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International audience; Polarity-controlled growth of ZnO by chemical bath deposition provides a method for controlling the crystal orientation of vertical nanorod arrays. The ability to define the morphology and structure of the nanorods is essential to maximizing the performance of optical and electrical devices such as piezoelectric nanogenerators; however, well-defined Schottky contacts to the polar facets of the structures have yet to be explored. In this work, we demonstrate a process to fabricate metal−semiconductor−metal device structures from vertical arrays with Au contacts on the uppermost polar facets of the nanorods and show that the Opolar nanorods (∼0.44 eV) have a greater effective barrier height than the Znpolar nanorods (∼0.37 eV). Oxygen plasma treatment is shown by cathodoluminescence spectroscopy to affect midgap defects associated with radiative emissions, which improves the Schottky contacts from weakly rectifying to strongly rectifying. Interestingly, the plasma treatment is shown to have a much greater effect in reducing the number of carriers in O-polar nanorods through quenching of the donor-type substitutional hydrogen on oxygen sites (HO) when compared to the zinc-vacancy-related hydrogen defect complexes (VZn −nH) in Zn-polar nanorods that evolve to lowercoordinated complexes. The effect on HO in the O-polar nanorods coincides with a large reduction in the visible-range defects, producing a lower conductivity and creating the larger effective barrier heights. This combination can allow radiative losses and charge leakage to be controlled, enhancing devices such as dynamic photodetectors, strain sensors, and light-emitting diodes while showing that the O-polar nanorods can outperform Zn-polar nanorods in such applications.

International audience; The wedge-tailed shearwater (WTS) population of New Caledonia is one of the largest in the world, yet its biology and foraging ecology are poorly known. We studied WTS from 4 colonies in New Caledonia. We examined foraging behaviour and habitats using GPS receivers and light sensors during and outside the breeding season, respectively, and compared our findings with those from other WTS populations worldwide. During breeding, New Caledonian WTS alternated short foraging trips close to the colony over the lagoon, or off the reef edge, with longer trips over distant, deep waters. Whereas neighboring colonies overlapped at sea, especially during short trips, there was a clear separation of foraging zones between the pairs of colonies located in the southern versus northwestern parts of New Caledonia. Although WTS actively foraged and commuted to foraging zones during the day, they mainly returned to the colony or rested at night, indicating that they feed mainly during the day. Active foraging did not take place in more productive areas, suggesting that it may instead be related to the presence of sub-surface predators. Outside the breeding season, birds from 3 colonies had similar trans-equatorial migratory behaviour. All left New Caledonia at the same time of the year with a fast, northeasterly movement and wintered over deep waters in the same sector of the northwestern tropical Pacific Ocean. At overwintering sites, they spent most of their non-foraging time presumably sitting on the water, especially at night, making a slow westward movement before returning to New Caledonia. WTS from New Caledonia forage over warm, oligotrophic deep waters throughout their life cycle, and the species appears to have a flexible foraging strategy adapted to the various environmental conditions encountered across its wide tropical range.

Aim The aim was to decipher Europe‐wide spatio‐temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming. Location Europe and North Africa (30‒70° N, 10° W‒35° E). Time period 1901‒2003. Major taxa studied Temperate and Euro‐Siberian trees. Methods We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree‐ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic, boreal, cold continental, Mediterranean and temperate). We also examine whether TRWi shows variable coupling with leaf‐level gas exchange, inferred from indexed carbon isotope discrimination of tree‐ring cellulose (Δ13Ci). Results We find spatial autocorrelation for TRWi and Δ13Ci extending over a maximum of 1,000 km among forest stands. However, growth synchrony is not uniform across Europe, but increases along a latitudinal gradient concurrent with decreasing temperature and evapotranspiration. Latitudinal relationships between TRWi and Δ13Ci (changing from negative to positive southwards) point to drought impairing carbon uptake via stomatal regulation for water saving occurring at forests below 60° N in continental Europe. An increase in forest growth synchrony over the 20th century together with increasingly positive relationships between TRWi and Δ13Ci indicate intensifying impacts of drought on tree performance. These effects are noticeable in drought‐prone biomes (Mediterranean, temperate and cold continental). Main conclusions At the turn of this century, convergence in growth synchrony across European forest ecosystems is coupled with coordinated warming‐induced effects of drought on leaf physiology and tree growth spreading northwards. Such a tendency towards exacerbated moisture‐sensitive growth and physiology could override positive effects of enhanced leaf intercellular CO2 concentrations, possibly resulting in Europe‐wide declines of forest carbon gain in the coming decades. Spanish Government, Grant/Award Number: AGL2015‐68274 ‐C3 ‐3‐R; Sixth Framework Programme, Grant/AwardNumber: EVK2‐2001 ‐00237; Seventh Framework Programme, Grant/AwardNumber: COST ‐STSM ‐ECOST ‐STSM ‐FP1304‐140915‐066395 and ERANET‐Mundus program (Grant agreement 20112573)

International audience; Precisely detecting solar Active Regions (AR) from multi-spectral images is a challenging task yet important in understanding solar activity and its influence on space weather. A main challenge comes from each modality capturing a different location of these 3D objects, as opposed to more traditional multi-spectral imaging scenarios where all image bands observe the same scene. We present a multi-task deep learning framework that exploits the dependencies between image bands to produce 3D AR detection where different image bands (and physical locations) each have their own set of results. We compare our detection method against baseline approaches for solar image analysis (multi-channel coronal hole detection, SPOCA for ARs (Verbeeck et al., 2013)) and a state-of-the-art deep learning method (Faster RCNN) and show enhanced performances in detecting ARs jointly from multiple bands.

