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Volume 25 № 3 2023

1. Konstantin E. Chekmyshev, Yuliya V. Ganziy, Sergey S. Makarov, Mikhail Yu. Alies. Numerical Investigation of the Process of the Fibre-Reinforced Polymer Bar Heating in a Curing Oven Taking into Account the Binder Curing Kinetics. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp.  287-302.  Download

A numerical investigation was conducted for the process of the fibre-reinforced polymer bar (FPB) heating in a curing oven taking into account the curing kinetics of the binder of the system: epoxy resin – anhydride curing agent – tertiary amine. The dependences of the temperature and the degree of the binder curing for FPB at the exit of the curing oven on the values of the infrared emitters temperature, the needletrusion speed, the binder volume fraction and the FPB diameter were established. It has been shown that in order to provide the degree of the binder curing of 0.95 or more of FPB with a diameter of 10 mm or less at the binder volume fraction of 0.36, it is recommended to use the needletrusion speed of no more than 2 m/min at the constant temperature of infrared emitters no more than 370 °С in all sections of the curing oven. The effectiveness of the above binder was compared with the binder of the system: epoxy resin – cycloaliphatic diamine. It has been established that under the same conditions, the considered binder cures more slowly: 1.26 and 1.87 times slower at the air temperature in the oven of 24 °C and the volume fraction of 0.2 and 0.6 respectively, and 1.11 and 1.52 times slower when the oven is heated up to 200 °C at the same volume fraction. This means that the considered binder will result in lower needletrusion process performance but it can provide higher values of FPB performance properties. The fields of the temperature, the heating rate and the degree of the binder curing in the FPB 10 mm in diameter were obtained after the FPB needletrusion at speed of 2 m/min in a four-section curing oven 4 m in length. The temperature regime for each section of the curing oven has been selected, which provides the binder curing degree of more than 0.95. The obtained results of the numerical investigation will permit to reduce the time for testing temperature regimes and to decrease the number of full-scale experiments at the manufacturing.
Keywords: fibre-reinforced polymer bar, curing oven, heating, binder curing, phase transition, mathematical modeling, numerical investigation.

DOI: https://doi.org/10.15350/17270529.2023.3.25


2. Irina V. Anisimova, Victor N. Ignatyev. Higher-Order Difference Schemes in Heat and Mass Transfer Problems. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp.  303-309. Download

The development of various technical devices  in thermal power engineering using liquid or gas as a working medium and optimization of their operating modes necessitate using   the numerical simulation of the processes of heat and mass transfer in this medium under appropriate conditions. Macroequations of heat and mass transfer are the the equations belonging to the type of differential equations with a small parameter at the highest derivative. The solutions of such equations have singularities of the boundary layer type. This is the reason why classical difference schemes poorly describe the original differential problem in the boundary layer region. Classical difference schemes can have an approximate (scheme) viscosity commensurate with the grid step, which can affect numerical simulation. In this paper, it is proposed to build schemes of high order of approximation ( HODS). As the order of approximation increases, theHODS more accurately takes into account the behavior of the boundary-layer type function in its solution. To increase the order of the approximation of the difference scheme, i.e. to reduce the approximation viscosity, the grid step reduction was not suitable, since the value of the small parameter was commensurate with the grid step. The order of the approximation of the constructed difference scheme on a three-point stencil was increased to 4 with the use of its first differential approximation and the introduction of a regularizer. HODSs were tested to calculate the flow of a viscous fluid in a pipe with a circular cross section. In comparison with the analytical solution, the error of the numerical calculations was 0.017% according to the space norm.
Keywords: Navier-Stokes equations, difference schemes, approximate viscosity, MatLab.

