The purpose of research. The hypothesis that the anisotropy of the properties of selective laser fusion powder products is solely related to their porosity is controversial. The authors substantiate the ideas about the significant effect on the anisotropy of the properties of SLM products, their heterogeneity and the unevenness of the plastic flow of local plasticity zones formed at the pores during loading. The purpose of this work is to model pore formation and mathematically analyze the effect of plasticity zones on anisotropy, heterogeneity of mechanical properties and plastic flow of SLM technology products on the micro and macroscale.
Methods. To achieve this goal, simulation and computational modeling of the pore formation process in samples of powder alloys 316L and Inconel 718 made by layered laser fusion, as well as their uniaxial tensile tests with microstructure analysis (optical and SEM) and X-ray computed tomography were used.
Results. The role of pores as stress concentrators and foci of local plasticity forming autowaves of plastic deformation is substantiated. This fact was confirmed by a mathematical analysis of the distribution of local deformations over the length of samples and test time using the decomposition of their arrays into a Fourier series and their subsequent Fourier interpolation.
Conclusion. Equations describing the effect of stress and strain intensity on the development of the indicator of heterogeneity of mechanical properties and the unevenness of the plastic flow of the studied alloys at the micro and macroscale are obtained. It is proposed to use them to automate the analysis of the evolution of anisotropy and heterogeneity of mechanical properties in SLM products.

The purpose of this work was to study the stability of products made from various textile materials, including cotton and viscose, exposed to friction and washing in various aggressive environments.
Methods. The resistance of cotton and viscose fabrics treated with flame retardants based on electroerosive Aluminum hydroxide powder to washing was studied on a mechanical device, which includes a water bath with a rotating shaft. To test the resistance of fabrics to friction, 18x8 cm samples were prepared. Before testing the tissue samples, they were impregnated with a new flame retardant based on electroerosive Aluminum hydroxide powder and compared with a new dry tissue sample. The tissue samples were subjected to several washing cycles. An increase in the number of washing cycles led to the loss of part of the flame-retardant impregnation and a decrease in the burning time of the treated fabric.
Results. According to the results of the conducted studies, it was found that the resistance of fabrics with flame-retardant impregnation to physico-chemical influences depends on the concentration of powder and the composition of the textile material. At the same time, a flame-retardant impregnation based on electroerosive Aluminum hydroxide (EEGA) is obtained from Aluminum metal waste by an environmentally friendly and low-energy-intensive method of electroerosive dispersion. The protective functions of the new flame retardant are manifested as follows: under the influence of high temperatures, the EEG releases crystallizing moisture (steam) and thereby lowers the temperature below the ignition point. In addition, the resulting water vapor prevents oxygen from entering the combustion zone. Gorenje.

The purpose of the work was to study the effect of laser microstructuring on changes in carbon concentration and zonal residual macro stresses of the first kind in the laser exposure zone of carbon steel sheet samples of grades 20, 35, 45 after laser microstructuring according to various modes.
Methods. Structural carbon steels of grades 20, 35, and 45 were selected as objects of research. To study the effect of laser modification on changes in the structure and mechanical properties of machine parts using laser cutting, special samples were made in the form of square plates (35×35 mm) with a thickness of 2 mm (St20 and St45) and 4 mm (St35). After laser cutting according to the modes, one of the sides of the sample was subjected to mechanical grinding in order to remove a layer with a modified structure of the material obtained during laser cutting. Next, laser microstructuring of the sample surfaces was performed using a continuous fiber laser. X-ray diffraction studies to determine the carbon content, sign, and level of residual stresses of the first kind (macro stresses) were performed using a DRON- 4.0 X-ray diffractometer in cobalt Ka radiation in the discrete point survey mode.
Results. Using the method of X-ray diffraction phase analysis, an increase in the carbon content in the surface layer of samples after laser microstructuring of medium-carbon steels of grades 35 and 45 was revealed, significantly exceeding the values established by GOST 1050-2013. The revealed increase in carbon concentration is probably related to the realization of the Soret effect (thermodiffusion) under conditions of exposure to high temperatures. It has been established that laser microstructuring of the working surfaces of medium-carbon steels of grades 34 and 45 leads to the formation of high zonal residual compression stresses (up to -2300...-3800 MPa). The obtained result indicates the positive effect of laser treatment on the mechanical properties of the surface layer.
Conclusion. The results obtained can be used in the creation of resource-saving material processing processes.

