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A method of casting surface alloying during casting using gasified models with the formation of a wear-resistant surface layer is considered. The increase in wear resistance is due to formation of boride and carbide components by means of self-propagating high-temperature synthesis between alloyed coating components that occurs during casting manufacture. Results of comparative tests for materials under abrasive wear are presented. Data are given for material composition, structure, and hardness.

The possible synthesis of hexagonal titanium carbohydride—copper composites by two- and three-stage mechanical activation of titanium and copper powders in liquid hydrocarbon followed by magnetic-pulse pressing has been studied in this work. Surfactant used for the three-stage synthesis enable one to restrain the formation of intermetallic phases in the process of mechanical activation and reduce the fraction of intermetallic phases in consolidated samples. The density, microhardness, abrasion resistance, and wear parameters under conditions of dry friction with a steel ball have been estimated. Two- and three-stage methods of producing powders have been shown to be preferable, since friction coefficients and wear in friction pairs are much lower than that of composites produced by the one-stage method.

The effect of chemical-thermal treatment (borating) on the structure, composition, depth and hardness of the surface layer of samples from chromium-bearing iron-carbon alloys: 95Kh18 steel and ChKh12 and ChKh32 cast iron is shown. The results of comparative tests of the studied materials on the wear resistance in the conditions of dry friction on fixed abrasive are presented.

The pharmacotherapy of hypoxia is an important task of modern experimental and clinical pharmacology. The medications with anti-hypoxic effect implemented into clinical practice unfortunately do not meet requirements of physicians due to poor efficiency, narrow range of active dosages and undesirable side effects. The complexes of zinc with N-alkenylimidazole demonstrated anti-hypoxic activity at various models of acute hypoxia within large range of dosage. Therefore, further studying of zinc-contained compounds as possible correctors of hypoxia is of particular interest. The experiments with white nonlinear male mice were used for comparative investigation of ant-hypoxic effect of complex compounds of zinc acetate with N-propargylimidazole and 3-hydroxipyridine, including complexes immobilized on sulfated arabinogalaсtan and also well-known anti-hypoxants and/or anti-oxidants: etomerzol, mexidol, nooglutil and hypoxen. It is demonstrated that anti-hypoxic effect of complex of zinc acetate with N-propargylimidazolein conditions of acute hypobaric hypoxia, acute hypoxia with hypercapnia acute hematic hypoxia by width of active dosages (1-100 mg/kg, intraperitoneally) and degree of expression (19-317% in comparison with control groups of animals) excels the similar effect in well-known anti-hypoxants and/or anti-oxidants: etomerzol (25-100 mg/kg, intraperitoneally), mexidol (100 mk per kg, intraperitoneally), nooglutil (25-100 mg/kg, intraperitoneally) and hypoxen (50-150 mg/kg, intraperitoneally). The protective effect of complex of zinc acetate with 3-hydroxipyridine by width of active dosages (25-100 mg/kg, intraperitoneally) and degree of expression (27-167% in comparison with control groups of animals) in conditions of exogenous hypoxia (acute hypobaric hypoxia and acute hypoxia with hypercapnia) excels similar effect of etomerzol and mexidol ans is comparable with effect of nooglutil and hypoxen. The complexes immobilized on sulfated arabinogalactan were ineffective.

The extraction mechanism has been considered and the crucial role of the dynamic interfacial layer has been noted. The microprocesses that take place in extraction systems and are associated with the Marangoni effect, the loss of hydrodynamic stability, partial dispersion, coalescence, flocculation, the Ostwald ripening of drops, chemical reactions, the emergence of a new phase, adsorption, coagulation, the formation of structures, and polymerization have been described. For LnCl3–H2O–diluent systems (heptane, toluene, tetrachloromethane), data on the shift in the boundaries of the observed transition region over time have been presented. The mechanism of the transfer of the substance in the transition region of the extraction system has been formulated.

Data on the wear tests of the material of a heat exchange tube and a spacer grid of the steam generator of the BREST-OD-300 nuclear reactor plant performed at a high temperature in argon atmosphere are presented. A mathematical model of the wear process based on which the identification of the corresponding wear law is carried out has been proposed. The wear durability of the heat exchange tube has been evaluated.