International audience; The purpose of this study was to examine the association between young players’ perception of mother’s and father’s responsiveness with their self-esteem, anxiety (i.e., worry), and thriving (i.e., positive affect, vitality, and life satisfaction). In total, 314 male British rugby players with a mean age of 16.23 years (SD = 0.26) completed the study in two phases: n = 124 (first dataset), and n = 192 (second dataset). Participants trained on average 3.14 times/week (SD = 0.94) and had been involved in rugby for an average of 8.21 years (SD = 2.89). Participants completed questionnaires measuring perceived parental responsiveness (PPR) for their mother and father, self-esteem, worry about sport performance, and thriving indicators (i.e., positive affect, vitality, and life satisfaction). The results consistently indicated that participants’ perceptions of their mother’s and father’s responsiveness positively related to thriving, and negatively related to their worry about sport performance, mediated by their self-esteem. Overall, the study highlights the need for parents to be provided with insights into the value of being responsive to their child and being encouraged to regularly talk with their child regarding their needs and desires, and seeking to understand how their child perceives the support they currently receive.

River fragmentation caused by instream barriers is a leading cause of biodiversity loss, particularly for freshwater migratory fish, the vertebrate group that has suffered the steepest decline. However, most studies have tended to focus on the impacts of large dams on only a few taxa. We estimated the cumulative impact of both large and small barriers on fish species richness and relative abundance along an altitudinal gradient in the main stem of the River Allier (France). Using eDNA metabarcoding, we identified 24 fish zero-radius operational taxonomic units (zOTUs), corresponding to 26 species distributed along the main stem of the river. Elevation explained the greatest amount of variation in fish distribution, together with average flow, barrier density and its interaction with cumulative barrier height. Based on eDNA, the largest discontinuity in species richness was not related to the location of Poutès, the largest dam in the system, but located downstream from it. Our results indicate that, in addition to the more obvious effects of large dams on migratory fish such as the Atlantic salmon, the cumulative effects of small barriers can have widespread impacts on fish species richness and relative abundance, which should not be overlooked. We suggest that, as for other fragmented rivers, acting on numerous small barriers might bring about greater benefits in fish species richness than focusing only on the largest dams. yes

Rationale: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare disease, manifested by syncope or sudden death in children or young adults under stress conditions. Mutations in the Ca 2+ release channel/RyR2 (type 2 ryanodine receptor) gene account for about 60% of the identified mutations. Recently, we found and described a mutation in RyR2 N-terminal domain, RyR2 R420Q . Objective: To determine the arrhythmogenic mechanisms of this mutation. Methods and Results: Ventricular tachycardias under stress conditions were observed in both patients with catecholaminergic polymorphic ventricular tachycardia and knock-in mice. During action potential recording (by patch-clamp in knock-in mouse cardiomyocytes and by microelectrodes in mutant human induced pluripotent stem cell-derived cardiomyocytes), we observed an increased occurrence of delayed afterdepolarizations under isoproterenol stimulation, associated with increased Ca 2+ waves during confocal Ca 2+ recording in both mouse and human RyR2 R420Q cardiomyocytes. In addition, Ca 2+ -induced Ca 2+ -release, as well as a rough indicator of fractional Ca 2+ release, were higher and Ca 2+ sparks longer in the RyR2 R420Q -expressing cells. At the ultrastructural nanodomain level, we observed smaller RyR2 clusters and widened junctional sarcoplasmic reticulum measured by gated stimulated emission depletion super-resolution and electron microscopy, respectively. The increase in junctional sarcoplasmic reticulum width might be due to the impairment of RyR2 R420Q binding to JPH2 (junctophilin-2), as there were less junctophilin-2 coimmunoprecipitated with RyR2 R420Q . At the single current level, the RyR2 R420Q channel dwells longer in the open state at low intracellular Ca 2+ ([Ca 2+ ] i ), but there is predominance of a subconductance state. The latter might be correlated with an enhanced interaction between the N terminus and the core solenoid, a RyR2 interdomain association that has not been previously implicated in the pathogenesis of arrhythmias and sudden cardiac death. Conclusions: The RyR2 R420Q catecholaminergic polymorphic ventricular tachycardia mutation modifies the interdomain interaction of the channel and weakens its association with JPH2. These defects may underlie both nanoscale disarrangement of the dyad and channel dysfunction.

