Formation of adhesive bonds under contact rotaprint lubrication

The mechanism of the formation of adhesive bonds of a friction modifier (a lubricant based on bitumen) with a wheel of railway transport is considered. Calculations performed using quantum chemical methods allow us to draw a conclusion on the existence of the physical adsorption of this lubricant on a wheel surface. The lubrication’s effectiveness can be improved using fatty acids whose introduction into the lubricating material leads to the formation of chemical bonds in the system; this is experimentally confirmed for the contact rotaprint lubrication technology.     

Determination of Geometric and Operating Parameters of Device for Spraying Molten Slag in a Dry Slag Granulation Plant

Metallurgist - In leading countries around the world, research is being conducted on the development of dry slag granulation plants (DSGPs) for blast-furnace slag; these plants support production...     

Forecasting Technological Parameters of Electrodialysis Apparatus for Solution Separation

Chemical and Petroleum Engineering - The paper presents a method for predicting the technological parameters of an electrodialysis apparatus using an improved mathematical model based on a friction...     

Method of Thermal Calculation of High-Performance Electrodialysis Apparatus with Cooling of Solution to be Separated

Chemical and Petroleum Engineering - A method is proposed for thermal calculation of a new improved design of electrodialysis apparatus. The calculations showed that the mean temperature of the...     

Foundations of a technology for the microbiological conversion of organic cellulose-containing wastes into electrical energy through the intermediate formation of biohydrogen

The screening of microorganisms that are able to degrade cellulose-containing wastes and release hydrogen release was performed. The foundations of a technology for the removal and utilization of hydrogen were established. Classic microbiological techniques were used in the screening. The technology of polymer nonporous membranes was used to remove the hydrogen from the culture liquid. The obtained hydrogen was constantly oxidized with the formation of electricity, using the innovative technology of a fermentation electrode based on hydrogenase. In the course of our work, several highly productive biocenoses of microorganisms were selected; the possibility of raising the microbiological conversion of cellulose-containing wastes into electrical energy from 20 mM(H₂)/(l h) to 68 mM(H₂)/(l h) through the formation of hydrogen and the application of membrane technology was shown; and the possibility of using the fermentation fuel electrode for the oxidation of hydrogen was demonstrated. The maximum capacity was increased to 250 μW/sm². It was shown that both technologies can be used to produce electrical energy and absolutely pure hydrogen.     

Possibility of enhancement of the high-temperature strength and the heat resistance of a nickel aluminide–based structural intermetallic alloy

The assimilation of a number of rare-earth metals (REM = praseodymium, neodymium, erbium) in a cast high-temperature nickel aluminide–based intermetallic alloy and the effect of REM alloying of the alloy on the critical temperatures, the high-temperature strength, and the heat resistance (time to failure) of the structural alloy are studied. It is shown that the heat resistance and the time to failure of the alloy at 1200°C can be increased by microalloying of the intermetallic alloy with REM.     

Investigation of the surface of the liquidus of the Fe-Ni-S system at X s<0.51

Methods of thermal analysis, X-ray, optical, and electron microscopy were used to study the liquidus surface of the Fe-Ni-S system in the field of 35 to 51 at. pct sulfur. The FeS-NiS, FeS-Ni₃S₂, Fe_0.55S_0.45-Ni_0.55S_0.45, and Fe_0.61S_0.39-Ni_0.61S_0.39 sections and some additional samples were examined. A microscopic study of the samples slowly cooled and annealed enabled referring of all the samples to the fields of primary crystallization of the monosulfide solid solution (Fe _x Ni_1−x )S_1+y (MSS), the Fe-Ni solid solution with the γ-Fe structure (TN), and the (Fe _x Ni_1−x )_3±y S₂ heazlewoodite solid solution (HZSS). The data, obtained by a method of derivative thermal analysis, have been used to describe analytically the MSS and HZSS surface of primary crystallization. Previous results were used together with our own data to construct the TN surface of primary crystallization. These parts of the liquidus surface have been approximated by polynomial equations, the coefficients of which were determined by the least-squares method. As a result of the absence of experimental data in the δ-Fe-based solid-solution primary crystallization field, this liquidus part is approximated on the basis of the Fe-S and Ni-Fe phase diagram data. The equations are used to construct the boundaries between various areas of phase primary crystallization, to define the coordinates of a triple point, and to construct isotherms.