The Transit and Light Curve Modeller Csizmadia, Sz
Monthly Notices of the Royal Astronomical Society,
08/2020, Letnik:
496, Številka:
4
Journal Article
Recenzirano
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ABSTRACT
Transit and Light Curve Modeller (TLCM), a computer code with the purpose of analysing photometric time series of transits simultaneously with the out-of-transit light variations and radial ...velocity curves of transiting/eclipsing binary systems, is presented here. Joint light-curve and radial velocity fits are possible with it. The code is based on the combination of a genetic algorithm and simulated annealing. Binning, beaming, reflection, and ellipsoidal effects are included. Both objects may have their own luminosities and therefore one can use TLCM to analyse the eclipses of both exoplanet and well-detached binary systems. A simplified Rossiter–McLaughlin effect is included in the radial velocity fit, and drifts and offsets of different instruments can also be fitted. The impact of poorly known limb darkening on the Rossiter–McLaughlin effect is shortly studied. TLCM is able to manage red-noise effects via wavelet analysis. It is also possible to add parabolic or user-defined baselines and features to the code. I also predict that light variations due to beaming in some systems exhibiting radial velocity drift should be observed by, e.g. PLATO. The fit of the beaming effect is improved by invoking a physical description of the ellipsoidal effects, which has an impact on the modelling of the relativistic beaming; I also point out the difficulties that are stemming from the fact that beaming and first-order reflection effects have the same form of time dependence. Recipe is given, which describes how to analyse grazing transit events. The code is freely available.
Two-dimensional transition metal carbides/nitrides, known as MXenes, have been recently receiving attention for gas sensing. However, studies on hybridization of MXenes and 2D transition metal ...dichalcogenides as gas-sensing materials are relatively rare at this time. Herein, Ti
C
T
and WSe
are selected as model materials for hybridization and implemented toward detection of various volatile organic compounds. The Ti
C
T
/WSe
hybrid sensor exhibits low noise level, ultrafast response/recovery times, and good flexibility for various volatile organic compounds. The sensitivity of the hybrid sensor to ethanol is improved by over 12-fold in comparison with pristine Ti
C
T
. Moreover, the hybridization process provides an effective strategy against MXene oxidation by restricting the interaction of water molecules from the edges of Ti
C
T
. An enhancement mechanism for Ti
C
T
/WSe
heterostructured materials is proposed for highly sensitive and selective detection of oxygen-containing volatile organic compounds. The scientific findings of this work could guide future exploration of next-generation field-deployable sensors.
Intense light attenuation in water/wastewater results in photocatalysts exhibiting a low quantum efficiency. This study develops a novel piezoelectrocatalysis system, which involves quartz microrods ...(MRs) abundantly decorated with active‐edge‐site MoS2 nanosheets to form a quartz microrods@few‐layered MoS2 hierarchical heterostructure (QMSH). Through theoretical calculations, it is found that the quartz MRs serve as a parallel‐plate capacitor, which is self‐powered to provide an internal electric field to the few‐layered MoS2 nanosheets surrounding the quartz MR surfaces, and the piezoelectric potential (piezopotential) effectively facilitates redox reactions with the free carriers in MoS2. The self‐powered quartz MRs in the QMSH present an internal bias to the MoS2 nanosheets, thus yielding a piezoelectrocatalysis system. An efficient piezoelectrocatalytic hydrogen evolution reaction and decomposition of wastewater without light irradiation can be achieved simultaneously. The second‐order rate constant of the QMSH is ≈0.631 L mg−1 min−1, which is 650‐fold that of quartz MRs, indicating that the piezoelectric heterostructural catalysts display exceptionally high efficiency on piezoelectrocatalytic redox reactions rather than in the piezocatalytic process. The H2‐production rate of QMSH catalysts approaches ≈6456 µmo1 g−1 h−1 and peaks at ≈16.8 mmol g−1 in 8 h. The piezoelectrocatalytic process may be a promising method for treating industrial wastewater and producing clean energy.
A novel piezoelectrocatalysis system is developed, which involves quartz microrods abundantly decorated with active‐edge‐site MoS2 nanosheets to form a quartz microrods@few‐layered MoS2 hierarchical heterostructure (QMSH). The quartz microrods in the QMSH present an internal bias to the MoS2 nanosheets, thus yielding a piezoelectrocatalysis system. An efficient piezoelectrocatalytic hydrogen evolution reaction and decomposition of wastewater can be achieved simultaneously without light irradiation.
Over recent decades, the practice of human resource management in the transitional countries of Eastern Europe and in Hungary has changed significantly. Especially in local subsidiaries of ...foreign-owned companies and in the leading domestic large organizations, HRM has become a strategic function, while in the practice of small and medium-sized enterprises it is less common. COVID-19 hit companies, institutions and individuals unexpectedly, not only in Hungary but also in the more developed regions of the world. This crisis has also highlighted the fact that larger and better prepared organizations and public institutions have found it easier to weather this global human catastrophe. We analyze how the key tasks of HRM have changed during the successive waves, along four hypotheses. Initially, health protection, communication and home-office organization were the focus of the work of human resource professionals. In the second and third waves, securing and retaining staff became more important.