DOI: https://doi.org/10.15350/17270529.2023.3.26


3. Alexey Yu. Krainov, Ksenia M. Moiseeva, Vasily A. Poryazov. Numerical Simulation of Non-Stationary Combustion of a High-Energy Material in a Closed Volume on the Basis of the Adjoint Combustion Model. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 310-320. Download

A theoretical study is presented of combustion in a manometric bomb of a constant volume charge consisting of grains of a high-energy material containing nanosized aluminum powder. The experimentally measured dependence of the pressure increase in a manometric bomb is compared with the calculations obtained with the use of the thermodynamic model of combustion of a sample of high-energy material in a manometric bomb based on the empirical law of the dependence of the burning rate on pressure and the calculation results obtained by the conjugate model of unsteady combustion. The non-stationary burning rate of a high-energy material, due to the high rate of pressure growth in a manometric bomb, differs from the quasi-stationary rate. This difference depends on the rate of pressure growth and on its absolute value, and decreases with increasing pressure. An analysis was made of the influence of the addition of a nanosized aluminum powder to the composition of a high-energy material on the dynamics of the charge combustion in a manometric bomb.
Keywords: high-energy material, aluminum nanopowder, non-stationary burning rate, numerical simulation.

DOI: https://doi.org/10.15350/17270529.2023.3.27


4. Gennady M. Poletaev, Viktor V. Kovalenko. Molecular Dynamics Simulation of Interdiffusion at the Initial Stage of High-Temperature Synthesis During the Dissolution of a Ni Nanoparticle in an Al Matrix. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 321-328. Download

The method of molecular dynamics was used to study interdiffusion at the initial stage of high-temperature synthesis during the dissolution of a Ni nanoparticle in an Al matrix under conditions of the crystalline and amorphous state of nickel and aluminum. Interactions between atoms in the Ni-Al system were described by the well-tested EAM potentials. Aluminum and nickel particles were originally produced in a crystalline state. The amorphous structure of aluminum or nickel was obtained by heating in the model of the corresponding phase to a temperature significantly higher than the melting point of the metal, holding for some time for the final destruction of the crystalline structure, and subsequent rapid cooling. It is shown that the decrease in the ignition temperature of the high-temperature synthesis reaction in the Ni-Al system is much stronger in the case of the amorphous state of nickel. The intensity of mutual diffusion at a constant temperature is almost independent of the state of the structure (crystalline or amorphous) of aluminum. In the case of the amorphous state of the nickel particle and the aluminum matrix, the dissolution occurs much more intensively than in the crystalline state of nickel. The rate of the dissolution of an amorphous particle already at a temperature of 700 K corresponds to the melting temperature of aluminum in the case of a crystalline nickel particle.
Keywords: molecular dynamics, nanoparticle, interphase boundary, nickel, aluminium.

DOI: https://doi.org/10.15350/17270529.2023.3.28


5. Mikhail A. Korepanov, Rudolf R. Sharifullin. Simulation of Processes in a Low-Power Indirect Diesel Heater. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 329-336. Download

The results of mathematical modeling of the processes occurring in an indirect diesel heater with power up to 20 kW are presented. The aim of the study was to develop technical solutions for optimizing and improving thermogasdynamic and thermal processes in the heater under conditions of size restrictions. It is proposed to make the flow sections of the two passes of the heat exchanger different in area, because the combustion products cool down moving through the heat exchanger, as a result the volume flow decreases, and flow cross section can be reduced. In accordance with this and taking into account the design features, the total angles of the forward and reverse flow sections were chosen – 145 and 215 degrees. Also, such a distribution of the flow sections of the gas ducts makes it possible to reduce the hydraulic resistance of the heat exchanger by 20 % by maintaining an approximately constant flow rate of the combustion products, compared with a heat exchanger with equal flow sections of the gas ducts. Comparison of the numerical simulation results with full-scale experiment is carried out, a good qualitative and quantitative agreement between the values of controlled quantities – gas flow and temperature is shown.
Keywords: diesel heater, thermogasdynamics, combustion, temperature field, velocity field.

