Vanadium oxide thin films were grown on both quartz and Si(111) substrates utilizing pulsed RF magnetron sputtering technique at room temperature with RF power at 100 W to 700 W. The corresponding thicknesses of the films were increased from 27.5 nm to 243 nm and 21 nm to 211 nm as RF power increased from 100 W to 700 W for quartz and silicon substrates, respectively. X-ray diffraction and field emission scanning electron microscopy were carried out to investigate the phase and surface morphology of the deposited films. Electronic structure and vanadium oxidation states of the deposited films were investigated thoroughly by X-ray photoelectron spectroscopy. As-grown films show stoichiometric vanadium oxide only where vanadium is in V 5+ and V 4+ states. Phase transition of vanadium oxide films were investigated by differential scanning calorimetric technique. The reversible i.e. smart transition was observed in the region from 337 °C to 343 °C. Average hemispherical emittance of the deposited vanadium oxide films was evaluated by an emissometer in the wavelength range of 3 µm to 30 µm. The sheet resistance of the deposited films was measured by two-probe method and data were in the range of 10 6 to 10 5 Ω/square. Optical properties of the films such as solar transmittance, solar reflectance and solar absorptance as well as optical constants e.g. optical band gap were also evaluated. Finally, mechanical properties such as nanohardness and Young's modulus at microstructural length scale were evaluated employing nanoindentation technique with continuous stiffness mode.

Background and Objectives: Dental caries is a well known major oral health problem in most developing countries which has multifactorial etiology caused by many facultatively anaerobes. S. mutans is the main pathogen associated with this disease. Recently Multi-Drug Resistant (MDR) species of S. mutans were identified from the dental caries patients against many commercial antibiotics. MDR is a natural phenomenon, posing a serious worldwide threat to public health. Several therapeutic agents are available to treat or prevent tooth decay, but still global burden of the disease with MDR are emerging. Therefore, the present study was designed for assessing the antibiotic sensitivity pattern of commercially available antibiotics. Material and Methods:This cross-sectional study was carried out by following Standard protocols of Bergey's Manual of Systematic Bacteriology to isolate and identify the organism and further followed by antibiotic susceptibility test of bacterial isolates by disc diffusion method.Results: Streptococcus mutans (40%) was the most predominant to cause dental caries followed by S. aureus with 28.92. Gram positive isolates were found to be frequently resistant towards penicillin and tetracycline whereas Gram negative isolates were found to be Cotrimoxazole resistant. Conclusion:A high frequency of penicillin resistance in oral isolates and its co-resistance to erythromycin, tetracycline, gentamycin and amipicillin among the pateints was observed. The various awareness programmes should be facilitating the appropriate use of antibiotic to re-establish dominance over diseases must be implemented.

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This article reports an experimental investigation of non-reacting flow in a low aspect ratio dump combustor with a tapered exit. The length of this combustor was less than the separated flow reattachment length. The turbulent intensity variation inside the combustor without swirl was found to be axi-symmetric. The turbulent intensity increases in the shear layer between the potential core and the recirculation eddy. The intensity in the core region increases as one moves along the centre-line in the axial direction. The turbulence behaviour significantly changed with the use of a swirler at the inlet of the combustor. The average turbulent intensity increased inside the combustor and the differences in the magnitude of the intensity along the axial and radial directions were less compared to the non-swirling flow. For a high swirl number (( SN) = 1.48), the intensity in the core region was higher compared to other regions inside the combustor. The intensity variation inside the combustor was more uniform than in the case of the low swirl number flow. The r.m.s. velocity studies also suggest more turbulence generation due to swirl. The presence of the swirler increased the turbulence kinetic energy and dissipation rate in the central vortex core region. The power spectral density distribution shows the alteration of the frequency content of the power spectrum, which can be attributed to the forced recirculation due to swirl. The effect of a high swirl number and Re on the frequency peak shows similar behaviour. Therefore, turbulence inside the combustor increased due to the swirler; hence, better mixing of the fuel and air and efficient and stable combustion is expected to be achieved.