Context. This paper is the fourth of a series evaluating the ASpiX cosmological method, based on X-ray diagrams, which are constructed from simple cluster observable quantities, namely: count rate ...(CR), hardness ratio (HR), core radius (rc), and redshift. Aims. Following extensive tests on analytical toy catalogues (Paper III), we present the results of a more realistic study over a 711 deg2 template-based maps derived from a cosmological simulation. Methods. Dark matter haloes from the Aardvark simulation have been ascribed luminosities, temperatures, and core radii, using local scaling relations and assuming self-similar evolution. The predicted X-ray sky-maps were converted into XMM event lists, using a detailed instrumental simulator. The XXL pipeline runs on the resulting sky images, produces an observed cluster catalogue over which the tests have been performed. This allowed us to investigate the relative power of various combinations of the CR, HR, rc, and redshift information. Two fitting methods were used: a traditional Markov chain Monte Carlo (MCMC) approach and a simple minimisation procedure (Amoeba) whose mean uncertainties are a posteriori evaluated by means of synthetic catalogues. The results were analysed and compared to the predictions from the Fisher analysis (FA). Results. For this particular catalogue realisation, assuming that the scaling relations are perfectly known, the CR-HR combination gives σ8 and Ωm at the 10% level, while CR-HR-rc-z improves this to ≤3%. Adding a second HR improves the results from the CR-HR1-rc combination, but to a lesser extent than when adding the redshift information. When all coefficients of the mass-temperature relation (M-T, including scatter) are also fitted, the cosmological parameters are constrained to within 5–10% and larger for the M-T coefficients (up to a factor of two for the scatter). The errors returned by the MCMC, those by Amoeba and the FA predictions are in most cases in excellent agreement and always within a factor of two. We also study the impact of the scatter of the mass-size relation (M-Rc) on the number of detected clusters: for the cluster typical sizes usually assumed, the larger the scatter, the lower the number of detected objects. Conclusions. The present study confirms and extends the trends outlined in our previous analyses, namely the power of X-ray observable diagrams to successfully and easily fit at the same time, the cosmological parameters, cluster physics, and the survey selection, by involving all detected clusters. The accuracy levels quoted should not be considered as definitive. A number of simplifying hypotheses were made for the testing purpose, but this should affect any method in the same way. The next publication will consider in greater detail the impact of cluster shapes (selection and measurements) and of cluster physics on the final error budget by means of hydrodynamical simulations.
ABSTRACT
Using archival X-ray observations and a lognormal population model, we estimate constraints on the intrinsic scatter in halo mass at fixed optical richness for a galaxy cluster sample ...identified in Dark Energy Survey Year-One (DES-Y1) data with the redMaPPer algorithm. We examine the scaling behaviour of X-ray temperatures, TX, with optical richness, λRM, for clusters in the redshift range 0.2 < z < 0.7. X-ray temperatures are obtained from Chandra and XMM observations for 58 and 110 redMaPPer systems, respectively. Despite non-uniform sky coverage, the TX measurements are $\gt 50{{\ \rm per\ cent}}$ complete for clusters with λRM > 130. Regression analysis on the two samples produces consistent posterior scaling parameters, from which we derive a combined constraint on the residual scatter, $\sigma _{\ln T \, |\, \lambda }= 0.275 \pm 0.019$. Joined with constraints for TX scaling with halo mass from the Weighing the Giants program and richness–temperature covariance estimates from the LoCuSS sample, we derive the richness-conditioned scatter in mass, $\sigma _{\ln M \, |\, \lambda }= 0.30 \pm 0.04\, _{({\rm stat})} \pm 0.09\, _{({\rm sys})}$, at an optical richness of approximately 100. Uncertainties in external parameters, particularly the slope and variance of the TX–mass relation and the covariance of TX and λRM at fixed mass, dominate the systematic error. The $95{{\ \rm per\ cent}}$ confidence region from joint sample analysis is relatively broad, $\sigma _{\ln M \, |\, \lambda }\in 0.14, \, 0.55$, or a factor 10 in variance.
