Godwin Wesley S.,Scott Christian College Autonomous |
Rajan M.P.,Bhabha Atomic Research Center
Journal of Environmental Radioactivity | Year: 2014
The present study focused on the determination of the alpha-emitter, 210Po, in two species of marine mussels (bivalve molluscs) commonly available in the southern coastal region of India. The brown mussel, Perna indica was collected from the west coast and the green mussel, Perna viridis from the east coast. The concentration of 210Po was related to the allometry (length of shell, wet/dry weight of shell/soft tissue) of the mussels and significant results were found. The study period focused on three seasons namely, pre-monsoon, monsoon and post-monsoon for a 1-year period (2010-2011). The results revealed higher activity levels in smaller-sized mussels compared to larger ones. Marked variation in 210Po activity concentration was noted in the whole-body soft tissues between seasons and sampling site (p<0.05). The dose rate assessment for mussels was performed using the ERICA Assessment tool. The chronic exposure to mussels due to 210Po was found to be lesser than the global benchmark dose rate of 10μGyh-1. The effective ingestion dose to adults who intake mussels was estimated to be in the range 5.1-34.9μSvy-1. The measurement contributes to the furthering of knowledge of 210Po, since no data exist in this region. © 2014 Elsevier Ltd.
Raj A.M.E.,Scott Christian College Autonomous |
Jayachandran M.,CSIR - Central Electrochemical Research Institute |
Sanjeeviraja C.,Alagappa University
CIRP Journal of Manufacturing Science and Technology | Year: 2010
During the past few decades, considerable research effort has been directed towards the development of fundamental peculiarities of wide-gap (E g > 5 eV) inorganic dielectric thin films. Wide-gap dielectrics are used for various technical and technological applications as laser materials, electronic components, radiation resistant materials, spectral transformers for luminescent lamps, detectors and dosimeters of several kind of radiations, various sensors and catalytic agents. The optical characteristics of intrinsic electronic excitations in inorganic wide-gap dielectric are shifted towards the vacuum ultra-violet spectral region and therefore being studied insufficiently that impedes the elaboration of new materials and the modernization of the existing ones based on wide-gap dielectrics. Besides, alkali halides, the value of energy band gap E g >6 eV is typical of numerous wide-gap oxides: MgO, CaO, Al 2O 3, SiO 2, Y 2O 3, etc. Among this, magnesia (MgO) is a well-known refractory oxide, has the potential advantages of a wide band gap (E g ∼ 7.8 eV) and is predominantly preferred to be used as lattice templates for growing oriented ferroelectric and superconducting over layers because of its higher Poisson's ratio and lower Gibb's free energy. Well-defined procedures to prepare MgO surfaces of very high quality is of importance in a number of areas of surface physics and imperfect due to their preparation kinetics, inclusion of foreign matter and compositional variations. Even though, increasing number of researchers, laboratories have engaged in the fabrication and characterization of MgO because of its excellent scientifically based applications. The scope of this review article is to summarize briefly the important research achievements on higher quality MgO thin films with novel physical properties and systematic interrelationship for fabrication conditions, crystal structure, composition predictions, surface morphology, electrical and optical characterizations. Particular attention is given to the secondary electron emission coefficient of the fabricated film due to their applications in the alternating current plasma display panel as a protecting layer of dielectrics to improve the discharge characteristics and the panel's lifetime. © 2010 CIRP.
Khan M.F.,Sadakathullah Appa College Autonomous |
Godwin Wesley S.,Scott Christian College Autonomous
Marine Pollution Bulletin | Year: 2011
The activities of 210Po and 210Pb were determined in commonly consumed seafoods to evaluate the internal exposure and risk to humans residing Kudankulam coast where a mega nuclear power plant is under construction. The concentration of 210Po in seafoods ranged from 1.2±0.7 to 248±8.1Bqkg-1. Meanwhile, 210Pb ranged between 1.1±0.05 and 14.8±1.6Bqkg-1. The committed effective dose (CED) due to 210Po and 210Pb varied from 11.04 to 515.6 and 3.93 to 23.5μSvyr-1, respectively. The lifetime cancer risk for the public due to 210Po was in the range of 3.47×10-5-1.62×10-3 and it was 4.03×10-5-1.96×10-4 due to 210Pb. The activity intake, effective dose and cancer risk was found lesser than international guidelines and the seafood intake was considered to be safe for human consumption. © 2010 Elsevier Ltd.
