Influence of secondary phases during annealing on re-crystallization of CuInSe2 electrodeposited films

Electrodeposited CuInSe2 thin films are of potential importance, as light absorber material, in the next generation of photovoltaic cells as long as we can optimize their annealing process to obtain dense and highly crystalline films. The intent of this study was to gain a basic understanding of the key experimental parameters governing the structural–textural-composition evolution of thin films as function of the annealing temperature via X-ray diffraction, scanning/transmission electron microscopy and thermal analysis measurements. The crystallization of the electrodeposited CuInSe2 films, with the presence of Se and orthorhombic Cu2−xSe (o-Cu2−xSe) phases, occurs over two distinct temperature ranges, between 220 °C and 250 °C and beyond 520 °C. Such domains of temperature are consistent with the melting of elemental Se and the binary CuSe phase, respectively. The CuSe phase forming during annealing results from the reaction between the two secondary species o-Cu2−xSe and Se (o-Cu2−xSe+Se→2 CuSe) but can be decomposed into the cubic β-Cu2−xSe phase by slowing down the heating rate. Formation of liquid CuSe beyond 520°C seems to govern both the grain size of the films and the porosity of the substrate–CuInSe2 film interface. A simple model explaining the competitive interplay between the film crystallinity and the interface porosity is proposed, aiming at an improved protocol based on temperature range, which will enable to enhance the film crystalline nature while limiting the interface porosity

Discrimination and visualization of ELM types based on a probabilistic description of inter-ELM waiting times

Discrimination and visualization of different observed classes of edge-localized plasma instabilities (ELMs), using advanced data analysis techniques has been considered. An automated ELM type classifier which effectively incorporates measurement uncertainties is developed herein and applied to the discrimination of type I and type III ELMs in a set of carbon-wall JET plasmas. The approach involves constructing probability density functions (PDFs) for inter-ELM waiting times and global plasma parameters and then utilizing an effective similarity measure for comparing distributions: the Rao geodesic distance (GD). It is demonstrated that complete probability distributions of plasma parameters contain significantly more information than the measurement values alone, enabling effective discrimination of ELM type

Precursor-Directed Assembly of Complex Oxide Nanobeads: The Role of Strongly Coordinated Inorganic Anions

International audienceThe use of an inorganic perrhenate ligand in the structure of early-transition-metal alkoxide precursors permits to achieve uniform self-assembly of the primary nanoparticles produced by their hydrolysis. The latter has been carried out in a hydrocarbon reaction medium by the addition of water with vigorous stirring, either in the pure form or in solutions in parent alcohols. The self-assembly is guided by the surface charge enhanced by the presence of strongly coordinated anions as determined by zeta potential measurements. The aggregation process has been followed in real time by nanoparticle tracking analysis (Nano Sight technique). The reaction products are spherical aggregates with a size that can be efficiently controlled through the polarity of the reaction medium. The produced nanobeads have been characterized by TEM, SEM-EDS, DLS, nitrogen adsorption, and FTIR The coordination of metal centers has been investigated using EXAFS spectroscopy. The aggregates remain amorphous on thermal treatment of up to 700 degrees C (24 h treatment) but crystallin when treated at 1000 degrees C. This latter process is associated with the total loss of rhenium content and offers early-transition-metal oxides as products

Performance de l’oxymétrie nocturne dans le diagnostic du syndrome d’apnées du sommeil. Etude monocentrique menée au centre Hospitalier de Longjumeau/France: Performance of nocturnal oximetry in the diagnosis of sleep apnea syndrome. Single-center study from Longjumeau Hospital Center / France

Context and objective. Sleep apnea-hypopnea syndrome (SAHOS) is currently under diagnosed or ignored, due to a poor access to polysomnography, the ’gold-standard’’ diagnostic test. Yet, sleep disorder is linked to many complications mainly, cardiovascular disorders. The present study aimed to assess the relevance of overnight pulse oximetry in diagnosing SAHOS. Methods. A cross-sectional analysis was conducted between January 1st and September 30th, 2017. All patients suspected of SAHOS syndrome underwent an overnight pulse oximetry (OPO) and a respiratory polygraphy (PG). Data were analysed using Excel 2010 and SSPSS 21.0, to establish the sensitivity, specificity, the positive and negative predictive value and ROC curve was calculated to determine the performance of OPO compared to PG. Results. 201 patients were enrolled (median age of 64.6 +/- 11.8 years). Males (55%) and obese (medium BMI of 32 kg/m² were preponderant. The sensitivity and specificity of overnight pulse oximetry were 87 % and 85 %, respectively with ROC curve prominently rising at 0.75. Conclusion. The study showing a high sensitivity and specificity suggests that the overnight oximetry could stand as a more accessible alternative to polygraphy in the diagnosis of Sleep apnea-hypopnea syndrome where the latter is not available. Contexte & objectif. Le syndrome d’apnées du sommeil est une pathologie fréquemment sous diagnostiquée et souvent méconnue; particulièrement à cause d’une accessibilité insuffisante au gold-standard du diagnostic, la polysomnographie ou la polygraphie ventilatoire. Et pourtant, l’affection est responsable des complications surtout cardiovasculaires majeures. L’objectif de la présente étude était d’évaluer le niveau de performance de l’oxymétrie nocturne dans le diagnostic du syndrome d’apnées du sommeil. Méthodes. Enquête transversale menée entre le 1er janvier 2016 et le 30 septembre 2017. Tous les patients hospitalisés pour suspicion du syndrome d’apnées du sommeil ont bénéficié d’une oxymétrie nocturne et d’une polygraphie ventilatoire. Les logiciels Excel 2010 et SSPSS 21.0 ont permis d’analyser les données. Nous avons déterminé la sensibilité, la spécificité, la valeur prédictive positive et la valeur prédictive négative. La courbe ROC a été calculée. p < 0,05. Résultats. Au total 201 patients d’âge moyen de 64,6±11,8 ans, avec une prédominance masculine (55%) et en majorité obèses (IMC moyen de 32kg/m²) ont été inclus. La sensibilité et la spécificité de l’oxymétrie nocturne sont respectivement de 87 et de 85% avec une courbe ROC montrant une surface importante sous la courbe de 0,75. Conclusion. Avec sa sensibilité et spécificité élevées, l’oxymétrie nocturne peut constituer une alternative valable au diagnostic du syndrome d’apnées du sommeil. Son innocuité et sa bonne acceptabilité en font un outil facilement exportable et recommandable en cas de carence de moyens appropriés

