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Comparison of the environmental impacts of perovskite/silicon tandem and silicon heterojunction photovoltaic modules using a parameterised approach
No full textInternational audienc
Extension of Sequence of Physical Processes framework relating the second Piola-Kirchhoff stress tensor to the Green-Lagrange strain tensor
No full textAn extension of the Sequence of Physical Processes using geometrical corrections of the Piola-Kirchhoff stress tensor and the Green-Lagrange strain tensor is addressed. More precisely, the usual Sequence of Physical Processes omits some geometrical non linearities that appear when the deformation becomes large. With this extension, geometrical corrections are added and let the opportunity to study rheological non linearities. Application on two famous classical viscoelastic models, namely the linear Maxwell model and the linear Kelvin-Voigt model, helps to understand how some complex behaviours may be rationalised to better understand the behaviours after some corrections
How To Keep Track On Impact Investing Promises: Exploring The Potentials Of New Governance Schemes
No full textInternational audienceImpact investing is gaining momentum but still calls for an examination of how such a promise regarding the allocation of capital toward social and environmental goals can be kept on track. This paper explores the role and different levers of governance, particularly formal structures, in the advancement of impact investing. Through a focus group convened by the French Sustainable Investment Forum, we build on an innovative framework, the Société à Mission, to uncover investor expectations regarding the need to transform governance schemes for impact. Our review shows that traditionally, governance has been utilized to address agency biases and mitigate the risk of opportunism among actors, thereby reinforcing transparency and alignment. However, we argue that some of the practical challenges regarding evaluation, integration, and institutionalization stem from the specific nature of impact, which calls for extending governance concerns to include cognitive and methodological matters, at every stage of the investment chain
Monde, nature, Cosmos: le tournant cosmologique de Karl Löwith
No full textInternational audienceFrom the 1950s onwards, Karl Löwith developed a cosmological project aimed at reclaiming the world that had been secularized and “denatured” during the Modern Age, a secularization whose nihilistic consequences led to the great catastrophes of the 20th century. Starting from the genealogy that enables him to trace the Christian sources of the divide between nature and history, we attempt here to identify the sources of this cosmology, mainly Heideggerian and Nietzschean. While Löwith's initial project in the 1920s is clearly anthropological, based based on a hermeneutic phenomenology of the worldlife, our aim is to show how he was led to reconsider it radically in the light of the Greek cosmos, while relating it to a broader conception of the world, aimed at overcoming the modern divide and reconciling contemporary man with his nature and natural origin.A partir des années 1950, Karl Löwith développe un projet cosmologique qui vise à regagner le monde qui aurait été sécularisé et « dénaturé » pendant les Temps modernes, sécularisation dont les conséquences nihilistes auraient débouché sur les grandes catastrophes du 20e siècle. Partant de la généalogie qui lui permet de remonter aux sources chrétiennes de la scission entre nature et histoire, nous tentons ici de dégager les sources de cette cosmologie, principalement heideggériennes et nietzschéennes. Si Löwith part d’un projet initialement anthropologique dans les années 1920, au fil directeur du Lebenswelt, nous souhaitons montrer comment il est amené à le repenser intégralement à la lumière du cosmos grec, tout en l’articulant à une conception plus large du monde, qui vise à dépasser le clivage moderne et à réconcilier l’homme contemporain avec sa nature et son milieu naturel
Dark Energy, and a Dark Fluid, from topology and a massless spinor
No full textInternational audienceUnder the existence of a massless spinor degrees of freedom in a spacetime with internal boundaries, such as black holes, we show that a topological mechanism naturally induces terms in the Einstein-Cartan gravitational action that can be interpreted as GR with dark energy and some dark fluid. This can alleviate the problems of dark energy, and perhaps of dark matter. The dark fluid term remains to be further analysed. The topological information is carried by a harmonic 1-form associated to the first co-holomology group of the spacetime, which induces a spacetime contortion acting on the horizontal bundle
Science Behind Closed Doors: On the Protection of the National Scientific Capability
No full textAccepted for publication in Law, Innovation and Technology, vol. 18, no. 2, 2026International audienceThe dissemination of data and the circulation of scientists are widely regarded as pivotal factors in the advancement of science. However, several countries, including the European Union, Canada and the United States, have recently adopted restrictive policies designed to protect scientific results against the risks of economic espionage, hostile military use or terrorist diversion. This article examines the legal frameworks that have been implemented in France to protect the nation's 'scientific and technological capability'. The French approach encompasses the establishment of restricted zones (ZRR), comprising three constituent elements: the creation of protected areas, the restriction of access to these areas, and the limitation of data circulation. This has resulted in a fragmentation of scientific communities, based on ‘communities of trust’ that are seeking to restore conditions favourable to the production of scientific knowledge in restricted and controlled areas. The article illustrates the resurgence of a legal framework for scientific research centred on national interests, suggesting a possible retreat in the openness of science.Preprint available at: https://osf.io/preprints/osf/zhxjf_v
