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A comprehensive study of highly concentrated Lithium-ion aqueous electrolytes: from structural characterizations to electrochemical properties
No full textInternational audienceDue to their scarce and expensive components, lithium‑ion batteries raise safety and cost concerns. Aiming for less toxic and cheaper batteries, aqueous electrolytes have emerged as a good alternative. To overcome their narrow electrochemical stability window, highly concentrated electrolytes have shown promising properties in reducing water reactivity. However, the lithium salts most commonly used in these electrolytes contain fluorinated organic anions, which have greater environmental and cost impacts when used in large amounts. Some low‑cost and more environmentally‑friendly salts started to emerge in aqueous electrolytes for battery and supercapacitor applications. In the present work, a comparative study between a low‑cost and highly concentrated lithium nitrate (LiNO3) based electrolyte and an electrolyte using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt as a reference was conducted. Electrochemical measurements reveal that LiNO3‑based electrolytes have a higher ionic conductivity but a narrower electrochemical stability window than LiTFSI‑based ones. Infrared spectroscopy, small‑angle X‑ray scattering and wide‑angle X‑ray scattering characterisations, coupled with self‑diffusion and viscosity measurements, shed light on the lack of structure formation in LiNO3‑based electrolytes compared to LiTFSI‑based ones which have well‑organised domains. It demonstrates that LiNO3 used alone in an aqueous electrolyte does not disrupt the network of water molecules and, therefore, does not reduce their reactivity. This study also proposes a systematic approach to evaluate salts or electrolyte formulations for application in low-cost aqueous batteries. By combining various characterisation techniques, it provides a framework to determine whether a given composition meets the essential criteria for widening the electrochemical stability window of aqueous electrolytes
Charge-transfer complexes as next-generation solid electrolytes: unlocking high-performance lithium batteries
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Do predictions based on peripheral scene information influence perception in central vision?
No full textInternational audienceOur previous studies showed that context-based predictions influence the visual appearance of blurred objects. Object that can be predicted based on a meaningful/congruent context are perceived sharper than the exact same objects in a meaningless or incongruent context. As object are usually processed in central vision, while scene context is mainly extracted from peripheral vision, the present study addressed whether predictions based on contextual information available in peripheral vision can also enhance perception in central vision. Participants (n = 19) were presented with stimuli composed of a central disk containing a scene embedded in 1/f noise at various scene-to-noise ratios and a peripheral ring containing either an intact congruent scene, an incongruent scene or a phase-scrambled scene. In the scene detection task, they had to report whether they perceived a scene within noise in the central disk. In the noise detection task, they had to report whether they perceived the presence of noise within the scene in the central disk. Preliminary results revealed that in the scene detection task, a congruent scene in the peripheral ring appears to facilitate scene detection in central vision compared to a non-informative peripheral ring. However, congruent peripheral information did not influence noise resistance in the noise detection task. These preliminary findings support the idea that predictions based on contextual information extracted from peripheral vision enhances perception of congruent information in central vision
Rapport d'étape: Effets des panneaux Solaires flottants sur les flux de matière à l'interface aquatique-terrestre (SOLFLUX)
No full textRF Characterization of New Generations of Bio-Based PCB Substrates in Harsh Environment
No full textInternational audienceThis paper presents the RF characterization of the complex permittivity of a novel biosourced PCB substrate, based on a PLA polymer matrix reinforced with a woven flax fiber fabric and laminated copper cladding, as a function of temperature and humidity. The measurements were performed using a cylindrical cavity and resonant transmission lines inside a climate-controlled chamber. Various copper removal techniques were investigated, including peeling, chemical etching, laser ablation, and mechanical milling. To analyze the observed trends on the measurement results, an effective medium model tailored for stratified materials was employed. A particular focus on substrate inhomogeneities has been also investigated for the explanation of the measurement discrepancies
Trait-explicit approaches cast new light on fragmentation’s effects on biodiversity
No full textInternational audienceWhile negative effects of landscape fragmentation on biodiversity are well documented, recent evidence suggests positive or neutral effects may also be common. The mechanisms driving these contrasting outcomes cannot be understood without assessing how species traits influence responses to landscape and patch characteristics. Here, we show that three key elements can enhance predictability of fragmentation effects across scales: (i) the trait distribution of the regional species pool; (ii) the relationship between taxonomic and trait diversity; and (iii) the effects of the landscape matrix on the distribution of species traits. Considering these elements will facilitate the development of generalizable hypotheses on the consequences of fragmentation across diverse taxonomic groups and regions, with broad applicability to ecology and conservation
A semi-analytical model for assessing nanoparticle collection efficiencies in the partial charging regime
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Analyse jurimétrique des délais de procédure en contentieux du dommage corporel : étude empirique des décisions judiciaires françaises de l'année 2025
No full textInternational audienceCette étude jurimétrique exploite les décisions rendues en 2025 en matière de dommage corporel dans la base de Themia.pro pour analyser les délais procéduraux du fait générateur à l'arrêt d'appel. L'analyse révèle que le déterminant principal de la temporalité procédurale réside dans la variable géographique, les médianes variant du simple au double selon les ressorts de cours d'appel, supplantant les caractéristiques intrinsèques des dossiers telles que l'âge de la victime ou la gravité de l'atteinte. La décomposition séquentielle identifie deux phases critiques : la mise en état en appel, présentant des variations extrêmes de 300 à plus de 1 000 jours, et la phase d'audiencement, révélant des divergences atteignant un rapport de 1 à 18 mois. Ces résultats permettent une prise de décision éclairée en matière transactionnelle et contentieuse, notamment pour le choix du for lorsque la compétence territoriale offre une latitude, et pour l'appréciation de l'opportunité d'un appel au regard de l'âge et de l'état de santé de la victime
A First Quantitative Assessment of Soil Health at European Scale Considering Soil Genesis
No full textInternational audienceABSTRACT Background Soil health degradation is a major threat to European food security, biodiversity, and climate stability. While scientists have debated how to define soil health during recent decades, a quantifiable framework for monitoring, management, and policy remains lacking. Aim We introduce SHERPA (Soil Health Evaluation, Rating Protocol, and Assessment) as a framework for discussion and present a first quantitative soil health assessment across Europe. Methods All major soil degradation processes (with the exception of organic contamination) were scored, averaged, and subtracted from the intrinsic soil health resulting in quantitative final scores. Results As reported before, cropland soils throughout Europe are highly degraded. Surprisingly, soil health of grasslands is also very negatively impacted. Soil erosion, nutrient surplus, and pesticide risk are largely driving poor soil health aligning with reported high biodiversity loss in agricultural land. Forest soils are also surprisingly low in health, mainly because of nitrogen surplus, reflecting documented widespread forest decline from nutrient imbalances. Interactive maps highlight specific threats to soil health across Europe, offering valuable insights for targeted action. Conclusions SHERPA is able to quantify soil health across Europe. However, at the current state of data availability, soil health is likely to be overestimated. Monitoring data of soil structure, compaction, pesticide spread and, in forest ecosystems, disturbance of humus layer are urgently needed for final assessment of soil health
Sensitivity tests on PEMFC short-stacks aiming heavy-duty transport
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