Electrically Conductive Carbon-Nanotube Framework Materials

Semiconductors - Conductive materials based on carbon and its modifications are most promising for creating biointerfaces. Such materials can be used for the targeted stimulation of cells and...     

Sulfhydryl phosphorus-containing collectors in flotation of copper–nickel platinum-group metals

The analysis involves influence of sulfhydryl phosphorus-containing collectors (SPC) on flotation of copper–nickel ore-bearing metals from platinum group. Efficiency of SPC and butyl xanthate combination is illustrated, and their optimal ratio is determined. The authors study influence of the test agents on electrode potential and hydrophobic behavior of pyrrhotine, pentlandite and platinum black. UV and IR spectrophotometry has shown origination of disulfide di-isobutyl dithiophosphinate on the surface of pyrrhotine.     

New graphene technologies of manipulation with molecular objects

A new technique of manipulating with fullerene C₆₀ over graphene on a SiO₂ substrate is proposed. To stop the chaotic motion of molecules and limit its range, it is suggested to use a corrugated substrate. The study has shown that, at the corrugation wavelength of 3.4 nm and depth of 1.6 nm, the fullerene motion becomes directed with a deviation within 0.5 nm. The fullerene motion becomes even more definite, with a deviation from a straight line within tenths of an angstrom by the action of an external electric field, which allows one to manipulate the motion along the bottom of a groove. The method proposed can serve as a basis for the controlled assembly of molecules to supermolecular structures of given configurations, which can be applied in bio- and nanoelectronics.     

Electronic properties of Bilayer Fullerene onions

HOMO–LUMO gaps of the bilayer fullerene onions were investigated. For this purpose, HOMO and LUMO energies for the isolated fullerenes were calculated using the parameterization of the tight binding method with the Harrison–Goodwin modification. Then, by the consideration of the van der Waals interaction, the thermodynamical stability of possible combinations of the fullerene molecules was verified and the unstable forms were excluded. Next, the difference of the Fermi levels of the outer and inner shells was calculated by the consideration of the hybridization of the orbitals by using the geometric parameters. The results were obtained by the combination of these calculations.     

Production of commutator bars for critical applications

The use of a series of progressive technical and technological measures has allowed the Kamensk-Ural’skii Nonferrous Metals Plant to significantly improve the service characteristics of commercial batches of electrical-grade semifinished bars used in key applications — commutator bars of trapezoidal cross section made of cadmium bronze BrKd1 and copper-silver alloy MS0.1. The bars are used to make commutators for electrical machinery that are subjected to large mechanical and electrical loads.     

Anisotropy of clays in diffusion transport of radionuclides

Comprehensive analysis of physicochemical and mineralogical properties of clays as surrounding rocks for radioactive waste repositories is performed with emphasis on the clay anisotropy. The results of a long-term experiment on diffusion transport of radionuclides in an experimental sample, a Cambrian clay monolith, are reported, and the anisotropy of the clay monolith with respect to diffusion properties along and perpendicular to the stratification plane is considered in detail.     

Development of a Sorption Technique for the Selective Separation of Plutonium and Americium from Nitric Acid Intermediate-Level Wastes of Chemical and Metallurgical Production

Radiochemistry - The sorption extraction of Pu and Am from nitric acid simulation solutions were studied on a solid extractant (TVEX) AXIONIT MND 40T in a static mode. It is shown that the...