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Alteration of archeological and natural analogues for radioactive waste glass under different environmental conditions
No full textInternational audienceHundreds of thousands of cubic meters of legacy radioactive waste from plutonium production stored at U.S. Department of Energy's Hanford site will be immobilized in glass for disposal.The glass must limit radionuclide release into the environment for thousands of years, which is challenging to assess in laboratory experiments. Long-term alteration behavior of analogue glasses can approximate how radioactive waste glass will perform over extended periods.Different glasses buried for tens to thousands of years at sites subject to variable climates and environments were selected for analysis, based on their fulfillment of criteria to be analogues for waste glass. Surface altered layers that formed during glass corrosion were characterized using X-ray tomography, SEM, XRD, EMPA and ToF-SIMS. The thickness, chemistry, and morphology of alteration layers are discussed in terms of glass chemistry and burial conditions.A key finding is that glass in arid environments, e.g., Timna (Israel), exhibits thinner surface layers (~2 µm) compared to glasses altered in humid conditions, e.g., Dobkowice (Poland: up to 59 µm), suggesting the important roles of burial environment and climate in determining glass durability. Newberry (USA) obsidian (1,350 years old) had alteration layers ~15 µm, while Broborg (Sweden) glass (1,500 years old) exhibited layers as thin as 8 µm. Quantification of archeological and natural analogue glass alteration upon exposure to variable environmental factors provides a unique insight into long-term glass alteration behavior. These findings support the use of glass for radioactive waste disposal at Hanford, and are applicable globally to disposal in near-surface facilitie
Seeing the Middle: Reconstructing 3D Internal Electrode Microstructures from Low‐Resolution Surfaces with Generative Diffusion Artificial Intelligence
No full textInternational audienceCharacterizing the 3D complex energy materials interface is critical to understand the correlative relationship between performance, degradation, and structures. Unfortunately, the resolution of microscopy and image acquisition speed are limited by the nature of the hardware, causing high‐throughput characterization of energy materials to be prohibitive. Herein, REMind, a generative diffusion artificial intelligence model for fast and accurate reconstruction of electrode microstructures via focused ion beam‐scanning electron microscopy, is presented. REMind can generate high‐resolution internal microstructures between two low‐resolution surfaces after training on sufficient high‐resolution microstructures, enabling larger milling thickness between slices while keeping high‐fidelity imaging. REMind is first demonstrated for reconstructing solid oxide fuel cell (SOFC) anode microstructures. REMind resolves relevant multi‐scale structures with low pixel‐wise reconstruction error (<10%) and quantifies the generated uncertainty by calculating the generated entropy. Additionally, a multi‐scale multi‐physics SOFC model is employed to further quantify the reconstructed error regarding the electrochemical performance, i.e., operating current density versus overpotential. REMind shows good transferability, as proven by its ability to reconstruct other energy materials, including catalyst layers of proton exchange membrane fuel cells and solid‐state battery composite electrodes, demonstrating the potential for REMind to be used as a general‐purpose platform for broad development of energy technology
Can sulfide solid electrolytes for lithium-ion batteries be handled in dry rooms? – A multiprobe approach
No full textInternational audienceSulfide-based solid electrolytes (SSEs) are promising for solid-state batteries (SSBs) due to their high room-temperature ionic conductivity and scalability. However, their strong moisture sensitivity hinders safe handling, even in dry-room atmospheres. Although hydrolysis has been extensively studied on SSE powders, there is a lack of understanding of its mechanism at multiple length scales in SSE pellets. Herein, we investigate the transformations occurring within a commercial Li₃PS₄ SSE exposed to humidity at dew points (D.P.) of -40 • C and 12 • C using a multi-technique approach, including X-ray nano-tomography and X-ray diffraction computed tomography, to systematically track morphological and chemical changes. Results reveal that SSE hydrolysis is a complex, multi-step cyclic process in which chemical and morphological evolution are closely linked. The main stages identified include a fast reaction at the pellet surface, leading to the formation of new compounds and accumulation of structural strains in the SSE main phase. It is subsequently followed by crack propagation and porosity increase, promoting deeper humidity penetration into the bulk of the pellet and exposing fresh surface to further hydrolysis. Comparison with another commercial SSE, Li₆PS₅Cl, provides broader insight into humidity-driven degradation mechanisms. This research provides practical guidance for handling SSEs in dry room environments and highlights the potential consequences of accidents involving ruptured SSB packages. The multi-probe approach presented here can be applied to a wide range of SSB components to quantify safety risks and performance impacts. These insights can help optimize dry room conditions and reduce the overall cost of SSBs processing
From Genes to Landscapes: Predicting the Resilience of Ungulate Populations
No full textInternational audienceUnderstanding how environmental change shapes genetic diversity is essential for predicting species resilience. Using large-scale genomic data, spatial modelling, and climate reconstructions, we explore how past and future landscape dynamics influence the genetic structure of ungulate populations across contrasting environments. First, we show how Pleistocene climate oscillations generated strong phylogeographic structure in caribou (Rangifer tarandus), with genetic diversity hotspots corresponding to regions of long-term climatic stability. Second, through spatially explicit simulations, we demonstrate that limited dispersal and topographic barriers have shaped the genomic structure of Northern chamois (Rupicapra rupicapra) in the Alps since the last glaciation. Finally, integrating genotype–environment associations reveals patterns of local adaptation and predicts how future climatic changes may disrupt adaptive genetic variation. Together, these results illustrate how combining genomic data with landscape and climate models helps anticipate population responses to global change. This interdisciplinary framework provides a scalable approach to forecast the evolutionary potential and resilience of mountain ungulates and other species under accelerating climate change
Une loi de finances pour 2025, Enfin !