The purpose of the study. To develop a carburizer for nitrocementation based on amorphous carbon DG-100 and nitrogen-containing components urea (NH2)2CO, potassium iron-sulphide K4Fe(CN)6. Study the features of nitrocementation of X12MF steel in nitrogen-carbon medium at different temperatures.
Methods. Metallographic and X-ray diffraction analyses of nitrocemented samples were carried out using Quanta FEG650 electron scanning microscope and EMMA diffractometer. Wear tests of carbonitrided samples were carried out under conditions simulating the operation of die tools.
Results. Experiments have shown that modified layers on 5ХНМ steel begin to form already at 500°C. The depth of these layers depends on the processing temperature: at 550°C the depth is about 5 microns, and at 650°C 15... 20 microns. X-ray diffraction analysis revealed the presence of hexagonal carbonitride ε on the surface of steel treated at 550°C, and carbonitrides of two types (ε-phase and phase isomorphic to cementite) at 650°C. The microhardness of surface layers reaches 10 GPa at 550°C and 8...9 GPa at 650°C. The depth of diffusion layers depends on the urea content in the paste, while the influence of potassium iron-sulphide is evident only at temperatures above 600°C. Conclusion. Nitrocementation in a highly active nitrogen-carbon medium is an effective method of hardening of stamping tools made of 5ХНМ steel. At low temperatures (550°C), preferential saturation with nitrogen occurs, and at 650°C joint saturation with nitrogen and carbon. The resulting carbonitride layers have high hardness and wear resistance, which makes this method promising for hardening tools operating under increased loads.

The purpose of the work was to study the effect of laser microstructuring on changes in the microhardness and structure of the laser exposure zone of U8A high-carbon steel sheets.
Methods. High-carbon steel sheet U8A grade (sheet thickness 10 mm) was selected as the objects of the study, from which samples for the study were cut using a continuous fiber laser equipped with an EIP1119 optical head manufactured by NTO IRE-Polyus. After gas laser cutting, laser microstructuring of the rolled Q-switch surface was performed using a fiber pulsed laser according to the following mode: speed 40 mm/s; power 100 Watts; frequency 100 kHz, pulse duration 100 ns, pulse energy 1MJ. To study the microstructure, slits were made, followed by etching the surface with a 5% HNO3 solution in alcohol. The microstructure was studied using a Nikon MA200 inverted metallographic microscope at different magnifications. The following equipment was used to measure the macrohardness: Rockwell TP150M hardness meters (scales HRC, HRB and HRA), Super-Rockwell TRS 5009-01M (scale HRN15 – at a load of 15 kgf). Microhardness was measured on a KBW1-V hardness tester under loads: 10 N, 1 N and 0.25 N.
Results. It was found that laser treatment of the surface of the samples led to an approximately two-fold increase in the hardness of the surface layer with a depth of 0.029-0.045 mm. It is revealed that the increase in hardness occurs due to a change in the structure of the surface layer of the samples as a result of an increase in the dispersion of granular perlite. It is shown that during laser exposure, the surface of the samples is heated and further cooled in air after laser removal, which corresponds to classical heat treatment – normalization. The obtained hardness values correspond to the troostite structure.
Conclusion. The results obtained can be used in the creation of resource-saving material processing processes.

