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Compte-rendu / Camille Montavon, Les Tribunaux d’opinion face à l’impunité des crimes de masse : quelle légitimité pour quelle effectivité ?, Bâle, Helbing Lichtenhahn, 2023, 523 p.
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Évolution du climat et de l’océan: [résumé des cours et travaux : 2021-2022]
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Louis de Mas Latrie, historien de Chypre et de la Grèce franques: Actes du colloque organisé à Nicosie, Université de Chypre, 30-31 octobre 2024
No full textInternational audienceThis volume brings together the contributions presented at the colloquium in Nicosia dedicated to the founder of Cypriot medieval studies, Louis de Mas Latrie.Cet ouvrage réunit les contributions données à l'occasion du colloque de Nicosie consacré au fondateur de la médiévistique chypriote, Louis de Mas Latrie
Économie des institutions, de l’innovation et de la croissance: [résumé des cours et travaux : 2021-2022]
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X-ray fluorescence spectroscopy for rapid identification of cathode chemistry in lithium-ion battery recycling
No full textInternational audienceEfficient identification of cathode chemistry in end-of-life lithium-ion batteries is essential for enabling effective battery recycling. Current approaches often rely on battery disassembly or time-consuming testing, limiting their practical use at scale. Here we report a rapid classification strategy based on X-ray fluorescence spectroscopy combined with statistical analysis. A reference dataset was established from high-quality elemental spectra collected from more than 100 end-of-life lithium-ion batteries. Statistical grouping was used to define cathode categories, which were validated by selective disassembly and complementary chemical analysis. The trained classification model was then applied to newly acquired spectra collected within seconds per battery, enabling fast identification without additional disassembly. The approach achieves high prediction accuracy across the studied dataset and demonstrates the feasibility of rapid cathode identification for battery recycling applications
A Covariant Formulation of Logarithmic Supertranslations at Spatial Infinity
No full textInternational audienceWe investigate the asymptotic symmetries of asymptotically flat spacetimes at spatial infinity. We propose a new symplectic structure and conservative boundary conditions in a polyhomogeneous Beig-Schmidt expansion. The asymptotic symmetries extend the BMS algebra by abelian sectors, notably incorporating regular log-translations and log-supertranslations. The associated charges are finite and conserved, and we show that their algebra admits a central extension between supertranslations and log-supertranslations, and between the singular translations and regular log-translations. Our analysis is compatible with, and extends, both the work of arXiv:1106.4045 and arXiv:2211.10941 : it extends the former by incorporating log-supertranslations, and the latter by allowing both parities of the log-supertranslations in the same phase space. These newly identified symmetries at spatial infinity encode novel physical information that has not been revealed in other regions of asymptotically flat spacetimes, thereby opening the door to new observables to consider at null and timelike infinity
Insights Into the Exchange of N ‐Heterocyclic Carbene Ligands on Gold Nanoparticles: Necessity of Oxygen
No full textInternational audienceGold nanoparticles (AuNPs) stabilized by N ‐heterocyclic carbenes (NHCs) represent robust alternatives to thiol‐protected counterparts owing to the NHCs’ strong Au-C bonds that provide enhanced stability. While NHC‐capped AuNPs with a single type of carbene have been reported many times, strategies to introduce multiple NHC ligands on the same nanoparticle remain unexplored. Here, we investigate NHC‐for‐NHC ligand exchange on AuNPs stabilized either by benzimidazol‐2‐ylidene or by mesoionic triazolylidene scaffolds, employing an in situ generated free carbene route. Prior to ligand exchange, the formation and stability of the studied NHCs from the corresponding azolium salts were examined and characterized by NMR spectroscopy. In situ NMR studies of the exchange reaction showed no evidence of ligand substitution under argon, the conventional atmosphere for free NHC intermediates. Although no exchange was detected by NMR, X‐ray photoelectron spectroscopy (XPS) analysis of the purified AuNPs revealed that ligand substitution had in fact occurred. Further investigation indicated that oxygen plays a key role in promoting the exchange, and that its involvement is also associated with oxidation of the gold core and the formation of NHC‐Au(I) complexes. Taken together, our results highlight the complexity of NHC‐for‐NHC exchange on AuNPs by the free carbene route and point to the need for alternative strategies to achieve controlled ligand substitution