An analytical method for the determination of Flubendiamide (FBD) was investigated for the first time in this study using disposable pencil graphite electrodes (PGE). A detailed study of the ...electrochemical properties of FBD was carried out in phosphate buffer solution (PBS, pH 7.0). The results showed a well-defined reversible system result from the transformation of FBD to the corresponding hydroxyl-derivative. The results showed a linear range from 1 to 500 µM (R
2
= 0. 9952), as well as detection limit of 0.53 µM. The PGE sensor was successfully applied for the detection of FBD in wastewater and white rice.
ABSTRACT
The XXL Survey is the largest homogeneous survey carried out with XMM-Newton. Covering an area of 50 deg2, the survey contains several hundred galaxy clusters out to a redshift of ≈2, above ...an X-ray flux limit of ∼6 × 10−15 er g cm−2 s−1. The GAMA spectroscopic survey of ∼300 000 galaxies covers ≈286 deg2, down to an r-band magnitude of r < 19.8 mag. The region of overlap of these two surveys (covering 14.6 deg2) represents an ideal opportunity to study clusters selected via two independent selection criteria. Generating two independently selected samples of clusters, one drawn from XXL (spanning a redshift range 0.05 ≤ z ≤ 0.3) and another from GAMA (0.05 ≤ z ≤ 0.2), both spanning 0.2 ≲ M500 ≲ 5 × 1014 M⊙, we investigate the relationship between X-ray luminosity and velocity dispersion (LX − σv relation). Comparing the LX − σv relation between the X-ray selected and optically selected samples, when not accounting for the X-ray selection, we find that the scatter of the X-ray selected sample is 2.7 times higher than the optically selected sample (at the 3.7σ level). Accounting for the X-ray selection to model the LX − σv relation, we find that the difference in the scatter increases (with the X-ray selected sample having a scatter 3.4 times larger than the optically selected sample). Although the scatter of the optically selected sample is lower, we find 13 optically selected GAMA groups undetected in X-rays. Inspection of the difference in magnitude between the first and second brightest galaxies in the cluster, and a stacked X-ray image of these 13 groups, suggests that these are young systems still in the process of forming.
Flubendiamide (FBD) is the first commercially available phthalic acid diamide that targets ryanodine receptors (RyRs) in insects, which play a major role in lepidoptera control. However, excessive ...use of FBD can influence the quality of treated products leading to toxic effects on human health. The availability of rapid and convenient methods for evaluating FBD amount in the environment is necessary. Therefore, analytical methods were developed for the determination of residues of FBD and its metabolite desiodo in different food matrices like tomato, cabbage, pigeon pea, apple, chilli and rice. The current review carries forward methods for FBD residues analysis in foods by using several chromatographic techniques including sample preparation steps. The comparison between the different methods employed for quantitative and qualitative analysis of food quality and safety is also discussed. Liquid chromatography (LC) is the predominant analytical method for assessing the quality of foods treated with FBD. Studies related to LC coupled multichannel detector (Ultraviolet (UV), Mass spectrometry (MS)) are also applied to detect pesticide residues. Extraction and clean up steps are essential to obtain reliable results. Moreover, this review reports the allowed limits of residues for the safety of consuming products treated with FBD.
Display omitted
•State of the art of flubendiamide as diamide insecticide is presented.•Significance of extraction and cleanup process used for sample preparation is exhibited.•Chromatographic methods used in FBD analysis in food samples are discussed.
Electrochemical modification of carbon-paste electrode (CPEs) by silver particles and its applicability for electroanalytical determination of 4-nitroaniline (4-NA) were reported in this study. ...Electrochemical surface modification was performed by cyclic voltammetry within the range from 600 to − 400 mV in solution containing 0.5 mmol L
−1
AgNO
3
dissolved in 0.1 mol L
−1
of KNO
3
at the scan rate of 10 mV s
−1
by applying 1.5 cycles (six segments). Silver particles deposited onto surface of carbon-paste electrode (Ag-CPE) were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The proposed catalyst exhibits remarkably an electro-catalytic performance toward 4-nitroaniline reduction. The catalytic peak current obtained by differential pulse voltammetry (DPV) was linearly dependent on the 4-NA concentration over the range of 8.0 × 10
−8
to 1.0 × 10
−4
mol L
−1
with a detection limit of 4.18 × 10
−8
mol L
−1
. The proposed sensor was successfully applied for 4-nitroaniline determination in drinking water samples.
