2,610 research outputs found
SARCS strong lensing galaxy groups: I - optical, weak lensing, and scaling laws
We present the weak lensing and optical analysis of the SL2S-ARCS (SARCS)
sample of strong lens candidates. The sample is based on the Strong Lensing
Legacy Survey (SL2S), a systematic search of strong lensing systems in the
photometric Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The SARCS
sample focuses on arc-like features and is designed to contain mostly galaxy
groups. We briefly present the weak lensing methodology that we use to estimate
the mass of the SARCS objects. Among 126 candidates, we obtain a weak lensing
detection for 89 objects with velocity dispersions of the Singular Isothermal
Sphere mass model ranging from 350 to 1000 km/s with an average value of
600km/s, corresponding to a rich galaxy group (or poor cluster). From the
galaxies belonging to the bright end of the group's red sequence (M_i<-21), we
derive the optical properties of the SARCS candidates. We obtain typical
richnesses of N=5-15 galaxies and optical luminosities of L=0.5-1.5e+12 Lsol
(within a radius of 0.5 Mpc). We use these galaxies to compute luminosity
density maps, from which a morphological classification reveals that a large
fraction of the sample are groups with a complex light distribution, either
elliptical or multimodal, suggesting that these objects are dynamically young
structures. We finally combine the lensing and optical analyses to draw a
sample of 80 most secure group candidates, i.e. weak lensing detection and
over-density at the lens position in the luminosity map, to remove false
detections and galaxy-scale systems from the initial sample. We use this
reduced sample to probe the optical scaling relations in combination with a
sample of massive galaxy clusters. We detect the expected correlations over the
probed range in mass with a typical scatter of 25% in the SIS velocity
dispersion at a given richness or luminosity, making these scaling laws
interesting mass proxie
PAYING PARTICIPANTS:THE IMPACT OF COMPENSATION ON DATA QUALITY
Poor-quality data has the potential to increase error variance, reduce statistical power and effect sizes, and produce Type I or Type II errors. Paying participants is one technique researchers may use in an attempt to obtain high-quality data. Accordingly, two secondary datasets were used to examine the relationship between participant payment and data quality. The first dataset revealed that data quality did not differ between paid and unpaid undergraduates. Similarly, the second dataset showed that data quality did not differ between unpaid community participants and MTurkers. A comparison across studies showed that undergraduate students engaged in lower levels of careless responding than the community samples but the unpaid community sample outperformed the MTurk sample and both undergraduate samples. Taken together, the current findings suggest that offering financial incentives to undergraduate or community samples does not improve data quality but may improve data collection rates and increase the diversity of participants.</p
Analysis of Labour Productivity in Construction Sector around Mumbai region
Productivity is an important aspect of construction industry that may be used as an index for efficiency of production. Efficient management of construction resources can lead to higher productivity which can help to achieve cost and time saving. Construction is labour oriented industry. It heavily relies on the skills of its workforce. The labour is industry’s most valuable asset. It is important to improve efficiency of production by improving productivity of labour. Aim of this paper is to give the data collection for calculation of labour productivity. The data have been collected by using time study technique in Mumbai region. Method study for placing and binding the reinforcement of column has been done previously. Applying the changes in method the data have been again collected and analysis for productivity have done which results in saving of project time, labour cost with maintaining quality of work
Evaluation of Antimitotic Activity of Momordica Dioica Fruits on Allium Cepa Root Meristamatic Cells
Natural occurring phenolic compounds play an important role in cancer prevention and shows antimitotic activity. Number of active constituents like phenolic acid, curcuminoids, coumarine, ligans, quinones, etc. is showing antimitotic activity of Momordica dioica. The present work is on phytochemical investigation and examines antimitotic activity of aqueous extract of fruits Momordica dioica at concentration of 15 mg/ml on Allium cepa root meristamatic cells.The fruits are air dried and extracted with solvents like water by maceration method. The evaluation of antimitotic activity is done by using Allium cepa root meristamatic cells parameters where and methotrexate was used as a standard drugs. In Allium assay, aqueous extract of fruits of Momordica diocia (15 mg/ml) and methotrexate act against cells of allium roots and lesser the growth of root and mitotic index when compared with distilled water as control group. The result indicated that cytotoxic property is due to presence of phenolic, alkaloids and flavonoids compounds in 15 mg/ml concentration of aqueous extract of Momordica diocia fruits extract.On the basis of result, we concluded that, 15 mg/ml concentration of Momordica dioica fruits shows good antimitotic activity on the Allium cepa root tip assay
Distanciamiento social ante la COVID-19: Simulación del aforo máximo de personas mediante PHP
Population confluence in internal or external areas considerably increases transmission of COVID-19, due to not respecting the social distancing established by the health system. The objective of this work was to make use of programming techniques,