Monte Carlo simulations are the numerical method of choice for the study of lattice field theories in a non-perturbative framework. Over the years, Monte Carlo methods in Lattice Field Theories have reached a level of maturity such that in several QCD applications they provide the most reliable predictions for the low-energy behaviour of the theory. However, for many interesting theories, a complex-valued action prevents the use of standard sampling techniques. This is generally known as the sign problem and is present if the Boltzmann weight associated with the field configurations is either non-positive or non-real. A class of models exhibiting this property are finite density theories. These are going to be our primary interest.In this work, we shall focus on the density of states approach to the sign problem. This is a numerical technique that enables us to use standard Monte Carlo techniques to evaluate the density of states relating to the imaginary part of the action. By doing this, the sign problem is reduced to a simpler one-dimensional oscillatory integral, amenable to standard deterministic quadrature methods.At the core of our implementation of the density of states method is the LLR algorithm. We will present the general implementation and recent developments regarding on the control of possible sources of bias. Then we will extend the current formulation to allow for the evaluation of generic observables. Both these topics will be supported by results from numerical studies of the relativistic Bose gas at finite density.Lastly, we will discuss the problem of applying this approach to fermionic models where the sign problem is generated by the complex-valued fermionic determinant. As a specific application, we will study the Thirring model in two different representations discussing the related challenges., Les simulations de Monte Carlo sont la méthode numérique de choix pour l'étude des théories des champs sur réseau dans un système non perturbatif. Au fil des ans, les méthodes de Monte Carlo dans les théories de champ sur réseau ont atteint un niveau de maturité tel que dans plusieurs applications QCD, elles fournissent les prédictions les plus fiables pour le comportement à basse énergie de la théorie. Cependant, pour de nombreuses théories intéressantes, une action à valeurs complexes empêche l'utilisation de techniques d'échantillonnage standard. Ceci est généralement connu sous le nom de problème de signe et est présent si le poids de Boltzmann associé aux configurations de champ est non positif ou non réel. Une classe de modèles présentant cette propriété sont les théories de densité finie. Celles-ci seront notre principal intérêt.Dans ce travail, nous nous concentrerons sur l'approche de la densité d'états au problème de signe. Il s'agit d'une technique numérique qui permet d'utiliser les techniques standards de Monte Carlo pour évaluer la densité d'états relatifs à la partie imaginaire de l'action. En faisant cela, le problème du signe est réduit à une intégrale oscillatoire unidimensionnelle plus simple, qui se prête aux méthodes de quadrature déterministes standard.Au cœur de notre implémentation de la méthode de la densité des états se trouve l'algorithme LLR. Nous présenterons la mise en œuvre générale et les développements récents concernant le contrôle des sources possibles de biais. Ensuite, nous étendrons la formulation actuelle pour permettre l'évaluation d'observables génériques. Ces deux sujets seront étayés par les résultats d'études numériques du gaz de Bose relativiste à densité finie.Enfin, nous discuterons du problème de l'application de cette approche aux modèles fermioniques où le problème des signes est généré par le déterminant fermionique à valeurs complexes. En tant qu'application spécifique, nous étudierons le modèle Thirring dans deux représentations différentes abordant les défis associés.

This paper presents a novel Smooth Particle Hydrodynamics computational framework for the simulation of large strain fast solid dynamics in thermo-elasticity. The formulation is based on the Total Lagrangian description of a system of first order conservation laws written in terms of the linear momentum, the triplet of deformation measures (also known as minors of the deformation gradient tensor) and the total energy of the system, extending thus the previous work carried out by some of the authors in the context of isothermal elasticity and elasto-plasticity (Lee et al., 2016; Lee et al., 2017; Lee et al., 2019). To ensure the stability (i.e. hyperbolicity) of the formulation from the continuum point of view, the internal energy density is expressed as a polyconvex combination of the triplet of deformation measures and the entropy density. Moreover, and to guarantee stability from the spatial discretisation point of view, consistently derived Riemann-based numerical dissipation is carefully introduced where local numerical entropy production is demonstrated via a novel technique in terms of the time rate of the so-called ballistic free energy of the system. For completeness, an alternative and equally competitive formulation (in the case of smooth solutions), expressed in terms of the entropy density, is also implemented and compared. A series of numerical examples is presented in order to assess the applicability and robustness of the proposed formulations, where the Smooth Particle Hydrodynamics scheme is benchmarked against an alternative in-house Finite Volume Vertex Centred implementation.

International audience

International audience; Fluoride-Ion Batteries (FIBs) have been recently proposed as a post-lithium-ion battery system. This review article presents recent progress of the synthesis and application aspects of the cathode, electrolyte, and anode materials for fluoride-ion batteries. In this respect, improvements in solid-state electrolytes for FIBs as well as liquid electrolytes will be discussed. Furthermore, the achievements regarding the development of cathode and anode materials will be considered. With the improvements made, the field is currently attracting a steady increase of interest, and we will discuss the potentials of this technology together with necessary future milestones to be achieved in order to develop FIBs for future energy storage.

Precisely localising solar Active Regions (AR) from multi-spectral images is a challenging but important task in understanding solar activity and its influence on space weather. A main challenge comes from each modality capturing a different location of the 3D objects, as opposed to typical multi-spectral imaging scenarios where all image bands observe the same scene. Thus, we refer to this special multi-spectral scenario as multi-layer. We present a multi-task deep learning framework that exploits the dependencies between image bands to produce 3D AR localisation (segmentation and detection) where different image bands (and physical locations) have their own set of results. Furthermore, to address the difficulty of producing dense AR annotations for training supervised machine learning (ML) algorithms, we adapt a training strategy based on weak labels (i.e. bounding boxes) in a recursive manner. We compare our detection and segmentation stages against baseline approaches for solar image analysis (multi-channel coronal hole detection, SPOCA for ARs) and state-of-the-art deep learning methods (Faster RCNN, U-Net). Additionally, both detection and segmentation stages are quantitatively validated on artificially created data of similar spatial configurations made from annotated multi-modal magnetic resonance images. Our framework achieves an average of 0.72 IoU (segmentation) and 0.90 F1 score (detection) across all modalities, comparing to the best performing baseline methods with scores of 0.53 and 0.58, respectively, on the artificial dataset, and 0.84 F1 score in the AR detection task comparing to baseline of 0.82 F1 score. Our segmentation results are qualitatively validated by an expert on real ARs.