An activated carbon modified carbon paste electrode (AC/CPE) was fabricated, and the electrochemical oxidation of resorcinol (RS) was studied in phosphate buffer solution. The results revealed that ...the activated carbon has a catalytic effect on the oxidation current of RS in buffered solution relative to an unmodified carbon paste electrode. The oxidation mechanism was studied using cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The results demonstrated that the oxidation of RS at this AC/CPE electrode was irreversible and co-contribution of adsorption and diffusion. Under the optimal chemical and DPV parameters, the anodic peak current showed a linear relation versus RS concentration in the range from 1.0 × 10
–7
to 1.0 × 10
–4
mol L
−1
with detection limit of 3.5 × 10
–8
mol L
−1
(3Sb/m). Moreover, the modified electrode demonstrated good repeatability (RSD = 3.12%, n = 8), long-term stability and excellent anti-interference property by peaks separation. This method has been applied to the determination of RS in tap water and commercial hair color samples. The obtained results are similar to those obtained using a high-performance liquid chromatography method (at 95% confidence level).
Graphic Abstract
ABSTRACT
We cross-match and compare characteristics of galaxy clusters identified in observations from two sky surveys using two completely different techniques. One sample is optically selected from ...the analysis of 3 years of Dark Energy Survey observations using the redMaPPer cluster detection algorithm. The second is X-ray selected from XMM observations analysed by the XMM Cluster Survey. The samples comprise a total area of 57.4 deg2, bounded by the area of four contiguous XMM survey regions that overlap the DES footprint. We find that the X-ray-selected sample is fully matched with entries in the redMaPPer catalogue, above λ > 20 and within 0.1 <$z$ <0.9. Conversely, only 38 per cent of the redMaPPer catalogue is matched to an X-ray extended source. Next, using 120 optically clusters and 184 X-ray-selected clusters, we investigate the form of the X-ray luminosity–temperature (LX –TX ), luminosity–richness (LX –λ), and temperature–richness (TX –λ) scaling relations. We find that the fitted forms of the LX –TX relations are consistent between the two selection methods and also with other studies in the literature. However, we find tentative evidence for a steepening of the slope of the relation for low richness systems in the X-ray-selected sample. When considering the scaling of richness with X-ray properties, we again find consistency in the relations (i.e. LX –λ and TX –λ) between the optical and X-ray-selected samples. This is contrary to previous similar works that find a significant increase in the scatter of the luminosity scaling relation for X-ray-selected samples compared to optically selected samples.
4-nitrophenol (4-NP) is considered to be a harmful solid waste because of its toxicity and persistence. It is categorised as a priority contaminant by the United States environmental protection ...agency. In this work, we present a simple, easy and comprehensive electrochemical investigation of the electrocatalytic reduction of 4-NP in Britton-Robinson buffer solution as the supporting electrolyte at the surface of zero-valent silver electrode (ZVAgE). Different electrochemical methods such as cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, and Tafel plots were used to evaluate heterogeneous kinetics and illustrate the reduction mechanism of 4-NP. The experimentally determined parameters confirm that ZVAgE has a significant electrocatalytic activity towards 4-NP electro-reduction as compared to glassy carbon electrode (GCE). Under optimal conditions, the detection of 4-NP was found to have a low detection limit of 3.03 × 10
−7
mol L
−1
in the range from 8.0 × 10
−6
to 1.0 × 10
−4
mol L
−1
. Additionally, the sensor was successfully applied in the determination of 4-NP even in the presence of other common electroactive interference and real samples analysis (wastewater and river water samples). Therefore, the proposed method is simple, rapid, stable, sensitive, specific, and cost-effective and can be applicable for real sample detection.
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