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Reversibility without over-potential of fluorinated graphite in lithium batteries
No full textInternational audienceWhen used as positive electrode in lithium batteries, fl uorinated carbons deliver capacities and energy densities that exceed those of other commercial primary batteries. In addition, these materials can be used over a wide range of temperatures, allowing them to diversify their utilization and have a lifespan of 15 years. However, when using the fluorinated carbon-based battery, a very stable compound, lithium fluoride, is formed and prevents the reversibility of the process, i.e. the use in secondary battery. Systems with a fluorinated carbon cathode are then called primary battery, non-rechargeable systems. In the present work, graphite fluorides with weakened covalency for the C–F bonds are considered as cathode in secondary lithium battery with polymer electrolyte. Such a combination of non-conventional graphite fluoride and polymer electrolyte allows the reversibility to be achieved without significant polarization contrary to the previous works in the literature. Non optimized reversible capacity of 65 mAh/g without high over-potential between the reduction and oxidation processes is achieved
Wild fish use visual cues to recognize individual divers
No full textInternational audienceMany animal species have been shown to discriminate between individual humans in captive settings and may use a variety of cues to do so. Empirical evidence remains scarce for animals in the wild, however, particularly in aquatic contexts. For the first time, we investigated discrimination of individual humans by fish in the wild. We first trained two species of fish, saddled sea bream Oblada melanura and black sea bream Spondyliosoma cantharus , to follow a human diver to obtain a food reward. We then investigated whether they could discriminate between two human divers and follow the correct one in an operant-conditioning paradigm. We show that both species were able to quickly learn to discriminate between the two divers when they wore different diving gear. However, they showed no preference when both divers wore identical gear, suggesting that discrimination is based predominantly on visual cues from the dive gear. We discuss the implications of these results for ethical considerations and research practices
Biochemical characterization of the Escherichia coli surfaceome: a focus on type I fimbriae and flagella
No full textInternational audienceThe Escherichia coli surfaceome consists mainly of the large surface organelles expressed by the organism to navigate and interact with the surrounding environment. The current study focuses on type I fimbriae and flagella. These large polymeric surface organelles are composed of hundreds to thousands of subunits, with their large size often preventing them from being studied in their native form. Recent studies are accumulating which demonstrate the glycosylation of surface proteins or virulence factors in pathogens, including E. coli . Using biochemical and glycobiological techniques, including biotin-hydrazide labeling of glycans and chemical and glycosidase treatments, we demonstrate (i) the presence of a well-defined and chemically resistant FimA oligomer in several strains of pathogenic and non-pathogenic E. coli , (ii) the major subunit of type I fimbriae, FimA, in pathogenic and laboratory strains is recognized by concanavalin A, (iii) standard methods to remove N -glycans (PNGase F) or a broad-specificity mannosidase fail to remove the glycan structure, despite the treatments resulting in altered migration in SDS-PAGE, (iv) PNGase F treatment results in a novel 32 kDa band recognized by anti-FliC antiserum. While the exact identity of the glycan(s) and their site of attachment currently elude detection by conventional glycomics/glycoproteomics, the current findings highlight a potential additional layer of complexity of the surface (glyco) proteome of the commensal or adhesive and invasive E. coli strains studied
La biomasse : le matériau de construction du futur pour un développement durable et responsable
No full textInternational audienceLa biomasse, matériau organique végétal, représente une alternative durable aux matériaux de construction traditionnels comme le béton purement minéral. Le béton bio-sourcé utilise diverses formes de biomasse, telles que les granulats pour bétons végétaux, les fibres renforçant enduits et isolants, et le biochar pour décarboner le ciment
Coarse cops and robber in graphs and groups
No full text25 pages, 3 figures. Some of our results have been obtained independently by Appenzeller and Klinge in arXiv:2502.04540(abstract shortened to meet arxiv's length requirements) We investigate two variants of the classical Cops and robber game in graphs, recently introduced by Lee, Mart\'inez-Pedroza, and Rodr\'iguez-Quinche. The two versions are played in infinite graphs and the goal of the cops is to prevent the robber to visit some ball of finite radius (chosen by the robber) infinitely many times. Moreover the cops and the robber move at a different speed, and the cops can choose a radius of capture before the game starts. Depending on the order in which the parameters are chosen, this naturally defines two games, a weak version and a strong version (in which the cops are more powerful), and thus two variants of the cop number of a graph : the weak cop number and the strong cop number. It turns out that these two parameters are invariant under quasi-isometry and thus we can investigate these parameters in finitely generated groups by considering any of their Cayley graphs; the parameters do not depend on the chosen set of generators. We answer a number of questions raised by Lee, Mart\'inez-Pedroza, and Rodr\'iguez-Quinche, and more recently by Cornect and Mart\'inez-Pedroza. This includes a proof that the weak and strong cop numbers are monotone under quasi-isometric embedding, characterizations of graphs of weak cop number 1 and graphs of strong cop number 1, and a proof that the grid has infinite strong cop number. Moreover we tie the weak cop number of a graph to the existence of asymptotic minors of large tree-width in , and use the result to prove that any finitely presented group has weak cop number 1 or . We have learned very recently that some of our results have been obtained independently by Appenzeller and Klinge, using fairly different arguments
Quels agriculteurs pour quelles agricultures demain ?
