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A simple derivation of the geometric theorems for averaging and Errata for the article Adv. Water Res., 32 (2013) 340-352
No full textInternational audienceThe derivation of upscaled models using the volume averaging method involves the use of the spatial averaging theorem. From its use, further geometrical identities arise when it is applied to a position vector or its dyadic products at the th-order, i.e., the -adic product. The derivation of these geometrical identities is revised in this work in a concise manner that corrects some inconsistencies in the technical note by Wood (2013). These new derivations strengthen the use of the volume averaging method in many transfer problems, in particular in porous media
A close-up at the paleoecology of the most western gelada relatives: Insights from dental microwear texture analysis
No full textInternational audienceExploring the paleoecology of extinct species of the genus Theropithecus, which was widespread and diversified in Africa during the Pliocene and the Pleistocene, is crucial to have a full picture of the evolutionary history of this taxon. It also gives insights into the fundamental ecological range of the genus, now restricted to the Ethiopian highlands in a reduced set of habitats. This study aims to investigate the diet of Theropithecus atlanticus (n = 8) from the Plio-Pleistocene site of Ahl al Oughlam (Morocco) through dental microwear texture analysis. We used a recently developed software, 'trident', that quantifies the heterogeneity of texture parameters through subsampled wear surfaces to improve dietary discriminations. We considered a comparative dataset of extant primates (n = 104) with different diets, including the leaf-eater Colobus guereza, the grass-eater Theropithecus gelada, and the generalists Papio hamadryas and Chlorocebus aethiops. In addition, we compared with specimens of theropiths (n = 80) from the eastern African Shungura Formation (Lower Omo Valley, Ethiopia) that are nearly contemporaneous to T. atlanticus. Our results indicate that T. atlanticus was mostly feeding on grasses, as its extant relative. Some similarities with opportunistic species suggest it might have consumed a substantial amount of challenging foods. This dental microwear texture is in line with open, arid and harsh environments, and the presence and abundance of C3 grasses at Ahl al Oughlam detected by enamel stable isotopes analysis on various mammals including theropiths. This contrasts with the environment described on nearly contemporaneous specimens from the Lower Omo Valley where grasses were abundant but composed of C4 ones
Disillusions and paradoxes of the massification of education in France
No full textInternational audienceBased on an analysis of French educational policies since the 1950s, this paper assesses their global impact and their unexpected effects upon individuals and society, concerning students’ learning, access to the labour market, and some attitudes and behaviours, notably civic ones. It shows that from an academic point of view, the lengthening of schooling does not increase pupils’ level as much as the multiplication of diplomas would suggest, nor reduce social inequalities. Moreover, when entering the job market, competition is harsher and the least qualified face more and more difficulties, and develop a resentment that feeds populism. These global unintended effects lead us to question the paradox of the French education system and the meritocratic equality of opportunities it is supposed to implement
Look for efficient Pr–Ni based SOCs oxygen electrodes in the Ruddlesden - Popper series: preliminary thermal stability studies focused on PrNiO3-δ and (Pr, La)4Ni3O10+δ
No full textInternational audienceThe present work investigates the thermal stability of Pr-Ni based nickelates belonging to the Ruddlesden-Popper (RP) series, specifically Pr4Ni3O10+δ, La4Ni3O10+δ, La3PrNi3O10+δ (n=3), and PrNiO3-δ (n = ∞), as promising oxygen electrode materials for solid oxide cells (SOCs). A detailed preliminary study is therefore essential to determine the optimal conditions, particularly temperature and oxygen partial pressure (pO2), required for the successful synthesis, sintering, and application of these materials as electrodes. Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) are employed to study their phase stability and decomposition behaviour under various atmospheres (argon, air, and oxygen). The results show that PrNiO3-δ has limited thermal stability, decomposing above 1040 °C in oxygen, while the other RP phases demonstrate greater stability, particularly Pr4Ni3O10+δ, which remains stable up to 1120 °C under oxygen. The substitution of La by Pr further improves the stability of the RP phases. Long-term aging experiments at 600–800 °C confirm that all materials maintain their phase integrity under air for up to three months. This study provides essential insights into optimizing synthesis and sintering conditions for these materials, supporting their application in high-temperature SOC devices.</p
