1,471 research outputs found
Digitized archive of the Kodaikanal images: Representative results of solar cycle variation from sunspot area determination
Photographic images are valuable data resources for studying long term
changes in the solar magnetic field and its influence on the Earth's climate
and weather.
We digitized more than 100 years of white light images stored in photographic
plates and films that are available at Kodaikanal observatory starting from
1904. The digitized images were calibrated for relative plate density and
aligned in such a way that the solar north is in upward direction. A
semi-automated sunspot detection technique was used to identify the sunspots on
the digitized images. In addition to describing the calibration procedure and
availability of the data, we here present preliminary results on the sunspot
area measurements and their variation with time. The results show that the
white-light images have a uniform spatial resolution throughout the 90 years of
observations. However, the contrast of the images decreases from 1968 onwards.
The images are circular and do not show any major geometrical distortions. The
measured monthly averaged sunspot areas closely match the Greenwich sunspot
area over the four solar cycles studied here. The yearly averaged sunspot area
shows a high degree of correlation with the Greenwich sunspot area. Though the
monthly averaged sunspot number shows a good correlation with the monthly
averaged sunspot areas, there is a slight anti-correlation between the two
during solar maximum The Kodaikanal data archive is hosted at
http://kso.iiap.res.in. The long time sequence of the Kodaikanal white light
images provides a consistent data set for sunspot areas and other proxies. Many
studies can be performed using Kodaikanal data alone without requiring
intercalibration between different data sources.Comment: 9 pages, A&A(accepted
Determination of the chromospheric quiet network element area index and its variation during 2008-2011
Generally it has been considered that the plages and sunspots are the main
contributors to the solar irradiance. There are small scale structures on the
sun with intermediate magnetic fields that could also contribute to the solar
irradiance. It has not yet been quantified how much of these small scale
structures contribute to the solar irradiance and how much it varies over the
solar cycle.
In this paper, we used Ca II K images obtained from the telescope installed
at Kodaikanal observatory. We report a method to separate the network elements
from the background structure and plage regions. We compute the changes in the
network element area index during the minimum phase of solar cycle and part of
the ascending phase of cycle 24. The measured area occupied by the network
elements is about 30% and plages less than 1% of the solar disk during the
observation period from February 2008-2011. During the extended period of
minimum activity it is observed that the network element area index decreases
by about 7% compared to the area occupied by the network elements in 2008. A
long term study of network element area index is required to understand the
variations over the solar cycle.Comment: 12 pages, 9 Figures, Accepted for publication in RA
Strong Forms of b-Continuous Multifunctions
In this paper we have introduced strong forms of b-continuous multifunctions namely b#-multicontinuity and *b-multicontinuity and studied their properties and characterizations. Also investigate the relationship with other type of functions with suitable examples
Low-Temperature Spin Dynamics of Doped Manganites: roles of Mn-t2g and eg and O-2p states
The low-temperature spin dynamics of doped manganites have been analyzed
within a tight-binding model, the parameters of which are estimated by mapping
the results of ab initio density functional calculations onto the model. This
approach is found to provide a good description of the spin dynamics of the
doped manganites, observed earlier within the ab initio calculations. Our
analysis not only provides some insight into the roles of the eg and the t2g
states but also indicates that the oxygen p states play an important role in
the spin dynamics. This may cast doubt on the adaptability of the conventional
model Hamiltonian approaches to the analysis of spin dynamics of doped
manganites.Comment: 12 pages; Includes 5 figure
4-[(E)-(HyÂdroxyÂimino)ÂmethÂyl]-N,N-diÂmethylÂanilinium chloride
In the title compound, C9H13N2O+·Cl−, the cation, apart from the methyl groups, is almost planar, with a maximum deviation of 0.040 (1) Å; the methyl C atoms deviate by 0.389 (2) and −1.247 (1) Å, from the mean plane. In the crystal, cations and anions associate through C—H⋯Cl hydrogen bonds, forming a helical arrangement. In addition, interÂmolecular O—H⋯Cl, N—H⋯Cl and C—H⋯N interÂactions are observed
Comparative evaluation of sulphur sources on growth, yield and quality of garlic (Allium sativum L.)