Purpose. Investigation of morphology, determination of material balance and dynamics of accumulation of electroerosive nickel powders.
Methods. To analyze the shape and morphology of the surface of nickel powder particles, as well as to compile the material balance and dynamics of their accumulation, electroerosion nickel powders were obtained by electroerosion dispersion from PNK-0T1 nickel waste in two different dielectric media: aviation kerosene and distilled water. The operating values of the EED parameters are: voltage at the electrodes 115-120 V for kerosene and 98-105 V for water, respectively; capacitor capacity 44.0–45.5 UF for kerosene and 60.0–62.0 UF for water, respectively; pulse frequency 60-65 Hz for kerosene and 100-110 Hz for water, respectively. Microanalysis of the powder particles was performed using a QUANTA 600 FEG scanning electron microscope.
Results. Morphological studies aimed at determining the shape of the surface of the EENP particles made it possible to establish that the particles are characterized by a spherical and, more rarely, an elliptical shape, and the formation of aggregates from particles of the smallest diameter was also noted. The maximum loss of material in the EED process is 0.7% of the total mass. The efficiency of the nickel waste EED process is 4.3 g/hour for distilled water and 2.3 g/hour for aviation kerosene.
Conclusion. The obtained research results can be used to develop a new heavy pseudo-alloy using metal waste from expensive nickel raw materials by electroerosion dispersion with subsequent improvement and optimization of the alloy composition and structure to achieve the necessary characteristics of a new heavy pseudo-alloy.

Purpose of research. To determine the influence of red colloidal quantum dots with the CdSe/CdS/ZnS structure on the luminous efficiency and color rendering index of LED devices.
Methods. Microscopic, fluorescent and micro-X-ray studies of a silicone composite with red colloidal quantum dots CdSe/CdS/ZnS and phosphor powder of yttrium-aluminum garnet in white LEDs with a single InGaN chip as a 453.7 nm excitation source were carried out. Goniophotometric measurements of the spatial distribution of luminous intensity together with a spectrocolorimeter made it possible to determine the luminous efficiency and color rendering index of white LEDs.
Results. The powder mixture of yttrium aluminum garnet particles obtained in this work with red colloidal quantum dots with a CdSe/CdS/ZnS structure stabilized with trioctylphosphine and trioctylphosphine oxide applied to their surface in the form of an island film and with wavelengths of luminescence maxima in the range from 590 to 630 nm under industrial production conditions made it possible to manufacture more than 100 white SMD LEDs with an improvement in luminous efficiency by 11%. For cold and neutral white light with chromaticity coordinates from x = 0.332 and y = 0.318 to x = 0.404 and y = 0.401 in the CIE 1931 color space, the color rendering index Ra of white LEDs with quantum dots exceeded 90 with red color index R9 values from 63 to 81.
Conclusion. This paper shows the efficiency of using red quantum dots based on II-VI semiconductors for white LEDs with a quantum yield of at least 50% at a controlled concentration corresponding to the yttrium-aluminum garnet powder weight, due to the absence of a luminescence shift to the IR region, which is characteristic of the CaAlSiN3 nitride phosphor.

Purpose of the study. Obtaining composite materials by hot pressing with different percentage ratios of Titanium dioxide and Cerium dioxide nanoparticles, studying their phase composition and microhardness.
Methods. Composite materials with inclusion of titanium Dioxide nanoparticles and Cerium dioxide particles with their different percentage content in samples were obtained by hot pressing. The nanometer size of particles in titanium dioxide powder was determined by atomic force microscopy. The presence of titanium dioxide and cerium dioxide particles in the obtained composite materials was shown using X-ray diffractometry. The average value of microhardness of composite samples was determined by the Vickers method.
Results. Composite materials with a diameter of 40 mm and a thickness of 9 mm based on acrylic resin with different percentage composition of Cerium dioxide and Titanium dioxide powders in the samples were obtained. Analysis of AFM images of titanium dioxide powder allows us to note the presence of both nanosized particles and their agglomerates in it. According to the results of X-ray structural analysis, the presence of cerium dioxide particles and titanium dioxide nanoparticles in the composite samples and the absence of impurities of other substances in them were revealed. The anatase phase in TiO₂ was determined. It was found that when Cerium dioxide particles and titanium dioxide nanoparticles are added to the acrylic matrix, the microhardness of the composite materials increases.
Conclusion: This paper describes a method for producing composite materials using hot pressing. It has been established that the microhardness values of composite materials increase with the growth of the percentage of fillers in them. The growth of the microhardness of composite materials is presumably due to the intermolecular interaction of the filler mixture and acrylic resin with each other during its melting.