using the PHP language (hypertext preprocessor), for the development of an application that simulates the maximum capacity of people who can enter an internal or external area. The methodology allowed recognizing common internal and external areas, configurating to the development environment, coding, simulation proposing and executing of the simulator where a practical case and ten places were evaluated to determine its reliability. The simulator provided the maximum capacity of people who can enter an internal or external area, complying with the social distancing of 2 m. The results made it possible to know that the use of information technologies through programming techniques and the PHP language contributed to being a technological alternative for the fight against the spread of the virus.La confluencia poblacional en áreas internas o externas incrementa considerablemente la trasmisiĂłn de la COVID-19, por no respetar el distanciamiento social que establece el sistema de salud. El objetivo de este trabajo fue hacer uso de tĂ©cnicas de programaciĂłn, empleando el lenguaje PHP (preprocesador de hipertexto), para el desarrollo de una aplicaciĂłn que simule el aforo máximo de personas que pueden ingresar a un área interna o externa. La metodologĂa permitiĂł el reconocimiento de áreas internas y externas comunes, configuraciĂłn al entorno de desarrollo, codificaciĂłn, propuesta de simulaciĂłn y ejecuciĂłn del simulador donde se ha evaluado un caso práctico y diez lugares para determinar su confiabilidad. El simulador brindĂł el aforo máximo de personas que pueden ingresar a un lugar de área interna o externa cumpliendo el distanciamiento social de 2 m. Los resultados permitieron conocer que el uso de las tecnologĂas de informaciĂłn a travĂ©s de las tĂ©cnicas de programaciĂłn y el lenguaje PHP contribuyĂł en ser una alternativa tecnolĂłgica para la lucha contra la propagaciĂłn del virus
Efficacy of sequential sprays of different fungicides against early blight Alternaria solani (Ellis and Martin) in potato Solanum tubrosum L.
Potato is one of the world's fourth most important food crop belongs to family solanaceae. More than one billion peoples consume potatoes and richest source of energy highest dry matter, energy and edible proteins. The field experiments on Efficacy of sequential sprays of different fungicides against early blight Alternaria solani (Ellis and Martin) in potato Solanum tubrosum L. was conducted during kharif season on potato (cv. K. Pukharaj) for consecutive three years. The experiment was laid out in RBD design with 6 treatments and 4 replications. The results revealed that spray of Chlorothalonil 75 WP (0.25%) @ 2.5 gm/ liter of water followed by Hexaconazole 5 EC (0.05%) @ 0.5 ml /liter of water and then Chlorothalonil 75WP (0.25%) @ 2.5 gm/liter of water at 10 days interval was found significantly superior in controlling the early blight on potato The yield differences due to spraying of fungicides were significant and the highest yield (18.10 t/ha) was obtained in same treatment
Characterization of Melt Infiltrated SiC/SiC Composite Combustor Liners Using Meso- and Micro-NDE Techniques
Melt-infiltrated ceramic matrix composite SiC/SiC material systems are under development for use in combustor liners for low-emission advanced gas turbines. Uncertainty in repeatability of processing methods for these large components (33--76 cm diameter), and hence possible reduced reliability for the end user. This requires that appropriate test methods, at both meso- and micro-scale, be used to ensure that the liners are acceptable for use. Nondestructive evaluation (NDE) methods, if demonstrated to reliably detect changes caused by processing, would be of significant benefit to both manufacturer and end user. This paper describes the NDE methods and their applications in detecting a process upset in a melt-infiltrated 33 cm combustor liner and how high-resolution scanning electron microscopy was used to verify the NDE data
Characterizing SL2S galaxy groups using the Einstein radius
We analyzed the Einstein radius, , in our sample of SL2S galaxy
groups, and compared it with (the distance from the arcs to the center of
the lens), using three different approaches: 1.- the velocity dispersion
obtained from weak lensing assuming a Singular Isothermal Sphere profile
(), 2.- a strong lensing analytical method ()
combined with a velocity dispersion-concentration relation derived from
numerical simulations designed to mimic our group sample, 3.- strong lensing
modeling () of eleven groups (with four new models presented in
this work) using HST and CFHT images. Finally, was analyzed as a function
of redshift to investigate possible correlations with L, N, and the
richness-to-luminosity ratio (N/L). We found a correlation between
and , but with large scatter. We estimate = (2.2 0.9)
+ (0.7 0.2), = (0.4 1.5) + (1.1
0.4), and = (0.4 1.5) + (0.9 0.3) for
each method respectively. We found a weak evidence of anti-correlation between
and , with Log = (0.580.06) - (0.040.1), suggesting
a possible evolution of the Einstein radius with , as reported previously by
other authors. Our results also show that is correlated with L and N
(more luminous and richer groups have greater ), and a possible
correlation between and the N/L ratio. Our analysis indicates that
is correlated with in our sample, making useful to
characterize properties like L and N (and possible N/L) in galaxy groups.
Additionally, we present evidence suggesting that the Einstein radius evolves
with .Comment: Accepted for publication in Astronomy & Astrophysics. Typos correcte
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