Besky Job C.,Scott Christian College Autonomous
International Journal of ChemTech Research | Year: 2015
Sodium Penta Borate Na(H4B5O10) crystal has been grown by slow evaporation technique using deionized water as solvent. The grown crystal was confirmed by powder and single crystal X-ray diffraction studies. FTIR spectrum reveals the presence of functional groups present in the grown crystal. UV-Vis spectral studies performed the cut off wavelength of the grown crystal as 202 nm in the UV region. The thermal properties of the grown crystal were studied by TGA-DTA and the melting point has been found out as 198°C. The dielectric behaviour of the grown crystal has been investigated with different frequencies at different temperatures. © 2015, Sphinx Knowledge House. All rights reserved.
Feroz Khan M.,Sadakathullah Appa College Autonomous |
Godwin Wesley S.,Scott Christian College Autonomous
Marine Pollution Bulletin | Year: 2012
Protection of non-human biota from ionizing contaminants, especially in the vicinity of nuclear installations is a very important aspect for nuclear engineers and ecologists. In this view, a baseline data on the activity concentration of 210Po and 210Pb were quantified in different tissues of molluscs inhabiting the intertidal region along the coast of Kudankulam. The activity concentration was noticed higher in the organs associated with digestion and metabolism. Filter feeding bivalve molluscs registered the maximum activity of 210Po in their whole body compared to grazing gastropods. 210Po: 210Pb ratio was calculated to be greater than unity in most of the analysed tissues. The ecological sensitivity of molluscs to the radiation exposure and the safeness of the environment was analysed by calculating the external and internal dose rate. The hazard quotient for molluscs was lesser than the global bench mark dose rate of 10μGyh -1. © 2011 Elsevier Ltd.
Satheesh S.,Scott Christian College Autonomous |
Wesley S.G.,Scott Christian College Autonomous
Estuarine, Coastal and Shelf Science | Year: 2011
The effect of test panel submersion season on the colonization of biofouling communities in a tropical coast revealed that the effects of panel submersion time should be taken into consideration for modelling fouling community recruitment dynamics in coastal systems or during the field trials of antifouling coatings. Wooden test panels fitted onto a raft were submerged during pre-monsoon, monsoon and post-monsoon seasons for the development of the biofouling community. Results showed considerable variation in the colonization of fouling communities on test panels submerged during different seasons. Barnacles, tubeworms, ascidians and seaweeds were the major fouling communities that colonized the test panels. The total biomass of the fouling communities that settled on the post-monsoon season panels varied from the initial value of 2.72 g dm -2 to a maximum of 44.5 g dm -2. On the panels submerged during monsoon season, the total biomass of fouling communities varied between 0.78 g dm -2 and 69.9 g dm -2. The total fouling biomass on the pre-monsoon season panels varied between 2.95 and 33.5 g dm -2. Barnacles were the initial colonizers on the panels submerged during pre-monsoon and post-monsoon seasons. Soft-bodied organisms such as ascidians dominated the monsoon season-initiated panel series during the initial period. © 2011 Elsevier Ltd.
Pillai C.N.,Scott Christian College Autonomous
Journal of molecular modeling | Year: 2014
Quantum molecular simulations of chemical systems can provide detailed information that is often inaccessible to direct experimental measurement. Pyrimidine is an interesting π-electron heterocyclic aromatic system which acts as the building block of many nucleic acid bases. The hydrogen bonds associated with the 2, 4, and 6-substituted pyrimidine and its hydrogen sulfate anion are considered for this current work. The experimental and computational evidence for the strength of these intra and intermolecular hydrogen are determined using vibrational spectra and quantum chemical calculations. Thus the effect of hydrogen bonding on the title compound is studied using its geometrical parameters, interaction energies, and vibrational spectra. Aromaticity and charge transfer studies have been performed to ascertain the aromatic behavior of the molecule. The PES scan studies have been done by varying the bond length to ascertain the protonation process of the compound. The IR spectral red shift (∼100 cm-1), blue shift (∼97 cm-1) and broadening of the polar stretching peaks shows the inter and intramolecular hydrogen bonding strength. Bond length alternation of proton donors along with the enormous interaction energies (∼0.5-150 kJ mol-1) between the lone pair and proton donors provides clear evidence for this hydrogen bonding. The charge transfer due to the methyl substitutions which enhances the possibility of hydrogen bonding has been discussed. The main scope of this work is to study the protonation and hydrogen bonding associated with charge transfer which has great effect on the 2-amino-4, 6-dimethyl pyrimidinium hydrogen sulfate (ADHS) molecule.