Purpose. Development and study of real-time neutron radiation spectrometers with an energy range from thermal to fast neutrons.
Methods. The following methods are used in the work: mathematical modeling, experimental research methods, circuit and design engineering.
Results. The scientific basis for a new method of neutron radiation spectrometry with an arbitrary energy spectrum shape in the energy range from 0.001 eV to 20 MeV with the reconstruction of the measured flux spectrum based on the responses of several detectors with different spectral characteristics using a neural network trained on a sample of over 1000 spectrums of various shapes has been developed.
A mathematical model of a neutron spectrometer has been developed and its study has been carried out with various combinations of detectors. An optimal combination of detectors/measuring channels has been determined, providing a minimum error in spectrum reconstruction averaged over all spectra of the training sample (~3%) with a minimum number of detectors/measuring channels used.
The structure and mathematical support for an automated test and verification complex for calibrating and verifying a neutron spectrometer have been developed.
A prototype of a gamma-neutron spectrometer-dosimeter with secondary processing of information received from the detection unit on a PC has been developed and manufactured. Its measuring channels have been adjusted for the radiation background of radon and its decay products and on a neutron setup with a plutonium-beryllium neutron source at the Research Institute of Nuclear Physics of Moscow State University.
The operability of the detection unit at an altitude of 20 km has been proven, graphs of the dependence of the count rate of all measuring channels on the altitude have been obtained.
Conclusion: The conducted experimental studies of the prototype of the multi-detector gamma-neutron spectrometerdosimeter confirmed the effectiveness of the adopted concept and the validity of the underlying theoretical principles justifying the development of the industrial prototype.

Purpose. Study of the dependence of the electronic structure and antioxidant properties of ablated cerium dioxide nanoparticles on the annealing temperature under photocatalytic reaction conditions in the presence of titanium dioxide nanoparticles.
Methods. Nanoparticles of cerium dioxide were obtained by laser ablation. The average sizes of ablated nanoparticles of cerium dioxide subjected to centrifugation and high-temperature annealing were calculated from AFM images. A change in the electronic structure of annealing was detected by spectrophotometry, and sedimentation of annealed nanoparticles was studied. Also, the dependence of the antioxidant activity of cerium dioxide nanoparticles on the annealing temperature in the photocatalysis process was determined using a spectrophotometer.
Results. The average sizes of ablated annealed centrifuged cerium dioxide nanoparticles were determined to be in the range from 46,3±0,5 nm to 82,8±0,5 nm. The studies revealed a bathochromic shift in the energy position of the 4f0 states of Ce4+ ions in the bandwidth of the bandgap of annealed cerium dioxide nanoparticles after annealing, and its effect on the sedimentation process of nanoparticles was not revealed. It was found that during the photocatalytic reaction in the presence of ablated annealed cerium dioxide nanoparticles, the degradation rate of the methylene blue dye increases, i.e., the antioxidant activity of CeO2 nanoparticles decreases.
Conclusion: From the results of the studies presented in this paper it follows that under the influence of high-temperature annealing the physicochemical properties of ablated cerium dioxide nanoparticles change, in particular, their antioxidant activity decreases, but the sedimentation rate of nanoparticles in an aqueous solution remains constant.

