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Second Carrier Phase TWSTFT Campaign in Europe Employing the SRS Modem
No full textInternational audienceA small consortium of European NMIs has agreed with NICT to conduct a measurement campaign with the SRS modem. A total of four modems will for one year be integrated into the existing TWSTFT installations of OP, PTB, INRiM and RISE and will measure alongside the current set-ups with SATRE modems used for TAI links. The main objective is to demonstrate carrier phase measurements using a Telstar T11-N transponder and exploit the setup to link optical frequency references
Optical lattice clocks at LTE: Progress and applications to Earth Sciences (invited talk)
No full textInternational audienc
Preliminary Accuracy Budget of a Cold-Atom-Based Commercial Microwave Clock
No full textInternational audienc
Time-resolved mid-infrared frequency comb spectroscopy in CO2 plasma environments
No full textInternational audienc
Le rôle de la polarisabilité explicite dans la modélisation moléculaire des interfaces argile–eau selon l’état d’hydratation
No full textInternational audienceClay minerals play a central role in soils by controlling fluid structure and transport at the nanoscale. Molecular dynamics (MD) simulations are powerful tools to investigate these processes, but their predictive capability strongly depends on the chosen force field. This work presents a comparative MD study of a montmorillonite mesopore at varying water saturation levels, from fully saturated systems to conditions with only an adsorbed water layer. Simulations were performed using both the polarizable ion model (PIM) force field and the non-polarizable ClayFF reference.The results reveal significant differences in ion distribution, water structuring, and interfacial dynamics between the two approaches. Under saturated conditions, PIM predicts enhanced ion pairing and long-range organization within the diffuse layer, whereas ClayFF yields smoother profiles consistent with continuum descriptions. At low saturation, polarizability-induced surface deformation in PIM leads to a more homogeneous hydration and partial exclusion of cations from adsorption sites, while ClayFF favors localized cation trapping and heterogeneous surface dehydration. Although average in-plane water diffusion coefficients are similar, ClayFF exhibits strong diffusion anisotropy under desaturated conditions, in contrast to the more isotropic dynamics observed with PIM. These results highlight the importance of explicit polarizability for accurately describing clay–water interfaces under environmentally relevant unsaturated conditions.Les minéraux argileux jouent un rôle central dans les sols en contrôlant la structure et le transport des fluides à l’échelle nanométrique. Les simulations de dynamique moléculaire (DM) constituent des outils puissants pour étudier ces processus, mais leur capacité prédictive dépend fortement du choix du champ de force. Ce travail présente une étude comparative par DM d’un mésopore de montmorillonite à différents niveaux de saturation en eau, allant de systèmes entièrement saturés à des conditions ne comportant qu’une couche d’eau adsorbée. Les simulations ont été réalisées à l’aide du champ de force polarisable basé sur le modèle ionique (PIM) et du champ de force de référence non polarisable ClayFF.Les résultats mettent en évidence des différences marquées entre les deux approches en termes de distribution ionique, de structuration de l’eau et de dynamique interfaciale. En conditions saturées, le modèle PIM prédit un appariement ionique renforcé ainsi qu’une organisation à longue portée au sein de la couche diffuse, tandis que ClayFF conduit à des profils plus lisses, en accord avec les descriptions continues. À faible saturation, les déformations de surface induites par la polarisabilité dans les simulations PIM entraînent une hydratation plus homogène et une exclusion partielle des cations des sites d’adsorption, alors que ClayFF favorise un piégeage localisé des cations et une déshydratation hétérogène de la surface. Bien que les coefficients de diffusion moyens de l’eau dans le plan soient similaires, ClayFF présente une forte anisotropie de diffusion en conditions désaturées, contrairement à la dynamique plus isotrope observée avec PIM. Ces résultats soulignent l’importance de la prise en compte explicite de la polarisabilité pour décrire avec précision les interfaces argile–eau dans des conditions non saturées pertinentes pour l’environnement
Capteurs quantiques basés sur les horloges optiques et les interféromètres atomiques : physique et applications
No full textNational audienc
Improved liquid argon ionization model and its impact on the DarkSide low-mass WIMP search programme
