scispace - formally typeset
Search or ask a question

Showing papers by "Bharathiar University published in 2007"


Journal ArticleDOI
TL;DR: Kinetic study showed that the adsorption of dye on coir pith carbon was a gradual process and pH effect and desorption studies suggest that chemisorption might be the major mode of the Adsorption process.

868 citations


Journal ArticleDOI
TL;DR: In this article, changes in content of organic acid and tea polyphenols in kombucha tea prepared from green tea (GTK), black tea (BTK) and tea manufacture waste (TWK) during fermentation were investigated.

312 citations


Journal ArticleDOI
TL;DR: In this article, the total phenolics and the antioxidative properties of two varieties of horse gram ( Macrotyloma uniflorum ) were studied, and the raw and dry-heated seed samples were extracted successively with methanol and 70% acetone separately.

236 citations


Journal ArticleDOI
TL;DR: The data obtained from this study suggested the possibility of the isolation of a high content of RA from in vitro callus cultures rather than field-grown plant organs of holy basil.
Abstract: In this study, the chemical constituents and antioxidant property of holy basil (Ocimum sanctum Linn.) field-grown plant parts (leaves, stems, and inflorescence) were compared with those of respective callus cultures induced from each explant in in vitro. The callus cultures were successfully initiated on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) (1 mg/L) combined with different concentrations (0.1-0.5 mg/L) of kinetin as plant growth regulators. The distribution of phenolic compounds in these extracts was analyzed using reverse phase high-performance liquid chromatography with reference standards. Interestingly, rosmarinic acid (RA) was found to be the predominant phenolic acid in all callus extracts in comparison with field-grown plant parts. In this study, the antioxidant activity of the extracts was evaluated with six different in vitro antioxidant-testing systems. Their activities of scavenging superoxide anion radicals, 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), hydroxyl radicals, hydrogen peroxide, chelating ferrous iron, and ferric ion reducing potential were assessed. The antioxidant activity was increased in all testing systems with increasing amounts of extract. However, at the same concentration, the callus extracts exhibited higher antioxidant activity in all of the testing systems than the extract obtained from field-grown plant parts. The data obtained from this study suggested the possibility of the isolation of a high content of RA from in vitro callus cultures rather than field-grown plant organs of holy basil.

155 citations


Journal ArticleDOI
TL;DR: In this paper, the results were discussed with respect to N2 concentration and thickness of the films at low and high N2 concentrations, respectively, and the results showed that the properties of the TiN films increased with increase in the film thickness and the presence of nitride, oxynitride and oxide phases associated with TiNx phases.
Abstract: Titanium nitride (TiN) thin films of different thickness were deposited by direct current (dc) magnetron sputtering under conditions of various N2 concentrations (05–34%) The electrical, optical, structural, compositional and morphological properties of the films were studied and the results were discussed with respect to N2 concentration and thickness of the films At low N2 concentration of 05% (of the total sputtering pressure 11 Pa), golden coloured stoichiometric TiN films were obtained and with increase in the N2 concentration non-stoichiometric TiNx phases resulted However, irrespective of the N2 concentration, the TiN stoichiometry in the films increased with increase in the film thickness In the surface of the films the presence of nitride (TiN), oxynitride (TiOxNy) and oxide (TiO2) phases were observed and the quantity of these phases varied with the N2 concentration and thickness The films of lower thickness were found to be amorphous and the crystallinity was observed in the films with increase in the thickness The crystalline films showed reflections corresponding to the (1 1 1), (2 0 0) and (2 2 0) orientation of the cubic TiN and also features associated with TiNx phases The transmission spectra of the films revealed the typical characteristics of the TiN films ie a narrow transmission band, however, the width varied with thickness, in the wavelength range of 300–600 nm and exhibited low transmission in the infrared region The TiN films deposited at low N2 concentration of 05% showed smooth and uniform morphology with densely packed crystallites With increase in N2 concentration various characteristics such as needle type crystallization, bubble precipitates and after bubble burst morphologies were observed in the films However, at higher N2 concentration conditions, uniformity developed in the films with increase in thickness

