Hal - Université Grenoble Alpes
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Emissions pricing instruments with intermittent renewables: Second-best policy
No full textInternational audienceI analyze emissions pricing to support the integration of prevailing renewable resources into an electricity mix composed of polluting technologies. I consider the intermittent nature of the resources such as wind energy and externalities due to emissions-intensive production. I show that an emissions tax is inefficient when consumers are on flat-rate electricity tariffs and do not necessarily adapt their consumption to varying production. The tax is inefficient even with flexibility in the markets when consumers are on variable tariffs. The renewable resource induces variability in the polluting electricity production and associated marginal damage that is not efficiently internalized by a predetermined tax. I then study an Emissions Trading Scheme that provides flexibility at the policy level: emissions permits are traded at market prices. Since the emissions cap must still be predetermined, I show that it leads to inefficient permit prices as they do not match the marginal damages. The two emissions pricing instruments are not necessarily equivalent since I find that the tax differs from the prices of permits
Validation of the DESI DR2 Ly BAO analysis using synthetic datasets
No full textInternational audienceThe second data release (DR2) of the Dark Energy Spectroscopic Instrument (DESI), containing data from the first three years of observations, doubles the number of Lyman- (Ly) forest spectra in DR1 and it provides the largest dataset of its kind. To ensure a robust validation of the Baryonic Acoustic Oscillation (BAO) analysis using Ly forests, we have made significant updates compared to DR1 to both the mocks and the analysis framework used in the validation. In particular, we present CoLoRe-QL, a new set of Ly mocks that use a quasi-linear input power spectrum to incorporate the non-linear broadening of the BAO peak. We have also increased the number of realisations used in the validation to 400, compared to the 150 realisations used in DR1. Finally, we present a detailed study of the impact of quasar redshift errors on the BAO measurement, and we compare different strategies to mask Damped Lyman- Absorbers (DLAs) in our spectra. The BAO measurement from the Ly dataset of DESI DR2 is presented in a companion publication
Universal Audio Generation
No full textThis report describe the research done during the third ESPERANTO/JSALT workshop from the 10th June 2024 to the 2nd of August 2024
A wafer-scale method for the characterization of 2D MoS2 layers
No full textInternational audienceWafer-scale deposition of 2D TMDs (Transition Metal Dichalcogenides) is a key point for their integration in future devices. While significant efforts have been dedicated to improving the quality and uniformity of 2D materials, their implementation requires a robust characterization protocol to assess the surface coverage, layer number, stoichiometry, homogeneity, crystallinity and morphology. In this work, we developed a characterization protocol that combined local analyses and large-scale methods. This protocol was applied to MoS2 films grown on SiO2 substrate by Atomic Layer Deposition (ALD) using two different precursors, enabling the determination of the number of ALD cycles required to achieve a strict monolayer with full wafer-scale coverage. Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS), and Scanning Transmission Electron Microscopy (STEM) provided insights into composition, surface coverage and equivalent thickness from sub-monolayer to above-monolayer thickness range at low scale. The combination of Wavelength-Dispersive X-ray Fluorescence (WDXRF), Scanning Electron Microscopy (SEM), Raman spectroscopy and Photoluminescence, enables a rapid and accurate evaluation of the uniformity at wafer scale, the equivalent thickness and composition of TMD films across the wafer
Secondary telephone cord buckle in thickness gradient and tapered delamination
No full textWe investigated the formation of telephone-cord buckling patterns in stressed nickel thin films deposited by ion beam sputtering on polycarbonate substrates with a controlled thickness gradient. Initially, the application of an external compressive stress induced straight-sided buckles in the nickel films. Upon releasing the applied stress, these buckles transformed into telephone-cord patterns oriented parallel to the thickness gradient, exhibiting stripe widths that varied accordingly. Experimental observations revealed that both the wavelength and width of the telephone-cord buckles decreased with decreasing film thickness. To further understand this behavior, finite element method simulations were performed to systematically study the effects of film thickness, stripe-width gradients and internal stress on the buckle wavelength. The numerical results are presented and compared with experimental data, showing good agreement and providing deeper insight into the mechanics of gradient-induced buckling in thin films
