2,134 research outputs found

    Integrated Water Vapor during Rain and Rain-Free Conditions above the Swiss Plateau

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    Water vapor column density, or vertically-integrated water vapor (IWV), is monitored by ground-based microwave radiometers (MWR) and ground-based receivers of the Global Navigation Satellite System (GNSS). For rain periods, the retrieval of IWV from GNSS Zenith Wet Delay (ZWD) neglects the atmospheric propagation delay of the GNSS signal by rain droplets. Similarly, it is difficult for ground-based dual-frequency single-polarisation microwave radiometers to separate the microwave emission of water vapor and cloud droplets from the rather strong microwave emission of rain. For ground-based microwave radiometry at Bern (Switzerland), we take the approach that IWV during rain is derived from linearly interpolated opacities before and after the rain period. The intermittent rain periods often appear as spikes in the time series of integrated liquid water (ILW) and are indicated by ILW ≥ 0.4 mm. In the present study, we assume that IWV measurements from radiosondes are not affected by rain. We intercompare the climatologies of IWV(rain), IWV(no rain), and IWV(all) obtained by radiosonde, ground-based GNSS atmosphere sounding, ground-based MWR, and ECMWF reanalysis (ERA5) at Payerne and Bern in Switzerland. In all seasons, IWV(rain) is 3.75 to 5.94 mm greater than IWV(no rain). The mean IWV differences between GNSS and radiosonde at Payerne are less than 0.26 mm. The datasets at Payerne show a better agreement than the datasets at Bern. However, the MWR at Bern agrees with the radiosonde at Payerne within 0.41 mm for IWV(rain) and 0.02 mm for IWV(no rain). Using the GNSS and rain gauge measurements at Payerne, we find that IWV(rain) increases with increase of the precipitation rate during summer as well as during winter. IWV(rain) above the Swiss Plateau is quite well estimated by GNSS and MWR though the standard retrievals are limited or hampered during rain periods

    Trends of atmospheric water vapour in Switzerland from ground-based radiometry, FTIR and GNSS data

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    Vertically integrated water vapour (IWV) is expected to increase globally in a warming climate. To determine whether IWV increases as expected on a regional scale, we present IWV trends in Switzerland from ground-based remote sensing techniques and reanalysis models, considering data for the time period 1995 to 2018. We estimate IWV trends from a ground-based microwave radiometer in Bern, from a Fourier transform infrared (FTIR) spectrometer at Jungfraujoch, from reanalysis data (ERA5 and MERRA-2) and from Swiss ground-based Global Navigation Satellite System (GNSS) stations. Using a straightforward trend method, we account for jumps in the GNSS data, which are highly sensitive to instrumental changes. We found that IWV generally increased by 2 % per decade to 5 % per decade,with deviating trends at some GNSS stations. Trends were significantly positive at 17 % of all GNSS stations, which of-ten lie at higher altitudes (between 850 and 1650 m above sea level). Our results further show that IWV in Bern scales to air temperature as expected (except in winter), but the IWV–temperature relation based on reanalysis data in the whole of Switzerland is not clear everywhere. In addition to our positive IWV trends, we found that the radiometer in Bern agrees within 5 % with GNSS and reanalyses. At the Jungfraujoch high-altitude station, we found a mean difference of 0.26 mm (15 %) between the FTIR and coincident GNSS data, improving to 4 % after an antenna update in 2016. In general,we showed that ground-based GNSS data are highly valuable for climate monitoring, given that the data have been homogeneously reprocessed and that instrumental changes are accounted for. We found a response of IWV to rising temperature in Switzerland, which is relevant for projected changes in local cloud and precipitation processe

    Basic study on the evaluation of thermoplastic polymers as hot-melt adhesives for mixed-substrate joining

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    A selection of 22 low-melting polymers was thermally and rheologically evaluated to be used as hot-melt adhesives in mixed-substrate joining samples. The choice of polymers was based on the published melting point. It was required to include a broad variety of different polymers backbones to study the influence of the different polymers comprehensively. A tool-box of widely applicable tests was developed to judge if a thermoplastic polymer is suitable for a hot-melt adhesive application. Melting temperature (onset, peak and offset temperature) and melting enthalpy were determined using standardized methods. Rheological methods were used to characterize the shear rate dependence and the flow behavior at the application temperature. The wetting behavior of the polymers was evaluated with contact angle measurements. The adhesive strength of the most promising candidates was analyzed using the Lumi Frac-adhesion method including the failure pattern