DOI: https://doi.org/10.15350/17270529.2023.3.29


6. Pavel V. Gulyaev. Recognition of Reference Microlabeling Images against the Background of Similar Relief Elements. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 337-342. Download

The problem of recognizing a reference microlabeling  by microscopic images containing elements of pseudo-labeling (similar to the real substrate relief elements ) is considered. The scope of such marking is the identification of the studied or modified surface areas as well as the lines connecting these areas with macroscopic landmarks on the surface. The microlabeling is formed using a probe microscope cantilever or a nanoindentor. Examples of images with pseudo-labeling elements and the results of their recognition by low-level structural analysis methods previously used for microlabeling recognition are given. In particular, a surface curvature detector was used, which has proven  to be good for discrete microlabeling recognition. The effect of pseudo-labeling is the formation of a large number of the image background key points, which reduce the effectiveness of recognition. The application of the linear Hough transform for approximation and subsequent recognition of separate labeling elements is described. It is also shown that to recognize the labelings obtained by the probe microscope cantilever, it is advisable to use morphological erosion before the Hough transformation. The procedure for setting the parameters of this transformation, which most significantly affect the recognition of markings, is described. The range of the recorded Hough transform segments and the Hough transform threshold were used as such parameters. An image processing algorithm and a recognition evaluation criterion are presented. In this case, a histogram of the distribution of the angles of mutual rotation of the segments detected by the Hough transform is used. The recognition criterion is the presence of dominant peaks with certain values in this histogram. The results showing the efficiency of the presented algorithm are presented.
Keywords: probe microscopy, reference microlabeling, image processing, structural recognition, Hough's method.

DOI: https://doi.org/10.15350/17270529.2023.3.30


7. Mikhail G. Kucherenko, Petr P. Neyasov, Ildar R. Alimbekov, Nikita Yu. Kruchinin, Sergey S. Masyutin, Vladimir N. Stepanov. Effect of Spheroidal Nanoparticles on the Fluorescence of Dye Molecules and Adsorbed MEH-PPV Macrochains in Solutions. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 343-361. Download

The anisotropic properties of nonspherical nanoparticles make it possible to significantly expand their spectral-optical applications associated with local field effects. The plasmon resonance characteristics of such particles have additional features that are absent in conductive nanoglobules. The results of the synthesis and AFM morphological analysis of ellipsoidal hematite nanoparticles coated with a gold shell and spherical magnetite nanoparticles are presented. The absorption spectra of the aqueous solutions of such nanoparticles, as well as conductive nanoparticles with chain molecules adsorbed on them, were obtained. Based on the methods of dynamic light scattering, histograms of the particle size distribution are constructed. The influence of spheroidal magnetic nanoparticles coated with a gold shell on the luminescence intensity of the molecules of an organic dye (fluorescein) and poly[2-methoxy-5(2'-ethylhexyloxy)-1,4-phenylenevinylene] has been studied. An increase in the luminescence intensity of both types of phosphors at certain concentrations of metallized spheroidal nanoparticles was found. A mathematical model of radiative and nonradiative processes in the studied colloidal system is presented, as well as the results of the calculations of spectral and velocity characteristics based on well-known application FDTD packages. Characteristic graphs are constructed for the spectral density of the number of photons emitted at a certain frequency of the combined system "molecule - nanoparticle" for various positions of the nanoparticle relative to the molecule and two characteristic directions of the transition dipole moment vector. The relationship between the frequencies of two plasmon resonances and the eccentricity of the spheroid revealed in the model is clearly manifested in the obtained spectral curves. The closer the spheroid eccentricity is to 0, the smaller the frequency interval is between two spaced plasmon resonance peaks, which merge into a single spectral band at zero eccentricity. The results obtained can be used in the development and modification of sensors with a tunable conformational structure of macrochains, such as luminescent optical testers for the concentration of molecular oxygen (including singlet oxygen) and chemical sensors based on the effects of surface plasmon resonance and surface-enhanced Raman scattering.
Keywords: composite spheroidal nanoparticles, conductive shell, absorption spectra, energy transfer, fluorescence.

