Journal of Nano Research Vol. 16

Abstract: In this research Cu-Ni nanostructure powders were prepared by using a chemical procedure including initial precipitating, calcining the precipitates and reducing the calcined powders. The influence of nickel contents on the characteristics of the synthesized powders was investigated. Copper and nickel sulfate and sodium hydroxide were used as raw materials. CuSO4.3Cu(OH)2, NiOOH and Ni(OH)2 precipitates were obtained by addition of sodium hydroxide into aqueous copper and nickel sulfate solution. Oxide powders were produced by calcinations of precipitates. Considering the information obtained from the TGA test, calcination was done on precipitates. Copper-nickel nanostructure powders were synthesized by reduction of calcined powders in a hydrogen atmosphere. Eventually powders were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Crystallite size of final synthesized powders was in the range of 30 to 33 nm.

Abstract: In this study, single-walled carbon nanotubes were generated in their perfect state as finite element models in the MSC.Marc software. The buckling behaviour and resonant frequency modes of the two limiting cases of carbon nanotubes, i.e. the armchair and zigzag models, were studied. The obtained results were compared with the classical analytical solutions related to a similar continuum structure of a hollow cylinder. The buckling behaviour of single-walled carbon nanotubes under cantilever boundary conditions proved to be almost identical to the prediction of the classical Euler equation. Furthermore, there was very good agreement between the analytical and finite element results of the studied single-walled carbon nanotubes; though the achieved value of the first mode of frequency, obtained from the finite element results, was more accurate than the higher modes.