The magnetic switching of ferromagnetic nanotubes as function of geometrical parameters has been investigated. The modes of magnetization reversal are observed to depend on the geometry of the nanotubes. Time dependent magnetization properties reveal that the nanotubes have strong magnetic viscosity effects. The values of magnetic viscosity coefficient ͑S͒ for different applied fields are high near the coercive field.

Calcium oxide (CaO) nanoparticles are known to exhibit unique property due to their high adsorption capacity and good catalytic activity. In this work the CaO nanocatalysts were prepared by hydrothermal method using anionic surfactant, sodium dodecyl sulphate (SDS), as a templating agent. The as-synthesized nanocatalysts were further used as substrate for the synthesis of alumina doped calcium oxide (Al2O3 ·CaO) nanocatalysts via deposition-precipitation method at the isoelectric point of CaO. The Al2O3 ·CaO nanocatalysts were characterized by FTIR, XRD, TGA, TEM, and FESEM techniques. The catalytic efficiencies of these nanocatalysts were studied for the photodegradation of 2,4,6-trinitrophenol (2,4,6-TNP), which is an industrial pollutant, spectrophotometrically. The effect of surfactant and temperature on size of nanocatalysts was also studied. The smallest particle size and highest percentage of degradation were observed at critical micelle concentration of the surfactant. The direct optical band gap of the Al2O3 ·CaO nanocatalyst was found as 3.3 eV.

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Fingermarks are one of the most useful forms of evidence in identification and can provide generalized proof of identity in crime investigation. They are developed using various conventional powders. The novel nanopowder ZnO-SiO2 was synthesized via the conventional heating method and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray (EDX) analysis, transmission electron microscope (TEM), and X-ray diffraction (XRD). The mean particle size of ZnO-SiO2 nanopowder calculated through TEM was 32.9 nm. The development of fingermarks was carried out by powder dusting and small particle reagent (SPR) methods. Powder dusting method was used for the development of latent fingermarks on various dry, nonporous, and semi-porous surfaces. The SPR method was also applied to wet nonporous surface. The developed latent fingermarks using ZnO-SiO2 nanopowder were found to have excellent quality with very clear third-level ridges detail and had better visibility than commercially available white powder.

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