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Allahābād, India

Mishra S.K.,Ewing Christian College | Srivastava G.K.,Allahabad University
Phytomorphology: An International Journal of Plant Morphology | Year: 2015

The pollen grains of the genera Cassia L. and Senna Mill, belonging to stenopalynous subtribe Cassiinae are generally radially symmetrical, isopolar, trizonocolporate or trizonocolpate. The shape varies from oblate-spheroidal to prolate. The sporoderm patterns may range from reticulate, foveolate, perforate, rugulate to verrucate and tuberculate in different species. The palynological data particularly the shape and sporoderm stratification provide crucial taxonomic information for delimiting the closely related Senna obtusifolia and Senna tora. In the former the large anther having bottleneck-like apex has pollen grains with psilate exine pattern while in the latter, subprolate pollen grains with warty and verrucate exine patterns are produced in the large anthers with rounded apex. Palynological data also provide valuable information in establishing the taxonomic relationship between some other closely related red Cassia and Senna species of the Indian Cassiinae. Despite their role in resolving the taxonomic riddles, the utility of pollen morphology in taxonomy of sub-tribe Cassiinae appears to be very limited.

Kripal R.,Allahabad University | Shukla A.K.,Ewing Christian College
Chinese Physics Letters | Year: 2011

An electron paramagnetic resonance study of vanadyl ions doped in ammonium selenate single crystals is carried out at room temperature. It is found that the VO2+ ion takes up an interstitial site. The spin Hamiltonian parameters obtained from the crystal rotations are g∥=1.9576 ± 0.0002, g⊥=1.9889 ± 0.0002, A ∥=203 ± 2 G, A⊥=78 ± 2 G. An optical absorption study is also carried out to evaluate various bonding parameters. On the basis of these parameters the nature of bonding in the complex is discussed. © 2011 Chinese Physical Society and IOP Publishing Ltd.

Kripal R.,Allahabad University | Shukla A.K.,Ewing Christian College
Spectroscopy Letters | Year: 2010

Electron paramagnetic resonance (EPR) studies of VO2+ impurity ion in single crystals of diammonium hexaaqua magnesium(II) sulfate are carried out at 9.5 GHz (X-band) at room temperature. Different spin-Hamiltonian parameters are determined. VO2+ is expected to enter the lattice substitutionally. Superhyperfine splitting is also observed. An EPR study of a powder sample is done that supports the data obtained from single crystal studies. Optical absorption studies are also performed at room temperature. The crystal field parameter (DVOq), tetragonal parameters (Ds and Dt), and various bonding parameters are evaluated to estimate the covalency and nature of bonding of VO2+ with its different ligands. © Taylor & Francis Group, LLC.

Nathan R.J.,Lok Nayak Jayaprakash Narayan National Institute of Criminology and Forensic Science | Sharma P.,Lok Nayak Jayaprakash Narayan National Institute of Criminology and Forensic Science | Nathan L.S.,Ewing Christian College
Medico-Legal Update | Year: 2014

Metal toxicity in humans is a result of long term or high level exposure to toxic metals which enter the body through common media as air, water, and food. More recently, with the increase in regular use of numerous cosmetic products, which have been reported to contain heavy metals as contaminants, human bodies are being exposed to them on a daily basis. A number of dermal absorption studies have been conducted which satisfy the assumption that harmful chemicals get absorbed into the blood stream through skin. Hair-dye powders are one of the most commonly used cosmetic products by all- young and old these days and are applied on a regular basis. If contaminated, direct application on hair and scalp can increase chances of absorption of toxic metals as lead and copper and can potentially add up to significant exposure levels as these have cumulative effect. This has drawn our attention to assess the levels of these metals in nine samples of common hair-dye powders available in markets of Delhi. The levels of these metals were determined by Flame Atomic Absorption Spectrophotometer after a wet digestion method for sample preparation. Lead and Copper were detected in different concentrations in all the studied samples, the highest being 1.42 ± 0.0814 ppm and 0.75 ± 0.0693 ppm for lead and copper respectively.

Maurya G.S.,Allahabad University | Jyotsana A.,Allahabad University | Pathak A.K.,Ewing Christian College | Kumar A.,Indian Institute for Plasma Research | Rai A.K.,Allahabad University
Optics and Lasers in Engineering | Year: 2014

Laser induced breakdown spectroscopy (LIBS) spectra of optical window and flange of Aditya tokamak have been recorded in the spectral range of 200-500 nm in open atmosphere. For qualitative analysis of these samples, the intensity variation of elemental impurities (Fe, Cr, Ni, Mn, Mo, Cu and C) on the surface of optical window and flange with radial distance has been studied. Depending on thickness of thin films of impurity, four different concentric color rings are observed on the surface of the flange. On moving from reddish brown to indigo color ring, the trends in spectral intensity of these impurities are found in decreasing order. Comparative spectral intensity variation of impurities in both the samples reveals that the impurity deposition on the flange surface is more in comparison to the optical window. Our study demonstrates the capability of LIBS to analyze the spatial distribution of deposited impurities on window and flange samples. © 2013 Elsevier Ltd.

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