1,600 research outputs found

    One-step deposition by slot-die coating of mixed lead halide perovskite for photovoltaic applications

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    Recent advances in the performance and stability of lead halide perovskite solar cells announce a promising future for this technology. As the understanding of lab scale device fabrication progresses technology developments in the area of up-scaling are required to demonstrate their viability on an industrial and pre-commercial scale. These developments include replacing slow spin coated deposition techniques with continuous roll to roll compatible slot-die methods. In this work we demonstrate the suitability of a one-step slot-die coating method for the deposition of lead halide perovskite layers, in particular for infiltration into a mesoporous titania scaffold. Appropriate crystallisation dynamics of the perovskite are achieved by careful control of the substrate temperature in combination with a post-processed rapid air knife application. We show that devices fully processed in air using this method deliver a photovoltaic conversion efficiency up to 9.2%, this is comparable to those manufactured using a spin coating process

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

    Measurement of the forward Z boson production cross-section in pp collisions at s=13\sqrt{s} = 13 TeV

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    A measurement of the production cross-section of Z bosons in pp collisions at s=13\sqrt{s} = 13 TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range 2.0η4.52.0 \eta 4.5, transverse momenta pT20p_\text{T} 20 GeV and dilepton invariant mass in the range 60m()12060 m(\ell\ell) 120 GeV. The integrated cross-section from averaging the two final states is \begin{equation*}\sigma_{\text{Z}}^{\ell\ell} = 194.3 \pm 0.9 \pm 3.3 \pm 7.6\text{ pb,}\end{equation*} where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable ϕη\phi^*_\eta

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of ttt\overline{t}, W+bbW+b\overline{b} and W+ccW+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays WνW\rightarrow\ell\nu, where \ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

    Psychological well-being in Europe after the outbreak of war in Ukraine

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    The Russian invasion of Ukraine on February 24, 2022, has had devastating effects on the Ukrainian population and the global economy, environment, and political order. However, little is known about the psychological states surrounding the outbreak of war, particularly the mental well-being of individuals outside Ukraine. Here, we present a longitudinal experience-sampling study of a convenience sample from 17 European countries (total participants = 1,341, total assessments = 44,894, countries with >100 participants = 5) that allows us to track well-being levels across countries during the weeks surrounding the outbreak of war. Our data show a significant decline in well-being on the day of the Russian invasion. Recovery over the following weeks was associated with an individual’s personality but was not statistically significantly associated with their age, gender, subjective social status, and political orientation. In general, well-being was lower on days when the war was more salient on social media. Our results demonstrate the need to consider the psychological implications of the Russo-Ukrainian war next to its humanitarian, economic, and ecological consequences

    A global experience-sampling method study of well-being during times of crisis : The CoCo project

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    We present a global experience-sampling method (ESM) study aimed at describing, predicting, and understanding individual differences in well-being during times of crisis such as the COVID-19 pandemic. This international ESM study is a collaborative effort of over 60 interdisciplinary researchers from around the world in the “Coping with Corona” (CoCo) project. The study comprises trait-, state-, and daily-level data of 7490 participants from over 20 countries (total ESM measurements = 207,263; total daily measurements = 73,295) collected between October 2021 and August 2022. We provide a brief overview of the theoretical background and aims of the study, present the applied methods (including a description of the study design, data collection procedures, data cleaning, and final sample), and discuss exemplary research questions to which these data can be applied. We end by inviting collaborations on the CoCo dataset

    Practice patterns and clinical outcomes in acute appendicitis differ in the elderly patient

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    Background: Appendicitis is the most frequent global abdominal surgical emergency. An ageing population, who often exhibit atypical symptoms and delayed presentations, challenge conventional diagnostic and treatment paradigms. Objectives: This study aims to delineate disparities in presentation, management, and outcomes between elderly patients and younger adults suffering from acute appendicitis. Methods: This subgroup analysis forms part of ESTES SnapAppy, a time-bound multi-center prospective, observational cohort study. It includes patients aged 15 years and above who underwent laparoscopic appendectomy during a defined 90-day observational period across multiple centers. Statistical comparisons were performed using appropriate tests with significance set at p < 0.05. Results: The study cohort comprised 521 elderly patients (≥65 years) and 4,092 younger adults (18–64 years). Elderly patients presented later (mean duration of symptoms: 7.88 vs. 3.56 days; p < 0.001) and frequently required computed tomography (CT) scans for diagnosis (86.1% vs. 54.0%; p < 0.001). The incidence of complicated appendicitis was higher in the elderly (46.7% vs. 20.7%; p < 0.001). Delays in surgical intervention were notable in the elderly (85.0% operated within 24 h vs. 88.7%; p = 0.018), with longer operative times (71.1 vs. 60.3 min; p < 0.001). Postoperative complications were significantly higher in the elderly (27.9% vs. 12.9%; p < 0.001), including severe complications (6.9% vs. 2.4%; p < 0.001) and prolonged hospital stays (7.9 vs. 3.6 days; p < 0.001). Conclusions: Our findings highlight significant differences in the clinical course and outcomes of acute appendicitis in the elderly compared to younger patients, suggesting a need for age-adapted diagnostic pathways and treatment strategies to improve outcomes in this vulnerable population

    New algorithms for identifying the flavour of B<sup>0</sup>mesons using pions and protons

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    Two new algorithms for use in the analysis of pp collision are developed to identify the flavour of B0mesons at production using pions and protons from the hadronization process. The algorithms are optimized and calibrated on data, using B0→D-π+ decays from pp collision data collected by LHCb at centre-of-mass energies of 7 and 8 TeV . The tagging power of the new pion algorithm is 60% greater than the previously available one; the algorithm using protons to identify the flavour of a B0meson is the first of its kind.</p
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