Karnataka Science College

Dharwad, India

Karnataka Science College

Dharwad, India
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Chavan P.,Karnatak University | Naik L.R.,Karnatak University | Belavi P.B.,Gogte Institute of Technology | Chavan G.N.,Karnataka Science College | Kotnala R.K.,National Physical Laboratory India
Journal of Alloys and Compounds | Year: 2017

Bi3+ substituted Ni-Cu ferrites with the particles size 0.28 μm–0.53 μm were prepared by solid state reaction method. X-ray diffraction analysis confirmed the single phase cubic spinel structure with the space group of Fd3m-Oh 7. IR absorption bands assigned at 580 cm−1 and 403 cm−1 corresponds to the stretching of vibrations of tetrahedral and octahedral complexes of the ferrites. The average grain sizes of the ferrites were estimated by SEM micrographs at around 1.04 μm which was found to be increased with Bi content. The decrease of DC resistivity as a function of temperature shows the semiconducting nature of ferrites and is attributed to the increase in thermally activated drift mobility of charge carriers. The dielectric constant decreases with increase in the frequency of all samples shows dispersion behavior. Hysteresis loop of the ferrites at room temperature were studied for the determination of saturation magnetization and magnetic moment. The maximum saturation magnetization obtained is about 41.27emu/gm for Ni0.5Cu0.5Fe2O4 ferrite. © 2016 Elsevier B.V.

Patil S.N.,NAVKIS PU Academy | Sanningannavar F.M.,Karnataka Science College | Navati B.S.,Karnataka Science College | Kusanur R.A.,Rashtreeya Vidyalaya College of Engineering | Melavanki R.M.,M.S. Ramaiah Institute of Technology
Canadian Journal of Physics | Year: 2014

The exited state (μe) dipole moment of a molecule is an important parameter, which gives information about electronic and geometrical structure of the molecule in the short-lived state. We have experimentally estimated the exited state (μe) dipole moment of two novel coumarin derivatives, namely, diethyl 2-acetamido-2-((6-methyl-2-oxo-2H-chromen-4-yl) methyl) malamute (DAM) and 5,6-Benzo-3-[1-(4,5-dicarbomethoxy-1,2,3-triazoloacetyl)] coumarin (5BDTC) by three methods, namely, Lippert's, Bakhshiev's, and Kawski-Chamma-Viallet's. In the Solvatochromic shift method, spectral shift is due to internal excitation of the molecule. We have recorded absorption and emission spectra of the above two novel coumarin derivatives at room temperature using solvents of different polarities. The geometry of the molecules were fully optimized and the ground state dipole moment (μg) were also calculated theoretically by Gaussian 03 software using B3LYP/6-31g∗ level of theory. The excited state dipole moment was calculated using CIS/6-31G∗ level of theory. The μg and μe were calculated using the solvatochromic shift method and μe was also determined in combination with μg. It was observed that μe were greater than those of μg, indicating a substantial redistribution of the π-electron densities in a more polar excited state for this coumarin. Further, the changes in dipole moment (Δμ) were calculated both from the solvatochromic shift method and on the basis of microscopic empirical solvent polarity (ETN) and the values are compared. © 2014 Published by NRC Research Press.

Naik V.,Karnataka Science College | Gaonkar N.,Tumkur University
International Journal of Energy, Environment and Economics | Year: 2016

The designing of a simple single axis automatic sun tracking system for the solar panel is presented. A low cost tracking system is constructed using microcontroller (ATMEL ATmega 16) which has inbuilt 10-bit ADC (Analog-to-digital-converter) to reduce the power consumption. This tracking system uses the voltage delivered to the load as a sensing parameter to orient the solar panel for normal incidence of sunrays. The continuous monitoring of load voltage by microcontroller with the help of ADC provides the instant tracking of sun. Experiment is conducted to verify the tracking capability of the model and the efficiencies of static solar panel and panel with tracking system are systematically investigated. The tracking system has shown the improvement in power conversion efficiency compared to static solar panel. © 2016 Nova Science Publishers, Inc.