International audience; Objective: The purpose of this study was to examine the influence of parental responsive support (observed) and perceived parental responsive support on athletes’ self-perceptions and thriving. Methods: Forty-one French-speaking Belgian individual sport athletes aged 12-15 years (M = 13.13, SD = 0.90) and one of their parent’s spent 10 minutes discussing three important athletes’ sport-related goals for the next season. The discussion was video-taped and coded to identify parents’ responsive support behaviors. After the discussion, athletes responded to a series of questionnaires measuring perceived parental responsiveness, self-efficacy, self-esteem, and thriving indicators (i.e., positive affect, vitality, life satisfaction, and health quality). Results: The results show that observed and perceived parental responsive support contributed to athletes’ proximal perceptions of self-efficacy. Both parental observed responsive support and athletes’ perceived parental responsiveness, mediated by athletes’ self-efficacy, were positively related to athlete’s self-esteem. Further, athletes’ perceived parental responsiveness was positively related with thriving while mediated in series by self-efficacy and self-esteem. Conclusion: Overall, it appears that parents’ responsive support (observed) and athletes’ perception of responsive support are associated with positive self-perceptions and optimal wellbeing in young athletes. This study demonstrates that parents can provide responsive support to their children in the sport context. These results add further weight to suggestions that sport organizations should actively include, rather than exclude, parents in their processes.

International audience; Silicone rubbers are promising materials that have extensively been used in many areas, including wearable electronic devices, actuator materials in soft robotics, and energy harvesters. Ecoflex, a commercially available polymer, is a group of silicone rubbers appearing with various Shore hardnesses that has become popular in recent years. While silicone rubbers in their real applications are subjected to repeated loadingunloading conditions, their mechanical behaviour under cyclic loading in different deformation modes and the corresponding stress recovery behaviour are yet to be well investigated. In this contribution, we conduct loading-unloading cyclic experiments in different time gaps between the first cycle and the second cycle to demonstrate the stress recovery behaviour after stress softening happens during the first cycle. For that, three different modes of deformations, i.e., uniaxial tension, planar tension, and equibiaxial tension tests are selected. Besides, Shore hardness dependence with different strain levels is also taken into consideration. The results show that the stress softening could recover significantly with time. These findings will help to understand the mechanical behaviour of Ecoflex silicone rubbers before selecting them in practical applications that are exposed to repeated loading-unloading cycles.

International audience; Scanning transmission electron microscopy experiments indicate that face-centered cubic (FCC) is the predominant ordered structure for Ag309 ± 7 nanoclusters, synthesized in vacuum. Historically, experiments do not present a consensus on the morphology at these sizes, whereas theoretical studies find the icosahedral symmetry for Ag309 and the decahedral shape for nearby sizes. We employ density functional theory calculations to rationalize these observations, considering both regular and defective Ag nanoparticles (281–321 atoms). The change of stability induced by the presence of defects, symmetry loss, and change of number of atoms is evaluated by the nanoparticle surface energy, which was measured previously. FCC and decahedral symmetries are found to be more favorable than icosahedral, consistent with our measurements of clusters protected from extended atmospheric exposure. In addition, an energy-free descriptor, surface atomic density, is proposed and qualitatively reproduces the surface energy data. Nonsymmetric and defective structures may be preferred over perfectly regular ones within a given size range.

International audience; The polar and piezoelectric nature of the wurtzite structure of ZnO nanowires with a high aspect ratio at nanoscale dimensions is of high interest for piezotronic and piezoelectric devices, but a number of issues related to polarity are still open and deserve a particular attention. In this context, chemical bath deposition offers a unique opportunity to select the O-or Zn-polarity of the resultant nanowires and is further compatible with the fabrication processes of flexible devices. The control and use of the polarity in ZnO nanowires grown by chemical bath deposition open a new way to greatly enhance the performance of the related piezotronic and piezoelectric devices. However, polarity as an additional tunable parameter should be considered with care because it has a strong influence on many processes and properties. The present review is intended to report the most important consequences related to the polarity in ZnO nanowires for piezotronic and piezoelectric devices. After introducing the basic principles involving crystal polarity in ZnO, a special emphasis is placed on the effects of polarity on the nucleation and growth mechanisms of ZnO nanowires using chemical bath deposition, defect incorporation and doping, electrical contacts and device properties.

