233 research outputs found

    Design of Electric Machine Taking Into Account the Partial Discharges Phenomena for Future Hybrid Propelled Aircrafts

    Get PDF
    Designing the electric motors to propel an aircraft represents a huge challenge. The constraint of weight requires such machines to be compact. Besides, the high specific power necessary (a few kW/kg, machine cooling included) leads to an increase of the voltage range of stator winding. Such characteristics increase considerably the risk of partial discharges (PD) in the stator winding. In this paper, the design of electric motors aimed to propel a future hybrid aircraft will be presented. It will be realized using 2 tools

    Hot Carrier Solar Cell: From Simulation to Devices

    No full text
    International audienceSingle junction III-V heterostructures based devices could overtake the Shockley-Queisser limit if thermalisation of photogenerated carriers can be strongly limited as in the hot carrier solar cell concept. Previous modelling and experiments have shown the interest of Multiple Quantum Wells heterostructures in the antimonide system and the importance of very thin structures. In this paper we report new data on the thermalisation rates in antimonide and phosphide heterostructures measured at ambient temperature. For the first time electrical control of hot carrier population is performed on hot carrier heterostructures device

    Physiologie de la reproduction et endocrinologie chez les cervidés : une revue

    Full text link
    peer reviewedKnowledge about cervids are rapidly growing. This work aims to present the more recent scientific information on reproductive physiology and endocrinology of the cervids: anatomy of the genital tract, length of breeding season, parameters and endocrinology of the reproductive cycle, endocrinology of pregnancy. It also aims to highlight differences between cervids and domestic ruminants such as embryonic diapause observed in Capreolus capreolus.Les connaissances relatives aux cervidés sont de plus en plus étendues. La présente synthèse vise à rapporter à partir des données récentes de la littérature les caractéristiques essentielles de la reproduction des principales espèces : anatomie de l’appareil reproducteur, durée de la saison de reproduction, différents paramètres du cycle sexuel, endocrinologie du cycle sexuel et de la gestation. Il vise également à mettre en évidence les particularités différenciant les cervidés des ruminants domestiques, telle par exemple la diapause embryonnaire rencontrée chez le chevreuil

    Pratique actuelle pour le retour au sport après une entorse de cheville: Sondage de médecins francophones

    Full text link
    peer reviewedBackground: Recommendations are available for assessment criteria for safe return-to-play (RTP) after a lateral ankle sprain. However, their current use among physicians is unknown. Methods: French-speaking physicians in Belgium, France and Switzerland were asked to complete an online survey and report their clinical assessment of selected RTP criteria. Results:The respondent sample (n = 109) included physicians with and without Sports Medicine education, varied level of experience and proportion of athletes in their practice population. Pain was the most selected criterion for safe RTP (90% of physicians), followed by ability to engage in functional tasks (82%), functional instability (73%), range of motion (61%), proprioception (47%), mechanical instability (39%), strength (38%) and swelling (31%). A low proportion of physicians use quantitative measures to assess these criteria (between 4% and 53%). Conclusions: A large proportion of physicians consider the recommended criteria for RTP decisions. However, physicians do not frequently use quantitative measures.Introduction: Il existe des recommandations concernant les critères d'évaluation pour un retour au sport (RTS) réussi à la suite d'une entorse latérale de la cheville. Cependant, leur utilisation actuelle par les médecins est inconnue. Méthodes: Des médecins francophones de Belgique, de France et de Suisse ont été invités à répondre à une enquête en ligne et à faire part de leur évaluation clinique de certains critères de RTS. Résultats: L'échantillon de répondants (n = 109) comprenait des médecins avec et sans formation en médecine du sport, un niveau d'expérience varié et une proportion d'athlètes différente dans leur patient. La douleur était le critère le plus sélectionné pour une RTS réussi (90 % des médecins), suivi de la capacité à s'engager dans des tâches fonctionnelles (82 %), de l'instabilité fonctionnelle (73 %), de l'amplitude des mouvements (61 %), de la proprioception (47 %), de l'instabilité mécanique (39 %), de la force (38 %) et du gonflement (31 %). Une faible proportion de médecins utilise des mesures quantitatives pour évaluer ces critères (entre 4% et 53%). Conclusions: Une grande proportion de médecins prend en compte les critères recommandés pour autoriser le RTS. Cependant, les médecins n'utilisent pas fréquemment des mesures quantitatives

    A model-strengthened imaging biomarker for survival prediction in EGFR-mutated non-small-cell lung carcinoma patients treated with tyrosine kinase inhibitors

    Get PDF
    International audienceNon-small-cell lung carcinoma is a frequent type of lung cancer with a bad prognosis. Depending on the stage, genomics, several therapeutical approaches are used. Tyrosine Kinase Inhibitors (TKI) may be successful for a time in the treatment of EGFR-mutated non-small cells lung carcinoma. Our objective is here to propose a survival assessment as their efficacy in the long run is challenging to evaluate. The study includes 17 patients diagnosed as of EGFR-mutated non-small cell lung cancer and exposed to an EGFR-targeting TKI with 3 computed tomography (CT) scans of the primitive tumor (one before the TKI introduction and two after). An imaging biomarker based on the texture heterogeneity evolution between the first and the third exams is derived and computed from a mathematical model and patient data. Defining the overall survival as the time between the introduction of the TKI treatment and the patient death, we obtain a statistically significant correlation between the overall survival and our imaging marker (p = 0:009). Using the ROC curve, the patients are separated into two populations and the comparison of the survival curves is statistically significant (p = 0:025). The baseline exam seems to have a significant role in the prediction of response to TKI treatment. More precisely, our imaging biomarker defined using only the CT scan before the TKI introduction allows to determine a first classification of the population which is improved over time using the imaging marker as soon as more CT scans are available. This exploratory study leads us to think that it is possible to obtain a survival assessment using only few CT scans of the primary tumor