The paper applies machine learning methods to the prediction of the abrasive weight wear rates for a set of wear resistance experiments with model samples made of electrical copper and pure aluminum. To assess the effect of rotation frequency and abrasive grit sizes on the results of the evaluation of wear resistance and the determining quantities, the samples are tested with various disc rotation frequencies and various sandpaper grit sizes. It is noteworthy that, during experiments with materials comparable to copper in hardness and with harder ones, the path specified by the test design is implemented completely. However, this test design is not always suitable for the analysis of the mechanical characteristics of aluminum since, in some cases, the sample becomes fully worn before the end of the test. To overcome this problem, machine learning (ML) methods are proposed.

It is established that the heteroadagulation of microdroplets of chlorobenzene or microdroplets of water brine on carbon tissue in the vicinity of the inversion point occurs in the kinetic mode or close to it. It is noted that the presence of the kinetic mode explains the linearity of kinetic curves along at least two-thords of their length. The sudden disappearance of microdroplets from the field of view upon a slight increase in grinding frequency is explained by the microdroplets achieving critical wavelength. It is concluded that at low concentrations of microdroplets, heteroadagulation curves acquire S-shaped form in any phase, due to the relative importance of interdroplet interactions in the subsurface layers. The abrupt transition of ascending kinetic lines and their transformation into horizontal lines indicates there are no more visible droplets; i.e., drops cannot be observed optically.

The statistical parameters of hydrodynamic heteroadagulation of microdrops of solar oil with sizes of 0.5–2 μm have been obtained for the first time. The problem is of a great practical significance because the agglomeration of microdrops leads to substantial acceleration of purification of aqueous phase from them according to hydrodynamic heteroadagulation (HHA). HHA has been studied in the broad range of the rotation frequencies of rotor discs from 200 to 2000 min−1. Root-mean-square deviations S have been calculated in all points of kinetic curves and also their relative errors δ% have been obtained. The methods of analyzing the u-distributions and Student t-distributions have been used. The trends of random deviations of kinetic curves of heteroadagulation from mean values have been determined.

We consider the hydrodynamic heteroadagulation method for water purification from microdrops of organic liquids with a size of 0.8–10 μm and concentration of 0.02–2.0%. A mathematical model of the process is proposed. The role of material for heteroadagulation, the rotation frequency of dispenser rotors and heteroadagulator mixer, and the pH level were discussed. Purification from microdrops is ascertained to be ∼93–99% fulfilled over 5–25 min. We reveal and interpret the reason for aliasing of kinetic curves of heterodynamic heteroadagulation and its appreciable acceleration or deceleration upon the introduction of a second set of drops larger than the first by a factor of 300–500.

The effect of the emulsifier formula on the stability of castor oil-water system was studied through compounding three groups of emulsifiers from the aspects of stability factor of absorbance, centrifuge stability, demulsification time in quiescence, appearance of the droplets, and viscosity. The best emulsifier formula for castor biomass oil was the composite formula of sorbitan monooleate and polyoxyethylene sorbitan monostearate. Correlation exists between the stability of emulsion and the viscosity/particle size of the droplets, with better stability in the case of greater viscosity or narrower distribution of particle size in the emulsion of castor oil-water system. Methanol added to the castor oil-water system may decrease the viscosity of the emulsion. Comparing the castor oil-water emulsion with methanol-castor oil-water emulsion, the optimal hydrophilic and lipophilic balance (HLB) value based on castor oil-water system was acquired between 6.6 and 7.5, while the optimal HLB value based on the methanol-castor oil-water system was between 5.5 and 6.0. The optimal HLB value of methanol-castor oil-water system gradually moved to that of castor oil-water emulsion with adding more water.

Effect of diluents on the coarsening of microdrops of tri-n-butyl phosphate by hydrodynamic heteroadagulation on a carbon fabric in water was studied.

Reaction kinetics of ozone destruction in water in the presence of an anion and a cation impurity has been examined. Cromates and, possibly, a complex anion of iron with a valence of three have the strongest catalytic property among all tested anions. Cations do not influence the reaction rate of ozone destruction.