No full textLe Club des juristesLe budget 2025 a été définitivement adopté par le Parlement grâce à l’article 49 alinéa 3 et au rejet assez net d’une motion de censure. Moins ambitieux sur la trajectoire budgétaire que le projet initial de Michel Barnier, le texte est le fruit d’un compromis. Si le Conseil constitutionnel a été saisi du texte et qu’il faut s’attendre à la neutralisation de certaines dispositions, la loi de finances devrait permettre de sortir du fonctionnement minimum qu’imposait la loi de finances spéciale
Cadmium et autres contaminants métalliques dans le cacao : Mise à jour des connaissances actuelles et des stratégies d'atténuation
No full textInternational audienceCadmium (Cd) is a non-essential metal classified as class 1 carcinogen, which can induce detrimental effects for humans. Food is the main route of Cd exposure for the general population (except smokers). Chocolate products account for 4% and 9% of the dietary Cd intake for adults and children, respectively, in Europe. Since 2019, the EU limits Cd concentration in chocolate. The maximum permitted concentration (MPC) varies from 0.30 to 0.80 mg Cd kg −1 depending on the% of total cocoa solids in the final product. Cacao ( Theobroma cacao L.) producers in Latin America and the Caribbean, who provide 19.4% of global cacao production, are strongly impacted because a significant fraction of their production exceeds these limits. In this review, the current knowledge on the factors influencing the soil Cd enrichments and Cd phytoavailability is discussed. The Cd transfer to cacao trees and to beans, and the responses of cacao trees to Cd exposure are also presented. Then, various mitigation strategies, including post-harvest treatments, soil amendments, microbial remediation (or bioremediation), breeding programs and grafting, are summarized. We also discuss the transfer of knowledge to stakeholders in the cacao supply chain. Finally, current knowledge on the presence of other metallic contaminants in cacao beans, particularly nickel (Ni), is reviewed.Le cadmium (Cd) est un métal non essentiel classé comme cancérogène de classe 1, qui peut avoir des effets néfastes sur l’Homme. L'alimentation est la principale voie d'exposition au Cd pour la population générale (à l’exception des fumeurs). En Europe, les produits à base de chocolat représentent 4% et 9% de l'apport alimentaire en Cd chez les adultes et les enfants, respectivement. Depuis 2019, l'UE limite la concentration de Cd dans le chocolat. La limite maximale pour cette concentration varie de 0,30 à 0,80 mg Cd kg −1 selon le pourcentage de cacao solide total dans le produit final. Les producteurs de cacao ( Theobroma cacao L.) d'Amérique latine et des Caraïbes, qui fournissent 19,4% de la production mondiale de cacao, sont fortement impactés puisqu'une fraction importante de leur production dépasse ces limites. Dans cette revue, les connaissances actuelles sur les facteurs influençant l'enrichissement en Cd du sol et la phytodisponibilité du Cd sont discutées. Le transfert du Cd vers les cacaoyers et les fèves, ainsi que les réponses des cacaoyers à l’exposition au Cd sont aussi présentés. Les stratégies d'atténuation, en particulier les traitements après récolte, l’apport d’amendements au sol, la remédiation microbienne ou bioremédiation, la sélection de variétés et le greffage, sont ensuite résumés. Nous discutons également du transfert de connaissances aux parties prenantes de la chaîne d'approvisionnement en cacao. Enfin, les connaissances actuelles sur la présence d'autres contaminants métalliques dans les fèves de cacao, en particulier le nickel (Ni), sont présentées
Charge signal formation in the TPC Vertical Drift design of DUNE
No full textInternational audienceGiant Liquid Argon Time-Projection Chambers (LArTPC) will be used for the far detectors of the next generation of neutrino oscillation experiment: Deep Underground Neutrino Experiment (DUNE). This work focuses on the design of the Vertical Drift module (DUNE-VD), where the chamber consists of two drift volumes separated by a central cathode. This novel anode enables the detection of the ionization electrons through two inductions views and a charge collection view. Extensive R&D has been carried out at CERN in the past years to optimize the VD anode design. In this paper, a numerical simulation of the signal formation based on the Shockley-Ramo’s theorem and the physics of charge carriers’ motion in liquid argon will be presented. Comparisons with radioactive sources data taken at CERN with prototypes will be shown. A good understanding of the collected signal shape and strength is essential to achieve the track reconstruction efficiency and the calorimetric measurement resolution needed by the DUNE experiment to study neutrino oscillations.Key words: Simulation / Charge Signal and LArTP
