Showing papers by "Bharathiar University published in 2009"
27 Oct 2009
TL;DR: In this article, the main aim is to understand the soft computing approach to image segmentation, which is an emerging field that consists of complementary elements of fuzzy logic, neural computing and evolutionary computation.
Abstract: Soft Computing is an emerging field that consists of complementary elements of fuzzy logic, neural computing and evolutionary computation. Soft computing techniques have found wide applications. One of the most important applications is image segmentation. The process of partitioning a digital image into multiple regions or sets of pixels is called image segmentation. Segmentation is an essential step in image processing since it conditions the quality of the resulting interpretation. Lots of approaches have been proposed and a dense literature is available In order to extract as much information as possible from an environment, multicomponent images can be used. In the last decade, multicomponent images segmentation has received a great deal of attention for soft computing applications because it significantly improves the discrimination and the recognition capabilities compared with gray-level image segmentation methods. In this paper, the main aim is to understand the soft computing approach to image segmentation.
371 citations
TL;DR: In this article, the authors focus on characterizing PVA: NH4X (X = Cl, Br, I) proton conducting polymer electrolyte prepared by solution casting technique using XRD, FTIR and ac impedance spectroscopic studies.
Abstract: The present study focuses on characterizing PVA: NH4X (X = Cl, Br, I) proton conducting polymer electrolyte prepared by solution casting technique using XRD, FTIR and ac impedance spectroscopic studies. The XRD patterns of all the prepared polymer electrolytes reveal the amorphous nature of the films. The FTIR spectroscopic study indicates the detailed interaction of PVA with proton. From ac impedance spectroscopic studies, it has been found that PVA doped with NH4I have high ionic conductivity (2.5 × 10−3S cm−1) than PVA doped with NH4Br (5.7 × 10−4S cm−1) and NH4Cl (1.0 × 10−5S cm−1) polymer electrolytes. This is due to the large anionic size and low lattice energy of NH4I (in comparison with NH4Br and NH4Cl).The temperature dependence of ionic conductivity for all the PVA: NH4X (X = Cl, Br, I) polymer films obey Arrhenius equation. Ionic transference number measured has been found to be in the range of 0.93–0.96 for all the polymer electrolytes proving that the total conductivity is mainly due to ions.
164 citations
TL;DR: In this paper, the authors deal with the adsorption potential of thermally activated carbon developed from maize cob for the removal of 2,4-dichlorophenol (2-4-DCP) from aqueous solutions.
135 citations
TL;DR: In this article, a DC glow discharge plasma has been used to improve the surface properties of polypropylene (PP) films and make it useful for technical applications, and the change in hydrophilicity of modified PP film surface was investigated by measuring T-peel and lap shear strength.
131 citations
TL;DR: A photodegradation study on Procion Red MX 5B was carried out, showing that the hexagonal WO3nanowire clusters had the highest photodegrades efficiency.
Abstract: Tungsten trioxide (WO3) nanostructures were synthesized by hydrothermal method using sodium tungstate (Na2WO4·2H2O) alone as starting material, and sodium tungstate in presence of ferrous ammonium sulfate [(NH4)2Fe(SO4)2·6H2O] or cobalt chloride (CoCl2·6H2O) as structure-directing agents. Orthorhombic WO3having a rectangular slab-like morphology was obtained when Na2WO4·2H2O was used alone. When ferrous ammonium sulfate and cobalt chloride were added to sodium tungstate, hexagonal WO3nanowire clusters and hexagonal WO3nanorods were obtained, respectively. The crystal structure and orientation of the synthesized products were studied by X-ray diffraction (XRD), micro-Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM), and their chemical composition was analyzed by X-ray photoelectron spectroscopy (XPS). The optical properties of the synthesized products were verified by UV–Vis and photoluminescence studies. A photodegradation study on Procion Red MX 5B was also carried out, showing that the hexagonal WO3nanowire clusters had the highest photodegradation efficiency.
128 citations
TL;DR: In this paper, the existence of solutions of fractional semilinear evolution equations in Banach spaces is proved by using fractional calculus and fixed point theorems, and a nonlocal Cauchy problem is discussed for the evolution equations.
Abstract: In this paper we prove the existence of solutions of fractional semilinear evolution equations in Banach spaces. Further nonlocal Cauchy problem is discussed for the evolution equations. The results are obtained by using fractional calculus and fixed point theorems.
