We study the interaction of circumcoronene molecule C54H18 with cobalt in the form of atoms, dimers and clusters of four atoms. We find that the cobalt atom prefers to be on a hollow site in the edge zone. The cobalt dimer is bonded perpendicularly to another different hollow site in the edge zone. The Co4 cluster adopts a tetrahedral shape with a face parallel to circumcoronene, placing each o...

Fischer-Tropsch synthesis is a part of Gas-to Liquids (GTL), Biomass-to-Liquids (BTL) and Coal to Liquids (CTL) technologies, which produce alternatives clean fuels from natural gas, biomass and coal. The catalytic performance of cobalt catalysts in Fischer-Tropsch synthesis strongly depends on the size of cobalt particles in nanoscale range (6-30 nm). Cobalt catalysts are usually prepared via ...

cobalt is an essential co-factor in red blood cell production and function and its deficiency may produce clinical signs in sheep. thus, present study was designed to evaluate the effect of cobalt nano-particles on serum biochemical factors and histopathological changes in liver and kidnies of lambs. study was carried out in 3 groups of lambs (4 lambs per group). one group of lambs was kept as ...

Silica nanoparticles were directly coated with cobalt hydroxide by homogeneous precipitation of slowly decomposing urea in cobalt nitrate solution. The cobalt hydroxide was amorphous, and its morphology was nanoflower-like. The BET (Brunauer-Emmett-Teller) surface area of the core-shell composite was 221 m²/g. Moreover, the possible formation procedure is proposed: the electropositive cobalt io...

background: dental cobalt base alloys are biocompatible dental materials and have been widely used in dentistry. however, metals are bioinert and may not present bioactivity in human body. bioactivity is the especial ability to interact with human body and make a bonding to soft and hard tissues. the aim of the present research was fabrication and bioactivity evaluation of novel cobalt alloy/ f...

an efficient, rapid, simple, and highly selective dispersive liquid–liquid microextraction basedon solidification of floating organic drop (dllme-sfod), combined with flame atomicabsorption spectrometry was developed for preconcentration and determination of trace amountsof cobalt in water samples. in this method, an appropriate mixture of acetone and1-undecanol was injected rapidly into the aq...

Cobalt oxide (Co3O4) nanoparticles were successfully prepared by thermal decomposition of cobalt hydroxide synthesized from cobalt acetate, ammonium hydroxide and 10% glycerol. The cobalt oxide nanoparticles calcined at 450 °C were characterized by using XRD. The XRD confirms the crystallinity and crystal structure of the sample. It also shows that the diffraction peak are broadened which revea...

Cobalt may be released to the environment by human activities, as well by weathering of rocks and soil. The primary anthropogenic sources of cobalt in the environment are from the burning of fossil fuels, application of cobalt-containing sludge or phosphate fertilizers, mining and smelting of cobalt-containing ores, processing of cobalt-containing alloys, and industries that use or process coba...

T HE essentiality of cobalt in the diet of sheep has been proved by Underwood and Filmer (I93~), Marston et al. (I938), Bowstead and Sackville (i939), Bowstead et el. (I94z), Pope et al. (1947), and by Keener et al. (I948). Numerous workers in this country and abroad also have identified cobalt deficiency m cattle. Little progress appears to have been made, however, in determining the function ...

An extensive study of Fischer-Tropsch synthesis (FTS) on alumina-supported cobalt catalysts with different amounts of cobalt is reported. Up to 40 wt % of cobalt, is added to the catalysts by impregnation method. The effect of the cobalt loading on the reducibility of the cobalt oxide species, dispersion of the cobalt, average clusters size, water-gas shift (WGS) activity and activity and s...