Showing papers by "Bharathiar University published in 1999"
TL;DR: Adsorption studies of mercury (II) from aqueous solutions on coirpith carbon were investigated under the varying conditions of agitation time, metal ion concentration, adsorbent dose and pH as discussed by the authors.
287 citations
TL;DR: In this article, an approximate solution for the steady laminar flow along a semi infinite horizontal plate in the presence of species concentration and chemical reaction has been obtained using Numerical Technique.
Abstract: An approximate solution for the steady laminar flow along a semi infinite horizontal plate in the presence of species concentration and chemical reaction has been obtained using Numerical Technique. It has been observed that in the presence of chemical reaction, (i) the velocity and concentration increase with decrease of Schmidt number Sc. (ii) Skin friction and rate of concentration decrease with the increase of chemical reaction parameter.
151 citations
TL;DR: In this article, polyvinyl alcohol (PVA) films were deposited on pre-cleaned glass substrates using an isothermal immersion technique, and the dielectric and conduction properties of PVA films were studied in the frequency range 1-30 kHz at various temperatures in the range 303-423 K.
67 citations
TL;DR: The changes in GOT and GPT levels in liver, muscle and brain following different periods of sub-lethal and lethal carbaryl exposures suggested that S mossambicus showed adaptive elevation in the activity levels of the two aminotransferase enzymes in the tissues, thereby probably aiding gluconeogenesis through transamination of glucogenic amino acids to meet the energy demand under carbaryl toxicity.
Abstract: The activity levels of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) enzymes were estimated in liver, muscle and brain tissues of the fish, Sarotherodon mossambicus (Peters), which had been exposed to sub-lethal (3 mg litre−1) and lethal (25 mg litre−1) concentrations of the carbamate insecticide carbaryl. Based on the results obtained, the changes in GOT and GPT levels in liver, muscle and brain following different periods of sub-lethal and lethal carbaryl exposures suggested that S mossambicus showed adaptive elevation in the activity levels of the two aminotransferase enzymes in the tissues, thereby probably aiding gluconeogenesis through transamination of glucogenic amino acids to meet the energy demand under carbaryl toxicity.
© 1999 Society of Chemical Industry
47 citations
TL;DR: In this paper, the authors caried out adaption studies of Cr(III) on biogas residual slurry (BRS) under varying conditions of shaking time (5−180 min), metal ion concentration (10−40 mg L-1), adsorbent concentration (1.0 to 8.0 g L 1 ) and initial pH ( 1.5−5.0).
Abstract: Adsorption studies of Cr(III) on biogas residual slurry (BRS) were caried out under varying conditions of shaking time (5–180 min), metal ion concentration (10–40 mg L-1), adsorbent concentration (1.0 to 8.0 g L-1) and initial pH (1.5–5.0). Adsorption follows Langmuir isotherm, being endothermic in nature. For a Cr(III) concentration of 10 mg L-1, a maximum removal of 85% by 4 g L-1 of adsorbent was obtained at an initial pH ≥ 3.0. Desorption of Cr(III) from the spent adsorbent has also been investigated. Removal of Cr(III) from tannery wastewater by BRS was testified.
43 citations
TL;DR: The data indicates that Hg was more toxic than Se, and the protective effect of Se against Hg toxicity was evident only at very low concentrations, and following the decay of leaves, a pink colour development was observed only on leaves exposed to Se.
41 citations
TL;DR: In this paper, the coordination of hydrazinium metal citrate hydrates with formulae M 3 (Hcit) 2 6N 2 H 4 (Mn, Co, Ni, Zn or Cd] and Cu 2 (cit)N 2H 4 2H 2 O has been verified by elemental analysis, IR spectroscopy, X-ray powder diffraction and thermal studies.
37 citations
01 Aug 1999
TL;DR: In this article, the existence of mild solutions for neutral functional integrodifferential equation in a Banach space was proved by using the Schaefer fixed-point theorem, and the results were obtained by using a Gaussian distribution.
Abstract: In this paper we prove the existence of mild solutions for neutral functional integrodifferential equation in a Banach space. The results are obtained by using the Schaefer fixed-point theorem.
