Simulation of aluminothermic smelting of Al-Zr and Al-Zr-Mo-Sn alloys

Aluminothermic smelting of Al-Zr and Al-Zr-Mo-Sn alloys has been simulated in terms of thermodynamics. The thermodynamic properties of molybdenum and zirconium intermetallic compounds are calculated. It is demonstrated that, with consideration for their formation, the calculated compositions of aluminothermic blends and the forecasted extraction of target metals into an alloy are in good agreement with the data obtained during pilot tests.     

Conversion functions of a cluster single-coil eddy-current sensor

A set of conversion functions of a cluster single-coil eddy-current sensor as the sensor inductance dependences on the blade tip coordinate displacement is described. A simplified model of electromagnetic interaction between the sensitive elements and the object simulator, that is, a rectangular plate, is developed. The model ensures calculating the set of conversion functions in an analytical form. Results of calculating the set of conversion functions, which were obtained for the given geometrical parameters of the measurement object, sensor, and current directions of its sensitive elements, are illustrated.     

Enzymatic Responses to Low-Intensity Radiation of Tritium

The present study considers a possible role of enzymatic reactions in the adaptive response of cells to the beta-emitting radionuclide tritium under conditions of low-dose exposures. Effects of tritiated water (HTO) on the reactions of bacterial luciferase and NAD(P)H:FMN-oxidoreductase, as well as a coupled system of these two reactions, were studied at radioactivity concentrations ≤ 200 MBq/L. Additionally, one of the simplest enzymatic reactions, photobiochemical proton transfer in Coelenteramide-containing Fluorescent Protein (CLM-FP), was also investigated. We found that HTO increased the activity of NAD(P)H:FMN-oxidoreductase at the initial stage of its reaction (by up to 230%); however, a rise of luciferase activity was moderate (<20%). The CLM-FP samples did not show any increase in the rate of the photobiochemical proton transfer under the exposure to HTO. The responses of the enzyme systems were compared to the ‘hormetic’ response of luminous marine bacterial cells studied earlier. We conclude that (1) the oxidoreductase reaction contributes significantly to the activation of the coupled enzyme system and bacterial cells by tritium, and (2) an increase in the organization level of biological systems promotes the hormesis phenomenon.     

Wear resistance and structure–phase states in the surface of the welding-deposited coating on steel

The elemental and phase composition, the state of a defect substructure, and the tribological characteristics of the layer deposited on the surface of a low-carbon low-alloy steel by a welding method are studied. The deposited layer on the steel surface causes the formation of a multilayer structure, and the wear resistance of the deposited layer is found to increase.     

Losses in the Input Channel of a Two-Rotor Vacuum Pump

Russian Engineering Research - A model of the input channel is developed for a two-rotor Roots vacuum pump. In numerical calculations of the input-channel gas flow by means of Ansys Fluent...     

Structure and phase composition of a V-Al-N master alloy

The structure and phase composition of the V-Al-N master alloys produced using out-of-furnace aluminothermic melting of charges containing nitrided vanadium filings or powdered electrolytic vanadium are studied. It has been found that the nitrogen-containing phase of these alloys is represented by aluminum nitride. The master alloy ingots melted using the nitriding agents are characterized by identical values of the integral parameters of nitride phases. Based on metallography results, certain similarity is found between inclusions and the nitriding agent added to the charge for melting of a V-Al-N master alloy.     

Tissue distribution of polybutylcyanoacrylate nanoparticles loaded with spin-labelled nitrosourea in Lewis lung carcinoma-bearing mice

The tissue distribution of polybutylcyanoacrylate nanoparticles (PBCN) with a diameter of 127 nm, loaded with 1-(2-chloroethyl)-3-(1-oxyl-2,2,6,6-tetramethylpiperidinyl)-1- nitrosourea (spin-labelled nitrosourea, SLCNU) is described. PBCN-suspensions were intraperitoneally (i.p.) injected into Lewis lung carcinoma bearing mice. The biodistribution of PBCN in the visceral organs, blood and tumor was studied by electron spin resonance (ESR) spectroscopy. A relatively low accumulation of nanoparticles in the liver and spleen was found. The accumulation was negligible in the i.m. implanted primary tumor. SLCNU-loaded nanoparticles were mainly found in the lungs, kidneys, and heart. The highest content of the particles studied was observed in the lungs of tumor bearing experimental animals damaged by metastases. These findings suggest that PBCN offer some opportunities in the targeting of SLCNU to lung metastases.     

Surface layer of commercially pure VT1-0 titanium after electric-explosion alloying and subsequent treatment by a high-intensity pulsed electron beam

The structure, phase composition, and mechanical, tribological, and corrosional properties of commercially pure VT1-0 titanium are investigated after electric-explosion alloying and subsequent treatment by a high-intensity pulsed electron beam. Treatment conditions that greatly increase the properties of the titanium are identified. The physical factors at work here are considered.