123 citations
TL;DR: In this article, a solution casting method with different molar ratios of polymer and salt using DMSO as solvent has been used to obtain poly vinyl alcohol (PVA) and ammonium iodide (NH4I) electrolytes.
96 citations
TL;DR: It is proposed that a DNA barcode may be a reliable tool to identify ethnotaxa, a cryptic species of grass not recognized by the SK classification which is very important to both aboriginal cultures with ritualistic and economic utility.
Abstract: Our research brought together traditional aboriginal knowledge (TK) and scientific knowledge (SK) to explore the relationship between scientific and aboriginal systems of botanical classification and the corresponding valorization(s) of biological diversity in the Western Ghats of southern India. We worked with two aboriginal cultures namely ‘Irulas’ and ‘Malasars’ of the Nilgiri Biosphere Reserve with an objective of evaluating the ability of different knowledge systems (SK and TK) to distinguish grass species belonging to the genus Tripogon, and assess the ability of DNA barcoding to discriminate a new cryptic species ‘Tripogon cope’ as deciphered by the hill tribes. We discovered that the aboriginal informants identified a common ethnotaxa ‘Sunai pul’, which is a cryptic species of grass not recognized by the SK classification.'sunai pul’ is very important to both aboriginal cultures with ritualistic and economic utility. Morphometric analysis confirms the cryptic nature of this new species, which was validated using DNA barcoding. DNA barcode regions matK and trnH-psbA showed distinct sequence variations among the closely related ethnotaxa. Given the cryptic nature of ethnotaxa, we propose that a DNA barcode may be a reliable tool to identify ethnotaxa. We have initiated further studies in other cultures to develop theoretically sophisticated insights concerning the encounter between ‘local’ and ‘scientific’ approaches to the use of biodiversity knowledge. Furthermore, the research will add to a unifying global effort to speed up the documentation and understanding of the planet’s natural diversity, while simultaneously respecting the cultural heterogeneity as a vital component of biological diversity.
87 citations
TL;DR: In this paper, the removal of nitrate from aqueous solutions of a synthetic medium and groundwater was examined usingvarious aquatic plants, such as water hyacinth, water lettuce and salvinia.
84 citations
TL;DR: In this article, the controllability of fractional integrodifferential systems in Banach spaces was studied by using fractional calculus, semigroup theory and the fixed point theorem.
82 citations
TL;DR: Antioxidant molecules produced during the fermentation period could be the reason for the efficient hepatoprotective and curative properties of KT against CCI4-induced hepatotoxicity.
Abstract: Kombucha tea (KT) is sugared black tea fermented with a symbiotic culture of acetic acid bacteria and yeasts, which is said to be tea fungus. KT is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature. In the present study, KT along with black tea (BT) and black tea manufactured with tea fungus enzymes (enzyme-processed tea, ET) was evaluated for hepatoprotective and curative properties against CCl4-induced toxicity, using male albino rats as an experimental model by analyzing aspartate transaminase, alanine transaminase, and alkaline phosphatase in plasma and malondialdehyde content in plasma and liver tissues. Histopathological analysis of liver tissue was also included. Results showed that BT, ET, and KT have the potential to revert the CCl4-induced hepatotoxicity. Among the three types of teas tried, KT was found to be more efficient than BT and ET. Antioxidant molecules produced during the fermentation period could be the reason for the efficient hepatoprotective and curative properties of KT against CCI4-induced hepatotoxicity.
TL;DR: The present study confirms the antihyperglycaemic effect of SAD and also demonstrated the consistently strong cytoprotective properties of S AD, which protected STZ-mediated cytotoxicity and nitric oxide production in RINm5F cells.
TL;DR: In this paper, the influence of both viscous and joules dissipation on the problem of magnetohydrodynamic flow past a stretching porous surface embedded in a porous medium is investigated.
Abstract: This paper investigates the influence of both viscous and joules dissipation on the problem of magnetohydrodynamic flow past a stretching porous surface embedded in a porous medium. Analytic solutions of the resulting nonlinear non-homogeneous boundary value problem in the case when the plate stretches with a velocity varying linearly with distance, expressed in terms of confluent hypergeometric functions, are presented for the case of prescribed surface temperature. Numerical calculations have been carried out for various values of suction parameter, magnetic field, Prandtl number, Eckert number and Schmidt number. The results show that increases in magnetic parameter decrease both the dimensionless transverse velocity, longitudinal velocity and also the skin friction coefficient. Also, formation of thin boundary layer is observed for higher value of magnetic parameter.