Multi-messenger observations of binary neutron star mergers: synergies between the next generation gravitational wave interferometers and wide-field, high-multiplex spectroscopic facilities
No full textInternational audienceThird-generation gravitational wave (GW) observatories such as the Einstein Telescope (ET) and Cosmic Explorer (CE) will detect hundreds of thousands of binary neutron star (BNS) mergers, reaching redshifts beyond . To fully exploit joint GW and electromagnetic (EM) detections, dedicated strategies and adapted EM facilities are essential. We investigate the role of Integral Field and Multi-Object Spectroscopy (IFS and MOS) with the Wide-field Spectroscopic Telescope (WST) on next generation GW multi-messenger (MM) observations. We consider simulations of BNS populations, their GW detections with ET(+CE), and their EM counterparts: kilonovae (KNe) and gamma-ray bursts (GRBs). We consider two strategies: one in synergy with wide-field photometric surveys, and a galaxy-targeted one exploiting WST high multiplexing. We estimate the number of galaxies in GW error volumes, and identify observational challenges and mitigation strategies. We find that WST can detect KNe up to and , and GRB afterglows beyond for . KN observations are best scheduled 12-24 hours post-merger. For poorly localised GRBs, WST IFS can aid the identification. Mini-IFUs and galaxy catalogues complete to are key to EM counterpart detection. Even at low , the number of galaxies can be huge-thousands at , tens of thousands at . Events at with localisation deg are golden cases for WST, requiring few exposures to target all galaxies. Detecting and characterising EM counterparts of BNS detected in the extended volume explored by next-generation interferometers will be challenging. We show that high-sensitivity, wide-field, high-multiplex spectroscopic facilities are powerful instruments to fully exploit the new multi-messenger science opportunities enabled by next generation GW detectors
A smooth filament origin for prolate galaxies "going bananas" in deep JWST images
No full textInternational audienceWe compare the abundant prolate shaped galaxies reported beyond z3 in deep JWST surveys, with the predicted {\it stellar} appearance of young galaxies in detailed hydro-simulations of three main dark matter contenders: Cold (CDM), Wave/Fuzzy (DM) and Warm Dark Matter (WDM). We find the observed galaxy images closely resemble the elongated stellar appearance of young galaxies predicted for both DM and WDM, during the first 500Myr while material steadily accretes from long, smooth filaments. The dark mater halos of WDM and DM also have pronounced, prolate elongation similar to the stars, indicating a shared, highly triaxial equilibrium. This is unlike CDM where the early stellar morphology is mainly spheroidal formed from fragmented filaments with frequent merging, resulting in modest triaxiality. Quantitatively, the excess of prolate galaxies observed by JWST matches well WDM and DM for particle masses of 1.4KeV and eV respectively. For CDM, several visible subhalos are typically predicted to orbit within the virial radius of each galaxy from subhalo accretion, whereas merging is initially rare for WDM and DM. We also verify with our simulations that DM may be distinguished from WDM by the form of the core, which is predicted to be smooth and centered for WDM, but is a dense soliton for DM traced by stars and measurably offset from the galaxy center by random wave perturbations in the simulations. We emphasise that long smooth filaments absent of galaxies may prove detectable with JWST, traced by stars and gas with comoving lengths of 150kpc predicted at z10, depending on the particle mass of DM or WDM
A propos du Christ préconnu avant l’avènement du monde (πρὸ καταβολῆς κόσμου), dans l’Ad Thalassium LX de Maxime le Confesseur
No full textInternational audienc
Antimicrobial peptide mechanism of action on S. aureus membranes determined by in vivo solid-state NMR
No full textInternational audienceStaphylococcus aureus (S. aureus) is a Gram-positive pathogenic bacterium and a major cause of nosocomial infections. Between 20 % and 50 % of S. aureus strains are resistant to a wide range of antibiotics. DMS-DA6-NH 2 (DA6) is a novel antimicrobial peptide (AMP) that exhibits high efficacy against various bacterial strains, particularly S. aureus, by disrupting its membrane through an as-yet-unknown mechanism. We employed in vivo 2 H solid state Nuclear Magnetic Resonance (NMR) to investigate the mode of action of AMPs on deuterated bacteria. This technique provides insights into membrane order and its changes with increasing AMP concentration. Our results enabled us to compare the mechanism of DA6 with those of AMPs with established modes of action. We found that DA6 induces pore formation in the membrane of S. aureus. This protocol serves as a template for determining the mechanisms of action of other peptides, an essential step for developing and patenting such drugs for the treatment of human diseases