Mayiladuthurai, India
Mayiladuthurai, India

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Asian wetlands are pivotal habitats for numerous globally declining migratory and resident waterbird species. Ironically 80% of the wetlands in East and South East Asia are classified as threatened, with 50% under grave threat. In particular the mangrove wetlands are under serious threat due to large scale conversion for commercial shrimp ponds and sea level rise. So, the impoverishment of natural wetlands has forced waterbirds to find alternative habitats. On the other hand, some recent studies have highlighted the potential role of anthropogenic, artificial and restored habitats such as coastal grazing marshes, salinas and rice fields to be good habitats for waterbirds. The present study was mainly designed to investigate the role of abandoned shrimp ponds near the mangroves supporting the migratory and resident waterbirds in the Kodiyampalayam area of Pichavaram mangroves. The results show that the abandoned aqua ponds support 26 species of waterbirds. Among them, 16 were migrant and three were in the near threatened (NT) category of IUCN. Suggestions were made in order to improve the habitat to attract more number of waterbird species in the near future. © 2017 Springer Science+Business Media Dordrecht


Rajkumar S.,Avc College | Jebanesan A.,Annamalai University
European Review for Medical and Pharmacological Sciences | Year: 2010

Background: Plant based repellent against mosquito borne diseases are used recently because synthetic repellents cause side effects like breathing problem, eye irritation, head ache, cough, etc. The use of natural products for dengue control would protect the environment, reduce dependence on expensive synthetic repellents and also generate local employment. Material and Methods: Essential oil was isolated by steam distillation which was used against the bites of Aedes aegypti and duration of protection period was assessed. Skin-irritant potential test was also conducted on 25 healthy volunteers by using four-point scale. Results: The increase in the concentrations of essential oil increased the mean protection time against the bites of Aedes aegypti. The lowest mean protection time was 180.0 min for 2.5% and highest time of 255.0 min for 10%. The mean score of zero for skin-irritant potential test for all the concentrations indicated that the essential oil did not cause irritation to human skin. Conclusions: Results indicated that the use of plant based repellent for the control of dengue fever would replace the currently used synthetic repellents which causes many side effects.


Karthikeyan N.,Parisutham Institute of Technology and Science | Joseph Prince J.,Anna University | Ramalingam S.,Avc College | Periandy S.,Tagore Arts College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

In the present methodical study, FT-IR, FT-Raman and NMR spectra of the (2,4,5-Trichlorophenoxy) Acetic acid are recorded. The observed fundamental frequencies (IR and Raman) are assigned according to their distinctiveness region. The hybrid computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are tabulated. The impact of the presence of tri-chlorine atoms in phenyl structure of the compound is investigated. The vibrational sequence pattern of the molecule related to CH2COOH is analyzed. Moreover, 13C NMR and 1H NMR are calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra are simulated and the chemical shifts related to TMS are compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, are performed by HF and DFT methods. The Kubo gap of the present compound is calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand group. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. NLO properties related to Polarizability and hyperpolarizability are also discussed. © 2014 Published by Elsevier B.V. All rights reserved.


Krishna K.S.,Jawaharlal Nehru Centre for Advanced Scientific Research | Vivekanandan G.,AVC College | Ravinder D.,Jawaharlal Nehru Centre for Advanced Scientific Research | Eswaramoorthy M.,Jawaharlal Nehru Centre for Advanced Scientific Research
Chemical Communications | Year: 2010

Unusual morphologies of silica, gold and carbon were obtained by using ZnO nanostructures as templates. Microdrums and pencil-shaped ZnO nanostructures are successfully replicated into silica, gold and carbon analogues which are otherwise difficult to make. © The Royal Society of Chemistry 2010.


Shakila G.,Government of Puducherry | Periandy S.,Tagore Arts College | Ramalingam S.,Avc College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

The FT-IR and FT-Raman spectra of the compound 1,2-dibromobenzene have been recorded in the region 4000-100 cm -1. The vibrational analysis has been made using HF and DFT (B3LYP and LSDA) level of theory by employing 6-31 +G (d, p) and 6-311 ++G (d, p) basis sets. Optimized geometrical parameters have been calculated, interpreted and compared with the reported experimental values of some halogen-substituted benzene. The experimental geometrical parameters show satisfactory agreement with the theoretical prediction of HF and DFT. The geometrical structure of the compound is fractured by the substitutions of couple of Br in the ring. From the vibrational assignments it is observed that, the vibrational pattern of the fundamental modes is realigned slightly with respect to the substitutions. The simulated FT-IR and FT-Raman spectra of the compound for different methods are compared with the experimental spectra. The impact of Br in the vibrational assignments of the molecule is also investigated. © 2011 Elsevier B.V. All rights reserved.


