Time filter

Source Type

Karwar, India

Bujurke N.M.,Karnataka University | Naduvinamani N.B.,Gulbarga University | Basti D.P.,Alagappa Chettiar College of Engineering And Technology
Tribology International

The effect of surface roughness on the magnetohydrodynamic squeeze film behavior between two rectangular plates is analyzed. A generalized form of surface roughness pattern is considered. A stochastic random variable with non-zero mean, variance and skewness is used to model mathematically the surface roughness of the squeeze film bearings. The modified averaged stochastic Reynolds equation governing the squeeze film pressure is derived. The expressions for the squeeze film pressure, load carrying capacity and squeeze film time are obtained. Numerical computations of the results show that the negatively skewed surface roughness pattern increases the load carrying capacity and squeeze film time. On the contrary the performance of squeeze film suffers due to positively skewed surface roughness pattern. Further the magnetic effect characterized by the Hartmann number improves the performance of the squeeze film lubrication as compared to the classical non-conducting lubricant case. © 2011 Elsevier Ltd. All rights reserved. Source

Sonalika W.G.,Hitkarini Dental College and Hospital | Bhat K.G.,Maratha Mandals Nathajirao lgekar Institute Of Dental Science And Research Center | Patil B.R.,Karnataka Cancer Treatment and Research Institute | Muddapur M.V.,Karnataka University
Oral Oncology

Objectives: Tobacco chewing habit, presence of squamous cell carcinoma in oral cavity and radiotherapy causes alterations in healthy oral microflora. Abnormal flora developed due to radiotherapy in oral squamous cell carcinoma (OSCC) patients can exacerbate mucositis and can cause systemic infections. The role of oral microorganisms in carcinogenesis is gaining interest recently. Abnormal flora in development of second tumor in the field of first tumor is to be established. The study fundamentally tries to evaluate the shift that occurs during the radiotherapy in OSCC patients. Methods: Microbial analysis of saliva samples from OSCC patients undergoing radiotherapy, tobacco chewers and controls was undertaken. The microorganisms were grouped into categories as total aerobes, total anaerobes, candida, coliforms and gram negative anaerobic bacteria. Results: The frequency of isolation of total aerobes, total anaerobes, coliforms and gram negative anaerobic bacteria was significantly high in OSCC patients compared to healthy controls whereas candida was isolated most frequently during radiation period. The tobacco chewers showed significant increase in colony forming units of total aerobes and coliforms. All the microbial groups were high in OSCC and radiotherapy patients. While OSCC patients showed significant increase in total anaerobes and gram negative anaerobes, candida was increased in radiotherapy patients only. Conclusion: Habits promote coliforms. Tumor supports efficiently anaerobes and candida. The latter is supported more by radiation. The study stresses the importance on administration of appropriate antimicrobial therapy right at the time of diagnosis of the lesion. © 2012 Elsevier Ltd. All rights reserved. Source

Hosamani M.T.,P.A. College | Ayachit N.H.,Alagappa Chettiar College of Engineering And Technology | Deshpande D.K.,Karnataka University
Journal of Thermal Analysis and Calorimetry

Thermodynamic parameters, like, change of activation energy for dipole orientation (DG), enthalpy (DH), and entropy (DS) of activation in the case of binary-, ternary-, etc. mixtures of polar molecules in pure liquid phase or in dilute solution phase in a non polar solvent helps in drawing certain quantitative conclusions regarding their relaxation behavior as to whether a single component is responsible for observed microwave absorption or a cooperative phenomenon (average) by all the dipoles of the mixture contribute to it. Dielectric relaxation behavior of polar molecules in a non-polar solvent, or mixtures of these substances at different microwave frequencies and over a range of temperatures and concentrations give a method of determining these quantities. Such an experimental investigation on verity of systems is necessary to draw quantitative conclusions regarding the system of the molecules which are not studied so as to examine if the results obtained are in favor or against the general conclusions already arrived at, in other systems. With this in view, systematic dielectric measurements in a range of temperatures are carried out at a single microwave frequency on a single weight fraction in benzene of the four substituted indoles, namely, 5-Bromoindole, 5-Fluoroindole, 2,3-Dimethylindole, 2,5- Dimethylindole and on binary (1:1) mixtures of 2,5- Dimethylindole5-Bromoindole and 2,3-Dimethylindole 5-Fluoroindole in benzene as solvent at different temperatures. The results are presented and discussed. © Akadémiai Kiadó, Budapest, Hungary 2011. Source

Phadke K.V.,Karnataka University | Manjeshwar L.S.,Karnataka University
Polymer Bulletin

Carboxymethyl guar gum (CMGG) was synthesized by carboxymethylation of guar gum (GG), which was blended with gelatin (GE) to obtain a novel semi-interpenetrating polymer network (semi-IPN) in the form of microspheres prepared by water-in-oil emulsion method to investigate the controlled release of theophylline (THP), an antiasthmatic drug. Electronic spectroscopy revealed the drug encapsulation ranging from 56 to 74 %. Fourier Transform infrared spectroscopy confirmed the carboxymethylation of GG as well as the semi-IPN structure of the blend polymer. Scanning electron microscopy indicated the smooth surfaces with spherical microspheres. Differential scanning calorimetric and X-ray diffraction studies showed the molecular level dispersion of drug in the microspheres. The in vitro drug release profiles were analyzed to study the effect of polymer blend composition, % drug loading and amount of glutaraldehyde added as a crosslinker. The drug release was extended up to 26 h. The in vitro release data performed in acidic and alkaline media were analyzed using the empirical equations to understand the release profiles of THP. © 2014 Springer-Verlag Berlin Heidelberg. Source

The tilapia, Oreochromis mossambicus, shows a short ovarian cycle of 24-26 days in nonmouthbrooding condition. In this study, the stripped female O. mossambicus were exposed to repeated mild acute stressors such as handling, chasing, frequent netting and low water levels daily for a period of 26 days. The follicular dynamics did not show significant difference during previtellogenic phase (day 12), whereas the mean number of stage IV (vitellogenic) follicles remained significantly lower compared with controls at the end of vitellogenic phase (day 18). The stage V (vitellogenic, preovulatory) follicles were completely absent in contrast to their presence in controls prior to spawning (day 23). The control fish spawned spontaneously after 24 days and entered mouthbrooding phase, whereas those exposed to stressors did not spawn. Furthermore, the serum levels of estradiol (E2) remained significantly lower concomitant with a significant increase in the serum cortisol concentration during vitellogenic and prespawning phase compared with those of the controls. The LH cells in the PPD of the pituitary gland showed weak immunoreactivity through vitellogenic and prespawning phase in fish exposed to stressors indicating the diminished secretory activity in contrast to the intensely stained ir-material in controls. The study reveals the disruptive effects of aquacultural stressors on the spawning cycle through suppression of LH and E2 secretion along the pituitary-ovary axis. The results suggest that the ovarian stress response depends on the phase of the cycle and that the interruption of the spawning cycle is due to inhibition of recruitment of preovulatory follicles in O. mossambicus. © 2012 Springer Science+Business Media B.V. Source

Discover hidden collaborations