Purpose. To theoretically investigate the optical response of compensated suspensions of ferromagnetic carbon nanotubes in a nematic liquid crystal induced by an external magnetic field.
Methods. The problem was solved within the framework of the continuum theory, which is based on the free energy functional. To describe the orientational structure of the liquid crystal and the impurity ferromagnetic carbon nanotubes, two vector quantities were used, i.e. directors, which specify the directions of the preferred orientation of the long axes of the molecules and nanotubes. Since the work considered a compensated suspension, which is a liquid crystal analogue of an antiferromagnet, two equal volume fractions of nanotubes with magnetic moments directed parallel and antiparallel to the director of the liquid crystal were additionally taken into account. Thus, the free energy of the suspension is a functional with respect to two vector and two scalar quantities. The equilibrium states of the system were determined from the condition of minimum free energy, as a result of which a system of integro-differential equations was obtained, which could be integrated. The numerical solution of the final system of equations was carried out using the multidimensional secant method. Integration was carried out using the Simpson method.
Results. A system of integral equations of orientational and magnetic equilibrium of a compensated liquid-crystal suspension of ferromagnetic carbon nanotubes was obtained. For different values of the magnetic field, the optical phase difference (phase lag) between ordinary and extraordinary beams of monochromatic light passed through a planeparallel cell with the suspension was calculated.
Conclusion. Impurity carbon nanotubes, which are additionally filled or covalently functionalized with magnetic particles, are capable of significantly enhancing the magneto-orientational response of the nematic matrix compared to a pure liquid crystal. This allows us to make a prediction about the potential use of liquid crystal suspensions of ferromagnetic carbon nanotubes in magneto-optical devices.

Purpose. Using a model of a magnetic polymersome, considering the substance located in the cavity, to study the features of the migration of particles of the transported substance depending on the permeability of the membrane and its magnetic properties using the method of coarse-grained molecular dynamics.
Methods. The polymersome under study is represented as a set of interacting particles of three types: polymer particles simulating the bilayer of an amphiphilic membrane; magnetic nanoparticles located in the membrane layer, and substance particles placed in the cavity. Polymer particles interact via elastic potentials that maintain equilibrium spherical vesicular geometry. Magnetic nanoparticles interact with each other as point dipoles. The steric interaction of magnetic particles with polymer walls is modeled as soft repulsion. The interaction of substance particles and polymer layers can be adjusted to account for their impermeability. Magnetic nanoparticles are considered impermeable for the substance carried by the polymersome. The model polymersome under study corresponds to a magnetopolymer particle with a diameter of about 100 nm located in an aqueous solution at 25°C, half of the cavity of which is filled by volume with substance particles. The behavior of the system is monitored over several realizations, followed by averaging using a numerical solution of the particle motion equations with introduced interactions and imposed conditions, and further analysis of the resulting sets of particles.
Results. In numerical experiments, the influence of the elastic properties of the membrane on the equilibrium state of a polymersome containing a given number of magnetic particles and particles of the transferred substance was investigated. The features of the migration of substance particles from the cavity of the polymersome were analyzed depending on the permeability of the membrane and the properties of magnetic nanoparticles located in the membrane layer.
Conclusion. The presented model allows us to describe the features of the release of particles of a substance enclosed in the cavity of a magnetic polymersome in the presence of a magnetoactive layer in the capsule membrane.

Purpose. To investigate the magnetic and magneto-orientational responses of a nanodisperse ferrocolloid to an external magnetic field under conditions when the carrier fluid is a viscoelastic medium.
Methods. The ferrocolloid is modelled as an ensemble of nanoparticles bearing `frozen-in’ dipolar (magnetic) moments. The considered particles possess only a single rotary degree of freedom (rotators). This approximation facilitates considerably the mathematical description yielding, however, the results which are in full qualitative resemblance with those, which could have been obtained via a very cumbersome way for a real system where the particles possess two rotational degrees of freedom. The viscoelastic medium is described with the aid of the Jeffreys rheological scheme. The theoretical framework for magnetodynamics of the ferrocolloid is based on the Fokker-Planck-type kinetic equation that describes the nanoparticle orientational motion in the presence of thermal fluctuations. Solution of the problem is obtained via transforming the kinetic equation in the set of moment ones. It is demonstrated that to obtain the static and dynamic susceptibilities, it suffices to use just a few first ones of the developed set of moment equations.
Results. The spectra of the first and third harmonics of the dipolar response (magnetization) are evaluated in a wide range of material parameters of the system and frequency. The same for the same conditions, the spectra of the second harmonic and static component (orientational anisotropy). It is shown that in the system with a high level of dynamic elasticity there exists a frequency interval within which the static component of quadrupole response becomes negative. Conclusions. An effective method to calculate the linear and nonlinear magnetic susceptibilities of the model ferrocolloid is proposed. The sign inversion of the static component of the quadrupole response – it is identically absent in linearly-viscous fluids – turns out to be an indicator (“signature”) of pronounced viscoelasticity.

