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Towards the development of safer by design mineral photocatalytic paint: influence of the TiO2 modifications on particle release
No full textInternational audienceThe development of safe nanomaterials has become a significant concern in various industry sectors using advanced materials. While there is variability in the definitions of Safe(r) by Design (SbD), the general concept is to minimise environmental, health and safety concerns implementing appropriate measures at an early stage of product design to control exposure and hazard, thus reducing risks. The SbD product strategy applied in this paper refers to the mitigation of exposure by the identification of release scenarios during the use and the end of life of the nano-enabled products (NEPs) that include engineered nanomaterials (ENMs). This strategy was applied to the development of a photocatalytic mineral paint containing TiO2 engineered nanomaterial. This ENM was then incorporated into a mineral matrix-based paint for photocatalytic application. The different paint formulations were applied to standardised substrates and artificially weathered in an accelerated weathering chamber with controlled parameters. Mechanical solicitation that simulate end of life (EoL) of the paint, through abrasion tests, were performed to assess the potential emission of airborne particles that could lead to human or environmental exposure. The release evaluation confirms that paints with TiO2 nanoparticles without SbD coating release more nanometric particles due to strong matrix degradation. The TiO2 nanoparticles coated with PEG or grafted onto CNC does not completely prevent the degradation of the paint surface during ageing. However, this degradation does not necessarily lead to an increase in aerosol emission. The coating degradation during accelerated ageing limits the degradation of the paint matrix, preventing the release of unbound TiO2 nanoparticles. Understanding the mechanisms of release and how they are influenced by the ENMs, the matrix material and the process characteristics is crucial for the exposure and risk assessment approach in occupational settings involving engineered nanomaterials. Moreover, establishing release rates makes it possible to increase the reliability of SbD e-infrastructure for performance testing and the implementation of Safe-by-Design approaches in the nanotechnology supply chain
The MACIV multiscale seismic experiments in the French Massif Central (2023-2027): deployment, data quality and availability
No full textInternational audienceIn the framework of the MACIV project, a consortium of French laboratories has deployed a temporary seismic network of 100 broadband stations in the French Massif Central (FMC) for 3-4 years (2023-2027). The project aims at imaging the crust and upper mantle of the FMC to better assess the sources of volcanism, and the impacts of the Variscan inheritance or the Cenozoic rift system on volcanic systems. A large-scale array of 35 broadband stations covers the entire FMC and complements the permanent networks to reach a homogeneous coverage with ~35 km spacing. This network, with XP code, is the French contribution to AdriaArray. The XP array is complemented with 3 quasi-linear north-south, east-west and northwest-southeast profiles with inter-station spacing of 5-20 km, making up the XF network of 65 stations. The profiles cross volcanic areas and the main Variscan structures. We describe the experimental setup designed to optimize the performance/cost ratio and minimize the number of field visits, the deployment, the state-of-health monitoring, the data management and the data quality control strategies, outcomes of our 15-years' experience with major temporary seismic experiments in France and neighboring countries, including AlpArray. We also show some preliminary results including hypocenter locations and receiver function analysis. The 2 broadband arrays will be supplemented in 2025 by a month-long deployment of 3 large-N dense arrays of 625 3-C short-period nodes. These dense arrays will complete our multi-scale seismic experiment and illuminate active faults and possible plumbing systems of the youngest volcanoes
Constraints on standard model effective field theory for a Higgs boson produced in association with W or Z bosons in the H → decay channel in proton-proton collisions at = 13 TeV
No full textInternational audienceA standard model effective field theory (SMEFT) analysis with dimension-six operators probing nonresonant new physics effects is performed in the Higgs-strahlung process, where the Higgs boson is produced in association with a W or Z boson, in proton-proton collisions at a center-of-mass energy of 13 TeV. The final states in which the W or Z boson decays leptonically and the Higgs boson decays to a pair of bottom quarks are considered. The analyzed data were collected by the CMS experiment between 2016 and 2018 and correspond to an integrated luminosity of 138 fb. An approach designed to simultaneously optimize the sensitivity to Wilson coefficients of multiple SMEFT operators is employed. Likelihood scans as functions of the Wilson coefficients that carry SMEFT sensitivity in this final state are performed for different expansions in SMEFT. The results are consistent with the predictions of the standard model.[graphic not available: see fulltext
Proton reconstruction with the TOTEM Roman pot detectors for high-β* LHC data
No full textInternational audienceThe TOTEM Roman pot detectors are used to reconstruct thetransverse momentum of scattered protons and to estimate thetransverse location of the primary interaction. This paper presentsnew methods of track reconstruction, measurements of strip-leveldetection efficiencies, cross-checks of the LHC beam optics, anddetector alignment techniques, along with their application in theselection of signal collision events. The track reconstruction isperformed by exploiting hit cluster information through a novelmethod using a common polygonal area in the intercept-slopeplane. The technique is applied in the relative alignment ofdetector layers with μm precision. A tag-and-probe method isused to extract strip-level detection efficiencies. The alignment ofthe Roman pot system is performed through time-dependentadjustments, resulting in a position accuracy of 3 μm in thehorizontal and 60 μm in the vertical directions. The goal isto provide an optimal reconstruction tool for central exclusivephysics analyses based on the high-β* data-taking period at√(s) = 13 TeV in 2018