Mahadevan D.,Government of Tamilnadu | Periandy S.,Tagore Arts College | Ramalingam S.,Avc College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2011

The FT-IR and FT-Raman vibrational spectra of 1,3-dichlorobenzene (1,3-DCB) have been recorded using Bruker IFS 66 V Spectrometer in the range 4000-100 cm -1. A detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The optimized molecular geometry, vibrational frequencies, atomic charges, dipole moment, rotational constants and several thermodynamic parameters in the ground state were calculated using ab initio Hartree-Fock (HF) and DFT (B3LYP) methods with 6-31++G (d, p) and 6-311++G (d, p) basis sets. With the help of different scaling factors, the observed vibrational wave numbers in FT-IR and FT-Raman spectra were analyzed and assigned to different normal modes of the molecule. Most of the modes have wave numbers in the expected range. The inductive effect of Chlorine atoms in the benzene molecule has also been investigated. © 2011 Elsevier B.V. All rights reserved.


Ramalingam S.,Avc College | Anbusrinivasan P.,Avc College | Periandy S.,Tagore Arts College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2011

In this work, the experimental and theoretical spectra of 4-chloro-2-bromoacetophenone (4C2BAP) are studied. FT-IR and FT-Raman spectra of title molecule have been recorded in the region 4000-100 cm-1. The structural and spectroscopic data of the molecule in the ground state have been calculated by using Hartree-Fock and density functional method (B3LYP) with the 6-31G (d, p) and 6-311G (d, p) basis sets. The vibrational frequencies are calculated and scaled values are compared with the experimental FT-IR and FT-Raman spectra. The DFT (B3LYP/6-311G (d, p)) calculations are more reliable than the ab initio HF/6-311G (d, p) calculations for the vibrational study of 4C2BAP. The optimized geometric parameters (bond lengths and bond angles) are compared with experimental values of the molecule. The alteration of vibrational bands of the carbonyl and acetyl groups due to the presence of halogens (Cl and Br) in the base molecule is also investigated from their characteristic region of linked spectrum. © 2010 Elsevier B.V. All rights reserved.


Prabhu T.,Avc College | Periandy S.,Tagor Arts College | Mohan S.,Hawassa University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2011

A combined experimental and theoretical study on molecular and vibrational structure of 2,3-dimethyl naphthalene (2,3-DMN) has been undertaken in the present work. The FTIR and FT Raman spectra of 2,3-DMN were recorded in the region 4000-100 cm-1. The optimized geometries were calculated by HF and DFT (B3LYP) methods with 6-31++G (d, p), 6-311G (d, p) and 6-311++G (d, p) basis sets. The harmonic vibrational frequencies, infrared intensities and Raman activities of the 2,3-DMN were evaluated with these methods. After scaling the computational wave numbers are in very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of 2,3-DMN is presented. The effects of substitution of methyl group on the molecule have also been discussed. © 2010 Elsevier B.V. All rights reserved.


Anbusrinivasan P.,AVC College | Madhurambal G.,ADM College | Mojumdar S.C.,University of Guelph | Mojumdar S.C.,Trencin University Of bcek
Journal of Thermal Analysis and Calorimetry | Year: 2012

Anthracene crystals were grown by solution growth technique by adopting slow evaporation method from the solvents CS2, CCl4 and CHCl3. The induction period was measured at various super saturations, and hence the interfacial energies were evaluated. Using the interfacial tension value, the nucleation parameters such as radius of the critical nuclei (r*), the Gibbs free energy change for the formation of a critical nucleus (ΔG*) and the number of molecules in the critical nucleus (i*) were also calculated for all these solvents at two different temperatures. The effect of surface tension, viscosity and density of these solvents are correlated with interfacial tension. The solution grown crystals were subjected to UV, FTIR, NMR and X-ray diffraction studies. The purity and high-thermal stability of the grown crystals were determined using thermal analysis. © 2012 Akadémiai Kiadó, Budapest, Hungary.


Larvicidal activity of essential oil and isolated compounds from Clausena dentata leaves were tested against early fourth instar Aedes aegypti larvae. GC-MS analysis of essential oil revealed the presence of fourteen compounds of which the major compounds were sabinene (21.27%), biofloratriene (19.61%), borneol (18.34%) and β-bisabolol (17.68%). The essential oil of C. dentata exhibited significant larvicidal activity, with 24 h LC50 and LC90 values of 140.2 and 341.6 mg/l, respectively. Larvicidal activities of the four major compounds of essential oil were also tested. The LC50 values of sabinene, biofloratriene, borneol and β-bisabolol were 27.3, 47.4, 43.5 and 33.2 mg/l, respectively. Results of this study show that the leaf essential oil of C. dentata and its four major compounds may be a potent source of natural larvicides. © 2010 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.

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