Purpose. To study the behavior of dispersed media based on nanodispersed magnetic fluids: non-magnetic liquid and gaseous inclusions in a magnetic fluid, drops of magnetic fluid in a non-magnetic medium, as well as non-magnetic bubbles and drops covered with a shell of magnetic fluid in non-uniform magnetic fields.
Methods. The results were obtained experimentally using generally accepted methods and approaches. The setups used for the studies were developed independently, and data were collected using standard measuring equipment. The magnetic field induction value was measured using a TPU-01 teslameter with a Hall transducer connected to it. The magnetic field topology was modeled using the FEMM software embedded in the MathLab interactive environment. The platform not only models the magnetic field, but also qualitatively transforms the calculation results and visualizes them. The images of non-magnetic inclusions were processed in a specially developed program in the NI Labview system. Theoretical processing of the experimental results was based on known expressions of condensed matter physics, magnetic and classical hydrodynamics.
Results. Experimental dependences of the coordinate, velocity, size of dispersed media based on magnetic fluid on the magnetic field parameters, physical properties of magnetic and non-magnetic fluids are obtained. Based on the results of computer modeling in the FEMM program, an assessment of the forces acting on a non-magnetic drop and bubble in a magnetic fluid is carried out. The obtained experimental and theoretical data are consistent with each other.Experimental dependences of the position, velocity, and size of magnetic fluid-based disperse media on magnetic field parameters and the physical properties of magnetic and non-magnetic liquids were obtained. Computer simulations were used to estimate the forces acting on non-magnetic droplets and bubbles in a magnetic fluid. The experimental and theoretical data are in good agreement.
Conclusion. An inhomogeneous magnetic field allows for the control of the dynamics and behavior of magnetic fluidbased disperse media, paving the way for the development of controllable dispensers and systems for synthesizing active droplets.

Purpose. The process of the crushing of polymer waste during the regeneration process is the main stage of the preparing the material for further use. It is usually accompanied by the formation of small particles of the polymer dust. These particles are unable to deposit into the receiving hopper under the influence of gravity; therefore, they are removed from the gas curve under the influence of centrifugal force. Small particles move towards the cyclone body wall and settle in the collectors.
This leads to the accumulation of a significant amount of polymer materials classified as waste "Dust of polymer materials from filters" (code 578 002 00 11 00 4), and involves the search for ways of further use. The size of polymer dust particles determines the volumetric density, flowability and other technological characteristics at the stage of waste preparation for processing, and the physico-chemical properties affect the selection of optimal technologies that allow efficient recycling of waste and obtaining useful products.
The aim of the work was to analyze the waste of polymer dust of polyesters TPE-Е in order to determine a number of technological properties as a potential raw material for creating various functional materials based on it.
Methods. The analytical gravimetric method of the measurement of humidity, hygroscopicity, moisture capacity, moisture content, physico-chemical methods for determining granulometric composition, melting point, and chemical resistance assessment.
Results. The paper evaluates the fundamental properties of TPE-Е polymer dust wastes, studies the technological properties of these bulk materials in terms of granulometric composition, humidity, flowability, specific volume, bulk density, and calculates second-order characteristics (indirect indicators), such as the angle of natural slope, coefficient of internal friction. The resistance of waste to solvents, acids, alkalis and their mixtures has been investigated Conclusion. The obtained characteristics are supposed to be used in the development of methods for processing and recycling of polymer dust TPE-Е.