    Sleep-disordered breathing on respiratory polygraphy in neonates with spina bifida

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    INTRODUCTION Studies have shown a high prevalence of sleep-disordered breathing (SDB) in children with spina bifida. International standards for regular testing for SDB in this population are lacking. While there are studies investigating the prevalence of SDB in children with spina bifida, there are close to no studies in neonates. AIM AND OBJECTIVE To evaluate if routine respiratory polygraphy (RPG) testing is indicated for neonates with spina bifida and if yes, with what therapeutic consequence. METHODS We conducted a retrospective cohort study of all neonates with spina bifida at the University (Children's) Hospital Zurich after fetal spina bifida repair born between 2017 and 2022, who had undergone at least 1 RPG evaluation during hospitalization on the neonatal ward. RPG were evaluated by a blinded group of experienced pediatric pulmonologists. Based on the neonatal RPG results and pediatric pulmonologist's recommendation for caffeine therapy the spina bifida cohort was divided into two groups. Neonatal baseline RPG and follow-up RPG at the age of the 3 months were evaluated. RESULTS 48 neonates with RPG were included. Compared to the standard values in healthy neonates, the RPG results of this spina bifida cohort showed findings of SDB with central apnea and hypopnea. 22 (45.8%) neonatal RPG evaluations detected central SDB, prompting caffeine therapy. Follow-up RPG conducted after 3 months showed significant improvement of SDB with (almost) no need for continuation of caffeine. CONCLUSION We recommend the implementation of routine RPG testing in neonates with spina bifida to detect SDB and facilitate early targeted treatment

    Self-reported impulsivity in women with borderline personality disorder: the role of childhood maltreatment severity and emotion regulation difficulties

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    Background: Childhood maltreatment, such as severe emotional, physical, and sexual abuse and neglect, has been linked to impulse control problems and dysfunctional emotional coping. In borderline personality disorder (BPD), a history of childhood maltreatment may worsen difficulties in emotion regulation, which may in turn give rise to impulsive behaviours. The aim of this self-report study was to investigate associations between childhood maltreatment severity, emotion regulation difficulties, and impulsivity in women with BPD compared to healthy and clinical controls. Methods: Sixty-one female patients with BPD, 57 clinical controls (CC, women with Attention Deficit Hyperactivity Disorder and/or Substance Use Disorder, without BPD), and 60 female healthy controls (HC) completed self-report scales on childhood trauma (Childhood Trauma Questionnaire, CTQ), difficulties in emotion regulation (Difficulties in Emotion Regulation Scale, DERS), and impulsivity (UPPS Impulsive Behaviour Scale). A conditional process analysis was performed to investigate whether emotion dysregulation statistically mediated the effect of childhood maltreatment severity on impulsivity depending on group (BPD vs. CC vs. HC). Results: Childhood maltreatment, particularly emotional maltreatment, was positively associated with impulsivity and emotion regulation difficulties across all groups. Difficulties in emotion regulation statistically mediated the effect of childhood maltreatment on impulsivity in BPD, but not in the other groups. Conclusion: In the context of current conceptualizations of BPD and previous research, findings suggest that problems with emotion regulation may be related to a history of childhood maltreatment, which may in turn enhance impulsivity. Targeting emotion dysregulation in psychotherapy and discussing it in relation to childhood maltreatment can help decreasing impulsive behaviors in individuals with BPD. Given the correlational design of our study which does not allow causal conclusions, future studies have to employ prospective, experimental designs and include larger sample sizes to corroborate associations between childhood maltreatment, emotion dysregulation, and impulsivity

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance and Operation of the CMS Electromagnetic Calorimeter

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    The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

    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

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Jets and energy flow in photon-proton collisions at HERA

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    Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to \overline{p}p data and QCD calculations. The comparisons show that the \gamma p events can be consistently described by QCD models including -- in addition to the primary hard scattering process -- interactions between the two beam remnants. The differential jet cross sections d\sigma/dE_T^{jet} and d\sigma/d\eta^{jet} are measured
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