Sulphur is a prime nutrient in Allium crops. Garlic fertilization with ammonium-based sulphur fertilizers in low pH soils is being practiced by farmers that culminate the soil acidity, which has an adverse effect on plant growth. Hence a field experiment was conducted at Horticultural Research Station, Woodhouse farm, Ooty, the Nilgris in 2021 to evaluate the appropriate sulphur sources and their levels for garlic at acidic hilly soil using four sulphur sources viz., potassium sulphate, magnesium sulphate, zinc sulphate and ammonium phosphate sulphate and three levels viz., 0, 40, 60 kg ha-1. Garlic variety Ooty 2 was used as test crop. The results revealed that application of magnesium sulphate @ 60 kg ha-1 produced the highest plant height, leaf numbers, clove numbers bulb-1, neck thickness, polar diameter, equatorial diameter, the weight of 10 cloves, fresh weight, dry weight and bulb yield (16.78 t ha-1) of garlic. Quality parameters viz., total soluble solids, ascorbic acid and total phenols of garlic bulbs were improved by the application of potassium sulphate @ 60 kg ha-1. Sulphur source of Magnesium sulphate had a minimal effect of rendering acidity to soil measured in terms of pH (4.74) and exchangeable acidity (0.22 meq 100 g-1). Hence, the promising source for acidic hilly soil and garlic crop was found to be magnesium sulphate @ 60 kg ha-1 followed by potassium sulphate @ 60 kg ha-1. This particular investigation focuses not only on yield improvement but also on maintaining soil quality of the area
Anti-inflammatory and analgesic effects of coral reef associated gastropod, Trochus tentorium from Tuticorin coastal waters, Southeastern India
The aim of this work was to investigate extensively, the biomedical potential of the mollusc Trochus tentorium which are abundantly associated with coral reef of the Tuticorin coastal water. The 100% acetone fraction of the gastropod tested for its analgesic effect on Swiss mice model and anti-inflammatory activity on albino rat showed promising results. T. tentorium at the concentration of 25 and 50 mg/kg (p.o) showed significant decrease in the paw thickness (41.15 and 73.6%, respectively) at the 5th hour of the experiment. The 100% column-purified fraction of the T. tentorium (200 mg/kg p.o) exhibited significant (p < 0.001) inhibition of 79.22% against acetic acid induced abdominal constrictions. The dose of 25 mg/kg showed the inhibitions in the writhings of 67.86% (p<0.001) of animals when compared to the standard (diclofenac sodium), and 56.83% (50 mg/kg) inhibition was observed. These facts suggest that T. tentorium is a potential source for anti-inflammatory and analgesic compounds.Key words: Analgesic activity, anti-inflammatory activity, mollusc, southeastern India
Effect of land configuration and fertilizer dosage on growth and yield of African marigold under vertic ustochrept soil regimes
Adopting proper land management systems and nutrient levels could improve growth, yield and quality by rendering better soil physical structure and mineral nutrition under heavy rainfall areas. An experiment was conducted to identify appropriate land configuration and fertilizer dose for African marigold var. Punjab Gainda-1, in split plot design with three land configuration methods viz., flat bed, raised bed and ridge & furrow system as main plots, and three fertilizer doses (RDF/ha) viz., 100%, 80% and 60% as subplots with recommended dose of fertilizer (RDF) being 10 t FYM + 150:100:100 kg/ha NPK. Results showed that adopting raised bed method of land configuration with the application of 8 t FYM + 120:80:80 kg/ha NPK exhibited enhanced vegetative growth and flower yield (16.26 t/ha) with greater benefit cost ratio (2.88) and, hence, found economically best for commercial production of African marigold
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