Electrochemical characterization of YSZ thick films deposited by dip-coating process

Yttria stabilized zirconia (YSZ, 8% Y2O3) thick films were coated on dense alumina substrates by a dip-coating process. The suspension was obtained by addition of a polymeric matrix in a stable suspension of commercial YSZ (Tosoh) powders dispersed in an azeotropic mixture MEK–EtOH. The suspension composition was improved by the addition of YSZ Tosoh particles encapsulated by zirconium alkoxide sol containing yttrium nitrate which are the precursors of the 8-YSZ oxide. This optimal formulation allowed preparing, via a dip-coating process, thick films which were, after thermal treatment, homogeneous, dense and crack-free. A specific method was performed to measure the electrical conductivity, i.e. to determine the ionic conductivity of the film: it uses the four-point probe technique combined with ac impedance spectroscopy. The good agreement between the classical two-electrode measurements performed on YSZ pellets and the four-electrode ones performed on YSZ films allows concluding that this method is relevant for characterizing the transport properties of thick films

Intermediate temperature SOFC single cell test using Nd1.95NiO4+δ as cathode

This work deals with SOFC single cell tests using neodymium nickelate Nd1.95NiO4+δ as cathode material. This MIEC oxide exhibits high values of both surface exchange coefficient (k) and oxygen diffusion coefficient (D*), as well as high electronic conductivity, which result in an enhanced electrochemical activity with respect to classical materials. The SOFC cells were fabricated from an anode-supported electrolyte half-cell provided by InDEC B.V. Corporation, with a 36mmdiameter. The Nd1.95NiO4+δ cathode was prepared as a two-stage electrode consisting of a thin interlayer of several hundred nanometers covered by a thicker layer of dozens microns. The Nd1.95NiO4+δ oxide powders were synthesized using different routes in order to reduce the final annealing temperature, and to subsequently obtain submicronic powders. I–V characteristics of the single cells were investigated under hydrogen–air conditions. The power densities versus current densities curves are reported and the results of impedance spectroscopy measurements performed under these operating conditions are discussed

Prediction and experimental evidence of the optimisation of the angular branching process in the thallus growth of Podospora anserina

Based upon apical growth and hyphal branching, the two main processes that drive the growth pattern of a fungal network, we propose here a two-dimensions simulation based on a binary-tree modelling allowing us to extract the main characteristics of a generic thallus growth. In particular, we showed that, in a homogeneous environment, the fungal growth can be optimized for exploration and exploitation of its surroundings with a specific angular distribution of apical branching. Two complementary methods of extracting angle values have been used to confront the result of the simulation with experimental data obtained from the thallus growth of the saprophytic filamentous fungus Podospora anserina. Finally, we propose here a validated model that, while being computationally low-cost, is powerful enough to test quickly multiple conditions and constraints. It will allow in future works to deepen the characterization of the growth dynamic of fungal network, in addition to laboratory experiments, that could be sometimes expensive, tedious or of limited scope.Comment: Submitted to Scientific Repor

The GenTree Platform: growth traits and tree-level environmental data in 12 European forest tree species

Background: Progress in the field of evolutionary forest ecology has been hampered by the huge challenge of phenotyping trees across their ranges in their natural environments, and the limitation in high-resolution environmental information. Findings: The GenTree Platform contains phenotypic and environmental data from 4,959 trees from 12 ecologically and economically important European forest tree species: Abies alba Mill. (silver fir), Betula pendula Roth. (silver birch), Fagus sylvatica L. (European beech), Picea abies (L.) H. Karst (Norway spruce), Pinus cembra L. (Swiss stone pine), Pinus halepensis Mill. (Aleppo pine), Pinus nigra Arnold (European black pine), Pinus pinaster Aiton (maritime pine), Pinus sylvestris L. (Scots pine), Populus nigra L. (European black poplar), Taxus baccata L. (English yew), and Quercus petraea (Matt.) Liebl. (sessile oak). Phenotypic (height, diameter at breast height, crown size, bark thickness, biomass, straightness, forking, branch angle, fructification), regeneration, environmental in situ measurements (soil depth, vegetation cover, competition indices), and environmental modeling data extracted by using bilinear interpolation accounting for surrounding conditions of each tree (precipitation, temperature, insolation, drought indices) were obtained from trees in 194 sites covering the species’ geographic ranges and reflecting local environmental gradients. Conclusion: The GenTree Platform is a new resource for investigating ecological and evolutionary processes in forest trees. The coherent phenotyping and environmental characterization across 12 species in their European ranges allow for a wide range of analyses from forest ecologists, conservationists, and macro-ecologists. Also, the data here presented can be linked to the GenTree Dendroecological collection, the GenTree Leaf Trait collection, and the GenTree Genomic collection presented elsewhere, which together build the largest evolutionary forest ecology data collection available

