Processing and Granulation of Carbon Black

Russian Engineering Research - Patented processes for the sintering of polydisperse materials with low packing density and porosity and poor hydrophobic properties are described. Industrial tests...     

The choice of optimum parameters for atomic power stations using a gaseous coolant

The article discusses a procedure for choosing the optimum parameters for atomic power stations with gaseous cooling of the reactors. These parameters correspond to a minimum value of the calculated cost of the power station. The methods take into account the thermal and economic characteristics of the power station, as well as the specific limitations of the maximum permissible surface temperature of the fuel elements. The article considers conditions where the thermal power of the reactor is given, as well as the more general case in which the optimum power of the reactor is to be determined together with the other desired power station parameters.Analytic design formulas are given for an approximate determination of the optimum values of coolant temperature rise in the reactor and of coolant temperature at the outlet of the steam generator.     

Single-atom manipulations in a microscopic dipole trap

We have realized a very small optical dipole trap that is designed to store and manipulate individual atoms. Due to the very small dipole-trap volume, a 'collisional blockade' mechanism locks the average number of trapped atoms at a value of 0.5 over a large range of loading rates. Here we describe methods to characterize the motion of a single trapped atom, and we also demonstrate the possibility of trapping two atoms individually at a short distance apart. Finally, we study theoretically the possibility to perform 'conditional quantum logic' by scattering photons from two such atoms.     

Electrodeposition of hard nanocrystalline chrome from aqueous sulfate trivalent chromium bath

A sulfate trivalent chromium bath is described which contains chromium(III) salt, sodium sulfate, aluminum sulfate, boric acid, formic acid, carbamide and surfactant. The bath is operated using either titanium-manganese dioxide anodes or platinized titanium anodes without separation of anodic and cathodic compartments. Effect of bath composition and electrolysis conditions on current efficiency of chromium electrodeposition was studied. At optimal bath composition and electrolysis conditions, the deposition rate does not practically change during electrolysis time; it is close to 0.8 μm min⁻¹. The nanocrystalline coatings with a thickness of several tens of micrometers are bright and smooth. The value of Cr-coatings hardness does not substantially differ from that observed in case of Cr(VI)-based baths. The possibility of continuous service of the proposed trivalent chromium bath was confirmed by means of a durational electroplating test (~ 2 months).     

Electrodeposition of composite Fe–TiO<Subscript>2</Subscript> coatings from methanesulfonate electrolyte

The process of electrodeposition of an iron–titania composite electrochemical coating from methanesulfonate electrolyte is studied. TiO₂ Degussa P 25 nanopowder (a mixture of crystalline modifications of rutile and anatase, with the latter prevailing) is used for preparation of suspension electrolyte. The dispersed phase content in the composition coating increases at a decrease in current density and increase in TiO₂ in the suspension. It is shown that kinetics of codeposition is adequately described by the improved Guglielmi model. It is shown that inclusion of TiO₂ particles into an iron matrix results in an increase in microhardness of the coating due to dispersion strengthening. Fe–TiO₂ (anatase+rutile) coatings manifest photocatalytic activity with respect to the reaction of destruction of the methyl orange dye in aqueous solutions under exposure to UV radiation, and this activity is higher than in the case of similar coatings containing TiO₂–rutile particles.