In line with the latest innovations in the packaging field, this joint project aims at implementing new and innovative micro- and nanoparticles for the development of active and intelligent packaging solutions dedicated to food and medical packaging applications. More specifically, the project combines two major developments which both falls within the scope of active and intelligent packaging. In this work, a specific focus was given to the development of an antibacterial packaging solution and to the development of smart gas sensors. The antibacterial strategy developed was based on the combination of two active materials - silver nanowires and cellulose nanofibrils - to prepare antibacterial surfaces. The formulation as an ink and the deposition processing has been deeply studied for different surface deposition processes that include coatings or screen-printing. Results showed surfaces that display strong antibacterial activity both against Gram-positive and Gram-negative bacteria, but also interesting properties for active packaging applications such as a highly retained transparency or enhanced barrier properties. Regarding the second strategy, gas sensors have been prepared using a combination of Copper benzene-1,3,5-tricarboxylate Metal Organic Framework and carbon-graphene materials, deposited on flexible screen-printed electrodes. The easy-to-produce and optimized sensors exhibit good performances toward ammonia and toward humidity sensing, proving the versatility and the great potential of such solution to be adapted for different target applications. The results of this project lead to innovative solutions that can meet the challenges raised by the packaging industry., En lien avec les dernières innovations dans le domaine des emballages, ce projet collaboratif a pour but d’implémenter de nouveaux micro- et nanomatériaux innovants pour le développement d’emballages actifs et intelligents dans le domaine alimentaire et médical. Il se focalise en particulier sur deux stratégies : le développement d’emballages antibactériens d’un côté et de capteurs de gaz de l’autre. La première stratégie est donc dédiée à l’utilisation combinée de nanofils d’argent et de nanofibrilles de cellulose pour la production de surfaces antibactériennes. La formulation d’encres ainsi que les paramètres de dépôt ont été optimisés pour différent procédés tels que l’enduction ou l’impression sérigraphique. Une forte activité antibactérienne contre des souches bactériennes Gram-positive mais aussi Gram-négative a été prouvée pour toutes les surfaces préparées. Des propriétés intéressantes relatives au domaine des emballage actifs ont aussi été démontrées telles que la conservation d’une haute transparence et l’amélioration des propriétés barrières. Dans la seconde stratégie, des capteurs de gaz ont été préparés en utilisant un mélange actif composé de Cuivre benzène-1,3,5-tricarboxylate Metal Organic Framework et de carbone-graphène, déposé sur des électrodes flexibles produites par sérigraphie. Les capteurs sont faciles à produire et ont été optimisés pour présenter de bonnes performances à la fois pour détecter et quantifier l’ammoniac gazeux mais aussi servir de capteurs d’humidité, ce qui prouve leur versatilité et leur important potentiel industriel. Ce projet a donc conduit à différentes solutions innovantes qui peuvent relever les défis de l’industrie des emballages.

In line with the latest innovations in the packaging field, this joint project aims at implementing new and innovative micro- and nanoparticles for the development of active and intelligent packaging solutions dedicated to food and medical packaging applications. More specifically, the project combines two major developments which both falls within the scope of active and intelligent packaging. In this work, a specific focus was given to the development of an antibacterial packaging solution and to the development of smart gas sensors. The antibacterial strategy developed was based on the combination of two active materials - silver nanowires and cellulose nanofibrils - to prepare antibacterial surfaces. The formulation as an ink and the deposition processing has been deeply studied for different surface deposition processes that include coatings or screen-printing. Results showed surfaces that display strong antibacterial activity both against Gram-positive and Gram-negative bacteria, but also interesting properties for active packaging applications such as a highly retained transparency or enhanced barrier properties. Regarding the second strategy, gas sensors have been prepared using a combination of Copper benzene-1,3,5-tricarboxylate Metal Organic Framework and carbon-graphene materials, deposited on flexible screen-printed electrodes. The easy-to-produce and optimized sensors exhibit good performances toward ammonia and toward humidity sensing, proving the versatility and the great potential of such solution to be adapted for different target applications. The results of this project lead to innovative solutions that can meet the challenges raised by the packaging industry.; En lien avec les dernières innovations dans le domaine des emballages, ce projet collaboratif a pour but d’implémenter de nouveaux micro- et nanomatériaux innovants pour le développement d’emballages actifs et intelligents dans le domaine alimentaire et médical. Il se focalise en particulier sur deux stratégies : le développement d’emballages antibactériens d’un côté et de capteurs de gaz de l’autre. La première stratégie est donc dédiée à l’utilisation combinée de nanofils d’argent et de nanofibrilles de cellulose pour la production de surfaces antibactériennes. La formulation d’encres ainsi que les paramètres de dépôt ont été optimisés pour différent procédés tels que l’enduction ou l’impression sérigraphique. Une forte activité antibactérienne contre des souches bactériennes Gram-positive mais aussi Gram-négative a été prouvée pour toutes les surfaces préparées. Des propriétés intéressantes relatives au domaine des emballage actifs ont aussi été démontrées telles que la conservation d’une haute transparence et l’amélioration des propriétés barrières. Dans la seconde stratégie, des capteurs de gaz ont été préparés en utilisant un mélange actif composé de Cuivre benzène-1,3,5-tricarboxylate Metal Organic Framework et de carbone-graphène, déposé sur des électrodes flexibles produites par sérigraphie. Les capteurs sont faciles à produire et ont été optimisés pour présenter de bonnes performances à la fois pour détecter et quantifier l’ammoniac gazeux mais aussi servir de capteurs d’humidité, ce qui prouve leur versatilité et leur important potentiel industriel. Ce projet a donc conduit à différentes solutions innovantes qui peuvent relever les défis de l’industrie des emballages.

International audience; This experimental study investigates blade root load fluctuations for a single turbine immersed in a regular current flow with different ambient turbulence conditions. Two scaled models of industrial prototypes were tested: a 1:28 scale model of the three-bladed horizontal axis turbine of Magallanes Renovables and a 1:20 scale model of the five-bladed horizontal axis turbine of Sabella. The rotor loads were directly measured on the rotation axis with a thrust and torque sensor. The blade roots were equipped with a load-cell measuring two forces and three moments. The variations of the rotor loads (thrust and torque) and the blade root loads (edgewise bending moments and streamwise forces) are compared and the impact of the blade angular position is investigated. A comparison of both scaled models results with those of the IFREMER generic turbine is also presented. The results are anonymised in order to ensure confidentiality.