DOI: https://doi.org/10.15350/17270529.2023.3.31


8. Veronika I. Tereshchenko, Nadezhda V. Semakina. Quantum-Chemical Modelling of Fullerene Endohedral Complexes with Non-Metals. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 362-374. Download

The next stage in the development of electronic computing is the creation of the quantum computer, a device that will revolutionise data handling. A special feature of such computers is the speed of information processing and transfer achieved by the use of quantum scale effects. A quantum computer is being developed by leading companies and leading groups of researchers; however, at present, there is no consensus about the architecture and principles of functioning of such computing devices. In this connection, many phenomena of quantum mechanics are being realized to achieve a qualitatively new level of information processing. An element of new generation computers, responsible for data storage and processing, can be a system limited to two quantum states. The purpose of this work is to investigate the electronic configuration of the valence energy level of the phosphorus atom encapsulated in a volume of fullerene С50 of D3 and D5h symmetries to establish the possibility of using orientations of unpaired electrons (their spins) as identifiers of information units. The calculations of the physico-chemical properties and structure of the above fullerenes and endofullerenes with a phosphorus atom formed from the original molecules were performed using the quantum-chemical PM3 method. The results demonstrate the lack of bonding between the carbon atoms and the phosphorus atom located in the inner space of each of the endofullerenes. In the endocomplex  P@C50(D5h) the phosphorus atom accepts an electron decreasing the number of unpaired valence electrons to two. In the molecule P(@C50(D3), for phosphorus the most probable electron configuration of the outer energy level is either the transition to excited state or the formation of an electron pair and the retention of other two unpaired electrons. The  molecular structure calculation results suggest the relative stability of the endofullerenes P@C50 (D5h and D3 symmetries) and the possibility of using the unpaired phosphorus electrons in these compounds for information processing in quantum computers.
Keywords: quantum chemical calculations, endofullerenes, phosphorus, quantum computer, HyperChem.

DOI: https://doi.org/10.15350/17270529.2023.3.32


9. Sergey V. Lenkov. Acoustic surface waves in porous-elastic biphasic media. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 375-384. Download

The aim of the research is to create a biphasic medium for porous gas-filled materials based on the theory of the Bio-model and to carry out the analysis based on the model of transverse wave propagation in these media having free boundaries. The developed model of a biphasic medium for porous gas-filled materials allows analyzing any types of volumetric, longitudinal and transverse waves at arbitrary porosity values. The features of the propagation of surface waves in porous-elastic two-phase materials such as isolon and foamed polyurethane with a free boundary are analyzed. The solutions of boundary value problems describing the propagation of surface waves in biphasic media with a closed and permeable boundary are obtained by the method of potentials. Calculations of the velocities of transverse waves with different variations of the parameters of porous bodies are carried out. It is shown that in the case of a closed-cellular structure (impermeable boundary), the transverse Rayleigh surface wave exists in a fairly narrow range of changes in the magnitude of the tortuosity of the pores, and in the case of an open cellular structure (permeable boundary) there is no restriction on this value. It is shown that there is a range of continuous porosity values from 0 to 0.55 in which Rayleigh waves persistently exist, at the same time the wave vectors have real values, which corresponds to a wave propagating over the surface without carrying energy into the body.
Keywords: porous medium, closed-cell polyethylenes, Bio model, Rayleigh wave.

DOI: https://doi.org/10.15350/17270529.2023.3.33


10. Elizaveta A. Batalova, Larisa V. Kamaeva, Alexander V. Belosludtsev, Vladimir I. Lad`yanov. Analysis of Concentration Changes in the Viscosity of Al-Zn Melts up to 25 at.% Zn. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 385-394. Download

It is known that by analyzing structurally sensitive properties, it is possible to qualitatively assess the change in interatomic interaction with a change in the concentration of atoms in a metal melt. One of these properties is viscosity, which also characterizes the casting properties of a melt. However, experimental material concerning the viscosity of Al-Zn melts is currently insufficient. Therefore, in this paper, detailed studies of the temperature and concentration dependences of the kinematic viscosity of Al-Zn melts with a content of up to 25 at.% Zn were carried out. The experiments were carried out by the method of damped torsional vibrations in an atmosphere of pure He using an Al2O3 crucible filled with a melt on an automated devise. It is shown that the temperature dependence of the viscosity of the studied melts is monotonic and can be described by the Arrhenius equation. The discrepancies between the temperature dependences in different temperature conditions were due to the decrease of the Zn concentration during the experiments. The greatest discrepancies were observed for alloys Al90Zn10 and Al75Zn25. However, they were within the overall error of 3.8 %. It has been established that the viscosity of Al-Zn melts decreases nonmonotonically with increasing zinc concentration in the studied concentration range. The concentration dependences of the melt viscosity have two minima: at 5-7 at.% Zn and in the region of 15-17 at.% Zn. In the concentration range of 5-7 at.% Zn, a Zn atom appears around the Al atom, and at 15 at. % Zn, another Zn atom appears around the Al atom, which leads to stratification in the system.
Keywords: viscosity, melts, Al-Zn alloys.

