2,643 research outputs found
Mass function and dynamical study of the open clusters Berkeley 24 and Czernik 27
We present a photometric study of the open clusters Berkeley 24 (Be
24) and Czernik 27 (Cz 27). The radii of the clusters are determined as
2\farcm7 and 2\farcm3 for Be 24 and Cz 27, respectively. We use the Gaia Data
Release 2 (GDR2) catalogue to estimate the mean proper motions for the
clusters. We found the mean proper motion of Be 24 as mas
yr and mas yr in right ascension and declination
for Be 24 and mas yr and mas yr for
Cz 27. We used probable cluster members selected from proper motion data for
the estimation of fundamental parameters. We infer reddenings =
mag and mag for the two clusters. Analysis of
extinction curves towards the two clusters show that both have normal
interstellar extinction laws in the optical as well as in the near-IR band.
From the ultraviolet excess measurement, we derive metallicities of [Fe/H]=
dex and dex for the clusters Be 24 and Cz 27,
respectively. The distances, as determined from main sequence fitting, are
kpc and kpc. The comparison of observed CMDs with
isochrones, leads to an age of Gyr and Gyr for
Be 24 and Cz 27, respectively.
In addition to this, we have also studied the mass function and dynamical
state of these two clusters for the first time using probable cluster members.
The mass function is derived after including the corrections for data
incompleteness and field star contamination. Our analysis shows that both
clusters are now dynamically relaxedComment: 16 pages including 8 tables. 22 figures. Accepted by MNRA
Solid Wastes Recyling through Sinter-Status at Tata Steel
Integrated steel plants generate several by-products rich in iron, flux and fuel values, categorised as waste. These by-products contain, besides mineral values, hazar-dous constituents causing damages to the environment. The environmental quality consciousness, the product cost competitiveness and high mineral values of these wastes have resulted in attempts to recyle these materials. Recycling recovers the mineral values, preserves the dec-reasing natural resources and deteriorating environment and eliminates the disposal cost. Sinter plant provides an avenue for recycling of these wastes. Recycling decreases the cost of sinter and hence the cost of steel produced. Present paper outlines the status of waste generation, their characteristics, and the quantity being recycled via the sinter plant at Tata Steel.Furthermore, it highlights the problems, which restricts its further recycling and
discusses its influence on cost and quality of sinter
ऊष्णीत गृह के बारे में जानें (Know Your Warming Planet-ClimEd Series:1B)
This instructional material "Know Your Warming Planet" has been developed as a
part of the Belmont funded project titled "Global Understanding and Learning for
Local solutions: Reducing Vulnerability of marine dependent coastal
communities" as a means to create awareness and impart climate change
knowledge across the target populace
Comparative biology and fertility parameters of two spotted spider mite, Tetranychus urticae Koch. on different grapevine varieties
The influence of the four grapevine varieties 'Thompson Seedless', 'Manjri Naveen', 'Gulabi' and 'Bangalore Blue' on fitness, development and reproductive characteristics of the two spotted spider mite, Tetranychus urticae was studied. The biology of two spotted spider mites consisted of egg, larvae, protonymph, deutonymph and adult stages. The total duration from egg to adult was found to be the least in 'Thompson Seedless' (16.2 days) followed by ''Manjri Naveen' (17.2 days), 'Gulabi' (17.2 days) and maximum in 'Bangalore Blue' (32.2 days). The survival rate of life stages of mites was found to be lower in 'Bangalore Blue'. The higher values of net reproductive rate, intrinsic rate of increase, finite rate of increase the shortest mean generation time was observed in 'Thompson Seedless' followed by 'Gulabi', 'Manjri Naveen' and 'Bangalore Blue'. The results suggested that 'Thompson Seedless' was the most suitable cultivar with higher survival rate of life stages of mites, shortest development period, higher value intrinsic rate of increase and fecundity whereas 'Bangalore Blue' was the least suitable cultivar because of the lowest intrinsic rate of increase, longest development period, lower survival rate of life stages of mites
अधिगम एंव जलवायु परिवर्तन से सामना (Learning & Coping Climate Change-ClimEd Series:2B)
The GULLS project funded by the Belmont Forum addresses coastal vulnerability
issues,- specifically the challenges that arise in food security and sustaining coastal