TL;DR: In this paper, the suitability of ab initio and density functional theory (DFT) methods for an accurate determination of ionization potential and chemical hardness is the subject of systematic analysis for a panel of molecules.
Abstract: The suitability of ab initio and density functional theory (DFT) methods for an accurate determination of ionization potential and chemical hardness is the subject of systematic analysis for a panel of molecules. Comparison of experimental ionization potential values with theoretical results indicates that using orbital energies obtained from the so-called statistical average of orbital potential (SAOP) model exchange correlation potential in Koopman's theorem is an efficient method to evaluate the correct ionization potentials. Experimental ionization potential and electron affinity values have been used to calculate the absolute chemical hardness. Comparative results show that the chemical hardness values calculated by using Hartree-Fock orbital energies in Koopman's theorem are sufficiently good rather than Moller-Plesset second order perturbation method and DFT-generalized gradient approximation (GGA) exchange correlation functional orbital energies. A new method given by Tozer et al. (J Phys Chem A 2005, 109, 8923) to calculate the chemical hardness works well with the orbital energies of DFT-GGA functionals together with the ionization potential values calculated from SAOP orbital energies. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem 109: 764 -771, 2009
TL;DR: The present study results clearly suggest that the catchment area of Serbo Health Center is prone for epidemic malaria and the situation is quite deteriorating.
TL;DR: Investigation on coir-based adsorbent, puresorbe, in the removal of chromium(VI) from the aqueous solutions suggests that chemisorption might be the mode of adsorption.
TL;DR: Assessment of the knowledge and usage custom of traditional insect/mosquito repellent plants among the Oromo ethnic group in Ethiopia found that usage of traditional repellers should be promoted among the local residents in order to reduce vector-borne disease prevalence.
TL;DR: Among the cytokinins tried for multiple shoot induction from the protocorm, 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ) was found to be superior and Indole-3-butyric acid (IBA) was effective for inducing healthy roots.
TL;DR: In this paper, the existence of mild solutions for impulsive neutral functional integrodifferential equations with infinite delay in Banach spaces is studied and the results are obtained by using the Krasnoselski-Schaefer type fixed point theorem.
Abstract: This paper is concerned with the existence of mild solutions for impulsive neutral functional integrodifferential equations with infinite delay in Banach spaces. The results are obtained by using the Krasnoselski–Schaefer type fixed point theorem. An example is provided to illustrate the theory.
TL;DR: In this paper, an attempt has been made to prepare a new proton conducting polymer electrolyte based on polyvinyl alcohol (PVA) doped with NH4NO3 by solution casting technique.
Abstract: An attempt has been made to prepare a new proton conducting polymer electrolyte based on polyvinyl alcohol (PVA) doped with NH4NO3 by solution casting technique. The complex formation between polymer and dissociated salt has been confirmed by X-ray diffraction analysis. The ionic conductivity of the prepared polymer electrolyte has been found by ac impedance spectroscopic analysis. The highest ionic conductivity has been found to be 7.5 × 10−3 Scm−1 at ambient temperature for 20 mol% NH4NO3-doped PVA with low activation energy (~0.19 eV). The temperature-dependent conductivity of the polymer electrolyte follows an Arrhenius relationship, which shows hopping of ions in the polymer matrix.
TL;DR: Results showed that the vinblastine-loaded PGD NPs were superior in properties such as drug encapsulation efficiency, the cellular uptake and the cancer cell mortality.
Abstract: Biodegradable and biocompatible polymers that are engineered to nanostructures play a key role in providing solution for sustained chemotherapy. This study is focused on preparation, drug encapsulation efficiency, in-vitro drug release, in-vitro cellular uptake and cell viability of poly(caprolactone) grafted dextran (PGD) nanoparticles (NPs) formulation containing vinblastine as the anticancer drug. Drug-loaded PGD NPs were prepared by a modified oil/water emulsion method and characterized by laser light scattering, atomic force microscopy (AFM), and zeta potential. The drug encapsulation efficiency was determined spectrophotometrically and in-vitro drug release was estimated using dialysis bag. Breast cancer cell line (MCF-7) was used to image and measure the cellular uptake of fluorescent PGD NPs. Cancer cell viability was assessed by treating MCF-7 cells with vinblastine-loaded PGD NPs by crystal violet staining method. Result showed that the vinblastine-loaded PGD NPs were superior in properties such as drug encapsulation efficiency, the cellular uptake and the cancer cell mortality.