Monicka J.C.,Scott Christian College Autonomous |
James C.,Scott Christian College Autonomous
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2011
The herbicide 2(4-chlorophenoxy)-2-methyl propionic acid (MCPP) has been subjected to NIR FT-Raman and infrared spectral studies. The optimized molecular structure, vibrational wavenumbers, IR intensities and Raman activities have been calculated by using density functional method (B3LYP) with the standard 6-31G(d) basis set. The calculated molecular geometry has been compared with the XRD data. The detailed assignments of the normal modes have been performed based on the potential energy distribution (PED) following the scaled quantum mechanical force field (SQMFF) methodology. The IR and Raman spectra have been plotted for the calculated wavenumbers. The simulated spectra satisfactorily coincide with the experimental spectra. The strong hyperconjugative interaction and charge delocalization that leads to the stability of the molecule have been investigated with the aid of natural bond orbital (NBO) analysis. © 2010 Elsevier B.V. All rights reserved.
Ross E.M.,Scott Christian College Autonomous |
Raj Y.L.,Scott Christian College Autonomous |
Wesley S.G.,Scott Christian College Autonomous |
Rajan M.P.,Environmental Survey Laboratory
Journal of Environmental Radioactivity | Year: 2013
The activity concentrations of certain radionuclides were quantified in some plant foods cultivated around Kudankulam, where a mega-nuclear power plant is being established. The activity concentrations were found more in the 'pulses' group and were the lowest in 'other vegetable' category. The annual effective dose was computed based on the activity concentration of radionuclides and it was found to be higher due to the consumption of cereals and pulses. Other vegetables, cereals, pulses and nuts recorded high transfer factors for the radionuclide 228Ra. Fruits, leafy vegetables, tubers and roots, and palm embryo registered high transfer factors for 226Ra. Group-wise activity concentration, radiation dose to the public and soil-plant-to-transfer factor are discussed in detail. © 2012 Elsevier Ltd.
Khan M.F.,Scott Christian College Autonomous |
Wesley S.G.,Scott Christian College Autonomous
Environmental Monitoring and Assessment | Year: 2011
Activities of 210Po and 210Pb in various tissues of four species of decapod crabs and two species of cephalopod mollusks (cuttlefishes) of Kudankulam coast were studied. A non-uniform distribution of these radionuclides was observed between the organs. Of all the tissues, 210Po and 210Pb were found accumulated more in the hepatopancreas and intestine of crabs and in the digestive gland, shell gland, and intestine of cephalopods. Among crabs, Charybdis lucifera registered a little higher 210Po and 210Pb activities. The cephalopod species Loligo duvauceli displayed higher 210Po and 210Pb in some organs when compared to Sepia pharaonis. The muscle of all the species registered lower activity. In cephalopods, the activity ratio of 210Po/210Pb fell within the range of 1-2 for most of the organs, and in crab tissues, it varied from 1.7 to 31.4. The biological concentration factor for organs of cephalopods ranged from 1.2 ×10 3 to 4.3 ×105 for 210Po and 4.8 ×102 to 8.4 ×104 for 210Pb and for organs of crabs it varied between 2.0 ×104 and 1.9 ×106 for 210Po and 9.2 ×102 and 2.4 ×104 for 210Pb. The study revealed that the organs associated with digestion and metabolism displayed a higher activity concentration than the other tissues. A significant variation in the accumulation of 210Po and 210Pb was noted between species (P<0.05). The activity levels recorded are in agreement with values recorded in related organisms in other parts of the world. The data generated will act as a reference database for these organisms of this coast in which a nuclear power station is under construction. © 2010 Springer Science+Business Media B.V.