livelihoods as a result of global warming and increasing human coastal populations. It
seeks to identify adaptation options and strategies for enhancing coastal resilience at
the local level and in doing so will contribute to capacity building and local
empowerment. The goal of the project is to provide insight to coastal communities to
adapt to climate change through trans-disciplinary approach
Bianchi Type III String Cosmological Models with Time Dependent Bulk Viscosity
Bianchi type III string cosmological models with bulk viscous fluid for
massive string are investigated. To get the determinate model of the universe,
we have assumed that the coefficient of bulk viscosity () is inversely
proportional to the expansion () in the model and expansion ()
in the model is proportional to the shear (). This leads to , and are constants. The behaviour of the model in presence
and absence of bulk viscosity, is discussed. The physical implications of the
models are also discussed in detail.Comment: 11 pages, no figur
Alpha-decay chains of and in the Relativistic Mean Field theory
In the recent experiments designed to synthesize the element 115 in the
Am+Ca reaction at Dubna in Russia, three similar decay chains
consisting of five consecutive -decays, and another different decay
chain of four consecutive -decays are detected, and the decay
properties of these synthesized nuclei are claimed to be consistent with
consecutive -decays originating from the parent isotopes of the new
element 115, and , respectively\cite{ogan.03}. Here in
the present work, the recently developed deformed RMF+BCS method with a
density-independent delta-function interaction in the pairing channel is
applied to the analysis of these newly synthesized superheavy nuclei
, , and their -decay daughter nuclei. The
calculated -decay energies and half-lives agree well with the
experimental values and with those of the macroscopic-microscopic FRDM+FY and
YPE+WS models. In the mean field Lagrangian, the TMA parameter set is used.
Particular emphasis is paid on the influence to both the ground-state
properties and energy surfaces introduced by different treatments of pairing.
Two different effective interactions in the particle-particle channel, i.e.,
the constant pairing and the density-independent delta-function interaction,
together with the blocking effect are discussed in detail.Comment: 17 pages, 5 figure
An indigenous cluster beam apparatus with a reflectron time-of-flight mass spectrometer
The design and fabrication of a Smalley-type cluster source in combination with a reflectron based time-of-flight (TOF) mass spectrometer are reported. The generation of clusters is based on supersonic jet expansion of the sampling plume. Sample cells for both liquid and solid targets developed for this purpose are described. Two pulsed Nd-YAG lasers are used in tandem, one (532 nm) for target vapourization and the other (355 nm) for cluster ionization. Methanol clusters of nuclearity up to 14 (mass 500 amu) were produced from liquid methanol as the test sample. The clusters were detected with a mass resolution of ~2500 in the R-TOF geometry. Carbon clusters up to a nuclearity of 28 were obtained using a polyimide target. The utility of the instrument is demonstrated by carrying out experiments to generate mixed clusters from alcohol mixtures
Instruments of RT-2 Experiment onboard CORONAS-PHOTON and their test and evaluation II: RT-2/CZT payload
Cadmium Zinc Telluride (CZT) detectors are high sensitivity and high
resolution devices for hard X-ray imaging and spectroscopic studies. The new
series of CZT detector modules (OMS40G256) manufactured by Orbotech Medical
Solutions (OMS), Israel, are used in the RT-2/CZT payload onboard the
CORONAS-PHOTON satellite. The CZT detectors, sensitive in the energy range of
20 keV to 150 keV, are used to image solar flares in hard X-rays. Since these
modules are essentially manufactured for commercial applications, we have
carried out a series of comprehensive tests on these modules so that they can
be confidently used in space-borne systems. These tests lead us to select the
best three pieces of the 'Gold' modules for the RT-2/CZT payload. This paper
presents the characterization of CZT modules and the criteria followed for
selecting the ones for the RT-2/CZT payload. The RT-2/CZT payload carries,
along with three CZT modules, a high spatial resolution CMOS detector for high
resolution imaging of transient X-ray events. Therefore, we discuss the
characterization of the CMOS detector as well.Comment: 26 pages, 19 figures, Accepted for publication in Experimental
Astronomy (in press
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