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Reproblematising maintenance, reconsidering infrastructures: The emergence of a more-than-corrective maintenance programme in French water networks management
No full textInternational audienceIn an increasing number of countries, mainly but not restrictively in the global North, the combination of infrastructures’ degradation, budgetary constraints and rising environmental issues has gradually shifted professional and public concerns from extension to upkeep. This constitutes the crystallisation of a specific configuration of infrastructure management, which the authors propose to term an “age of infrastructure maintenance” and which contrasts dramatically with the modern infrastructural ideal. Focussing on French water network management, this paper draws on an 18-month in-depth institutional ethnography to investigate what this age of maintenance concretely encompasses. It shows that in France, and in Europe, such an age rests on a reproblematisation of maintenance, whose scope is reframed in a “more-than-corrective” perspective. This leads to a practical and ontological reconsideration of infrastructures, which is illustrated by three main transformations: infrastructures are rediscovered through proximal enquiries, they are carefully monitored as living entities, and they are put at the centre of new valuation processes. This specific moment of infrastructure maintenance appears to be generative, opening up multifaceted transformations that pave the way for a less modernist and industrial vision of infrastructure management
Coexistence of two adaptation processes in a visuomotor rotation task
No full textInternational audienceMotor adaptation is a learning process that enables humans to regain proficiency when sensorimotor conditions are sustainably altered. Many studies have documented the properties of motor adaptation, yet the underlying mechanisms of motor adaptation remain imperfectly understood. In this study, we propose a computational analysis of adaptation to a visuomotor rotation task and examine it through an experiment. Our analysis suggests that two distinct processes contribute to produce adaptation: one which straightens trajectories, and another which redirects trajectories. We designed a visuomotor rotation task in a 3D virtual environment where human participants performed a pointing task using a head-mounted display controller represented by a cursor that was visually rotated by an angular deviation relative to its actual position. We observed that: (1) the trajectories were initially curved and misdirected, and became straighter and better directed with learning; (2) the straightening process occurred faster than the redirection process. These findings are consistent with our computational analysis and disclose a new and different perspective on motor adaptation
Multimodal super-resolution for fast image-based simulation of crystal plasticity
No full textInternational audienc
Comment l'Analyse du Cycle de Vie (ACV) évalue et contribue à réduire les impacts environnementaux des parcs éoliens en mer ?: [Bulletin COME3T n° 13, septembre 2025]
No full textL’ACV environnementale est un outil d’évaluation qui permet de quantifier les impacts environnementaux potentiels pour chaque étape du cycle de vie d’un système. Elle permet d’identifier quelles sont les étapes du cycle de vie les plus impactantes pour l’environnement afin (i) d’évaluer l’impact environnemental d’un système, (ii) de proposer des systèmes plus respectueux de l’environnement en travaillant sur les principales sources d’impact, (iii) en informant sur les impacts environnementaux d’un système et (iv) en orientant les politiques publiques et les entreprises dans leur stratégie de réduction des impacts environnementaux (stratégie bas carbone, etc.). C’est un processus normé qui peut être appliqué à tous types de systèmes, comme les parcs éoliens
Spatialized and Prospective LCA of Agrivoltaism in the Mediterranean basin under Climate Change
No full textInternational audienc
NickPay, an Auditable, Privacy-Preserving, Nickname-Based Payment System
No full textInternational audienceIn this paper, we describe the motivation, design, security properties, and a prototype implementation of NickPay, a new privacy-preserving yet auditable payment system built on top of the Ethereum blockchain platform. NickPay offers a strong level of privacy to participants and prevents successive payment transfers from being linked to their actual owners. It is providing the transparency that blockchains ensure and at the same time, preserving the possibility for a trusted authority to access sensitive information, e.g., for audit purposes or compliance with financial regulations. NickPay builds upon the Nicknames for Group Signatures (NGS) scheme, a new signing system based on dynamic ``nicknames'' for signers that extends the schemes of group signatures and signatures with flexible public keys. NGS enables identified group members to expose their flexible public keys, thus allowing direct and natural applications such as auditable private payment systems, NickPay being a blockchain-based prototype of these
Photo-oxidation of semicrystalline polymers: Effect of stress triaxiality on ductility
No full textInternational audienc
Modélisation de la propagation de fissure et formation d'écaille dans une piste de roulement sous chargement de contact Hertzien
No full textUne thématique beaucoup plus sur la fissuration : la ruptureInternational audienceCette étude propose de modéliser l’écaillage comme la propagation multi-branchée de fissures en fatigue, à partird’une fissure principale initiée en surface. La méthode des éléments finis, couplée avec la mécanique linéaireélastique de la rupture, est utilisée pour calculer les états de contraintes locaux sur un modèle 2D de piste deroulement muni d’une fissure inclinée, soumis à un chargement de contact hertzien. Pour prendre en comptele contact frottant au niveau des lèvres de fissures, une modélisation originale utilisant des éléments de zonescohésives a été mise en place. Les facteurs d’intensité de contraintes sont calculés pour différentes tailles defissures sur ce modèle. L’insertion d’une branche secondaire, dérivée de la fissure principale dans le modèle 2Dpermet d’affiner la compréhension du mécanisme d’écaillage et ses implications sur la durée de vie des roulementshybrides céramiques
Non-Invasive Rayleigh, Raman, and Chromium-Fluorescence Study of Phase Transitions: β-Alumina into γ-Alumina 'Single' Crystal and Then to α-Alumina
No full textInternational audienceIn many advanced materials production processes, the analysis must be non-invasive, rapid, and, if possible, operando. The Raman signal of the various forms of alumina, especially transition alumina, is very weak due to the highly ionic nature of the Al-O bond, which requires long exposure times that are incompatible with monitoring transitions. Here, we explore the use of the fluorescence signal of chromium, a natural impurity in alumina, and the Rayleigh wing to follow the crystallization process up to alpha alumina. To clarify the assignment of the fluorescence components, we compare the transformation of beta alumina single crystals into transition (gamma and theta) alumina and then into alpha alumina with the transformation of optically transparent alumina xerogel and glass, obtained by very slow hydrolysis-polycondensation of aluminum sec-butoxide, into alpha alumina. Vibrational modes are better resolved in thermally treated single crystals than in thermally treated xerogels. Measurements of the Rayleigh wing, the Boson peak, and the fluorescence signal are easier than those of vibrational modes for studying the evolution from amorphous to alpha alumina phases. The fluorescence spectra allow almost instantaneous (<1 s) quantitative control of the phases present
Presentation and Research Perspectives of Collective Photovoltaic Self-Consumption and Energy Communities: A New Solution to Favorize the Energy Transition in Urban Areas
No full textInternational audienceFaced with the continuous increase in electricity consumption, particularly in urban areas, it is necessary to find sustainable, efficient and inexpensive energy-supply solutions. This necessarily involves the development of renewable energies which, due to their intermittency, are not always easily integrated into the electricity grid. Emerging solutions, made possible by the development of new information technologies and by changes in regulations, have emerged. Among them, collective renewable self-consumption, coupled with smart micro-grids and the development of storage, is a serious and rapidly developing candidate. The objective of this article is to present the principle of this collective self-consumption, its advantages as well as its constraints and the wide range of research that this sector opens up in the fields of energy, electrical engineering, new technologies without forgetting the sociological aspects