145 citations


Journal ArticleDOI
TL;DR: In this article, the removal of Congo Red was carried out using biogas waste slurry as an adsorbent at different concentrations of dye and dosage, agitation time and pH.
Abstract: Removal of Congo Red was carried out using biogas waste slurry as adsorbent at different concentrations of dye, adsorbent dosage, agitation time and pH. The process follows the first-order rate expression. The equilibrium data fit well in the Freundlich model of adsorption. Maximum removal of dye, 95%, was observed in the pH range 2.3–9.4. Desorption of Congo Red showed that it is solubilised in 50% acetic acid to the extent of 6% and the remainder appears to be chemically complexed irreversibly to the adsorbent. Low desorption of dye from the adsorbent surface in water indicates that the process may not be, essentially, a reversible one.

137 citations


Journal ArticleDOI
TL;DR: Investigations were made to test the larval toxicity and smoke repellent potential of Albizzia amara and Ocimum basilicum against the different instar larvae and pupae of Aedes aegypti and the smoke toxicity of A. aeEgypti was more effective than the O. basilicum.

124 citations


Journal ArticleDOI
TL;DR: In this article, the feasibility of removing toxic anions, dyes, heavy metals and organic compounds from water was investigated using jatropha husk activated carbon (JHC), which was used as a starting material to produce activated carbon.

119 citations


Journal ArticleDOI
TL;DR: In this paper, the ionic coordination in polymeric electrolytes, as determined by Raman spectroscopy, has been discussed in relation to the conductance behavior of polyvinyl pyrrolidone and ammonium thiocyanate.
Abstract: Polymer electrolytes based on poly ( N -vinyl pyrrolidone) (PVP) and ammonium thiocyanate (NH 4 SCN) prepared by solution cast technique have been studied using X-ray diffraction (XRD), Raman and impedance spectroscopic techniques. The XRD and Raman spectra for the electrolytes indicate that the amorphous nature of PVP increases with the increase of the concentration of ammonium thiocyanate. The spectral changes in the Raman bands of the C O and the C N stretching indicate the interaction between the salt and the polymer. The conductivity analysis shows that the 20 mol% ammonium thiocyanate doped polymer electrolyte exhibits high ionic conductivity and it has been found to be 1.7×10 −4 S cm −1 , at room temperature. The ionic coordination in the polymeric electrolytes, as determined by Raman spectroscopy, has been discussed in relation to the conductance behavior.

118 citations


Journal ArticleDOI
TL;DR: In this paper, the removal of CI acid orange 10 from aqueous solutions was studied by electrocoagulation and electrooxidation techniques for electro-oxidation, metallic iron was used as electrodes whereas graphite and IrO 2 /TaO 2/RuO 2 coated titanium were used in the case of electrooxification.

109 citations


Journal ArticleDOI
TL;DR: Individual completely deficient in BChE have only minor abnormalities in clinical test results, however, they respond abnormally to standard doses of succinylcholine and mivacurium, which indicates they are unusually susceptible to the toxicity of cocaine and organophosphorus pesticides, and resistant to bambuterol and irinotecan.

Journal ArticleDOI
TL;DR: A qualitative study on adhesion of the oral bacteria Porphyromonas gingivalis on titanium (Ti), titanium nitride (TiN), fluorine modified hydroxyapatite (FHA), and zinc modified FHA (Zn-FHA) thin films is investigated in this paper.

Journal ArticleDOI
TL;DR: In this article, the effect of aspect ratio on the natural convection of a fluid contained in a rectangular cavity with partially thermally active side walls is investigated and the results are obtained for Grashof numbers between 103 and 105 and the effects of the aspect ratios on the flow and temperature fields and the rate of heat transfer from the walls of the enclosure are presented.

Journal ArticleDOI
TL;DR: In this article, the effect of process parameters like contact time, concentration of dye, temperature and pH on the extent of procion orange adsorption from solution has been investigated.

Journal ArticleDOI
TL;DR: A combined system of biological and chemical treatments was found to be more effective for the complete removal of nitrate from groundwater.

Journal ArticleDOI
TL;DR: In this article, LiClO4-PVAc-LiO4 polymer electrolytes were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively.

Journal ArticleDOI
TL;DR: In this article, the composition, structure, optical and electrical properties of the deposited ZnSe thin films were studied using the energy dispersive X-ray analysis (EDAX), Xray diffraction (XRD), optical transmittance and current voltage measurements.