Maridevarmath C.V.,Karnataka Science College | Malimath G.H.,Karnataka Science College
Journal of Molecular Liquids | Year: 2017

In the present study, the dielectric relaxation behaviour of four polar molecules namely 2-Nitroaniline, 4-Bromoaniline, 4-Chloroaniline and 4-Chlorophenol were studied in dilute solutions of benzene using microwave bench at 9.59 GHz frequency. The different parameters like, dielectric constant (ε′), dielectric loss (ε″), static dielectric constant (ε0) and optical permittivity (ε∞) have been determined. Further from these values, dipole moment (μ) and relaxation time (τ) were calculated for all the molecules following Gopalkrishna, microwave conductivity and the Higasi method. The dipole moment for all the molecules were also estimated theoretically from ab initio computations by using Density Functional Theory (DFT) calculations with the help of Gaussian 09W software. Dipole moments determined experimentally and through DFT computations are in good agreement with the dipole moments estimated by taking vector sum of group moments of Aniline, Nitrobenzene, Bromobenzene, Chlorobenzene and Phenol by neglecting interaction between pendant groups. The experimentally determined relaxation times were analyzed in terms of Stokes-Einstein-Debye (SED) theory and the results are compared with molecular radii estimated from DFT and Edward's atomic increment methods. Further, in order to understand the chemical stability and reactivity of all these molecules, highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and HOMO-LUMO energy gap were also estimated from DFT computations. Our experimental findings suggest that, 2-Nitroaniline exhibits simple Debye type relaxation behaviour while the other three samples exhibit Higasi's distribution of relaxation times which may be due to both overall and intra-molecular rotation of the molecules. Further, the HOMO-LUMO studies revealed that, 2-Nitroaniline is more chemically reactive having least energy gap and 4-Chlorophenol is least chemically reactive having highest energy gap among the four samples. © 2017 Elsevier B.V.

Malimath G.H.,Karnataka Science College | Maridevarmath C.V.,Karnataka Science College
Journal of Chemical and Pharmaceutical Research | Year: 2016

Acoustical studies have been conducted on the binary mixtures of Amitriptyline and Benzene at 2.9979 MHz and at different temperatures from 299K to 328 K using Ultrasonic interferometer. The experimentally determined ultrasonic velocity and density are used to calculate the various thermo-acoustical parameters like adiabatic compressibility (β), intermolecular free length (Lf), specific acoustic impedance (Z), molar volume (Vm), available volume Va(s), Rao’s number (Ra) and Wada’s number (W). From these various parameters the molecular interactions present in the binary mixture are studied with respect to change in temperature. It is observed that, there are weak molecular interactions present between the components of the mixture and these interactions are found to be decreasing with increase in temperature. © 2016, Journal of Chemical and Pharmaceutical Research. All rights reserved.

Prashanth M.S.,Kuvempu University | David M.,Karnataka Science College
Bulletin of Environmental Contamination and Toxicology | Year: 2010

Activities of ATPase in different organs of Cirrhinus mrigala exposed to cypermethrin with lethal (5.13 μg/L) and sublethal (1.02 μg/L) concentration was investigated. Decrease of Na +-K +-ATPase activity was observed in gills, liver and muscle to about 60.22%, 22.13% and 48.89% respectively, by lethal concentration. Whereas in sublethal concentration activity was increased to about 7.84%, 10.70% and 5.96%. Similarly, in case of Mg 2+-ATPases activity as 57.61%, 48.82% and 28.59% for lethal and for sublethal it was 10.15%, 4.64% and 11.92%. Ca 2+-ATPase activity was observed to be 55.24%, 41.66% and 47.66% by lethal and for sublethal it was 8.02%, 24.89% and 6.47%. © 2009 Springer Science+Business Media, LLC.