Carbon‐based materials have been widely used in heterogeneous catalysis because of their advantages of high surface area, thermal stability, and chemical inertness. However, their role in the ...catalysis is not fully understood although most studies conclude that the coupling between the carbon support and catalyst could reduce the charge transfer resistance and improve the kinetics of catalytic reactions such as water splitting. In this study, a carbon‐modified FeP2 electrocatalyst with a one‐step strategy is synthesized. The tensile strain is introduced in situ in the ab crystal plane of the FeP2 catalyst. This leads to charge redistribution between H and O atoms in the OH bonds and enhances the adsorption of reaction intermediates. In the water oxidation process, this results in a decrease in the energy barrier for the rate‐determining step, specifically, the chemical step of *OH adsorption preceded by one‐electron transfer. Benefiting from the optimized adsorption energy, the strained catalysts exhibit excellent oxygen evolution reaction (OER) activity with a low overpotential in addition to their increased stability. This study provides a new strategy for the introducing of strains in functional materials and provides new insights into the influence of carbon modification on OER activity.
Tensile strain is introduced in situ at the surface of an FeP2 electrocatalyst by carbon modification. In addition to the increased chemical stability, the existence of strain could also optimize the adsorption energy of reaction intermediates, thereby decreasing the energy barrier for the rate‐determining step.
An increasing number of studies have demonstrated that acupuncture can influence Autonomic Nervous System functions. Heart Rate variability (HRV) is one widely used marker of autonomic activity. The ...main objective of this systematic review is to critically assess the evidence from randomized clinical trials (RCTs) regarding the effect of acupuncture on HRV as compared to placebo methods.
EMBASE, Pubmed, The Cochrane Library, Web of Science, Scopus electronic databases were searched until 9 September 2020 for RCTs in which human subjects were treated with needle acupuncture using acupoints of the body without electric stimulation.
The searches identified 1698 potentially relevant articles, 9 RCTs were included. The statistical analysis of the available data showed that the changes between pre and post treatment HF (high frequency) and LF/HF (high frequency/low frequency) values in Verum group were significant, while there were no significant changes in these parameters in Sham groups.
the results of this meta-analysis suggest that real acupuncture has superior effect over placebo acupuncture in increasing parasympathetic tone and in this way may improve physical well-being. Due to the quality of primary studies and degree of heterogeneity the results should be interpreted cautiously.
•The reliability of Heart Rate Variability (HRV) as a non-invasive index of Autonomic Nervous System (ANS) activity is well documented.•Our hypothesis has been that acupuncture can influence ANS functions as proved by modifying the HRV.•The statistical analysis of the available data showed that in all the three groups we formed for statistical analysis the changes between pre and post treatment HF and LF/HF values in verum group were significant, while there were no significant changes in these parameters in Sham groups.•This result may explain the empirical knowledge of practicing clinicians that acupuncture can be effective in wide variety of physical illnesses related to chronic stress.
Abstract Objective Abdominal obesity was suggested to be a better predictor than Metabolic Syndrome (MetS) for cardiovascular mortality, however this is has not been extensively studied in ...schizophrenia. Hyperuricemia (HU) was also suggested to be both an independent risk factor for greater somatic comorbidity and a global metabolic stress marker in patients with schizophrenia. The aim of this study was to estimate the prevalence of MetS, abdominal obesity and HU, to examine the association between metabolic parameters with HU in a cohort of French patients with schizophrenia or schizo-affective disorder (SZ), and to estimate the prevalence rates of treatment of cardio-vascular risk factors. Method 240 SZ patients (age = 31.4 years, male gender 74.3%) were systematically included. Metabolic syndrome was defined according to the International Diabetes Federation and HU if serum uric acid level was above 360 μmol/L. Results MetS, abdominal obesity and HU were found respectively in 24.2%, 21.3% and 19.6% of patients. In terms of risk factors, multiple logistic regression showed that after taking into account the potential confounders, the risk for HU was higher in males (OR = 5.9, IC95 1.7–21.4) and in subjects with high waist circumference (OR = 3.1, IC95 1.1–8.3) or hypertriglyceridemia (OR = 4.9, IC95 1.9–13). No association with hypertension, low HDL cholesterol or high fasting glucose was observed. Only 10% of patients with hypertension received a specific treatment, 18% for high fasting glucose and 8% for dyslipidemia. Conclusions The prevalence of MetS, abdominal obesity and hyperuricemia is elevated in French patients with schizophrenia, all of which are considerably under-diagnosed and undertreated. HU is strongly associated with abdominal obesity but not with psychiatric symptomatology.
Context . Ultra-hot Jupiters (UHJs) orbiting pulsating A/F stars represent an important subset of the exoplanetary demographic. They are excellent candidates for the study of exoplanetary ...atmospheres, and are astrophysical laboratories for the investigation of planet-to- star interactions. Aims . We analysed the TESS light curve of the WASP-167 system, consisting of an F1V star and a substellar companion on a ~ 2.02 day orbit. Methods . We modelled the combination of the ellipsoidal variability and the Doppler beaming to measure the mass of WASP-167b, and the reflection effect to obtain constraints on the geometric albedo, while placing a special emphasis on noise separation. We implemented a basic model to determine the dayside ( T Day ), nightside ( T Night ), and intrinsic ( T Internal ) temperatures of WASP-167b, and put a constraint on its Bond albedo. Results . We confirm the transit parameters of the planet seen in the literature. We find that a resonant ~ 2 P −1 stellar signal (which may originate from planet-to-star interactions) interferes with the phase curve analysis. After careful and thought-out treatment of this signal, we find M p = 0.34 ± 0.22 M J . We measure a dayside temperature of 2790 ± 100 K, classifying WASP-167b as an UHJ. We find a 2 σ upper limit of 0.51 on its Bond albedo, and determine the geometric albedo at 0.34 ± 0.11 (1 σ uncertainty). Conclusions . With an occultation depth of 106.8 ± 27.3 ppm in the TESS passband, the UHJ WASP-167b is an excellent target for atmospheric studies, especially those at thermal wavelength ranges, where the stellar pulsations are expected to be less influential.
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