The IR spectra in the hydroxyl group stretching vibration region of the simplest hydroxyalkylpyrrolizidines have been examined. The spectra were taken in the form of pure liquids, dilute solutions in carbon tetrachloride, and for individual bases in the gas phase. It was shown that in dilute solutions ΔνOH depends on the geometric parameters of the intramolecular hydrogen bond (IMHB). The energy of the IMHB of 3-(2-hydroxyethyl)pyrrolizidine was measured in dilute solution and in the gas phase.

Coalescence of KHA-30 compressor oil microdroplets on a carbon fabric, aimed to remove them from air and water streams used for compressor cooling, was examined.

The kinetics of the spreading of polymolecular films are studied. It is shown that they move slower than monomolecular films with the polar liquid Midel 7131 moving especially slowly. The cause of the considerably slower motion of surfactants is explained.

The linearization of kinetic curves of the decoloration of direct green and methylene blue dyes and humic acids is performed. It is shown that the kinetic curves can be linearized in the time-square root of the negative logarithm of reduced optical light absorption or ozone concentration coordinates. This provides a simple way of modeling and optimizing ozonation processes.

The problem of purifying water from microscopic oil drops without using reagent heating has been solved using the technique of a directed motion of drops, i.e., the method of heterogeneous hydrodynamic coagulation. The efficiency of water purification from microscopic oil drops, including those of the petroleum origin, is equal to 95–99% per one stage. The purification process lasts 10–30 min.

Ultra-fine zinc oxalate powders were prepared through a precipitation stripping method with bis(2-ethylhexyl) phosphate (HDEHP) diluted by tetrachloride carbon as the extractant, and oxalic acid ethanol aqueous solution as the re-extractant and precipitator. Zinc oxide powders were obtained by decomposing zinc oxalate powders at 450uC. The prepared zinc oxide powders were characterized by transmission electron microscope (TEM), Scanning electron microscope (SEM), Thermogravimetric analysis (TG), X-ray diffraction (XRD) and Fourier transmission infrared (FT-IR) spectrum. The photocatalytic performance of methylene blue by zinc oxide was studied based on the Langmuir model and Photo-Layer model. The results show that some zinc oxide powders were micro-multipore materials with hexagonal crystal. The particle size was around 32 nm. The photocatalytic process was the control step in the chemical reaction. The photo catalytic process followed pseudo-first order kinetics and •OH concentration inside the photo-layer in different reaction condition were calculated according to the Photo-Layer model.

This study continues an earlier work devoted to simulation of mass transfer in liquid-liquid systems taking into account mass transfer across fractal interfacial structures. Earlier, using methods of nonequilibrium thermodynamics, we obtained an expression for the generalized thermodynamic force taking into account colloidal chemical phenomena in the interfacial region, such as the formation of disperse interfacial layers and films. Here, using a differential equation with a fractional-order derivative, we estimate the diffusion coefficient of the extractable substance in the interfacial film and the porosity of this film, which is its structural characteristic.

A unit was designed for investigating the effects of low electrostatic fields on exchange reactions in extraction systems. The dynamics of oxalic acid transfer across the interface during the reextraction of copper ions under the action of copper oxalate deposition was studied. The peculiarities of reextraction dynamics were explained by the formation and migration of discontinuities in the copper alkyl phosphate film along the interphase surface under the action of an electrostatic field. The dynamics of the process is characterized by the appearance of specific exchange rate maxima and by a drastic decrease in the rate in the presence of an electric field.

A mass transfer model in which the generalized thermodynamic force accounting for colloidal and chemical phenomena in the interfacial zone, such as the formation of disperse interfacial layers and films, is taken to be the driving force is considered. A method for calculating the difference between the pressures in the film and in the phase, the interfacial-film thicknesses, and mass transfer coefficients is proposed. It is found that the resistance to mass transfer in porous films varies with time, passing through a maximum.

The kinetics of heterogeneous hydrodynamic coagulation and coalescence of motor oil droplets 0.4–1.5 μm in size with a concentration of 0.15–0.5 vol % is investigated in a convoluted tube, a centrifugal pump, and their combination. Kinetic parameters of the coagulation-coalescence process, which proceeds hundreds times faster than sedimentation, are determined.

