div
Safe and wind-aware synchronous path planning for a fleet of fixed-wing constant speed aircraft
No full textPath planning for multiple vehicles is a difficult task, but even more so for fixed-wing aircraft. When flying several of them, multiple constraints may apply: constant airspeed, to maintain optimal operational conditions; synchronous arrival to destination, to achieve formation flight; taking into account wind, for limiting deviation from plan, especially for smaller Unmanned Aerial Vehicles. We present a method to solve this problem based on enumerating variations of Dubins paths until a conflict-free solution is found. This provides a simple and parallelizable scheme that can be extended to handle sequencing tasks. We showcase different situations solved in simulation to illustrate the possible applications: transitions between formations, getting into formation and airport arrival sequencing
Dissolved iron distribution and budget in the Solomon Sea
No full textInternational audienceAs part of the PANDORA cruise (GEOTRACES GP12), concentrations of dissolved iron (dFe) were measured at 11 stations inside and outside the Solomon Sea, a semi-enclosed sea in the western tropical Pacific, with complex topography and straits, and strong western boundary currents supplying the equatorial current system. These measurements aimed to better assess the various sources of dFe in our study area and the Solomon Sea's potential as a source of dFe for the Equatorial Undercurrent (EUC). A simple box model allows calculating and discussing the fate of the dFe in the different water layers flowing through the Solomon Sea and suggests that the amount of dFe enrichment within the enclosed sea was not significant for the lower thermocline and intermediate waters, indicating that most of the dFe was acquired prior to reaching the Solomon Sea at the entrance and/or that inputs are approximately balanced by scavenging within the basin for these two layers. In contrast, dFe enrichment was significant for the upper thermocline layer and the deep waters, highlighting enrichments from external sources, as well as combination of internal processes, such as scavenging and/or organic complexation. The relative dFe contribution of the Solomon Sea to EUC was 20 %, on average. Other sources might thus provide dFe to the EUC, along the water transport downstream of the Solomon Sea (e.g. Bismarck Sea) or from the northern hemisphere. Diazotrophs such as Trichodesmium might also contribute to the dFe enrichment of the EUC after export and remineralization at depth outside the Solomon Sea
Corrélations entre la personnalité du propriétaire et le profil comportemental du chien : vers une optimisation du processus d’adoption
No full textThis study aims to identify combinations of human personality traits and canine temperament that promote a harmonious relationship, in order to reduce adoption failures. Using the Big Five questionnaire (owner) and the DPQ and C-BARQ tools (dog), it analyzes the links between psychological profiles and canine behavior. Results show that certain trait pairings increase relational satisfaction, while others lead to behavioral issues or breakdowns in the bond. Emotional synchronization and affective contagion are also explored to understand mutual adjustment within the dyad. By combining ethology, psychology, and behavioral data, this work proposes compatibility prediction tools and suggests practical criteria to guide adopters toward more sustainable and fulfilling human-dog relationships.Ce travail vise à identifier les combinaisons de traits de personnalité humain et de tempérament canin favorisant une relation harmonieuse, afin de limiter les échecs d’adoption. À partir des questionnaires Big Five (propriétaire), DPQ et C-BARQ (chien), il analyse les liens entre profil psychologique et comportement animal. Les résultats montrent que certaines associations de traits augmentent la satisfaction relationnelle, tandis que d’autres exposent à des troubles ou à une rupture du lien. La synchronisation émotionnelle et les effets de contagion affective sont également étudiés pour comprendre l’adaptation mutuelle au sein de la dyade. En croisant éthologie, psychologie et données comportementales, cette thèse propose des outils de prédiction de compatibilité et suggère des critères concrets pour mieux orienter les futurs adoptants
Prise de décisions des copreneurs et création de valeur en CSE en contexte de crise pandémique: Le cas de biontech fondée par un couple de scientifiques-entrepreneurs
No full textInternational audienceSi la Responsabilité Sociale des Entreprises (RSE) prône un processus vertueux dans lequel la santé pour tous devient égalitaire, éthique et équitable, la crise pandémique (Covid-19) a mis en lumière certaines limites à ce processus. L’objectif de notre recherche est de comprendre les facteurs influençant les prises de décision des copreneurs en termes de Corporate Social Entrepreneurship (CSE) en contexte de crise. Notre revue de littérature explore les interactions entre la CSE et la RSE, notamment sous l’angle de la création de valeurs sociale et économique par les copreneurs. Notre méthode de recherche est qualitative avec l’investigation d’un cas unique : le couple de scientifiques-entrepreneurs fondateur de BioNTech qui développera le vaccin Comirnaty (Pfizer-BioNTech). Nos résultats suggèrent que la CSE, fondée sur un leadership ancré dans les valeurs personnelles des couples dirigeants, constitue un levier d’adaptation pour les entreprises en temps de crise, favorisant la création de valeur durable