Intérêts des microbiotes et place des probiotiques dans la polyarthrite rhumatoïde
No full textAmong chronic diseases, rheumatoid arthritis affects approximately 0.5 to 1% of the adult population in France. The disease typically manifests with proximal joint involvement of the hands and feet, although multiple joints are often affected simultaneously. Without appropriate therapeutic management, rheumatoid arthritis tends to progress toward functional disability. The development of rheumatoid arthritis is influenced by various genetic, environmental, and immune factors. The microbiota has also been implicated in numerous studies. The constant need to balance treatment efficacy with the risk of adverse effects has led to growing interest in complementary and alternative medicine, including probiotics, which also benefit from the perception of being “safe” natural products. The aim of this thesis is to explore the relationships between the microbiota and rheumatoid arthritis, and to evaluate the potential role of probiotics as a complementary approach in disease management. Scientific evidence indicates that patients with rheumatoid arthritis exhibit increased intestinal permeability as well as oral and/or gut dysbiosis. The imbalance of certain bacterial strains suggests their involvement in the loss of immune tolerance and the maintenance of inflammation. Modulating the microbiota through diet, probiotic supplementation, or fecal microbiota transplantation may serve as an adjunct to conventional treatment to improve patients’ quality of life. The study of the microbiota and its modulation represent a promising scientific and therapeutic perspective for understanding and supporting the management of rheumatoid arthritis. To validate these clinical benefits and define optimal supplementation strategies, further large-scale randomized controlled trials and meta-analyses are necessary.Parmi les maladies chroniques, la polyarthrite rhumatoïde représente 0,5 à 1% de la population adulte française. Cette maladie se déclare généralement par des atteintes articulaires proximales des mains et des pieds, bien que souvent plusieurs articulations soient touchées. La maladie sans prise en charge thérapeutique tend à évoluer vers une incapacité fonctionnelle. Le développement de la polyarthrite rhumatoïde est influencé par différents facteurs génétiques, environnementaux et immunitaires. Le microbiote est aussi mis en cause par de nombreuses études. La nécessité permanente de concilier efficacité des traitements et effets indésirables conduit à un enthousiasme pour les médecines alternatives et complémentaires, dont les probiotiques. De plus, il bénéficie de la perception du « sans danger » du produit naturel. L’objectif de cette thèse est d’explorer les liens entre microbiotes et polyarthrite rhumatoïde, et d’évaluer l’intérêt des probiotiques comme approche complémentaire dans la prise en charge de cette maladie. Les résultats de la littérature scientifique montrent que les patients atteints de polyarthrite rhumatoïde présentent une perméabilité intestinale accrue, ainsi qu’une dysbiose buccale et, ou intestinale. Le déséquilibre de certaines souches bactériennes suggère leur implication dans la perte de tolérance immunitaire et le maintien de l’inflammation. La modulation de la flore, par l’alimentation, la supplémentation en probiotiques ou encore la transplantation de matière fécale, représente un soutien au traitement conventionnel pour améliorer la qualité de vie des patients. L’étude du microbiote et ses modulations sont une perspective scientifique et thérapeutique dans la compréhension et l’accompagnement de prise en charge de la polyarthrite rhumatoïde. Pour ce faire de nouvelles études randomisées contrôlées, ainsi que des méta-analyses de plus grandes tailles sont indispensables pour confirmer en clinique leur efficacité réelle et préciser les modalités de supplémentation
Salience-SGG: Enhancing Unbiased Scene Graph Generation with Iterative Salience Estimation
No full textInternational audienceScene Graph Generation (SGG) suffers from a longtailed distribution, where a few predicate classes dominate while many others are underrepresented, leading to biased models that underperform on rare relations. Unbiased-SGG methods address this by implementing debiasing strategies, but often at the cost of spatial understanding-resulting in over-reliance on semantic priors. We introduce Salience-SGG, a novel framework featuring an Iterative Salience Decoder (ISD) that emphasizes triplets with salient spatial structures. To support this, we propose semantic-agnostic salience labels guiding ISD. Evaluations on Visual Genome, Open Images V6, and GQA-200 show that Salience-SGG achieves state-of-the-art performance and improves existing Unbiased-SGG methods in their spatial understanding as demonstrated by the Pairwise Localization Average Precision
Imaginaires et gestes de la mort en cendres: une recherche-création pour explorer la dispersion hors des cimetières et des jardins du souvenir