International audience; High Entropy Alloys (HEA) can be classified in three domains according to their e/a and r values, with e/a, the number of itinerant valence electrons and r the average radius for a 12 nearest atoms neighborhood. The phase composition, thermal stability and possible phase transformations of a series of HEA alloys, CoCrzFeNi-XY (with X and Y = Al, Cu, Pd, Ru, Ti and z=0 or 1), selected according to their e/a ratio were investigated in cast conditions (T0), after 3 hours homogenization at 1100°C (T1) and after 3 hours annealing at 700°C (T3). It is observed that for the alloys from domain I which contains fcc structures, the microstructure transforms from multi-to almost single-phase under homogenization (T1). In domain III alloys contains cubic (bcc and/or B2) structures very small multi-structural changes are observed. Alloys in domain II have mixed structure, i.e. several different structures in the diffraction pattern, which changes during heat treatments.

International audience; High dose selenium acts as a cytotoxic agent, with potential applications in cancer treatment. However, clinical trials have failed to show any chemotherapeutic value of selenium at safe and tolerated doses (

International audience; The seismoelectric method holds great promise in the delineation and hydraulic characterization of thin subglacial layers of deformable sediments, subglacial water bodies, and deeper groundwater and heat‐bearing rocks. Of particular value are subglacial interfacial conversions and, potentially, evanescent electromagnetic waves converted at shallow englacial interfaces. We present three case studies that examine the seismoelectric direct field in wet snow, coseismic responses of wet glacier ice and till substrate, and interfacial conversions in a dry glacier and bedrock substrate, having amplitudes on respective orders of ~10^1–10^2, 10^0–10^1, and 10^{−3} mV. The electrokinetically controlled direct field and coseismic responses are large and consistent with strong electrical streaming potential amplitudes in wet snow and wet glacier ice, probably because electrical conductivities of meltwaters are commonly very low (~10^{−4}–10^{−6} S/m). Interfacial conversions in the wet glacier case may likewise have been amplified, but could not be unequivocally identified here due to a lack of diagnostic move‐out information. In the dry glacier case, direct field and coseismic effects were negligible and interfacial responses readily detected despite their small amplitudes. Vast swathes of continental ice sheets and glaciers reside in electromagnetically quiet environments, and have dry upper ice, firn, and snow layers as well as substrates saturated with low‐conductivity meltwaters. They should therefore provide favorable environments for the measurement and physical evaluation of interfacial conversions from either wet or dry basal environments, with crucial implications for the dynamics, hydrology, microbiology, and thermal budget of and methane deposits beneath the world's ice sheets and glaciers.

International audience; Type II solar radio bursts have proven to be a useful tool for gaining insights into the behaviour of complex solar events and for forecasting and mitigating their damages on Earth. In this work, we detect and segment the occurrence of type II bursts in solar radio spectrograms, thereby facilitating the extraction of parameters needed to gain insight into solar events. We utilise prior knowledge of how type II bursts drift through frequencies over time to assist with these tasks of detection and segmentation. A new adaptive Region of Interest (ROI) is proposed, to constrain the search to regions that follow the burst curvature at a given frequency. It comes with an implicit data normalisation that reduces the variance of burst appearance in the data, hence simplifying the learning process from small datasets. We demonstrate the effectiveness of our methodology using a simple and popular HOG and logistic regression detector and basic segmentation based on voting and background subtraction. On a custom dataset representative of different levels of solar activity, at a wavelength range where no other detection algorithm currently operates, our adaptive ROI significantly improves over traditional sliding windows. In future work, it may be applied to other, state-of-the-art, machine learning algorithms.

Nanotechnologies have reached maturity and market penetration that require nano‐specific changes in legislation and harmonization among legislation domains, such as the amendments to REACH for nanomaterials (NMs) which came into force in 2020. Thus, an assessment of the components and regulatory boundaries of NMs risk governance is timely, alongside related methods and tools, as part of the global efforts to optimise nanosafety and integrate it into product design processes, via Safe(r)‐by‐Design (SbD) concepts. This paper provides an overview of the state‐of‐the‐art regarding risk governance of NMs and lays out the theoretical basis for the development and implementation of an effective, trustworthy and transparent risk governance framework for NMs. The proposed framework enables continuous integration of the evolving state of the science, leverages best practice from contiguous disciplines and facilitates responsive re‐thinking of nanosafety governance to meet future needs. To achieve and operationalise such framework, a science‐based Risk Governance Council (RGC) for NMs is being developed. The framework will provide a toolkit for independent NMs' risk governance and integrates needs and views of stakeholders. An extension of this framework to relevant advanced materials and emerging technologies is also envisaged, in view of future foundations of risk research in Europe and globally., This study received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 814425 (RiskGONE) and No 814572 (NanoSolveIT).

