we evaluated the effect of fe/alumina catalyst contained different cadmium contents and two synthesis temperatures on producing carbon nanotubes by chemical vapor deposition of methane as a feedstock.  x-ray powder diffraction (xrd), n2 adsorption-desorption, scanning electron microscopy (sem), transmission electron microscopy (tem), raman spectroscopy and thermogravimetry analysis (tga) were u...

iron oxide (fe2o3) nanoparticles were synthesized by a simple approach using sodium borohydride (nabh4) and iron chloride hexahydrate (fecl3.6h2o). their physicochemical properties were characterized by high resolution transmission electron microscopy (hrtem), scanning electron microscopy (sem), x-ray diffraction (xrd) and electron dispersive spectroscopy (eds). xrd pattern showed that the iron...

In this study, the biosynthesis of gold nanoparticles by Penicillium chrysogenum, isolated from Ahar copper mine, was investigated. The gold nanoparticles were synthesized by reducing the aqueous gold ions using the culture supernatant of the filamentous fungi. The UV–vis spectrum displayed a characteristic peak at 532 nm that is very specific for gold nanoparticles. The XRD spectrum confirmed ...

We review recent experimental and theoretical work on ultrasmall metallic grains, i.e. grains sufficiently small that the conduction electron energy spectrum becomes discrete. The discrete excitation spectrum of an individual grain can be measured by the technique of single-electron tunneling spectroscopy: the spectrum is extracted from the current-voltage characteristics of a single-electron t...

In this paper, we report the synthesis of tin oxide (SnO2) nanoparticles by co-precipitation technique. The structural, surface morphology, thermal and optical properties of the SnO2 samples were analysed using X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM), Fourier transformed infrared (FTIR) spectrum, thermo gravimetric analysis (TGA/DT...

We present a study of the compatibility of some current models of the diffuse Galactic continuum γrays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The models are computed with our GALPROP cosmic-ray propagation and gamma-ray production code. We confirm that the “conventional mo...