Abstract: Gold nanoparticles (AuNPs) stabilized by poly(N-vinylpyrrolidone) (PVP) were prepared by “one-pot” synthetic protocol and characterized by UV-Vis spectroscopy, DLS and TEM. According to DLS measurements the average size of AuNPs stabilized by PVP in aqueous solution is varied from 10 to 25nm. The PVP stabilized AuNPs (AuNPs-PVP) were deposited on the surface of aluminum oxide (Al2O3/AuNPs-PVP) and its catalytic activity was evaluated with respect to decomposition of hydrogen peroxide. It was found that the amount of AuNPs-PVP deposited onto Al2O3 is extremely low and in the range of 0.06-0.1%. TEM images reveal that the average size of AuNPs-PVP deposited on the surface of Al2O3 is equal to 10-30 nm. The rate of H2O2 decomposition in the presence of Al2O3/AuNPs-PVP exhibits induction period in dependence of the molecular weight of PVP and increases in the following order PVP-350•103 > PVP-40•103 > PVP-10•103.

Abstract: The use of silver nanoparticles in the field of nanomedicine is keeping pace and innovating with the ever expanding horizon of Nanobiotechnology. Ipomea species is widely cultivated and use for different purposes, such as, nutritional, medicinal, ritual and agricultural. The present study deals with the synthesis and characterization of silver nanoparticles using methonolic extract of Ipomoea indica flowers. UV-visible spectroscopy studies were carried out to assess the formation silver nanoparticles. The formation of Ag-NPs was confirmed by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) studies. SEM image revealed that silver nanoparticles are quite polydispersed, the size ranging from 10nm to 50nm. The formation of crystalline silver nanoparticles was zconfirmed using X-ray diffraction analysis. Extracellular synthesis of Ag nanoparticles using dried biomass appears to be cost effective, eco-friendly to that of conventional methods of nanoparticles synthesis.

Abstract: In the present work, zinc substituted cobalt nanoferrites, with formula Co(1-x)ZnxFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4), have been prepared by solution combustion method and are investigated for their electric and dielectric properties such as dc resistivity, dielectric constant and dielectric loss. Analysis of the X-ray diffraction pattern of all the samples confirmed the formation of spinel structure. The surface morphology of the samples is studied by using TEM. The dc resistivity was found to be increasing with an increasing substitution of zinc ions and the high value of dc resistivity, 108 Ω cm, make these nanoferrites more suitable at high frequency applications. Dielectric constant and dielectric loss tangent, measured in the frequency range from 1kHz to 1MHz, are found to be decreasing with an increase in frequency. Possible mechanisms responsible for the results are discussed minutely in this paper.

Abstract: The article focuses on photon drag effect under laser radiation in solid state materials. This effect causes a high concentration of nonequilibrium electrons in the area of the laser beam the exit out of material. Coulomb interaction of spatial charge of these electrons with the charged impurity atoms can cause their drift in the direction of laser radiation. The photon drag effect can be used in laser doping technology of thin films. In multilayer magnetic nanofilms the photon drag effect of polarized electrons can lead to magnetic reversal of magnetic layers, which can be used to control a high speed spin current in the elements of spintronics.

Abstract: Biosorption technology has gained tremendous importance in bioremediation and microbes could become the cheapest tool in detoxification of effluent streams. Aspergillus sp. isolated from the soil sample collected from the area near Hyderabad Metal Plating Industry, I.D.A, Balanagar, Hyderabad, India have been investigated in this study. The growth kinetics of Aspergillus sp. was studied by growing the fungi at different concentration of iron ranging between 0.2mM – 12 mM (Ferrous sulphate). The culture showed considerable inhibition of growth with iron when compared to the metal free controls. The maximum amount of iron was observed in the medium containing 3.0 mM concentration and further increase in the metal concentration was found to increase metal adsorption. Transmission Electron Microscopy analysis revealed the adsorption of iron nanoparticles on the cellwall.

Abstract: The capability of already available antibiotic drug ‘amoxicillin’ based on its fluorescent property has been explored. The fluorescent sodium salt of amoxicillin was used for the detection of heavy metals in aqueous solutions. It was found that Copper and Silver has a quenching effect on the fluorescence of amoxicillin. Cu²⁺ ions were detected in aqueous solution up to 1x10^-7 M and Ag¹⁺ ions up to 1x10^-6 M. Hg²⁺ ions were also detected in aqueous samples but in high concentration.

Abstract: In this paper we will analyse the feromagnetism in nanoparticles. We will try to explain why materials that do not exhibit magnetism at large scales, exhibit magnetism when nanoparticles of the same material are formed. This occurs because when the particle size is reduced, only one domain can form in one nanoparticle. These nanomaterials then exhibit magnetism at a large scale.

Abstract: This paper describes a simple and convenient procedure for the preparation of crystalline silver nanoparticles. One pot synthesis of silver nanoparticles free from stabilizing agent has been investigated. Aqueous solution of AgNO₃ has been reduced by N₂H₄.H₂O in presence of CH₃COONa. The aggregation of silver nanoparticles were prevented by CH₃COONa in chemical bath and then washed away, leaving crystalline silver nanoparticles. The whole experiment has been carried out at room temperature, using water as solvent and also within very less time. The particles synthesized were characterized by UV-Visible, FTIR, TGA, TEM & X-ray diffraction studies.

Abstract: The effects of various ionic strengths and concentrations on the structure and gel properties of rice bran globulin(RBG) at pH 2.0 were investigated using atomic force microscopy(AFM) and rheometer. AFM showed the assembling RBG fibrils translated from strand beads to branch clustered, when electrostatic repulsive forces attenuated gradually with increasing ionic strength. The percolation model G'~(C-Cp)ⁿ calculate the theoretical critical concentration formed RBG gels at various ionic strengths(0), which decreased from 15.17±0.63 to 2.26±0.27 wt%. RBG gels according to the actual complexion had been drawn by computer, the color and state of cubes were simulated. A granular dense structure and intensive mesh like gel network was observed, and a more homogenous structure were formed at low ionic strength.