TL;DR: It can be concluded that a mixture of betel leaf, areca nut, and tobacco is unsafe for oral health.
Abstract: Betel quid containing areca nut and chewing tobacco is used in many parts of India. In this study we evaluated the micronuclei (MN) in buccal mucosa of healthy individuals from southern India, who were regularly chewing a mixture of betel leaf, areca nut and tobacco. A total of 44 subjects were examined. The study population included 15 chewers, 14 chewers with smoking habit and 15 controls with the mean age of 38.57 +/- 0.54, 34.50 +/- 0.95, and 33.28 +/- 0.89 years, respectively. The mean percentage of MN was 1.90 +/- 1.03 in chewers, 2.00 +/-1.12 in chewers with smoking habits and 0.81 +/- 0.66 in controls. There was no significant difference between the mean percentages of the two experimental groups. It can be concluded that a mixture of betel leaf, areca nut, and tobacco is unsafe for oral health.
TL;DR: In this article, the authors investigated the magnetoconvection of an electrically conducting fluid in a square cavity with partially thermally active sidewalls and found that the flow and the heat transfer rate in the cavity are affected by the sinusoidal temperature profile and by the magnetic field at lower values of Grashof number.
TL;DR: In this article, the authors evaluated 20 agro-industrial residues to check the possibility of potential utilization of substrates in SSF for milk clotting enzyme protease production by Mucor circinelloides.
Abstract: Agro-industrial residues, a cheap source of energy have high potential in the area of fermentation for the production of enzymes. Twenty agro-industrial residues were evaluated to check the possibility of potential utilization of substrates in SSF for milk clotting enzyme protease production by Mucor circinelloides. In this study, dhal husk holds the greatest promise for cost effective production of the milk clotting enzyme. The dhal husk supported maximum milk clotting protease production, and yield was improved with the supplementation of sucrose and yeast extract as carbon and nitrogen source, respectively. Among all the physico-chemical parameters tested, the best results were obtained in a medium having moisture content of 20% at pH 7.0, when inoculated with 30% of spore suspension and incubated at 30°C for 5 days. The activity was increased further on addition of Ca2+, Cu2+, and Mg2+ ions. The purified milk-clotting protease obtained from M. circinelloides was successfully applied and compared with commercial rennet in the manufacture of a cheddar cheese.
TL;DR: The surface energies of the modified PET films were estimated using contact angle measurements, and the changes in crystallinity of the plasma-modified PET film surfaces were investigated by X-ray diffraction (XRD) analysis.
TL;DR: It is confirmed that A. macrophthalmus that was reared on L. leucocephala was able to utilize aphagously postharvest mature seeds for oviposition and larval development, which is a trait of post‐dispersal seed predators.
Abstract: An endophagous seed predator, Acanthoscelides macrophthalmus (Coleoptera: Chrysomelidae: Bruchinae), utilizes Neotropical Leucaena (Fabaceae: Mimosoideae). One of its hosts, Leucaena leucocephala, is a fast-growing nitrogen-fixing tree that serves as a multipurpose beneficial plant but eventually becomes an aggressive invader where it was introduced. Herein, we report A. macrophthalmus invasion of the Far East, South Asian tropics and subtropics (Japanese Pacific Islands, Taiwan, Southern China, Northern Thailand and Southern India). Of other field-collected mimosoid legumes, an introduced tree, Falcataria moluccana, in Taiwan was found to be used by the seed predator. Conversely, our published work review revealed that the seed predator had retained high host specificity to Leucaena species in its native and introduced regions. Acanthoscelides macrophthalmus was able to utilize aphagously postharvest mature seeds for oviposition and larval development, which is a trait of post-dispersal seed predators. We confirmed that A. macrophthalmus that was reared on L. leucocephala was able to utilize F. moluccana as well. Although the relatively high host specificity of the oligophagous beetle is suitable for controlling the weedy L. leucocephala, the potential host range expansion confirmed by this study must be cautioned.
TL;DR: In this paper, the performance of Trichoderma harzianum WL1 laccase with the commonly employed redox mediator 1-hydroxybenzotriazole (HBT) was evaluated.
