1,471 research outputs found

    Digitized archive of the Kodaikanal images: Representative results of solar cycle variation from sunspot area determination

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    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

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    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

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    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

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    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)-(Hy­droxy­imino)­meth­yl]-N,N-di­methyl­anilinium chloride

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    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, inter­molecular O—H⋯Cl, N—H⋯Cl and C—H⋯N inter­actions are observed

    Comparative evaluation of sulphur sources on growth, yield and quality of garlic (Allium sativum L.)

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    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

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    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

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    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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