Les sols de savanes des llanos vénézuéliens et le sol ferrugineux tropical de Barinas = Los suelos de sabanas de los llanos venezolanos y el alfisol de Barinas

Les savanes constituent une des dernières ressources en terres dont la mise en culture est relativement facile malgré de faibles réserves organiques et minérales qui ne leur assurent qu'un équilibre assez fragile. La station expérimentale du Jardin botanique de l'université expérimentale des Llanos à Barinas sert de cadre depuis 1977 à des expériences effectuées sur un sol ferrugineux tropical lessivé. Le présent travail est consacré à la description : du contexte régional de la station; du profil du sol utilisé en comparaison avec d'autres sols de savanes; de quelques résultats obtenus dans la station et dans la région sur des types de sol voisins. Avant de conclure est discutée la représentativité de la station de Barinas au niveau des savanes en général en vue d'établir la portée des expériences qui y sont ou y seront effectuées. (Résumé d'auteur

Local Youth Groups in Georgia Working Towards Policy, Systems, and Environmental Changes

Background: The Georgia Youth Tobacco Survey (YTS) is a survey of public middle school (MS) and high school (HS) students. The Georgia YTS was first conducted in 2001. According to YTS, students who attended a tobacco free schools’ youth summit were significantly more likely to be aware of students who use tobacco products (MS: 21% for smoking and 20% for smokeless tobacco; HS: 42% for smoking and 39% for smokeless tobacco) on school property than students who did not attend a tobacco free schools’ youth summit (MS: 10 % for smoking and 9 % for smokeless tobacco; HS: 32 % for smoking and 35 % for smokeless tobacco. Methods: During the fall of 2014, the Chronic Disease Prevention Section of the Georgia Department of Public Health (DPH) hosted a youth summit for youth groups across the state. In total, 149 youth and 49 adult leaders attended the summit. The youth summit provided training for middle and high school youth to become tobacco use control advocates in their communities. The youth were involved in creating the messages they would deliver to their school boards. Results: The local youth groups who attended the summit in 2014 were instrumental in four school districts adopting the model 100% Tobacco-Free Schools policy: Lowndes County Schools and Irwin County Schools (Valdosta, GA); Emanuel County Schools and Jenkins County Schools (Augusta, GA). Conclusions: These findings support the growing literature on youth involvement in advocacy work towards policy change. Youth should be recruited to work with public health professionals in building coalitions to change community norms

Ultrasound evaluation of pelvic masses seen within a university gynecologic oncology clinic: does the scan location matter?

To quantify variations in the reporting of ultrasound characteristics of adnexal masses between local ultrasound centers and a tertiary care center for women referred to gynecologic oncology for evaluation of a pelvic mass. This study also sought to evaluate whether a gynecologic oncologist’s impression regarding the suspicion for malignancy differed based upon the information provided in the local ultrasound report as compared to the tertiary care center ultrasound report

Partnership Approach to Establishing Tobacco-Free Colleges and Universities in Georgia

Background: Smoking rates in young adults ages 18-24 have been steadily declining since 2011 (2011:25.0%, 2012:22.3%, 2013:16.5% (BRFSS). The Georgia Department of Public Health (GDPH) partnered with the Georgia Board of Regents to adopt the 100% Tobacco Free Colleges/Universities policy. Methods: The Behavioral Risk Factor Surveillance System (BRFSS) is a state-based surveillance system, administered by the GDPH in collaboration with the CDC. The survey began in 1984 with 15 states participating, including Georgia. The data from this survey were used to inform key shareholders of smoking prevalence to encourage policy adoption as a method of decreasing tobacco use. The GDPH used the CDC’s Partnership Toolkit to recruit and retain partnerships with various multi-sector organizations in working towards systems change. Results: The Georgia Board of Regents—the governing body for the state’s system of colleges and universities –adopted the model 100% tobacco free colleges/universities policy resulting in a systems change of 31 campuses now having the model policy in place. The policy not only impacted the students who fall in the 18-24 age group, but the staff and visitors as well. Conclusions: Partnerships play a key role in creating systems changes. The partnership between the Georgia Board of Regents and the Georgia Department of Public Health contributed to the growing number of colleges and universities who are now 100% Tobacco Free. Using the CDC’s Partnership Toolkit allowed for sustainable partnerships leading to positive social change

New Insights into HIV-1 Group O Diversity

International audienc

Out of equilibrium correlations in the XY chain

We study the transversal XY spin-spin correlations in the non-equilibrium steady state constructed in \cite{AP03} and prove their spatial exponential decay close to equilibrium