Design of a monomodal porous metamaterial for passive daytime radiative cooling: Impact of spherical void radius and volume fraction
No full textInternational audiencePassive daytime radiative cooling (PDRC) enables a body exposed to sunlight to dissipate heat through thermal radiation without the need for external energy input. To be effective, such systems must strongly reflect solar radiation across the solar spectral band while simultaneously exhibiting a high thermal emittance within the atmospheric transparency window. In this work, we investigate the cooling performance of a porous metamaterial composed of air voids embedded in a polydimethylsiloxane (PDMS) matrix. Using a combination of Monte Carlo simulations, which take into account dependent scattering effects, and effective medium theories such as the extended Maxwell-Garnett model and a Nicholson-Ross-Weir-type retrieval method associated with finite-element electromagnetic simulations, we study the influence of void radius and volume fraction on the spectral properties relevant to PDRC. We identify a range of void radii that optimize performance and demonstrate the existence of an optimal radius that maximizes the cooling potential regardless of ambient temperature. These results provide practical design guidelines for the development of efficient PDRC materials and contribute to the broader field of radiative thermal management.</div
De la (re)définition juridique de l’espace de travail ou du milieu de travail pur une meilleure application du droit de la santé au travail
No full textInternational audienceL'accélération de l'évolution technologique associée à celles de l'organisation du travail et des modes de travail remet profondémenten cause les conditions de travail et l'application du droit de la santé au travail. Si le temps de travail retient le plus souvent l'attention,l'espace de travail est également vivement bousculé par les transformations de la manière de travailler en devenant beaucoup plusvolatile concernant certaines professions. L'espace de travail délimité au périmètre du bureau est moribond, rendant nécessaire des'attaquer à une définition juridique renouvelée de cet espace pour reconsidérer le champ d'application de l'exécution du contrat detravail, des responsabilités et de l'effectivité du droit de la santé au travail, y compris des accidents et des maladies professionnelles.Ces transformations pourraient également faire naître une acception plus large de l'espace de travail pour considérer un milieu detravail effectif
Impossibilité de prononcer la remise en état des lieux à titre de peine principale
No full textInternational audience1. Cour de cassation, crim., 12 novembre 2025, no 25-81.179, inédit 2 Cour de cassation, crim., 12 novembre 2025, no 24-82.784, inédi
The Future in Mind: Aspirations and Long-Term Outcomes in Rural Ethiopia
No full textInternational audienceAbstract Aspirations may condition the future-oriented choices of individuals and thus may play a role in the persistence of poverty or the effort to break out of it. We run a randomised control trial in remote, rural Ethiopia to explore this and evaluate an intervention which aims to change how poor people perceive their future opportunities, alter their aspirations and, through that, modify their investment decisions. A treatment group was shown video documentaries featuring individuals from similar communities who escaped poverty through their own efforts and serve as relatable role models. Five years after the screening took place, the treated households had increased future-oriented investments in agriculture, children’s education and assets. The results can be explained by an increase in aspirations in terms of lifetime goals. Overall, this research uniquely provides evidence that a light-touch behavioural intervention can have persistent economic impacts on a poor population
Simon Naylor. The Observatory Experiment Meteorology in Britain and Its Empire. 285 pp.. Cambridge: Cambridge University Press, 2024
No full textConvergence of Hermite expansions in modulation spaces
No full textThe aim of this paper is to give an elementary proof that Hermite expensions of a function in the modulation space converges to in when 1< p<+\infty and may diverge when . The result was previously established for 1< p<+\infty by Garling and Wojtaszczyk and for by Lusky in an equivalent setting of Fock spaces by different methods. Higher dimesional results are also considered.In an appendix, we also establish upper bounds for the Zak transform of Hermite functions