No full textNational audienceComment assurer notre souveraineté alimentaire dans un contexte de changement climatique et favoriser une alimentation durable qui contribue à la santé des populations ? Alors que l’agriculture est une clé essentielle pour répondre à ces problématiques, pas moins de 166 000 agriculteurs et agricultrices partiront à la retraite d’ici 2030. Quels sont les leviers pour assurer le renouvellement des générations en agriculture ? Comment appréhender ce défi, au cœur des priorités d’INRAE
Signal shape studies and rate dependence of HFO-based gas mixtures in RPC detectors
No full textInternational audienceThe RPCs employed at the LHC experiments are currently operated in avalanche mode, with a mixture containing a large fraction of CHF (90% or more) with the addition of i-CH and SF in different concentrations. However, CHF and SF are fluorinated greenhouse gases (F-gases) with Global Warming Potential (GWP) of 1400 and 22800, respectively. EU regulations imposed a progressive phase-down of CHF production and consumption, aiming at strongly reducing its emission. This is already resulting in an increase of its price and reduction in availability. The most desirable long-term solution to this problem is to find an alternative, F-gases-free gas mixture, able to maintain similar detector performance. To address this challenge, the RPC ECOGasas@GIF++ collaboration (including RPC experts of ALICE, ATLAS, CMS, SHiP/LHCb, and the CERN EP-DT group) was created in 2019. The collaboration is currently studying a gas from the olefine family, the CHF (or simply HFO, with GWP 6), to be used, in combination with CO, as a substitute for CHF. This contribution will focus on the signal shape studies that have been carried out by the collaboration during dedicated beam test periods. The methodology used in the data analysis will be presented, together with the results obtained with several HFO-based gas mixtures, and with the currently employed one. Furthermore, results on the counting-rate dependence of the RPC performance, obtained by combining the muon beam with the GIF++ Cs source with different attenuation factors, will also be presented
Search for resonance-enhanced and angular asymmetries in the decay at LHCb
No full textInternational audienceThe first measurement of the asymmetry of the decay rate () and the average () and asymmetry () of the forward-backward asymmetry in the muon system of decays is reported. The measurement is performed using a data sample of proton-proton collisions, recorded by the LHCb experiment from 2016 to 2018 at a center-of-mass energy of 13, which corresponds to an integrated luminosity of 5.4. The asymmetries are measured in two regions of dimuon mass near the -meson mass peak. The dimuon-mass integrated results are \begin{align*} A_{CP} &= (-1.1 \pm 4.0 \pm 0.5)\%,\\ \Sigma A_{\text{FB}} &= (\phantom{-}3.9 \pm 4.0 \pm 0.6)\%,\\ \Delta A_{\text{FB}} &= (\phantom{-}3.1 \pm 4.0 \pm 0.4)\%, \end{align*} where the first uncertainty is statistical and the second systematic. The results are consistent with the conservation of symmetry and the Standard Model expectations
Cryptoactifs, gestion de patrimoine et pratique notariale
No full textInternational audienceRapidement devenus incontournables, les cryptoactifs se rencontrent dans de nombreuses stratégies patrimoniales. Face à l’engouement des investisseurs pour ces actifs d’un nouveau genre, les professionnels de la gestion de patrimoine se trouvent confrontés à de multiples questionnements pratiques, souvent inédits.Outre une étude des caractéristiques juridiques des différents actifs numériques, cet ouvrage présente une analyse complète des conséquences patrimoniales de leur détention. Sont notamment traités le démembrement de propriété des cryptoactifs, leur détention par des époux communs en biens ou encore leur apport à une société.Résolument didactique, cet ouvrage apporte des réponses claires et concrètes aux principales problématiques civiles et fiscales rencontrées par les praticiens en la matière. Plusieurs opérations patrimoniales sont notamment développées, telles que la donation avant cession de cryptomonnaies ou encore la donation de cryptomonnaies préalable à leur apport à une société.Ce livre est destiné aux professionnels de la gestion de patrimoine, dont les notaires font bien évidemment partie au premier chef. Les avocats, experts-comptables et ingénieurs patrimoniaux trouveront également en son sein des éléments de réponse aux questions soulevées par leur pratique quotidienne. Enfin, il s’adresse aux universitaires présentant un intérêt particulier pour le droit des cryptoactifs, mais aussi aux étudiants souhaitant développer leurs connaissances en la matière