High SiO abundance in the HH212 protostellar jet

Previous SiO maps of the innermost regions of HH212 set strong constraints on the structure and origin of this jet. They rule out a fast wide-angle wind, and tentatively favor a magneto-centrifugal disk wind launched out to 0.6 AU. We aim to assess the SiO content at the base of the HH212 jet to set an independent constraint on the location of the jet launch zone with respect to the dust sublimation radius. We present the first sub-arcsecond (0"44x0"96) CO map of the HH212 jet base, obtained with the IRAM Plateau de Bure Interferometer. Combining this with previous SiO(5-4) data, we infer the CO(2-1) opacity and mass-flux in the high-velocity jet and arrive at a much tighter lower limit to the SiO abundance than possible from the (optically thick) SiO emission alone. Gas-phase SiO at high velocity contains at least 10% of the elemental silicon if the jet is dusty, and at least 40% if the jet is dust-free, if CO and SiO have similar excitation temperatures. Such a high SiO content is challenging for current chemical models of both dust-free winds and dusty interstellar shocks. Updated chemical models (equatorial dust-free winds, highly magnetized dusty shocks) and observations of higher J CO lines are required to elucidate the dust content and launch radius of the HH212 high-velocity jet.Comment: 4 pages, 2 figure

Unconventional aspects of electronic transport in delafossite oxides

The electronic transport properties of the delafossite oxides ABO$_2$ are usually understood in terms of two well separated entities, namely, the triangular A$^+$ and (BO$_2$)$^-$ layers. Here we review several cases among this extensive family of materials where the transport depends on the interlayer coupling and displays unconventional properties. We review the doped thermoelectrics based on CuRhO$_2$ and CuCrO$_2$, which show a high-temperature recovery of Fermi-liquid transport exponents, as well as the highly anisotropic metals PdCoO$_2$, PtCoO$_2$ and PdCrO$_2$ where the sheer simplicity of the Fermi surface leads to unconventional transport. We present some of the theoretical tools that have been used to investigate these transport properties and review what can and cannot be learned from the extensive set of electronic structure calculations that have been performed.Comment: 35 pages, 19 figure

Intrinsic effects of substitution and intercalation on thermal transport in two-dimensional TiS2_2 single crystals

The promising thermoelectric material TiS$_2$ can be easily chemically doped and intercalated. We present here studies of single crystals that are intercalated with excess Ti or Co, or substituted with Ta. We demonstrate the intrinsic impact of these dopants on the thermal transport in the absence of grain boundary scattering. We show that Ta doping has the greatest impact on the thermal scattering rate per ion added, leading to a five-fold reduction in the lattice thermal conductivity as compared to stoichiometric single crystals.Comment: 5 pages, 2 figure

Monitoring Drowsiness On-line Using a Single Encephalographic Channel

Non

Large anisotropic thermal conductivity of intrinsically two-dimensional metallic oxide PdCoO2_2

The highly conductive layered metallic oxide \pdcoo{} is a near-perfect analogue to an alkali metal in two dimensions. It is distinguished from other two-dimensional electron systems where the Fermi surface does not reach the Brillouin zone boundary by a high planar electron density exceeding $10^{15}$ cm$^{-2}$. The simple single-band quasi-2D electronic structure results in strongly anisotropic transport properties and limits the effectiveness of electron-phonon scattering. Measurements on single crystals in the temperature range from 10-300K show that the thermal conductivity is much more weakly anisotropic than the electrical resistivity, as a result of significant phonon heat transport. The in-plane thermoelectric power is linear in temperature at 300\,K and displays a purity-dependent peak around 50K. Given the extreme simplicity of the band-structure, it is possible to identify this peak with phonon drag driven by normal electron-phonon scattering processes.Comment: 3 figure

Short Communication : Long-term intake of the illegal diet pill DNP reduces lifespan in a captive bird model

Acknowledgements The authors wish to thank A. Hranitzky for support in bird mainte-nance, numerous students for their help in data collection, and N. Metcalfe, S. Dobson as well as S. Reichert for helpful comments on a previous draft. Funding AS was funded by a Marie Sklodowska-Curie Postdoctoral Fellowship (#658085) and a TCSM fellowship at the time of analyzing the results and writing the manuscriptPeer reviewedPostprin

Seed Spillage from Grain Trailers on Road Verges during Oilseed Rape Harvest: An Experimental Survey

Context: Anthropogenic vectors enhance the natural dispersal capacity of plant seeds significantly in terms of quantity and distance. Human-mediated seed dispersal (i.e. anthropochory) greatly increases the dispersal of crop species across agroecosystems. In the case of oilseed rape (OSR), spillage of seeds from grain trailers during harvest has never been quantified. Methods: Our experimental approach involved establishing 85 seed trap-sites on the road verges of an agricultural area around the grain silo of Selommes (Loir-et-Cher, France). We recorded OSR spillage during harvest and applied a linear model to the data. Results: The amount of seed spilled was related positively to the area of the OSR fields served by the road, whereas the amount of seed spilled decreased with other variables, such as distance from the trap-site to the verge of the road and to the nearest field. The distance to the grain silo, through local and regional effects, affected seed loss. Local effects from fields adjacent to the road resulted in a cumulative spillage on one-lane roads. On two-lane roads, spillage was nearly constant whatever the distance to the silo due to a mixture of these local effects and of grain trailers that joined the road from more distant fields. From the data, we predicted the number of seeds lost from grain trailers on one road verge in the study area. We predicted a total spillage of 2.05610 6 seeds (64.76610 5) along the road length, which represented

Problématique des systèmes miniaturisés in-vivo pour le remplacement d'une fonction dans le milieu médical orthopédique

Cet article propose une synthèse des systèmes orthopédiques instrumentés afin de dégager les études qui pourraient conduire à une amélioration des prothèses. Pour cela, nous mettons en évidence l'intérêt d'utiliser des systèmes in vivo auto adaptatifs pour le remplacement d'une fonction dans le domaine orthopédique. Or dans ce domaine, il n'existe pour l'instant que des systèmes pour l'instrumentation des prothèses. Nous présentons également la problématique de l'alimentation de ces systèmes et quelques idées de générateurs basées sur la récupération d'une énergie primaire produite par le corps humain

Reversible optical doping of graphene

The ultimate surface exposure provided by graphene monolayer makes it the ideal sensor platform but also exposes its intrinsic properties to any environmental perturbations. In this work, we demonstrate that the charge carrier density of graphene exfoliated on a SiO$_2$/Si substrate can be finely and reversibly tuned between electron and hole doping with visible photons. This photo-induced doping happens under moderate laser power conditions but is significantly affected by the substrate cleaning method. In particular, it is found to require hydrophilic substrates and to vanish in suspended graphene. These findings suggest that optically gated graphene devices operating with a sub-second time scale can be envisioned but also that Raman spectroscopy is not always as non-invasive as generally assumed

Évreux – Le Clos au Duc, 3bis rue de la Libération

Identifiant de l'opération archéologique : 27 229 005 Date de l'opération : 2005 (EX) Le diagnostic réalisé a été motivé par la construction d’un logement individuel au cœur de la nécropole antique (Fig. n°1 : Localisation des opérations de terrain). L’emprise au sol de la construction est de 193 m2 et la parcelle concernée de 1 811 m2. La nécropole antique du « Clos au Duc » est située à flanc de coteau, au sud de la ville, le long de la voie reliant Évreux à Chartres. Elle est connue dep..