Evidence for similar collectivity of high transverse momentum particles in pPb and PbPb collisions
No full textInternational audienceCharged hadron elliptic anisotropies () are presented over a wide transverse momentum () range for proton-lead (pPb) and lead-lead (PbPb) collisions at nucleon-nucleon center-of-mass energies of 8.16 and 5.02 TeV, respectively. The data were recorded by the CMS experiment and correspond to integrated luminosities of 186 nb and 0.607 nb for the pPb and PbPb systems, respectively. A four-particle cumulant analysis is performed using subevents separated in pseudorapidity to effectively suppress non-collective effects. At high ( 8 GeV), significant positive values are observed that are similar between pPb and PbPb collisions at comparable charged particle multiplicities. This observation suggests a common origin for the multi-particle collectivity for high- particles in the two systems
Development of systematic uncertainty-aware neural network trainings for binned-likelihood analyses at the LHC
No full textInternational audienceWe propose a neural network training method capable of accounting for the effects of systematic variations of the data model in the training process and describe its extension towards neural network multiclass classification. The procedure is evaluated on the realistic case of the measurement of Higgs boson production via gluon fusion and vector boson fusion in the decay channel at the CMS experiment. The neural network output functions are used to infer the signal strengths for inclusive production of Higgs bosons as well as for their production via gluon fusion and vector boson fusion. We observe improvements of 12 and 16% in the uncertainty in the signal strengths for gluon and vector-boson fusion, respectively, compared with a conventional neural network training based on cross-entropy
Translation-classification loss for SAR image understanding with deep learning
No full textInternational audienceSAR-to-optical translator networks are especially used to overcome the lack of optical images under cloudy conditions. Those translations being used for downstream tasks, they require the reconstruction of reliable patterns with respect to the underlying objects. In this paper, we propose a novel training strategy to account for land-cover complexity through a conjoint Translation-Classification Loss (TCL). The proposed loss evaluates the classifiability of translated images with a pre-trained land-cover classifier by assessing the reliability of its predictions and the relevance of its extracted hidden features. This new loss is applied to nine translators from the literature and to a tenth architecture introduced in the paper. Experiments show that applying the TCL not only improves the credibility of structures, patterns and textures but it also allows for better class discrimination and transitions while avoiding unreliable hallucinated artifacts produced by standard losses in adversarial approaches
Oxide glasses materials: potential candidates as positive electrodes active materials for Li-ion and Na-ion batteries
No full textInternational audienceDevelopment of new positive electrode (or cathode) active materials is important to improve Li-ion and Na-ionbatteries performances. Commercial materials are crystalline (LFP, NMC, …), but some studies reach interestingperformances developing Vanadium-containing glass cathodes [1], up to 1000 Wh/kg at the material level after 10cycles [2]. Glass asset is its disordered network which could theoretically incorporate high amount of transition metalsproviding high specific discharge capacities. It is also structural change tolerant, making alcalin insertion/deinsertionpossible during battery discharge/charge.Nevertheless, Vanadium is a toxic critical element, and the literature is scarce on Vanadium-free glass cathodes. Here,we explore new Vanadium-free phosphate based glass compositions as cathode active materials. The glasses weresynthetized using the melt-quenching technique, and characterized by X-ray diffraction (XRD), differential thermalanalysis-thermogravimetric analysis (DTA-TGA), scanning electron microscopy (SEM), energy-dispersive X-rayspectroscopy (EDX), and X-ray fluorescence (XRF) to determine their properties. Electrochemical ImpedanceSpectroscopy and Chronoamperometry were also performed on bulk glass to assess electrical and ionic conductivitiescontributions.Glass powders were then integrated in composite electrodes and assembled into coin cell in both Li-ion and Na-ionconfigurations. The electrochemical performances were evaluated through galvanostatic cycling using ARBIN benchat a low rate of C/50.Post-mortem analyses (Raman spectroscopy, XRD) were also conducted to investigate glass structure during cycling,as alkaline incorporation inside the positive electrode is frequently associated with phases formation or structuralchanges.As a whole, these characterizations will elucidate the mechanisms driving electrochemical performance. Results willbe added to a database to correlate glass composition with electrochemical performance, identify key parameters, andpredict optimized compositions. The aim is to achieve 1000 Wh/kg energy density with stable cycle life.References:[1] Wang et al., Journal of Non-Crystalline Solids, 619 (2023).[2] Afyon et al., Scientific Reports, 4:7113 (2014)
Study of the operation of Lead-Acid Battery Electrodes under hybrid battery-electrolyzer cycling profiles
No full textInternational audienceFlooded bead-acid batteries start producing oxygen and hydrogen during the final stages of the charge and the subsequent overcharge. The collection of the produced hydrogen allows increasing the overall energy efficiency and transforms the system into a hybrid device typically referenced as “Battolyzer” (battery-electrolyzer). The present work explores the feasibility of the above approach throughout a detailed study of the long-term ageing process of flooded tubular lead-acid cells subjected to various rates of discharge and overcharge emulating four different scenarios of Battolyzer use, starting from 70% Depth of Discharge cycling to nearly continuous water electrolysis. The combined results from the electrochemical and corrosion studies showed that the Battolyzer cells degradation is driven by the corrosion of the positive current collectors. The progressing of the corrosion process is strongly correlated with the amount of hydrogen produced. The increase of the depth of discharge results in minor decrease of the corrosion current indicating that the battery functionality of the Battolyzer is more advantageous than the continuous water electrolysis