2,643 research outputs found

    Mass function and dynamical study of the open clusters Berkeley 24 and Czernik 27

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    We present a UBVIUBVI 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 0.35±0.060.35\pm0.06 mas yr1^{-1} and 1.20±0.081.20\pm0.08 mas yr1^{-1} in right ascension and declination for Be 24 and 0.52±0.05-0.52\pm0.05 mas yr1^{-1} and 1.30±0.05-1.30\pm0.05 mas yr1^{-1} for Cz 27. We used probable cluster members selected from proper motion data for the estimation of fundamental parameters. We infer reddenings E(BV)E(B-V) = 0.45±0.050.45\pm0.05 mag and 0.15±0.050.15\pm0.05 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]= 0.025±0.01-0.025\pm0.01 dex and 0.042±0.01-0.042\pm0.01 dex for the clusters Be 24 and Cz 27, respectively. The distances, as determined from main sequence fitting, are 4.4±0.54.4\pm0.5 kpc and 5.6±0.25.6\pm0.2 kpc. The comparison of observed CMDs with Z=0.01Z=0.01 isochrones, leads to an age of 2.0±0.22.0\pm0.2 Gyr and 0.6±0.10.6\pm0.1 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

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    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)

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    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

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    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)

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    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

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    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 (ξ\xi) is inversely proportional to the expansion (θ\theta) in the model and expansion (θ\theta) in the model is proportional to the shear (σ\sigma). This leads to B=CnB = \ell C^{n}, \ell and nn 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 173288115^{288}_{173}115 and 172287115^{287}_{172}115 in the Relativistic Mean Field theory

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    In the recent experiments designed to synthesize the element 115 in the 243^{243}Am+48^{48}Ca reaction at Dubna in Russia, three similar decay chains consisting of five consecutive α\alpha-decays, and another different decay chain of four consecutive α\alpha-decays are detected, and the decay properties of these synthesized nuclei are claimed to be consistent with consecutive α\alpha-decays originating from the parent isotopes of the new element 115, 288115^{288}115 and 287115^{287}115, 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 288115^{288}115, 287115^{287}115, and their α\alpha-decay daughter nuclei. The calculated α\alpha-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

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    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

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    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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