Shettar A.K.,Karnatak University | Kotresha K.,Karnataka Science College | Kaliwal B.B.,Karnatak University | Vedamurthy A.B.,Karnatak University
Asian Pacific Journal of Tropical Disease | Year: 2015

Objective: To evaluate in vitro antioxidant and anti-inflammatory activity of Ximenia americana extracts. Methods: Herbal extraction was done by Soxhlet extraction method with increasing polarity of solvents viz., chloroform, ethyl acetate, methanol, ethanol and water. Phytochemical analysis was done using different biochemical tests. Antioxidant potential of plant extracts were analyzed by ferric ion reducing antioxidant power, phosphomolybdenum and 2,2-diphenyl-1-picrylhydrazyl, and anti-inflammatory activity by using protein denaturation in vitro bioassay. Total phenolic content of each extract was also determined to assess their corresponding effect on antioxidant capacity of plant. Results: Phytochemical analysis showed that each solvent extract contained broad spectrum of secondary metabolites, phenolic compounds, flavonoids, tannins and glycosides, whereas compared to other solvent extracts, chloroform extract showed negative result for phenolic compounds whereas aqueous extract exhibited the highest phenolic content and the significant antioxidant capacity based on the test performed. Out of all extracts, methanol extract showed high anti-inflammatory activity. Conclusions: The present study revealed that different solvent extracts of Ximenia americana leaves contain broad spectrum of bioactive compounds. Results confirm that aqueous extract exhibited high antioxidant activity and methanol extract exhibited high anti-inflammatory activity. Further study requires purification, characterization and structural elucidation of phenolic compounds in both extracts that may help in the development of new phytopharmaceuticals. © 2015 Asian Pacific Tropical Medicine Press.

Havanur V.C.,Karnatak University | Badiger D.S.,Karnatak University | Ligade S.G.,Karnataka Science College | Gudasi K.B.,Karnatak University
Der Pharma Chemica | Year: 2011

The heterocyclic ligand 2-anilino-N'-[(1E)-1-pyridin-2-ylethylidene]acetohydrazide (Apeah) was synthesized by coupling of 2-anilinoacetohydrazide with 2-acetylpyridine and characterized by IR, 1H and 13C-NMR spectra, it was then reacted with Lanthanide(III) nitrates to form complexes of the type [Ln(Apeah) 2 NO 3 H 2O]·2NO 3 where, Ln = La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Y(III). The metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, TG/DTA and spectral (IR, 1H and 13C-NMR, UV-Visible and EPR) studies. The spectral data revealed that the Apeah behaves in tridentate fashion coordinating through carbonyl oxygen, azomethine nitrogen and pyridine nitrogen. The molar conductance values adequately supported their 1:2 electrolytic natures. Both Apeah and complexes were screened for their antimicrobial study. An enhancement of antimicrobial activity of the Apeah was observed on complexation.

Sannaningannavar F.M.,Karnataka Science College | Navati B.S.,Karnataka Science College | Ayachit N.H.,Alagappa Chettiar College of Engineering And Technology
Journal of Applied Polymer Science | Year: 2012

Thermodynamic parameters, like change in free energy of activation (ΔG τ *), enthalpy of activation (ΔH τ *), and entropy of activation (ΔS τ *) of poly(ethylene glycol) with average molecular mass 400 Delton (PEG 400) in dilute solution of benzene were computed on the basis of theory of Eyring rate process. To estimate these, the dielectric relaxation time (τ), determined at various temperatures adopting Whiffen and Thompson model have been used. X-band microwave bench working at 9.59 GHz was employed to find temperature dependent real part ε of the complex dielectric permittivity ε* and dielectric loss ε″. The values of these ε and ε″ are used to find τ values. Based on the results reported, the relaxation behavior of the stated polymer in nonpolar solvent is discussed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 Copyright © 2012 Wiley Periodicals, Inc.

Dodamani A.F.,Karnataka Science College
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2012

The study of the adduct formation of Ni(Il) di(3-chloro,2-methylphenyl) carbazonate has been undertaken by synthesising and characterizing it by magnetic susceptibility, UV-VIS, IR and 'H-NMR spectral measurements. The distorted square planar Ni(TT) chelate forms adducts with heterocyclic nitrogen bases; spectrophotometric method has been employed for the study of the adduct formation in a monophase chloroform. Both bidentate and unsaturated monodentate heteronuclear nitrogen bases form hexacoordinated adducts with 1:1 and 1:2 stoichiometry, respectively (metalchelate:base). However, the saturated nitrogen bases form pentacoordinated adducts with 1:1 stoichiometry. The results are discussed in terms of basicity and steric factors of the bases.

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