Analysis of test beam data taken with a prototype of TPC with resistive Micromegas for the T2K Near Detector upgrade

In this paper we describe the performance of a prototype of the High Angle Time Projection Chambers (HA-TPCs) that are being produced for the Near Detector (ND280) upgrade of the T2K experiment. The two HA-TPCs of ND280 will be instrumented with eight Encapsulated Resistive Anode Micromegas (ERAM) on each endplate, thus constituting in total 32 ERAMs. This innovative technique allows the detection of the charge emitted by ionization electrons over several pads, improving the determination of the track position. The TPC prototype has been equipped with the first ERAM module produced for T2K and with the HA-TPC readout electronics chain and it has been exposed to the DESY Test Beam in order to measure spatial and dE/dx resolution. In this paper we characterize the performances of the ERAM and, for the first time, we compare them with a newly developed simulation of the detector response. Spatial resolution better than 800 ${\mu \rm m}$ and dE/dx resolution better than 10% are observed for all the incident angles and for all the drift distances of interest. All the main features of the data are correctly reproduced by the simulation and these performances fully fulfill the requirements for the HA-TPCs of T2K

Characterization of Charge Spreading and Gain of Encapsulated Resistive Micromegas Detectors for the Upgrade of the T2K Near Detector Time Projection Chambers

An upgrade of the near detector of the T2K long baseline neutrino oscillation experiment is currently being conducted. This upgrade will include two new Time Projection Chambers, each equipped with 16 charge readout resistive Micromegas modules. A procedure to validate the performance of the detectors at different stages of production has been developed and implemented to ensure a proper and reliable operation of the detectors once installed. A dedicated X-ray test bench is used to characterize the detectors by scanning each pad individually and to precisely measure the uniformity of the gain and the deposited energy resolution over the pad plane. An energy resolution of about 10% is obtained. A detailed physical model has been developed to describe the charge dispersion phenomena in the resistive Micromegas anode. The detailed physical description includes initial ionization, electron drift, diffusion effects and the readout electronics effects. The model provides an excellent characterization of the charge spreading of the experimental measurements and allowed the simultaneous extraction of gain and RC information of the modules

Les résidus de pesticides dans les framboises et laitues : comparaison de trois techniques chromatographiques

The purpose is the analytical method of three pesticides, iprodion, vinclozolin and cymoxanil, usually used in the production of raspberries and lettuces in the Rhône-Alpes region. We present the methodology reliable and reproductible with a comparison on the chromatographic measurement by H.P.L.C., G.C. and T.L.C. / Cette étude analytique a été orientée sur trois pesticides, l'iprodione, la vinclozoline et la cymoxanil, couramment employés dans le cadre de la production des framboises et des laitues dans la région Rhône-Alpes. Nous présentons la mise au point de méthodes d'analyses fiables et reproductibles avec une comparaison sur les dosages effectués en chromatographies en phase liquide (C.L.H.P.), en phase gazeuse (C.P.G.) et sur couche mince (C.C.M.)

Foraminifères et Ostracodes de l'Albien inférieur dans le "Gault" basal du Massif des Bornes (Haute-Savoie, France)

La découverte et la détermination de Foraminifères et d'Ostracodes dans le « Gault » basal du synclinal de Cenise (Massif des Bornes) permettent de préciser l'âge Albien inférieur de la partie inférieure du « Gault », ce qui conduit à admettre une lacune sédimentaire à l'Aptien supérieur dans le synclinal de Cenise et dans une large partie du massif des Bornes

One step synthesis of lamellar R-3m LiCoO2 thin films by an electrochemical-hydrothermal method

International audienceIn this study, we report the synthesis of lamellar R-3m LiCoO2 thin films electrodes for lithium rechargeable batteries by a single step method based on an electrochemical-hydrothermal synthesis in a concentrated LiOH solution with a cobalt salt. This process combines the effect of temperature (between 150 °C and 200 °C), pressure and galvanostatic current. The obtained films were not annealed after the electrochemical-hydrothermal synthesis. For the first time, the theoretical study of the potential-pH diagram of cobalt was carried out at high temperature and high concentration. These calculations show that a pH value higher than 12 is necessary to avoid the direct precipitation of cobalt hydroxide Co(OH)2 inside the solution. An improvement of the soluble species stability with an increase of the temperature and a decrease of the cobalt concentration is predicted. The influence of the deposition conditions (temperature and concentration) at a constant current density was experimentally studied. X-ray diffraction (XRD) shows the formation of well-crystallized LiCoO2 thin films. Raman spectroscopy confirmed the achievement of the electrochemically active R-3m LiCoO2 phase without any trace of the Fd3m phase at temperatures as low as 150 °C. Electrochemical measurements demonstrate good performances of the material synthesized between 150 °C and 200 °C with better capacity retention at higher temperature

Development of a thin flexible Li battery design with a new gel polymer electrolyte operating at room temperature

In this study, we develop a new Li-metal battery design merging with IoT requirements, mainly the low thickness, the thermal stability and the flexibility. To reach these specifications, we firstly prepared an efficient gel polymer electrolyte (GPE) composed of a PVDF-HFP polymer network, a LiFSI: Pyr13FSI liquid binary solution and a lithium montmorillonite Li-MMT clay. The as-synthesized material exhibits a high ionic conductivity (0.48 mS cm-1 at 25 ◦C) and a good thermal stability, up to 140 ◦C. In parallel, a new battery design with an optimized ratio of packaging to active material thickness is developed. In this design, copper foils act both as current collector and as battery casing, decreasing the overall cell thickness. Li metal batteries are realized using the developed GPE material and this new battery design. The cell thickness is 360 and 760 μm for single side and double-sided architectures respectively. These batteries show well functioning under high bending and exhibit a good cycling ability with a remaining capacity higher than 85% after more than 200 cycles at 25 ◦C. Thanks to the combination of the original Cu packaging and the flexible GPE membrane, developed Li-metal batteries exhibit promising properties to merge with the new IoT requirements.EnSO projec

Impact of a theory-informed and user-centered stroke information campaign on the public's behaviors, attitudes, and knowledge when facing acute stroke: a controlled before-and-after study

International audienceBACKGROUND: Public awareness of stroke symptoms is a key factor to ensure access to reperfusion strategies in due time. We designed and launched a regional theory-informed and user-centered information campaign and assessed its impact on emergency medical services (EMS) calls for stroke suspicion, time-to-call, and public attitudes and awareness concerning stroke. METHODS: A controlled before-and-after study was conducted during 3 sequential time-periods in 2 separate counties. Key messages of the campaign were underpinned by stroke representations and the theory of planned behavior, and focused on recognition of stroke warning signs and the need to call EMS urgently. The campaign included posters, leaflets, adverts and films displayed in bus and subway stations, internet, social networks, and local radio. Outcome measures on behavior, attitudes, and knowledge were assessed before the launch of the campaign, at 3 months, and 12 months. RESULTS: The number of EMS calls for stroke suspicion increased by 21% at 12 months in the intervention county and this change was significantly different to that observed in the control county (p = 0.02). No significant changes were observed regarding self-reported attitudes in case of stroke. An 8% significant increase in recognizing at least 2 stroke warning signs was observed in the intervention county (p = 0.04) at 3 months, while it did not change significantly in the control county (p = 0.6). However, there was no significant difference in warning sign recognition between both counties (p = 0.16). CONCLUSION: The campaign significantly improved public's behavior of calling EMS, although stroke knowledge was not improved as much as expected. Repeating these campaigns over time might further help improve timeliness and access to reperfusion strategies. TRIAL REGISTRATION: Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT02846363