International audience; Silicone polymers have enormous applications, especially in the areas of biomedical engineering. Ecoflex, a commercially available room temperature cured silicone polymer, has attracted considerable attention due to its wide range of applications as medical-grade silicones and as matrix materials in producing nano-filled stretchable sensors and dielectric elastomers for soft robotics. In this contribution, we have conducted a wide range of experiments under thermo-mechanical loadings. These experiments consist of loading-unloading cyclic tests, single-step relaxation tests, Mullins effects tests at different strain rates and stretches, stress recovery tests at different rest time etc. In order to assess the temperature influences on Ecoflex, a number of viscoelastic tests are performed in a thermal chamber with temperature ranging from-40 • C to 140 • C. Extensive experimental findings illustrate that Ecoflex experiences a significant stress softening in the first cycles and such a softening recovers gradually with respect to time. It also shows a significant amount of cyclic dissipation at various stretch levels as well as a considerable stress relaxation only for virgin samples. Cyclic dissipations and stress relaxation almost disappear for the case of pre-stretched samples. Furthermore, the material is more or less sensitive under a wide range of temperature differences.

The liver is the largest internal organ and plays an important part in maintaining the homeostatic balance in the body. It is also one of the primary sites of nanoparticle accumulation. HepG2 spheroids were used as an in vitro model to assess iron oxide (magnetite, Fe3O4 and maghemite, γ-Fe2O3) nanoparticle (NP) toxicity. The development of HepG2 spheroids by the hanging drop method was illustrated through cell viability and tissue morphology assessment of spheroids generated from 1000, 5000, and 10,000 cells per drop. The spheroids generated from 5000 cells per drop had the most optimal configuration. Liver function was assessed by albumin, urea and aspartate transaminase which were expressed in physiologically relevant concentrations by the HepG2 spheroid.Synchrotron X-ray fluorescence (SXRF) was used to assess NP distribution and metal homeostasis. The SXRF studies showed a dose-dependent accumulation of NPs inHepG2 spheroid transverse tissue sections. This accumulation also affected ironhomeostasis by significantly increasing intracellular copper levels. The elemental distribution of calcium and selenium also increased upon challenge with NPs, whichmay be involved in the removal of reactive oxygen species (ROS). Glucose metabolism shifted towards anaerobic respiration in presence NPs, exhibiting the Warburg effect. Transmission electron microscopy also shows intracellular localisation of the iron oxide NPs. Cytokinesis block micronucleus (CBMN) and single-cell gel electrophoresis (comet) assays were used to assess genotoxicity. Both NPs induced a significant increase in micronuclei frequency. Pan-centromeric staining further indicated that the primary mode of action of DNA damage caused by iron oxide NPs was clastogenic. Comet scores showed no significant increases in tail intensities percentages. In conclusion, the HepG2 spheroid model is representative of an in vivo liver due to its ability to mimic glucose metabolism, liver functionality and metal homeostasis responses. Iron oxide NPs cause the HepG2 spheroids to respire anaerobically and disrupt iron homeostasis which can potentially lead to the generation of ROS resulting in the DNA damage., Le foie est le plus grand organe interne et joue un rôle important dans le maintien de l'équilibre homéostatique dans le corps. C'est également l'un des principaux sites d'accumulation de nanoparticules. Les sphéroïdes HepG2 ont été utilisés comme modèle in vitro pour évaluer la toxicité des nanoparticules (NP) d'oxyde de fer (magnétite, Fe3O4 et maghémite, γ-Fe2O3). Le développement des sphéroïdes HepG2 par la méthode des gouttes suspendues a été quantifié par l’évaluation de la viabilité cellulaire et de la morphologie des tissus des sphéroïdes générés à partir de 1000, 5000 et 10 000 cellules par goutte. Les sphéroïdes générés à partir de 5000 cellules par goutte avaient la configuration la plus optimale. La fonction hépatique a été évaluée par l'albumine, l'urée et l'aspartate transaminase, qui ont été exprimées à des concentrations physiologiquement pertinentes par le sphéroïde HepG2.La fluorescence des rayons X synchrotron (SXRF) a été utilisée pour évaluer la distribution des NP et l'homéostasie des métaux. Les études SXRF montrent une accumulation dépendante de la dose de NP dans les coupes transversales de tissu sphéroïde HepG2. Cette accumulation a également affecté l'homéostasie du fer en augmentant de manière significative les niveaux de cuivre intracellulaire. Lesconcentrations du calcium et du sélénium ont également augmenté en présence desNP, ces deux éléments pouvant être impliquées dans l'élimination des espèces réactives de l'oxygène (ROS). Le métabolisme du glucose s'est déplacé vers la respiration anaérobie en présence de NP, montrant l'effet Warburg. La microscopie électronique à transmission montre également la localisation intracellulaire des NP d'oxyde de fer. L'analyse des micronoyaux par blocage de la cytokinèse (CBMN) et l'électrophorèse en gel unicellulaire (comet) ont été utilisées pour évaluer la génotoxicité. Les deux NP ont induit une augmentation significative de la fréquence des micronoyaux. La coloration pan-centromérique a en outre indiqué que le principal mode d'action des dommages à l'ADN causés par les NP d'oxyde de fer était le clastogène. Les résultats comet n'ont montré aucune augmentation significative des pourcentages d'intensité de la queue.En conclusion, le modèle sphéroïde HepG2 est représentatif d'un foie in vivo en raison de sa capacité à imiter le métabolisme du glucose, la fonctionnalité du foie et les réponses à l'homéostasie des métaux. Les NP d'oxyde de fer amènent un métabolismedes sphéroïdes HepG2 anaérobie et perturbent l'homéostasie du fer, ce qui peut potentiellement générer la génération de ROS entraînant des lésions de l'ADN.

