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Virudhunagar, India

Shanmugapriya G.,Vvv College For Women | Shanmugapriya G.,Bharathiar University | Rajamanickam N.,Physics Research Center | Bagare S.P.,Indian Institute of Astrophysics
Solar Physics

It is essential to know the composition of atoms or molecules present in the astrophysical objects concerned to determine the physical and chemical nature of a solar or stellar region. With the aim to identify them clearly, we therefore analyzed the rotational lines of eleven bands of the A1Σ–X1Σ+ system and three bands of the A′1Π–X1Σ+ system of the barium oxide (BaO) molecule in high-resolution sunspot umbra spectra provided by the National Solar Observatory, Kitt Peak, in the visible and infrared wavenumber range 13 600 – 25 000 cm−1. We confirm rotational lines in several bands of the BaO molecule by following the line identification technique, in which the positive result of chance coincidences is observed. We additionally confirmed the BaO molecule in sunspots by evaluating the rotational temperature. The equivalent widths for the well-resolved lines have been observed in the spectra, and accordingly, the rotational temperature of the band systems were determined by plotting the graph between J(J+1) and log(W/J). The estimated effective rotational temperature values for the bands of A–X and A′–X vary from 1000 to 3500 K, which agrees well with the reported temperatures obtained by identifying other diatomic molecules in sunspot umbrae. The present work therefore provides clear evidence of the existence of the BaO molecule in sunspot umbral regions. © 2015, Springer Science+Business Media Dordrecht. Source

Sakthikumar L.,Saiva Bhanu Kshatriya College | Kavitha J.,Vvv College For Women | Mahalakshmi R.,Thiagarajar College of Engineering
Der Pharma Chemica

Nitromethane (1) upon treatment with Carbon disulfide (2) under ice cold condition in presence of dry methanol / Potassium hydroxide gave dipotassium salt of nitroketene dithioacetal (3). Further treatment of dipotassium salt (3) with alkyl and substituted chloro benzyl bromide furnished bis S,S-alkyl and Substituted chlorobenzyl derivatives (4-10). The structure of the synthesised compounds was characterised using UV, IR, 1H and 13C NMR spectral evidences. The antibacterial activities of products (3-10) were evaluated using Disc-Diffusion method. Source

Abiramipriya P.,Vvv College For Women | Pooja N.,Vvv College For Women | Jeyakumari J.J.L.,Vvv College For Women | Nair M.R.G.,Mahatma Gandhi University | Anbarasan R.,National Taiwan University
Journal of Non-Crystalline Solids

Magnesium oxide (MgO) nano particle was synthesized by ultrasound assisted one pot method and thus synthesized nano MgO was mixed with poly(vinyl alcohol) (PVA) to prepare the polymer nano composite. The influence of the nano sized MgO on the structural modification of PVA was evaluated. The particle size and morphology of MgO was confirmed by High Resolution Transmission Electron Microscopy (HRTEM). The properties of PVA/MgO nano composite materials were characterized by Fourier Transform Infrared analysis (FTIR), Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) like analytical tools. © 2010 Elsevier B.V. All rights reserved. Source

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