37 citations
TL;DR: In this article, stable ruthenium(II) complexes of Schiff bases have been prepared by reacting [RuHCl(CO)(PPh3)2(B)] (B = PPh3, pyridine or piperidine) with bis( o-vanillin)ethylenediimine (valen), bis(o-vanillin)propylene-diimine(valpn), bis-o-villin)tetramethylenedion (valtn), bis
Abstract: Stable ruthenium(II) complexes of Schiff bases have been prepared by reacting [RuHCl(CO)(PPh3)2(B)] (B = PPh3, pyridine or piperidine) with bis(o-vanillin)ethylenediimine (valen), bis(o-vanillin)propylene-diimine (valpn), bis(o-vanillin)tetramethylenediimine (valtn), bis(o-vanillin)o-phenylenediimine (valphn), bis(salicylaldehyde)tetramethylenediimine (saltn) and bis(salicylaldehyde)o-phenylenediimine (salphn). These complexes have been characterised by elemental analyses, i.r., electronic, 1H- and 31P{1H}-n.m.r. spectral studies. In all the above reactions, the Schiff bases replace two molecules of Ph3P, a hydride and a halide ion from the starting complexes, indicating that the Ru–N bonds present in the complexes containing heterocyclic nitrogen bases are stronger than the Ru–P bond to Ph3P. The new complexes of the general formula [Ru(CO)(B)(L)] (B = PPh3, py or pip; L = tetradentate Schiff bases) have been assigned an octahedral structure. Some of the Schiff bases and the new complexes have been tested against the pathogenic fungus Fusarium sp.
33 citations
TL;DR: In this article, Fe(III)/Cr(III) hydroxide has been used as an adsorbent for the effective removal of copper from aqueous solution and the results showed that the adsorption capacity (Q 0) calculated from the Langmuir isotherm was 92.59 mg/g at an initial pH of 5.0.
Abstract: “Waste” Fe(III)/Cr(III) hydroxide has been used as an adsorbent for the effective removal of copper from aqueous solution. The parameters studied include agitation time, Cu(II) concentration, adsorbent dose, temperature, and pH. The percent adsorption of Cu(II) increased with a decrease in the concentration of Cu(II) and an increase in temperature. Quantitative removal of Cu(II) by 50 mg/50 mL adsorbent was observed at pH 5.0 for a Cu(II) concentration of 40 mg/L. The equilibrium data fit well with the Langmuir isotherm. The adsorption capacity (Q 0) calculated from the Langmuir isotherm was 92.59 mg/g at an initial pH of 5.0 at 32°C. Desorption of Cu(II) from a Cu(II)-loaded adsorbent was 55.4% at pH 3.0. Application of the adsorbent for the removal of Cu(II) was successfully demonstrated using radiator manufacturing industry wastewater.
24 citations
TL;DR: In this paper, the capacitance and dielectric constant have been measured from 303 K to 383 K in the frequency range of 10 kHz to 10 MHz, the a.c. conductivity σ is calculated at different frequencies for various temperatures.
Abstract: Thin films of Bi 3 Si 3 have been prepared by vacuum deposition technique onto well cleaned glass and freshly cleaved KBr substrates. The film thicknesses are measured by Tolansky technique. The capacitance and dielectric constant have been measured from 303 K to 383 K in the frequency range of 10 kHz to 10 MHz, The a.c. conductivity σ is calculated at different frequencies for various temperatures. The relation σ ω 1 fits well and the value of n is found to be greater than 1.5 and above at high frequencies suggests that the conduction mechanism in Bi 2 Se 3 thin fil is hopping. The d.c. conduction studies revealed the non-ohmic type of conduction Log 1 versus Log V plot). From the Log 1 versus F 2 plot, the field lowering coefficient β is evaluated.
TL;DR: The effect of a magnetic field on the buoyancy-driven flow of water inside a square cavity with differentially heated side walls is studied numerically in this article, where a finite difference scheme consisting of ADI (Alternating Direction Implicit) and SOR (Successive Over Relaxation) methods are used to solve the coupled nonlinear equations.