Journal ArticleDOI
TL;DR: All the complexes exhibited catalytic activity for the oxidation of benzyl alcohol and cyclohexanol in presence of N-methylmorpholine-N-oxide as co-oxidant and exhibited antibacterial activity against E. coli, Aeromonas hydrophilla and Salmonella typhi.

Journal ArticleDOI
TL;DR: In this article, ZnSe thin films were deposited onto glass substrates under a vacuum of 3×10 −5 ǫ Torr by using vacuum evaporation technique.
Abstract: ZnSe thin films were deposited onto glass substrates under a vacuum of 3×10 −5 Torr by using vacuum evaporation technique. Rutherford backscattering spectrometry technique is used to measure the composition and thickness of the deposited films. The composition of the deposited films is found to be nearly stoichiometric. The X-ray diffractogram reveals a preferential orientation along (1 1 1) direction, and the structural parameters such as crystallite size, dislocation density, strain and lattice parameters are calculated, and also the effect of film thickness and substrate temperature of the deposited films was also discussed. It is observed that the crystallite size increases from 20.11 to 55.56 nm with the increase in film thickness. The X-ray diffraction (XRD) studies show that the structure of the deposited films is cubic. The crystalline nature of the deposited films is also confirmed by Raman scattering measurements. In the optical studies, optical band-gap values decrease with the increase in film thickness and substrate temperatures. In the DC conduction studies, the conduction mechanism is found to be exponential trap distribution and the results are discussed.

Journal ArticleDOI
TL;DR: The results of the present study suggest that ginger might be useful as a potential antitumour agent.
Abstract: Ginger (Zingiber officinale Roscoe, Zingiberaceae) is a commonly used medicinal herb throughout the world. Although some studies have demonstrated its antitumour activities on cancer cells in vitro and in vivo, the exact mechanism is not fully elucidated. Hence, the present study was designed to examine the in vitro cytotoxic activities of saline extract prepared from ginger extract on HEp-2 cell line. The cytotoxic effect of the drug was confirmed by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and cell counting and estimation of protein, DNA and RNA. Meanwhile, propidium iodide staining and agarose gel electrophoresis were performed for determining the induction of apoptosis. In addition, superoxide radical generation, nitrite formation and glutathione studies show involvement of free radicals. The present results show that the extract exerts dose-dependent suppression of cell proliferation; the IC(50) value was found to be 900 microg/ml. At a dose of 250 microg/ml, marked morphological changes including cell shrinkage and condensation of chromosomes were observed. Agarose gel electrophoresis of DNA from HEp-2 cells treated with 250 microg/ml ginger powder for 24 hr showed marked DNA ladder pattern. The involvement of free radicals was confirmed by increased superoxide production, decreased nitrate formation and depletion of glutathione in ginger-treated cells. Further screening of active components using gas chromatography-mass spectrometry analyses showed the presence of clavatol, geraniol and pinostrobin in the extract. The results of the present study suggest that ginger might be useful as a potential antitumour agent.

Journal ArticleDOI
TL;DR: In this article, the structure and electronic properties of armchair boron nitride nanotubes have been investigated as a function of tube diameter using density functional theory, where the length of each nanotube is kept constant.
Abstract: The structure and electronic properties of armchair boron nitride nanotubes have been investigated as a function of tube diameter using density functional theory. The length of each nanotube is kept constant. The structural parameters of the open end nanotube are studied. The variation in structural parameters is analyzed based on atomic charges of Mulliken and natural population analyses schemes. A topological analysis for charge density (ρ), and its second derivative (∇2ρ) for bonds have been performed using atoms in molecules (AIM) theory. Finally, the analysis of the charge distribution and charge transfer processes have been studied using the NBO partitioning scheme, which helps us to understand the interactions inside the boron nitride nanotubes which are responsible for the stabilization of the armchair boron nitride nanotubes.

Journal ArticleDOI
TL;DR: The study implies that it is possible to develop a dye removal system by using T. harzianum biomass, which occurs as sludge in waste stream of fermentation industries, and shows that the pseudo-second-order kinetic model provided the best correlation of the equilibrium data.