Abstract: The efficiency of crude and partially purified Trichoderma harzianum WL1 laccase for the decolorization of synthetic dyes (Rhodamine 6G, Erioglaucine and Trypan blue) with complex aromatic structures were evaluated. Selection of dyes was based on their extensive usage in local dyeing and textile industries around the study area. Studies on the role of redox potential of laccases on dye decolorization are rarely discussed and hence, for the first time we have shown the redox mediated dye decolorizing efficiency of T. harzianum WL1 laccase with the commonly employed redox mediator 1-hydroxybenzotriazole (HBT). The process parameters such as initial dye concentration, enzyme load and HBT concentration were studied and found that they had a great influence on dye removal process. When the dyes were treated with increased concentration of enzyme, it showed a greater percentage of decolorization. Compared to the crude laccase, partially purified laccase accounts for maximum decolorization of all the dyes studied. In addition, the rate of dye decolorization was considerably enhanced in presence of 4 mM HBT. Maximum and minimum decolorization were recorded for Rhodamine 6G and Trypan blue, respectively. The results of this study further confirmed that, T. harzianum laccase was found to be suitable with HBT and this laccase-mediator system (LMS) could be applied for the decolorization of various classes of dyes.
TL;DR: The details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human α7nAChR are provided and thereby point to the design of novel lead compounds.
Abstract: The nicotinic Acetylcholine Receptor (nAChR) is the major class of neurotransmitter receptors that is involved in many neurodegenerative conditions such as schizophrenia, Alzheimer's and Parkinson's diseases. The N-terminal region or Ligand Binding Domain (LBD) of nAChR is located at pre- and post-synaptic nervous system, which mediates synaptic transmission. nAChR acts as the drug target for agonist and competitive antagonist molecules that modulate signal transmission at the nerve terminals. Based on Acetylcholine Binding Protein (AChBP) from Lymnea stagnalis as the structural template, the homology modeling approach was carried out to build three dimensional model of the N-terminal region of human alpha(7)nAChR. This theoretical model is an assembly of five alpha(7) subunits with 5 fold axis symmetry, constituting a channel, with the binding pocket present at the interface region of the subunits. alpha-neurotoxin is a potent nAChR competitive antagonist that readily blocks the channel resulting in paralysis. The molecular interaction of alpha-Bungarotoxin, a long chain alpha-neurotoxin from (Bungarus multicinctus) and human alpha(7)nAChR was studied. Agonists such as acetylcholine, nicotine, which are used in a diverse array of biological activities, such as enhancements of cognitive performances, were also docked with the theoretical model of human alpha(7)nAChR. These docked complexes were analyzed further for identifying the crucial residues involved in interaction. These results provide the details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human alpha(7)nAChR and thereby point to the design of novel lead compounds.
TL;DR: In this article, a three-cluster model is proposed to explain the particle-accompanied binary fission of radioactive nuclei, and the model is developed as an extension of the preformed cluster model of Gupta and collaborators.
Abstract: A three-cluster model is proposed to explain the particle-accompanied binary fission of radioactive nuclei. The model is developed as an extension of the preformed cluster model of Gupta and collaborators. The advantage of this model is that, for a fixed third fragment, we can calculate the fragmentation potential minimized in charge coordinate. For our study we chose the various neutron-deficient to neutron-rich californium nuclei, whose analysis reveals that the closed-shell effect of any one of the fragments in ternary fragmentation presents itself as the most favorable configuration to be observed. As one goes from a neutron-deficient to a neutron-rich californium isotope, the role of the neutron closed shell associated with any one of the preferred fragments changes to that of the proton closed shell, and for very neutron rich isotopes of californium the presence of a double closed shell nucleus enhances the decay probability. The quadrupole deformation of the light fragment $({A}_{2})$ associated with the preferred configuration in the symmetric mass region also has a transition from positive to negative deformation as one goes from neutron-deficient to neutron-rich californium isotopes. The calculated relative yields of different fragmentation channels are compared with the available experimental yields for $^{252}\mathrm{Cf}$.
TL;DR: A two-photon fluorescent probe (ACaL) is reported that can be excited by 780 nm fs pulses, shows high photostability and negligible toxicity, and can visualize near-membrane Ca2+ in live cells and deep inside live tissues by two-Photon microscopy.