Abstract: The effect of a magnetic field on the buoyancy-driven flow of water inside a square cavity with differentially heated side walls is studied numerically. A finite difference scheme consisting of ADI (Alternating Direction Implicit) and SOR (Successive Over Relaxation) methods are used to solve the coupled nonlinear equations. The flow pattern and the heat transfer characteristics inside the cavity are presented for Hartmann number Ha varying over 0 to 100, while the vertical walls are maintained at uniform but different temperatures withθc = 0°C (cold wall) and 4°C≤θh≤12°C (hot wall), while the horizontal walls are thermally insulated. The magnetic fieed dampens the flow field and the heat transfer. As the Hartmann number Ha increases, the temperature field resembles that of conduction type. The average Nusselt number\(\overline {Nu} \), the heat transfer coefficient, decreases with the increase of the Hartmann number Ha. The temperature distribution and flow fields are depicted in the form of streamlines, isotherms and mid-height velocity profiles in the graphs attached for 0≤Ha≤100, varying the hot wall temperatures from 0°C to 12°C.
TL;DR: In this paper, various pure and hybrid density functionals with three larger basis sets have been used to study the troublesome and the most forensic molecule, SiC2, and it is concluded that BLYP and B3LYP functionals have failed to predict the cyclic form of SiC 2 as the most stable structure over its linear counterpart even with the most flexible basis set, 6-311+G(3df).
Abstract: For the first time various pure and hybrid density functionals with three larger basis sets have been used to study the troublesome and the most forensic molecule, SiC2. It is concluded that BLYP and B3LYP functionals have failed to predict the cyclic form of SiC2 as the most stable structure over its linear counterpart even with the most flexible basis set, 6-311+G(3df). On the contrary, the other two pure density functionals of Perdew, Perdew and Wang with larger basis sets correctly identify the minimum energy structure. Finally, the two hybrid functionals B3P86 and B3PW91 predict the cyclic isomer of SiC2 to be more stable than the linear and the increase in the size of the basis set increases the stability of the former. The energy difference between the cyclic and the linear structures, 2.89 kcal/mol, obtained in B3PW91/6-311+G(3df) is better than that of MBPT(2) using the largest 120 CGTO basis set. This difference in energy is better than that of most of the highly sophisticated ab initio levels. ...
TL;DR: The thermal decomposition behavior of these hydrazinium derivatives has been studied by simultaneous TG and DTA as discussed by the authors, showing that the higher dicarboxylates decompose exothermically with the complete elimination of the sample to gaseous products.
TL;DR: In this article, sufficient conditions for controllability of Sobolev-type semilinear integrodifferential systems in a Banach space were established by using the Schaefer fixed-point theorem.
TL;DR: Twenty five plant species from the Maruthamalai hills, Coimbatore, were screened for the presence of phytoconstituents and tests indicated the existence of rotenoids in all the plants.
TL;DR: In this article, a metal glutarate dihydrazinate hydrates of the types; M(C5H6O4).2N2H4.H2O, where M is Co(ll), Ni (ll), Zn(ll) and Cd(ll).
Abstract: New metal glutarate dihydrazinate hydrates of the types; M(C5H6O4).2N2H4.H2O, where M is Co(ll) and Ni(ll), Zn(C5H6O4).2N2H4.2H2O and Cd(C5H6O4).2N2H4.5H2O and metal adipate dihydrazinates of the formula M(C6H8O4).2N2H4, where M is Co(ll), Ni(ll), Zn(ll) and Cd(ll), have been prepared and characterised by spectral, magnetic, XRD and thermal studies. Infrared spectra reveal the bidentate coordination of both hydrazine and dicarboxylate moities. The magnetic and electronic spectral data indicate octahedral coordination for the cobalt and nickel compounds. The simultaneous TGA-DTA data show that all of the complexes decompose via the respective metal glutarate or adipate intermediates undergoing exothermic decomposition to give metal oxide as the residual product. The loss of hydrazine is exothermic for the cobalt and nickel compounds, whereas it is endothermic for the zinc and cadmium compounds. The X-ray powder diffraction patterns of the similar type of complexes indicate isomorphism among themselves
TL;DR: In this article, single crystals of Rubidium Hydrogen Tartrate (RbHT) and Strontium Tartrate Tetrahydrate (SrTT) have been grown by a gel technique using a chemical reaction method.