Impact of a shared medical decision-making aid on patient decisional conflict regarding human papillomavirus vaccination: a mixed-methods study
No full textInternational audienceIntroduction: Human papillomaviruses (HPVs) cause several vaccine-preventable cancers, including cervical cancer. In France, HPV vaccination coverage remains low. Decision aids (DAs) can help individuals make informed health choices. This study assessed the impact of an online DA (SOSHPV) on decisional conflict and vaccination intention, and explored user perceptions in real-life contexts.Methods: A convergent mixed-methods design was used (November 2023-June 2024). The quantitative component included a pre-post questionnaire assessing knowledge, vaccination intention, and decisional conflict. The qualitative component involved semistructured interviews with a subsample of users, analyzed using grounded theory.Results: Among 943 website visitors, 187 participants (54 males, 12 adolescents) completed the presurvey, and 44 (12 males, 6 adolescents) completed both assessments. Over half (54%) were young parents using the tool to support HPV vaccination decisions for their child. Post-intervention, knowledge improved (P < 0.001), and decisional conflict decreased (P < 0.001). Vaccination intention shifted: 55%-75% in favor and 32%-18% undecided (P < 0.001). Qualitative analysis (n = 12) revealed three themes: social ambivalence around vaccination, the DA as a support for informed choices, and its role in enhancing communication with healthcare providers.Discussion: This study showed a reduction in decisional conflict and increased vaccination intention. These findings suggest that DAs may play an important role in addressing vaccine hesitancy and supporting value-aligned choices in real-world settings.Conclusion: This study highlights the potential of an online DA to improve vaccine acceptance by reducing decisional conflict and enhancing dialog. Further research is needed to assess its large-scale impact on vaccine uptake
Effects of Narrow- versus Wide-Pulse Neuromuscular Electrical Stimulation Training on Isometric Strength and Underlying Neuromuscular Adaptations
No full textInternational audiencePurpose:The training effects of neuromuscular electrical stimulation (NMES) delivered with narrow pulses are relatively well known. Wide-pulse NMES has recently received increasing attention, but mainly for acute applications. The aim of the present study was to investigate the effect of NMES training with narrow versus wide pulses on isometric strength and on the underlying neuromuscular adaptations. Methods: Thirty-six healthy men were randomly allocated to a control group and two NMES training groups (narrow-pulse group (NG) and wide-pulse group (WG)). Trained participants completed a 6-wk NMES program, followed by a 6-wk detraining period. NMES with narrow (0.2 ms) or wide (1 ms) pulses was applied to the quadriceps at a stimulation frequency of 50 Hz and at maximal tolerable current intensity. All participants completed three testing sessions: before (PRE) and after (POST) training, as well as after the detraining period (DE). Measurements included ultrasonography, maximal voluntary contractions (MVC) with the twitch interpolation technique, and transcranial magnetic and peripheral nerve stimulations. Results: MVC torque increased significantly and similarly for the two NMES training groups, from PREto-POST (11% and 12% for NG and WG, respectively) and PRE-to-DE (12% and 7% for NG and WG, respectively). This was associated with significant and similar increases of voluntary activation, evoked doublet torque, and muscle thickness in both groups. A significant cross-education effect was also observed for both groups (8% and 10% for NG and WG, respectively). No changes in corticospinal responsiveness were observed. Conclusions: Despite differences in total applied current, narrow-and wide-pulse NMES training induced similar isometric strength gains, and neural and muscular adaptations in healthy men, likely due to a comparable level of evoked torque throughout the training programs.</div