    Adherence to and effectiveness of Highly Active Antiretroviral Treatment for HIV infection: assessing the bidirectional relationship

    Get PDF
    It is well-established that high adherence to HAART is a major determinant of virological and immunological success. Furthermore, psycho-social research has identified a wide range of adherence factors. Our objective was to assess the bi-directional relationship between adherence and response to treatment among patients enrolled in the ANRS CO8 APROCOCOPILOTE study. An econometric approach was implemented through a bivariate twoequation simultaneous system, studying the factors associated with both adherence and undetectability of HIV plasma viral load. Our results highlight that good biological results induced by adherence reinforce continued adherence. This strengthens the argument that patients who do not experience rapid improvements in their immunological and clinical statuses after HAART initiation should be prioritized when developing adherence support interventions. Furthermore, it rules out the hypothesis that HAART leads to "false reassurance" among HIV infected patients.Adherence ; HIV ; relationship between adherence and effectiveness ; simultaneous equations ; GEE

    Nanoscale electrical analyses of axial-junction GaAsP nanowires for solar cell applications

    Get PDF
    Axial p-n and p-i-n junctions in GaAs0.7P0.3 nanowires are demonstrated and analyzed using electron beam induced current microscopy. Organized self-catalyzed nanowire arrays are grown by molecular beam epitaxy on nanopatterned Si substrates. The nanowires are doped using Be and Si impurities to obtain p- and n-type conductivity, respectively. A method to determine the doping type by analyzing the induced current in the vicinity of a Schottky contact is proposed. It is demonstrated that for the applied growth conditions using Ga as a catalyst, Si doping induces an n-type conductivity contrary to the GaAs self-catalyzed nanowire case, where Si was reported to yield a p-type doping. Active axial nanowire p-n junctions having a homogeneous composition along the axis are synthesized and the carrier concentration and minority carrier diffusion lengths are measured. To the best of our knowledge, this is the first report of axial p-n junctions in self-catalyzed GaAsP nanowires

    Optical simulations and optimization of perovskite/CI(G)S tandem solar cells using the transfer matrix method

    Get PDF
    In this work we employ the transfer matrix method for the analysis of optical materials properties to simulate and optimize monolithic tandem solar cell devices based on CuIn1−x_{1−x}Gax_xSe2_2, CI(G)S, and perovskite (PVK) absorbers. By finding models that fit well the experimental data of the CI(G)S solar cell, the semitransparent perovskite solar cell (PSC) and the PVK/CI(G)S monolithic tandem solar cell, we were able to perform a detailed optical loss analysis that allowed us to determine sources of parasitic absorption. We found better substitute materials for the transport layers to increase the power conversion efficiency and, in case of semitransparent PSCs, sub-bandgap transmittance. Our results set guidelines for the monolithic PVK/CI(G)S tandem solar cells development, predicting an achievable efficiency of 30%

    Clinical and MRI outcomes 10 years after repair of massive posterosuperior rotator cuff tears

    Get PDF
    BACKGROUND: Massive rotator cuff tears are challenging to treat, with few or no studies on long-term outcomes of repair. The purpose of this study was to report 10-year outcomes following repair of massive posterosuperior rotator cuff tears, with and without extension into the subscapularis, and to determine prognostic factors that could influence clinical scores and retear rates. METHODS: The records of 234 patients who underwent repair of a massive posterosuperior rotator cuff tear at a total of 15 centers were retrieved. Patients were asked to return for evaluation at 10 years; 78 patients could not be contacted, 7 had died, and 19 had undergone a reoperation. A total of 130 patients (68% men) with a mean age (and standard deviation) of 56.1 ± 7.7 years (range, 26 to 79 years) were evaluated clinically, and 102 of them were also evaluated using magnetic resonance imaging (MRI). The tear was confined to the supraspinatus and infraspinatus tendons in 94 shoulders and also involved the superior portion of the subscapularis in 36 shoulders. Univariable and multivariable regressions were performed to determine whether 10-year total Constant-Murley scores and repair integrity were associated with patient characteristics, tear patterns, or repair techniques. RESULTS: In the study cohort, complications were noted in 14 shoulders (11%) (stiffness in 10 and infection in 4). For the 130 shoulders evaluated clinically, the mean total Constant-Murley score improved from 53.1 ± 15.9 (range, 14 to 83) preoperatively to 78.5 ± 11.3 (range, 36 to 98) at 10 years. Of the 102 shoulders evaluated using MRI, 32 had a retear (Sugaya type IV or V). Of the 19 shoulders that underwent a reoperation (excluded from the study cohort), 9 had a retear. The overall prevalence of retears was 34%. Multivariable regression analysis revealed a significant association between the 10-year Constant-Murley score and preoperative retraction of the infraspinatus tendon, but no association between retears and any of the variables. Involvement of the subscapularis had no significant effect on preoperative or postoperative Constant-Murley scores or retear rates. CONCLUSIONS: Patients who had repair of a massive posterosuperior rotator cuff tear maintained considerable improvements in clinical and radiographic outcomes at 10 years. Partial concomitant tears of the subscapularis did not affect the total postoperative Constant-Murley scores or retear rates
    • …
    corecore