Abstract: Single crystals of Rubidium Hydrogen Tartrate (RbHT) and Strontium Tartrate Tetrahydrate (SrTT) have been grown by a gel technique using a chemical reaction method. A controlled reaction has been employed between tartaric acid and feed solution (RbCl for RbHT and Sr(NO 3 ) 2 ) at room temperature. The laser Raman and FT-IR spectra of these crystals are recorded in the frequency range 100 - 4000 cm -1 . The presence of tartrate ion, monohydrogen tartrate ion, water molecules and external mode vibrational frequencies are identified and discused. The doublet and broad nature of tartrate ion vibrational frequencies have also been observed and analysed.
TL;DR: In this article, thin films of CuInSe2 were prepared by thermal evaporation onto well cleaned glass substrates kept at 303 K. The thicknesses of the films were measured by Tolansky (Fizeau fringes) technique.
TL;DR: In this article, the authors studied the effect of evaporation on the heat transfer between a thermal plasma and a particle injected into it, with emphasis on the effects which the eva-oration of the latter imposes on heat transfer from the former.
TL;DR: In this article, the isolation and spectral data of two new anthraquinones from Cassia obtusa roots were reported, which are derived from the same root set as the one described in this paper.
TL;DR: The effects of neem seed kernel extract (NSKE), neem oil (NO) and nucleopolyhedrovirus (NPV) of the Spodoptera litura Fabricius (Lepidoptera): Noctuidae on the mortality, feeding and development of S. litura were evaluated in the laboratory.
Abstract: The effects of neem seed kernel extract (NSKE), neem oil (NO) and nucleopolyhedrovirus (NPV) of the Spodoptera litura Fabricius (Lepidoptera: Noctuidae) on the mortality, feeding and development of S. litura were evaluated in the laboratory. Dose-dependent mortality was evident after NPV treatment, which also depended on larval age at treatment. Upon combining NPV with neem products, the percentage mortality was enhanced threefold even at reduced concentrations. The NSKE and NO significantly inhibited the growth and development of S. litura, and extended the duration of its larval and pupal stages. Oviposition period, adult longevity and fecundity were significantly reduced following treatment with neem products and with neem + NPV treatment. The efficiencies of conversion of ingested food (ECI) and digested food (ECD) were also significantly decreased by treatment with NSKE, NO and NPV, either alone or in combination.
TL;DR: In this article, a few linear molecules containing electronegative atoms were used to study the structure and properties of these molecules by using a higher level of DFT and ab initio methods.
Abstract: We have chosen a few linear molecules [NCCCX, X=H, F, Cl, Br; FCCH, FCCF, ClCCCl], containing electronegative atoms to study the structure and properties of these molecules by using a higher level of DFT and ab initio methods. The molecular geometries were optimized employing the atomic basis sets 6-311++G(2d,2p), 6-311++G(3df,3pd) in BLYP, B3LYP, BP86 level of theory of DFT and 6-13G* basis set at MP2 level of theory in the ab initio method. The optimized structural parameters and other properties of the molecules obtained by the post-Hartree–Fock and DFT methods are discussed with experimental values. Density functional theory parameters chemical hardness and chemical potential were calculated employing the atomic basis set 6-13G* at the MP2 level of theory in the ab initio method. These parameters were discussed in relation to the electronegativity of the atoms.
Journal Article•
TL;DR: The present paper deals with the changes in plasma electrolyte levels of fish Cyprinus carpio when exposed to acute and sublethal concentrations of copper sulphate, finding that sodium and chloride levels declined significantly, whereas potassium level elevated.
Abstract: The present paper deals with the changes in plasma electrolyte levels (Na*, K* & CI") of fish Cyprinus carpio when exposed to acute and sublethal concentrations of copper sulphate. In both the treatments, sodium and chloride levels declined significantly, whereas potassium level elevated. Comparing the treatments, the alterations in electrolyte levels were found high in sublethal treatment. The probable reasons governing the facts are interpreted and discussed in the light of earlier literature.