Between but not within species variation in the distribution of fitness effects

New mutations provide the raw material for evolution and adaptation. The distribution of fitness effects (DFE) describes the spectrum of effects of new mutations that can occur along a genome, and is therefore of vital interest in evolutionary biology. Recent work has uncovered striking similarities in the DFE between closely related species, prompting us to ask whether there is variation in the DFE among populations of the same species, or among species with different degrees of divergence, i.e., whether there is variation in the DFE at different levels of evolution. Using exome capture data from six tree species sampled across Europe we characterised the DFE for multiple species, and for each species, multiple populations, and investigated the factors potentially influencing the DFE, such as demography, population divergence and genetic background. We find statistical support for there being variation in the DFE at the species level, even among relatively closely related species. However, we find very little difference at the population level, suggesting that differences in the DFE are primarily driven by deep features of species biology, and that evolutionarily recent events, such as demographic changes and local adaptation, have little impact

L'amiante (caractéristiques, pathologies ; importance de l'exposition et prévention du risque)

TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

Le banquet de Pauline Schmitt Pantel. Genre, Mœurs et politique dans l’Antiquité grecque et romaine, Paris, Publications de la Sorbonne

International audienc

Avant-propos

Pauline Schmitt Pantel sur le chantier archéologique de Moio della Civitella Réunissant chercheurs français et étrangers, jeunes doctorants et professeurs émérites, ce volume collectif entend rendre hommage à l’œuvre de Pauline Schmitt, une année après son départ en retraite. Après un premier « banquet » célébré en son honneur, en octobre 2010, nombreux sont ceux, parmi ses étudiants, ses collègues et ses amis, qui ont en effet tenu à lui offrir une contribution originale. À n’en pas douter, ..

Le banquet de Pauline Schmitt

Historienne et enseignante du monde grec, Pauline Schmitt Pantel a incontestablement marqué plusieurs générations de chercheurs et de chercheuses, tout en s’adressant à un large public intéressé par la Grèce antique. Au fil des années, elle a contribué non seulement à renouveler des thématiques classiques en histoire politique, sociale et religieuse, mais aussi à défricher de nouveaux champs de recherche comme l’histoire des femmes et du genre. Depuis sa thèse d’État sur La Cité au banquet, qui éleva le repas commun au rang de « fait social total », jusqu’à son tout récent ouvrage sur les Hommes illustres de Plutarque, qui bouleverse bien des certitudes sur l’identité politique dans l’Athènes classique, en passant par Aithra et Pandora, où elle se penche sur la construction sociale du féminin et du masculin, l’historienne a soumis de nombreux domaines à sa volonté de savoir et d’interroger pratiques et discours grecs, en croisant sources littéraires, épigraphiques et iconographiques. Ses collègues et amis, français et étrangers, ainsi que ses étudiants ont ressenti l’envie et le besoin d’offrir un banquet d’hommages à Pauline Schmitt Pantel, qui a su faire vivre et défendre avec détermination les pratiques de sociabilité comme lieu d’échange, de collaboration, de formation et d’expérimentation du politique, aussi bien dans les cités grecques que dans l’équipe de recherche en histoire ancienne qu’elle a contribué à fonder dans les universités Paris 1 et Paris 7, Phéacie, désormais intégrée dans le centre de recherches Anhima