No full textInternational audienceDarkSide-50 achieved leading WIMP limits down to 1.2 GeV/c2 with an ionization-only analysis, despite its small active mass of 46 kg compared to multi-ton noble-liquid detectors. Accurate modelling of the nuclear-recoil ionization yield (Qy) is central to interpreting such searches. A new global fit combining nuclear-recoil response measurements from DarkSide-50, ARIS, SCENE, and the recent ReD experiment constrains Qy between 0.4 and 150 keV within the Thomas-Imel box framework. The dependence on screening potentials is addressed through a Bayesian model comparison, which rejects the ZBL and Molière functions and strongly favours the Lenz-Jensen one. The resulting model improves DarkSide-50 sensitivity below 3 GeV/c2 and refines the DarkSide-20k sensitivity accordingly
Website with interactive visualization of multivariate astronomical time series
No full textInternational audienceLight curves represent astronomical time series of flux measured across one or more photometric bands. With the rapid growth of large-scale sky surveys, time-domain astronomy has become an essential area of modern astrophysical research. Interactive visualization of extensive light-curve datasets plays a key role in exploring transient phenomena and in planning large follow-up campaigns. In this work, we introduce two web-based platforms designed for interactive light-curve visualization: Fulu, for transient event studies, and VALC, for investigations of low-mass active galactic nuclei (AGNs). These tools provide a user-friendly interface for examining, comparing, and interpreting vast collections of astronomical light curves, supporting scientific discovery
Investigating two configurations of flowing dielectric barrier discharges to trigger immune response for non-small cell lung carcinoma
No full textInternational audienceNon-small cell lung carcinoma (NSCLC) is a highly lethal cancer, asymptomatic in early stages and prone to rapid metastasis. Conventional therapies are unsuccessful in the major cases, except immunotherapy which can be curative for 30% of patients. Therefore, disruptive and combinative therapies should be explored to benefit a broader patient population. Recently, cold atmospheric plasma (CAP), also considered as an efficient source of reactive oxygen and nitrogen species (ROS/RNS), has shown potential to trigger immunogenic cell death, resulting in an antitumor immune response 1. In this purpose, we are investigating cold plasma processes for NSCLC therapy. Two plasma devices are designed: a dielectric capillary with outer ring electrodes, generating a plasma jet (ORJET) and a Dielectric Barrier Device with gas flowing through Mesh counter-ElectroDe (DBD-MED). Both are supplied in helium (1 L/min) and powered by a nanopulse high-voltage generator device (3-5 kV/10-20 kHz/1 %). Physical characterizations of the plasma are performed for various gap distances between the outlet of the source and an artificial model mimicking the human body electrical response (R = 1.5 kΩ // C = 100 pF 2). While the plasma plume produced by ORJET can propagate through 10 mm guaranteeing contact with the artificial model, ROS (O and OH radicals) as well as nitrogen ions N2+ quickly decrease at the vicinity of the target in favor of neutral nitrogen molecules N2. DBD-MED generates a homogenous plasma flowing afterglow beyond the grounded mesh counter-electrode in the range 0-2 mm, producing a gradient of ROS/RNS (O, OH, N2+ and nitrogen oxide NO) from the high-voltage electrode to the artificial model. Then, operating parameters are selected to ensure plasma electrical and thermal safety (I < 100 mA and T < 40°C) for subsequent experiments on murine and porcine models. Therapeutic effects of the two devices are assessed on NSCLC tumors subcutaneously grafted in immunocompetent mice exposed 5 times to plasma. Significant tumor regression is observed from the third treatment, persisting at least 20 days after the final treatment. Interestingly, the two sources have shown similar effects on tumor growth, metastasis and abscopal effect, involving an immune cell activation mediated by immunogenic cell death. We demonstrate the involvement of CD8+ T and CD20+ B cells in this antitumoral immune response. In conclusion, CAP holds strong potential to stimulate an antitumor immune response and could complement conventional immunotherapies for NSCLC treatment
A search for dark matter produced in association with a dark Higgs boson decaying into a Higgs boson pair in 3 or 4 final states using collisions at TeV with the ATLAS detector
No full textInternational audienceA search is performed for dark matter particles produced in association with a resonant pair of Higgs bosons using 140 fb of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. This signature is expected in some extensions of the Standard Model predicting the production of dark matter particles, and is interpreted in terms of a dark Higgs model containing a Z′ mediator in which the dark Higgs boson s decays into a pair of Higgs bosons. The dark Higgs boson is reconstructed through final states with at least three b-tagged jets, produced by the pair of Higgs boson decays, in events with significant missing transverse momentum consistent with the presence of dark matter. The observed data are found to be in good agreement with Standard Model predictions, constraining scenarios with dark Higgs boson masses within the range of 250 to 400 GeV and Z′ mediators up to 2.3 TeV.[graphic not available: see fulltext