Journal ArticleDOI
TL;DR: In this paper, as-deposited copper selenide and indium telluride films were annealed in a vacuum at different temperatures and the influence on composition, structure and optical properties of the films was investigated using energy dispersive X-ray analysis.

Journal ArticleDOI
09 Sep 2007-Ionics
TL;DR: In this paper, the ionic transference number of polyvinyl alcohol (PVA) was estimated by Wagner's polarization method, and the results reveal that the conducting species are predominantly ions.
Abstract: Solid polymer electrolytes based on poly(vinyl alcohol) (PVA) doped with NH4Br have been prepared by the solution-casting method. The complex formation between the polymer and the salt has been confirmed by Fourier transform infrared spectroscopy. The highest conductivity at 303 K has been found to be of the order of 10−4 Scm−1 for 25 mol% NH4Br-doped PVA system. The ionic transference number of polymer electrolyte has been estimated by Wagner’s polarization method, and the results reveal that the conducting species are predominantly ions.

Journal ArticleDOI
TL;DR: In this paper, a batch biosorption experiments were carried out for the removal of Congo red from aqueous solution using native and pretreated mycelial pellets/biomass of Trametes versicolor.
Abstract: Batch biosorption experiments were carried out for the removal of Congo red from aqueous solution using native and pretreated mycelial pellets/biomass of Trametes versicolor. The effect of process parameters such as contact time, dye concentration, and pH on the extent of Congo red biosorption has been investigated. Higher dye concentrations resulted in lower biosorption. Increases in biomass dosage led to increases in the levels of biosorption. Biosorption kinetics and equilibrium data are essential basic requirements to develop an effective and accurate design model for the removal of the dye. A kinetic study showed that the biosorption of the dye on fungal biomass was a gradual process. Pseudo-first-order, pseudo-second-order, and Bangham's model were used to fit the experimental data. The results of the kinetic studies showed that the second-order kinetic model fitted well for the present experimental data. Equilibrium isotherms were analyzed by Langmuir, Freundlich, Dubnin-Radushkevich, and Temkin isotherms. The biosorption equilibrium data obeyed the Langmuir and Temkin isotherms well. Acidic pH was favorable for the biosorption of the dye. Studies on the pH effect and desorption show that chemisorption seems to play a major role in the biosorption process. Among the native and pretreated biomass studied, autoclaved biomass showed a better biosorption capacity.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the transient natural convection of cold water around its density maximum in a square cavity and solved the governing equations using control volume method with power low scheme.

Journal ArticleDOI
TL;DR: In this paper, the authors used Cationic surfactant, hexadecyltrimethylammonium bromide (HBMB) as a modifier for the coir pith and found that the adsorption capacity of the adsorbent was 8.6mg/g −1.

Journal ArticleDOI
TL;DR: In this article, the structural, optical dispersion and electrical conductivity properties of the CuSe thin film have been investigated using X-ray diffraction, electrical and optical characterization methods.
Abstract: The structural, optical dispersion and electrical conductivity properties of the CuSe thin film have been investigated using X-ray diffraction, electrical and optical characterization methods. X-ray diffraction results indicate that CuSe thin film has an amorphous structure. The electrical conductivity of the CuSe film increases with increasing temperature. The activation energy and room temperature conductivity values of the film were found to be 1.32 meV and 3.89 × 10 −3 S/cm, respectively. The refractive index dispersion of the thin film obeys the single oscillator model and single oscillator parameters were determined. The E o , n ∞ , and S o values of the CuSe thin film were found to be 5.08 eV, 3.55 and 1.92 × 10 14 m −2 , respectively. The obtained results suggest that CuSe film is an amorphous semiconductor.

Journal ArticleDOI
28 Feb 2007-Vacuum
TL;DR: In this article, a hot wall deposition of copper indium diselenide (CuInSe2) compound was performed on glass substrates using quartz tubes of different lengths.

Journal ArticleDOI
TL;DR: The study of the Vilsmeier-Haack reagent on 4-Hydroxyquinaldines resulted in a new versatile intermediate 4-chloro-3-formyl-2-(2-hydroxy-ethene-1-yl)quinolines, which on further treatment with hydrazine hydrate yielded the desired diazepino quinoline derivatives.