The mechanism of purification of an aqueous phase from droplets of Midel 7131 transformer oil with the use of heterogeneous hydrodynamic coagulation in the presence of a second organic solvent is considered. Models of heterogeneous hydrodynamic coagulation are proposed, and the simplest and most probable model variants are chosen.

A setup is designed to study the kinetics of heterogeneous hydrodynamic coagulation in the presence of a second organic solvent, which significantly accelerates the coagulation. Without coagulants, 5–20 min is sufficient to remove 80% of suspended transformer oil drops 2–10 μm in size. Addition of aluminum salts or ferrous salts to a concentration of 10−5–10−4 M increases the treatment rate by about an order of magnitude.

The Eley-Rideal and Langmuir concepts of surface reactions were used to develop a model of heterogeneous hydrodynamic coagulation of diluted “oil-in-water” emulsions (0.1–2.0 vol %). The mathematical model was verified, and factors that govern the coagulation rate were revealed.

A prototype reactor for heterogeneous hydrodynamic coagulation of emulsions was developed and tested. The efficiency of coagulation of water emulsions of some organic liquids was studied in relation to process conditions.

The kinetics of migration of monomolecular layers of surface-active extractants on water is studied. The problem is important in the context of radioactive contamination of the surface of water reservoirs and watercourses. The migration velocities of eight extractants used in the radiochemical industry and 37 systems containing these reagents are determined.

The migration velocities of surfactants on the surface of tap water are measured by the tracer method. The results are well reproducible, although the surfactants and the water are used without special purification. A decrease in the surfactant migration velocity with time was observed. It is found that the main cause of the decrease is an increase in the weight of the water adjacent to the surface film. The radial migration after a very short time is characterized by uniform surfactant motion.

The discovery and development of effective antihypoxic drugs is an important issue in modern experimental and clinical pharmacology. Complexes of zinc containing imidazole cycles as ligands are promising candidates for the design of novel drugs, including pharmacotherapeutic tools for patient’s protection under conditions of oxygen deficiency. Herein, we report antihypoxic activity of zinc complexes with N-alkenylimidazoles, and, specifically, a novel drug Acyzol, which can be used as efficient antidote after poisoning by carbon monoxide and other combustion products.

The influence of surfactants and temperature on the intensity of interphase mass transfer in back extraction under conditions of forced Marangoni flows was studied.

Experimental evidence was obtained in favor of the existence of the fine structure of the interface region in the liquid-liquid system far from equilibrium. The predominant interface phenomenon in the liquid-liquid system proved to be the formation of dispersed layers, whose occurrence and evolution determine the mass and momentum transfer through the interface.

The hydrodynamics and kinetics of CO2 absorption by water when the interface is disturbed by partially immersed disks that execute torsional oscillations or uniform unidirectional motion (rotation) was studied. It is shown that interface disturbance and generated surface flows enhance mass transfer by a factor of 2.5 and lead to extremum dependences of the mass transfer coefficient on the area and thickness of the insoluble film covering the water surface. The surface flows generated by disks at the gas-liquid interface were examined. Two types of surface flows that differ by their direction and the nature of driving forces are revealed. The role of these flows in enhancing mass transfer at small Re numbers was elucidated.

Oil-in-water emulsions at concentrations of 0.001‐ 1 vol % are very important objects because they are involved in fine water treatment to remove oil microdrops and in the formation of cruds, which cause a nuclear hazard in radiochemical extraction processes. In this work, a method was proposed for studying the coalescence of microdrops of organic liquids on the surface of solids and cloths. It was shown that the determining step is a second-order process occurring on the collision of microdrops coming from the bulk with drops of surface clusters. Once the microdrop size has become smaller than a certain value, the process rate constant significantly decreases. It was found that the decisive role in the microdrop coalescence is played by the pH of the oil-in-water emulsion and the specific surface area of solids. The proposed mechanism accelerates the separation of oil drops from water by a factor of hundreds or thousands.

The principal interphase phenomena accompanying the transfer of a substance through liquid membranes (chemical reactions, the formation of supersaturation and microheterogeneity zones, spontaneous interphase convection), which are related to many important characteristics of the kinetics of ion transport, have been examined. By influencing these processes it is possible to control the rate of trans-boundary transfer. The bibliography contains 61 references.