International audience; According to a recent Hume-Rothery approach, the electron concentration, e/a, and the average radius can be used to identify the domain of stability of HEAs and to estimate the phases that may occur in the alloy. The present study investigates the influence of the electronic polymorphism of nickel on the efficiency of the classification and on the design of HEAs for magnetic applications. Many different compositions were used, based on 4 to 7 elements out of a total 13 different elements (Co, Cr, Fe, Ni, Al, Cu, Pd, Ti, Mn, V, Nb, Sn, Ru). Phases have been determined by X-ray and neutron diffraction as well as in some cases high energy X-ray diffraction. The e/a for the constituent elements is calculated according to Massalski. The two polymorphic electronic structure of nickel, namely (e/a) Ni ¼ 1 or (e/a) Ni ¼ 2 are considered. The average e/a for the alloy is calculated assuming a solid solution case. The electronic structure [Ar] 3d 9 4s 1 seems to be more appropriate for the classification of HEAs. Based on a Self-organising Map predictions are made for the average magnetic moment at saturation for this electronic structure of Ni. Non-saturated values and data from the literature are compared with the predictions. The consequences of such results when modelling the structure and properties of Ni containing HEAs are presented, in particular the consideration of the shape and transformation of the Brillouin zone.

Workshop, Due to the COVID-19 pandemic, the event has been cancelled.; International audience; Art and design are essential aspects of our culture and how we interact with the world. Artists and designers use a wide selection of tools, whose impact is rapidly growing with the progression of digital technologies. This change has opened up new opportunities for the CHI community to build creative supportive tools. The digital switch has come with many benefits such as lowering barriers, mobile work environments and mass production for distribution of work. Along with these benefits we also see challenges for art and design work and its future perception in society. As technology takes a more significant role in supporting art and design what will this mean for the individual artist or designer? The focus of this workshop is to bring together researchers and practitioners to explore what the future of digital art and design will hold. The exploration will centre around synthesizing key challenges and questions, along with ideas for future interaction technologies that consider mobile and tangible aspects of digital art.

It is evidently not trivial to analytically solve practical engineering problems due to their inherent (geometrical and/or material) nonlinearities. Moreover, experimental testing can be extremely costly, time-consuming and even dangerous, in some cases. In the past few decades, therefore, numerical techniques have been progressively developed and utilised in order to investigate complex engineering applications through computer simulations, in a cost-effective manner.An important feature of a numerical methodology is how to approximate a physical domain into a computational domain and that, typically, can be carried out via mesh-based and particle-based approximations, either of which manifest with a different range of capabilities. Due to the geometrical complexity of many industrial applications (e.g. biomechanics, shape casting, metal forming, additive manufactur-ing, crash simulations), a growing attraction has been received by tetrahedral mesh generation, thanks to Delaunay and advancing front techniques [1, 2]. Alternatively, particle-based methods can be used as they offer the possibility of tackling specific applications in which mesh-based techniques may not be efficient (e.g. hyper velocity impact, astrophysics, failure simulations, blast).In the context of fast thermo-elastodynamics, modern commercial packages are typically developed on the basis of second order displacement-based finite element formulations and, unfortunately, that introduces a series of numerical shortcomings such as reduced order of convergence for strains and stresses in comparison with displacements and the possible onset of numerical instabilities (e.g. detrimental locking, hour-glass modes, spurious pressure oscillations).To rectify these drawbacks, a mixed-based set of first order hyperbolic conservation laws for isothermal elastodynamics was presented in [3–6], in terms of the linear momentum p per unit undeformed volume and the minors of the deformation, namely, the deformation gradient F , its co-factor H and its Jacobian J. Taking inspiration of these works [4, 7] and in order to account for irreversible processes, the balance of total energy (also known as the first law of thermodynamics) is incorporated to the set of physical laws used to describe the deformation process. This, in general, can be expressed in terms of the entropy density η or total energy density E by which the Total Lagrangian entropy-based and total energy-based formulations {p, F , H, J, η or E} are established, respectively. Interestingly, taking advantage of the conservation formulation framework, it is possible to bridge the gap between solid dynamics and Computational Fluid Dynamics (CFD) by exploiting available CFD techniques in the context of solid dynamics.From a computational standpoint, two distinct and extremely competitive spatial discretisations are employed, namely, mesh-based Vertex-Centred Finite Volume Method (VCFVM) and meshless Smooth Particle Hydrodynamics (SPH). A linear reconstruction procedure together with a slope limiter is employed in order to ensure second order accuracy in space whilst avoiding numerical oscillations in the vicinity of sharp gradients, respectively. Crucially, the discontinuous solution for the conservation variables across (dual) control volume interfaces or between any pair of particles is approximated via an acoustic Riemann solver. In addition, a tailor-made artificial compressibility algorithm and an angular momentum preservation scheme are also incorporated in order to assess same limiting scenarios.The semi-discrete system of equations is then temporally discretised using a one-step two-stage Total Variation Diminishing (TVD) Runge-Kutta time integrator, providing second order accuracy in time. The geometry is also monolithically updated to be only used for post-processing purposes.Finally, a wide spectrum of challenging examples is presented in order to assess both the performance and applicability of the proposed schemes. The new formulation is proven to be very efficient in nearly incompressible thermo-elasticity in comparison with classical finite element displacement-based approaches. The proposed computational framework provides a good balance between accuracy and speed of computation.