Advanced methods for improved child occupant safety in cars

The European project CHILD (2002 – 2005 ) aims to a more comprehensive understanding of the injury mechanisms experienced by children as car occupants of different ages in road accidents. Through innovative tools and methods, CHILD will contribute to revise or improve standards and more efficient design of child restraint systems. It is conducted in association with thirteen partners representing a balance between research, industry, regulation and testing institutes, from seven European countries. The basis is in-depth accident studies, experimental and virtual testing including development of new tools (dummies, models,…) for the evaluation of child protection. CHILD will enable the investigation of injury mechanisms and tolerances for different ages of children and to reinforce injury criteria and risk curves previously proposed for frontal and lateral impacts, in the European project CREST (1996-2000). The methods used to achieve these goals are described in this article, illustrated with several examples. The stakes of this project are to significantly decrease the number of killed children (more than 700) or severely injured each year on European roads, which is an unacceptable high burden on Europe’s society and economy

Hydropeaking impacts on the Lez river and studies to define mitigation measures

Hydropeaking impacts on the Lez river and studies to define mitigation measure

Silicon Differential Receiver With Zero-Biased Balanced Detection for Access Networks

[EN] We present an optimized differential receiver in silicon with a minimized footprint and balanced zero-biased Ge photodiodes. The receiver integrates a delay-line with a 2 ¿ 4 multimode interferometer 90° hybrid and two balanced photodiodes for differential quadrature phase-shift keying demodulation. Two receivers are tested, for 10 and 20 Gb/s operation, and well opened eye-diagrams and symbol constellations are obtained with error vector magnitude values as low as 12.5% and 19.57%, respectively. The results confirm the potential of integrated silicon receivers to become key building blocks for future passive optical access networks based on advanced modulation formats. © 1989-2012 IEEE.This work was supported in part by the European Community’s Seventh Framework Program under Grant 224312 HELIOS.Aamer, M.; Sotiropoulos, N.; Brimont, ACJ.; Fedeli, J.; Marris-Morini, D.; Cassan, E.; Vivien, L.... (2013). Silicon Differential Receiver With Zero-Biased Balanced Detection for Access Networks. IEEE Photonics Technology Letters. 25(13):1207-1210. https://doi.org/10.1109/LPT.2013.2262931S12071210251

A chemical survey of exoplanets with ARIEL

Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

Découverte de la première planète extrasolaire tellurique

Pour détecter les planètes extrasolaires, l’utilisation du phénomène de microlentille gravitationnelle présente le grand avantage par rapport aux autres méthodes d’être la seule sensible aux planètes de faible masse situées à relativement grande distance de leur étoile – telle une Neptune ou une Terre en orbite à une dizaine d’unités astronomiques (UA). Nous présentons ici la découverte, grâce à cette technique, de la première planète tellurique, OGLE-2005BLG-390Lb, une cousine glacée de la Terre environ cinq fois plus massive, évoluant sur une orbite de 2,6 UA autour d’une étoile naine rouge