TL;DR: In this paper, sufficient conditions for controllability of semilinear second order ODEs in Banach spaces were established using the theory of strongly continuous cosine families, based on the Schaefer theorem.
Abstract: Sufficient conditions for controllability of semilinear second order ordinary differential systems in Banach spaces are established using the theory of strongly continuous cosine families. The results obtained are based on the Schaefer theorem.
TL;DR: In this article, a DC plasma spray torch operating with argon at atmospheric pressure with power level in the range of 5.2-20 kW was designed to improve electrothermal efficiency.
Abstract: Anode for a non-transferred DC plasma spray torch was designed to improve electrothermal efficiency. A theoretical calculation was made for the electrothermal efficiency in a DC plasma torch operating with argon at atmospheric pressure with power level in the range of 5.2–20 kW using energy balance equations. ANOVA for the two level factorial design was done. Plasma gas flow rate, current intensity, nozzle diameter and length were found to influence the efficiency. The efficiency was found to decrease with increase in current intensity and nozzle length and to increase with increase in nozzle diameter and gas flow rate. The overall energy balance calculations showed that the heat transfer to the plasma-forming gas decreases with increase in arc current and the same was more significant at higher flow rates. Plasma jet velocity for different flow rates, input to the torch and nozzle dimensions was calculated from the gas enthalpy. It was found that the velocity increased with increase in the power input to the torch and gas flow rate and decreased with increase in nozzle length and diameter. The current–voltage characteristics of the torch operating with argon gas were studied for different gas flow rates. The Nottingham coefficients were calculated using least – square method.
TL;DR: In this paper, the molecular structure of both trans and cis conformers of XC(O)OY (X, Y=F and Cl) molecules were determined employing ab initio molecular orbital technique and density functional theory (DFT) method.
Abstract: Molecular structure of both trans and cis conformers of XC(O)OY (X, Y=F and Cl) molecules were determined employing ab initio molecular orbital technique and density functional theory (DFT) method. Different vibrational correction schemes were applied to correct the bond lengths obtained from the ab initio methods. BLYP and B3LYP methods of DFT were used to optimize the molecules. The atomic basis sets 6-311++G (2d,2p) and 6-311++G(3df,3pd) were used for the above methods. Potential energy surface scan was performed for the FC(O)OF molecule at HF/6-31G*, MP2/6-31G*, BLYP/6-311++G(2d,2p) and B3LYP/6-311++G(2d,2p) levels of theory, and interconversion barrier from cis to trans was calculated and these values were found to be 40.06, 42.72, 47.02 and 54.01 kJ/mol respectively and for the same, the experimental value was found to be 35 kJ/mol. The ΔE (Ecis−Etrans) values were computed at HF-SCF, electron correlated and DFT methods. The various basis sets from a very small size to a very large size i.e., basis sets were used for the ΔE calculation. Nowek et al. have also reported the ΔE values both at ab initio and DFT methods for the FC(O)OF molecule. The complete spectrum of ΔE values of the FC(O)OF molecule is now available and it is a suitable testing bed for experiment and theory. The higher basis set of BLYP level of theory reverses the order of conformation. The ΔE values for the FC(O)OF, ClC(O)OF and ClC(O)OCl molecules were obtained at HF, MP2, BLYP and B3LYP levels of theory. The values of BLYP level of theory is not found to be close to the other theoretical values. The DFT parameters such as chemical hardness and chemical potential were used to discuss the conformational stability of the molecule. The Fourier decomposition for the rotational potential energy of the FC(O)OF molecule are studied.
Journal Article•
TL;DR: G-6-P.D.H. enzyme activity showed significant reduction in treatments with both lethal and sublethal concentration of the detergent, however, there was a notable reduction in the inhibition of the enzyme at the end of the 30"^ day of the sublethal treatment.
Abstract: Lethal and sublethal effects of a common house hold detergent 'Green Aerial Micro System' on Glucose-6-phosphate dehydrogenase (G-6-P.D.H) enzyme activity in blood of Laheo rohita was studied. G-6-P.D.H. enzyme activity showed significant reduction in treatments with both lethal and sublethal concentration of the detergent, however, there was a notable reduction in the inhibition of the enzyme at the end of the 30"^ day of the sublethal treatment.