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Kumar J.,Government Girls Post Graduate College | Kailash,Bn Post Graduate College | Kumar V.,Bn Post Graduate College | Chaudhary A.K.,Atarra Post Graduate College
Asian Journal of Chemistry | Year: 2011

A proper and systematic evaluation of the elastic constants of isostructural oxides and their dependence on temperature provides the fundamental data for determining the characteristics of cation-oxygen bonding interactions, which are pertinent to the understanding and theoretical modelling of more complicated oxide compounds. The information about higher order elastic constants is valuable in understanding nature of short range forces in crystals. Tellurium oxide is a divalent crystals and possess FCC crystal structure. In this work, an attempt has been made to evaluate higher order elastic constants for tellurium oxide at an elevated temperature starting from 50 K to near its melting point. The melting point for tellurium oxide is 643 K. The data of second, third and fourth order elastic constants (SOECs, TOECs and FOECs) are used to evaluate the first order pressure derivatives (FOPDs) of SOECs and TOECs, second order pressure derivatives (SOPDs) of SOECs and partial contractions. While evaluating these properties it is assumed that the crystal structure does not change during temperature variation. The data of these oxides obtained through different techniques also give important and valuable information about internal structure and inherent properties of materials and can be used in future for different industrial purposes and further investigations of divalent FCC structured solids and other isostructural oxides. Source

Kumar V.,Bn Post Graduate College | Kailash,Bn Post Graduate College | Kumar J.,Government Girls Post Graduate College | Chaudhary A.K.,Atarra Post Graduate College
Asian Journal of Chemistry | Year: 2011

Nanofluids are attracting a great deal of interest with their enormous potential to provide enhanced performance properties, particularly with respect to heat transfer. Metal nanoparticles can be used in various application fields, such as optical filters or nanolithography. Platinum nanoparticles with narrow size distribution dispersed onto smooth, non-catalytic surfaces are of interest as model systems for the investigation of particle shape and size dependence of the catalytic activity of platinum towards reactions of interest in fuel cell systems. Measurement of ultrasonic velocity gives the valuable information about the physico-chemical behaviour of the liquid and liquid mixtures. Ultrasonic velocity is the velocity with which the ultrasound propagates through the material. It depends on material density and elasticity. It is related in a simple way to the various coefficients of compressibility, isentropic, isenthalpic and isothermal, hence the importance of its measurement and modeling in temperature and pressure ranges are widely used. Here we have measured the ultrasonic velocity at different temperature and frequencies of nanofluid of platinum using Interferometer technique and phase transition in the experimental temperature range has been discussed. Source

Devpura A.,Bn Post Graduate College | Sharma P.,Bn Post Graduate College | Chundawat S.S.,Bn Post Graduate College | Shaktawat S.,Bn Post Graduate College | Dulawat S.S.,Bn Post Graduate College
Asian Journal of Chemistry | Year: 2011

In an effort to develop antibacterial agents, a series of chalcones were prepared by Claisen-Schmidt condensation of appropriate acetophenones with appropriate aromatic aldehydes in the presence of basic alumina as solid support reagent under microwave irradiation. The synthesized compounds were characterized by their IR, 1H NMR, mass spectral data and elemental analysis. The compounds have been screened for their antibacterial activity against S. aureus, S. fecalis, E. coli and P. mirbilis. Source

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