The Auroral Planetary Imaging and Spectroscopy (APIS) service

The Auroral Planetary Imaging and Spectroscopy (APIS) service, accessible online, provides an open and interactive access to processed auroral observations of the outer planets and their satellites. Such observations are of interest for a wide community at the interface between planetology and magnetospheric and heliospheric physics. APIS consists of (i) a high level database, built from planetary auroral observations acquired by the Hubble Space Telescope (HST) since 1997 with its mostly used Far-UltraViolet spectro-imagers, (ii) a dedicated search interface aimed at browsing efficiently this database through relevant conditional search criteria and (iii) the ability to interactively work with the data online through plotting tools developed by the Virtual Observatory (VO) community, such as Aladin and Specview. This service is VO compliant and can therefore also been queried by external search tools of the VO community. The diversity of available data and the capability to sort them out by relevant physical criteria shall in particular facilitate statistical studies, on long-term scales and/or multi-instrumental multi-spectral combined analysis

Evaluation of a sol–gel process for the synthesis of La1−xSrxMnO3+δ cathodic multilayers for solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are electrical energy conversion devices with high efficiency and low pollution. In order to increase performances of SOFCs at intermediate temperature (700–800 °C) and to decrease materials cost, an alternative sol–gel synthesis method has been investigated to deposit La1−xSrxMnO3+δ (LSMx) as cathode thin films. Polycrystalline LSMx thin films were prepared by dip-coating using a polymeric solution. Lanthanum, strontium and manganese nitrates were used as raw materials. The viscosity of the solution was adjusted and the solution was deposited on polycrystalline ZrO2–8% Y2O3 ceramics. Prior to experiments, the substrate surface was eroded until a roughness of 20 nm and then cleaned with ethanol and dried. Film thicknesses were adjusted with the number of layers. Porosity and grain size of monolayers or multilayers were evaluated. Typical thickness of monolayer is 250 nm. A key parameter in the multilayer process was the intermediate calcination temperature (400, 700 or 1000 °C) of each further layer deposition. A correlation between this intermediate temperature and morphology, thickness and porosity was found; porosity is ranging from 3 to 40% and thickness can reach 1 micron for multilayers. Concerning electrochemical performances, the best results were obtained for LSM0.4 multilayers with an intermediate calcination temperature (called Ti) of 400 °C

Temperature and duration of heating of sunflower oil affect ruminal biohydrogenation of linoleic acid in vitro

Sunflower oil heated at 110 or 150°C for 1, 3, or 6 h was incubated with ruminal content in order to investigate the effects of temperature and duration of heating of oil on the ruminal biohydrogenation of linoleic acid in vitro. When increased, these 2 parameters acted together to decrease the disappearance of linoleic acid in the media by inhibiting the isomerization of linoleic acid, which led to a decrease in conjugated linoleic acids and trans-C18:1 production. Nevertheless, trans-10 isomer production increased with heating temperature, suggesting an activation of Δ9-isomerization, whereas trans-11 isomer production decreased, traducing an inhibition of Δ12-isomerization. The amount of peroxides generated during heating was correlated with the proportions of biohydrogenation intermediates so that they might explain, at least in part, the observed effects. The effects of heating temperature and duration on ruminal bacteria community was assessed using capillary electrophoresis single-strand conformation polymorphism. Ruminal bacterial population significantly differed according to heating temperature, but was not affected by heating duration. Heating of fat affected ruminal biohydrogenation, at least in part because of oxidative products generated during heating, by altering enzymatic reactions and bacterial population

Condensation of helium in aerogels and athermal dynamics of the Random Field Ising Model

High resolution measurements reveal that condensation isotherms of $^4$He in a silica aerogel become discontinuous below a critical temperature. We show that this behaviour does not correspond to an equilibrium phase transition modified by the disorder induced by the aerogel structure, but to the disorder-driven critical point predicted for the athermal out-of-equilibrium dynamics of the Random Field Ising Model. Our results evidence the key role of non-equilibrium effects in the phase transitions of disordered systems.Comment: 5 p + suppl. materia

Multivariate dynamic model for ordinal outcomes

Individual or stand-level biomass is not easy to measure. The current methods employed, based on cutting down a representative sample of plantations, make it possible to assess the biomasses for various compartments (bark, dead branches, leaves, . . .). However, this felling makes individual longitudinal follow-up impossible. In this context, we propose a method to evaluate individual biomasses by compartments when these biomasses are taken as ordinals. Biomass is measured visually and observations are therefore not destructive. The technique is based on a probit model redefined in terms of latent variables. A generalization of the univariate case to the multivariate case is then natural and takes into account the dependency between compartment biomasses. These models are then extended to the longitudinal case by developing a Dynamic Multivariate Ordinal Probit Model. The performance of the MCMC algorithm used for the estimation is illustrated by means of simulations built from known biomass models. The quality of the estimates and the impact of certain parameters, are then discussed