No full textInternational audienceIn this article, based on an ongoing research-creation project, we take a look at practices that are emerging outside the traditional funeral framework : the scattering of human ashes in “natural” spaces not set aside to accommodate human remains. Because these practices invoke questions of space, gesture, communication and symbolism, and touch on intimate and creative dimensions of the experiences of the bereaved in new environments and situations, we need to rely on open and receptive methods of investigation, collection and analysis in order to identify and study these new developments. We present an experimental method combining the artistic and scientific practices, developed in several complementary stages. Firstly, a collection of micro-narratives of experiences of dispersal, gathered anonymously via an online form that is still open to this day, which will give us access to people's subjective perceptions and reflections, and allow us to explore what is currently being done and thought within individual and family contexts. An initial classification by theme has been proposed, categorizing the range of ways we have of dealing with the dead, and questioning what these ways say about loss and absence, but also about our capacity to reinvent the practice of mourning. Secondly, workshops sessions in which we re-enacted a number of these collected micro-narratives in order to articulate perceptions that had been passed over in silence in the micro-narratives themselves and reflect on the ways these practices are shared in vivo. While the ultimate aim of this ongoing research-creation project is to add to the body of scientific knowledge around death and ashes (practices, imaginaries, gestures, impact on design, site management, public policy, citizenship, etc.), to achieve this, it aims to use creative methods of collection and analysis, that can best reveal the full breadth of these experiences. In this article, we share some of the initial methodological and scientific results of these exploratory approaches.Dans cet article basé sur une recherche-création en cours, nous nous intéressons à des pratiques qui naissent en dehors du cadre funéraire traditionnel : les dispersions de cendres humaines en espaces naturels non aménagés. Parce qu’elles touchent à la fois à l’espace, aux gestes, à la communication et à la symbolique, parce qu’elles relèvent de l’intime, mais aussi de la créativité des endeuillés dans des environnements et des situations inédits, nous devons, pour identifier et étudier les évolutions, nous appuyer sur des modes d’enquête, de collecte et d’analyse ouverts, réceptifs. Nous présenterons une méthode expérimentale entre arts et sciences développée en plusieurs étapes complémentaires. Premièrement, un recueil de micro-récits anonymes d’expériences de dispersion, récolté via un formulaire en ligne encore ouvert à ce jour, nous aide à accéder à des représentations et perceptions confidentielles, à découvrir ce qui se fait et ce qui se pense actuellement dans le cadre individuel et familial. Un premier classement a été proposé par thèmes, nous informant sur nos manières de faire avec les morts, sur ce que ces manières traduisent de la perte et de l’absence, mais aussi de notre capacité à réinventer la pratique du deuil. Deuxièmement, l’explicitation d’interprétations actionnées (re-enactment), performées et commentées d’un certain nombre de micro-récits, effectuées lors de temps de workshop, révèlent des perceptions passées sous silence dans les micro-récits et la manière dont elles se partagent in vivo. Si l’objectif de cette recherche-création en cours est à terme d’enrichir les connaissances scientifiques sur la mort en cendres (pratiques, imaginaires, gestes, impact sur la conception, la gestion des lieux, les politiques publiques, la citoyenneté…), elle vise pour y parvenir, dans le recueil et l’analyse du corpus, à emprunter des méthodes créatives à même de révéler au mieux toute l’épaisseur de ces expériences. C’est avec des premiers résultats méthodologiques et scientifiques que nous partageons dans cet article certaines de ces voies exploratoires
Operando 5D tomography uncovers carbonation-driven water transport and cracking in hydrated cement paste
No full textInternational audienceConcrete production is responsible for roughly eight percent of globalcarbon dioxide emissions and generates more than a third of construction and demolition waste. Accelerated carbonation of recycled aggregates emerges as a promising solution, enabling simultaneous carbon dioxide sequestration and circular use of materials. Yet, the coupled physical processes governing carbonation under industrially realistic conditions remain poorly understood. Here we show, using time-resolved neutron and X-ray tomography, how heat, moisture, chemical reactions, and mechanical damage interact during cement paste carbonation. Conducted at eighty degrees Celsius and high carbon dioxide concentrations, our experiments reveal that carbonation drives rapid release of bound water, alters moisture distribution, and induces crack formation and sealing. These results</div
