6,945 research outputs found
Star Clusters in the Magellanic Clouds-1: Parameterisation and Classification of 1072 Clusters in the LMC
We have introduced a semi-automated quantitative method to estimate the age
and reddening of 1072 star clusters in the Large Magellanic Cloud (LMC) using
the Optical Gravitational Lensing Experiment (OGLE) III survey data. This study
brings out 308 newly parameterised clusters. In a first of its kind, the LMC
clusters are classified into groups based on richness/mass as very poor, poor,
moderate and rich clusters, similar to the classification scheme of open
clusters in the Galaxy. A major cluster formation episode is found to happen at
125 +- 25 Myr in the inner LMC. The bar region of the LMC appears prominently
in the age range 60 - 250 Myr and is found to have a relatively higher
concentration of poor and moderate clusters. The eastern and the western ends
of the bar are found to form clusters initially, which later propagates to the
central part. We demonstrate that there is a significant difference in the
distribution of clusters as a function of mass, using a movie based on the
propagation (in space and time) of cluster formation in various groups. The
importance of including the low mass clusters in the cluster formation history
is demonstrated. The catalog with parameters, classification, and cleaned and
isochrone fitted CMDs of 1072 clusters, which are available as online material,
can be further used to understand the hierarchical formation of clusters in
selected regions of the LMC.Comment: 19 pages, 19figures, published in MNRAS on August 16, 2016
Supplementary material is available in the MNRAS websit
and bifurcations in rotational bands of diatomic molecules
It is shown that the recently observed bifurcation seen in
superdeformed nuclear bands is also occurring in rotational bands of diatomic
molecules. In addition, signs of a bifurcation, of the same order
of magnitude as the one, are observed both in superdeformed
nuclear bands and rotational bands of diatomic molecules.Comment: LaTex twice, 10 pages and 5 PS figures provided upon demand by the
Author
Bending Of Aelotropic Blocks II
In part I the authors had obtained a solution for bending an aelotropic circular block into an ellipsoidal and obtained the solution for the problem of bending and aelotropic circular block into a spherical shell as a particular case. In this paper, the solution for bending a circular block into a paraboloidal shell has been obtained on the same lines in terms of a completely general energy function for both compressible and incompressible materials
The effect of mutagens on M1 population of black gram (Vigno mungo L. Hepper)
This study was carried out with black gram (urdbean) variety TNAUCo(Bg)6 to determine the effects of gamma rays (150, 200, 250, 300 and 350 Gy) and ethyl methane sulphonate (10, 15, 20, 25, 30 mM). Data collected were on seed germination and survival, pollen and seed fertility, plant height, number of primary branches, number of clusters per plant, number of pods per plant, pod length, number of seeds per plant, hundred seed weight and yield per plant in M1 generation. Thereafter, progressive reduction in germination and survival percentage, pollen and seed fertility and yield related traits were observed in the mutagenic treatments. Deleterious effects were more pronounced in higher doses, indicating almost a linear relationship. LD50 values of 41.30 and 43.50% were observed in 20 mM of ethyl methane sulphonate and 250 Gy of gamma rays, respectively. The increasing doses of gamma rays and ethyl methane sulphonate decreased in phenotypic and yield related parameters. The reduction in quantity and yield traits has been attributed to the physiological disturbance or chromosomal damage of the cells of the plant caused by the mutagens. Ethyl methane sulphonate was observed to be more effective than gamma rays as it generated more number of mutants, which later caused higher physical injury.Keywords: Vigna mungo, variety TNAUCo(Bg)6, gamma rays, ethyl methane sulphonate (EMS)
Broad Band Optical Polarimetric Study of IC 1805
We present the BVR broad band polarimetric observations of 51 stars belonging
to the young open cluster IC 1805. Along with the photometric data from the
literature we have modeled and subtracted the foreground dust contribution from
the maximum polarization (P_{max}) and colour excess (E_{B-V}). The mean value
of the P_max for intracluster medium and the foreground are found to be 5.008
+/-0.005 % and 4.865 +/-0.022 % respectively. Moreover, the mean value of the
wavelength of maximum polarization (lambda_{max}) for intracluster medium is
0.541 +/- 0.003 micro m, which is quite similar as the general interstellar
medium (ISM). The resulting intracluster dust component is found to have
negligible polarization efficiency as compared to interstellar dust. Some of
the observed stars in IC 1805 have shown the indication of intrinsic
polarization in their measurements.Comment: 8 pages, 7 figures, Accepted for publication in MNRA
Phosphate mediated changes in fatty acid composition in Neurospora crassa.
Phosphate mediated changes in fatty acid composition in Neurospora crassa
Variable structure control for an isolated boost converter used in fuel cell applications
In recent years fuel cells have become prominent as an alternative source of energy to meet the society’s energy requirements. A control strategy derived from variable structure theory known as Sliding Mode Control (SMC) was proposed for an Isolated Boost topology which was mostly used in fuel cell systems. Converter operation and its detailed mathematical modelling are also presented. Then the converter with the control strategy suggested is simulated in MATLAB/SIMULINK and compared with other controllers. The results show that transient response of the converter is very fast and steady state error is reduced throughout the load change period with proposed control topology
Is intra articular injection of triamcinolone acetonide a better option in management for primary osteoarthritis knee than methylprednisolone acetate?
Background: Intra articular corticosteroid injections are commonly using in management of osteroarthritis of knee. Most commonly used ones are methylprednisolone acetate (MPA) and triamcinolone acetonide (TA). The aim of our study is to compare the efficacy of these two agents in treating osteoarthritis of knee and find out if any one agent is superior to other if so.Methods: Selected patients with symptomatic OA knee with kellgren-Lawrence grade III were given intra articular steroid injections (40 mg TA or 40 mg MPA) and were reassessed on day 0, 1 month, 3 months and 6 months. VAS and Knee society scores were calculated using questionnaire method and compared the scores.Results: The VAS and KSS was improved significantly on day 0,1 month and 6th month and it was found to be increased at 6th month in both the groups and the values were comparable in both the groups. The effect of both the agents last for 3-6 months and the effects found to be maximum at 1st month and the effects starts to wean off at the end of 6 months in both the groups.Conclusions: Both methylprednisolone acetate (MPA) and triamcinolone acetonide (TA) are equally effective in reducing pain in patients with osteoarthritis of knee and thereby improving their functional ability upto 6 months
Molecular theory of elastic constants of liquid crystals. III. Application to smectic phases with tilted orientational order
Using the density functional formalism we derive expression for the
distortion free energy for systems with continuous broken symmetry and use it
to derive expression for the elastic constants of smectic phases in which
director is tilted with respect to the smectic layer normal. As in the previous
papers of the series (Phys. Rev. A {\bf 45}, 974 (1992), E {\bf 49}, 501,
(1994)) the expressions for the elastic constants are written in terms of order
and structural parameters. The structural parameters involve the generalised
spherical harmonic coefficients of the direct pair correlation function of an
effective isotropic liquid. The density of this effective isotropic liquid
depends on the nature and amount of ordering present in the system and is
evaluated self- consistently. We estimate the value of elastic constants using
reasonable guess for the order and structural- parameters.Comment: 31 pages; 1 Fig. in GIF format, To be appear in Phys. Rev.
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