DOI: https://doi.org/10.15350/17270529.2023.3.34


11. Rishat G. Valeev, Andrey I. Chukavin. On the Scaleability of the Morphological Structure of Porous Anodic Aluminum Oxide Films. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 395-405. Download

A methodical study of the issues of scaling the two-stage anodization for obtaining samples of porous alumina films with different areas from 38.47 to 1256 mm2, with the used lower cover of the cell specified by the hole diameter, was carried out during the synthesis with the use of electrochemical cells of the "clamping" type. The results of the statistical analysis of the parameters of the porous structure of the samples showed a good correlation of the local order parameter знак.jpg with the proportion of pores with the neighboring number of pores 6, and within the confidence interval the average distance between the pores Dint is almost the same. The value of the average pore diameter D can vary both within the same sample and between samples due to the differences in the porous structure for different crystallographic grain orientations on the aluminum surface; grain orientations are formed in the aluminum substrate during recrystallization annealing. For more precise control of pore diameters over the entire area of the sample, it is necessary to use single-crystal aluminum with a certain orientation of crystallographic planes.
Keywords: anodic Al2O3, porous structure, scaleability, scanning electron microscopy.

DOI: https://doi.org/10.15350/17270529.2023.3.35


12. Vyacheslav B. Dementyev, Tatyana N. Ivanova, Aleksandr I. Korshunov. Studies of the Influence of Temperature Distribution on the Condition of Hot Cut Knives. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 406-414. Download

Hot metal cutting knives are subjected to severe dynamic conditions: periodic impacts, uneven repeated heating and abrupt cooling - leading to deformation of the cutting edge, heat cracks and changes in the structure of the surface layer of the knife. Taking into account the heating-cooling cycle, the effect of temperature propagation over the cross section and deep into the surface of the knife depends on the time of the movement of rolls, the material of hot cutting knives and cutting modes. Thus, the difficult operating conditions of hot cutting knives lead to the fact that their durability is on average 15-20 days. The conducted studies show that the surface layer of knives experiences sharp temperature jumps in the upper layers; as you move deeper into the surface, the maximum temperature quickly decreases. Failure to comply with cutting conditions and time leads to a cyclic increase in temperature, which can reach critical values. In addition, periodic cycles of short-term intense heating and cooling lead to the appearance of micro and macro cracks on the working surface of the knife; the resulting stresses contribute to additional intensive wear and uneven chipping of the cutting edge of the knife. Studies have been carried out to improve the quality and depth of hardening with the use of high-temperature surface treatment (HTMST) with vibroplastic deformation. Taking into account the heating-cooling cycle, the revealed features of the influence of the temperature distribution over the cross section of the knife, make it possible to control the time of the movement of knives, as well as to recommend optimal material for hot.
Keywords: temperature, knife, cooling, hardness, steel.

DOI: https://doi.org/10.15350/17270529.2023.3.36


13. Marat A. Timirgazin, Anatoly K. Arzhnikov. Canted spiral magnetic order in Hubbard model. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 415-424. Download

The canted spiral magnetic order in a simple cubic lattice is considered within the Hubbard model. A review of materials in which such a magnetic structure can be detected was carried out. For diagonalization of the Hamiltonian the generalized noncorrelated mean-field (Hartree-Fock) approximation and generalized slave-boson approach by Kotliar and Ruckenstein were used. A self-consistent system of equations was obtained, the solution of which allowed us to determine the ground state of the model among the wide range of possible magnetic structures, including commensurate ferromagnetic, antiferromagnetic and incommensurate spiral magnetic phases with an arbitrary wave vector and interlayer canting at an arbitrary angle. Based on the data analysis, the range of model parameters that favor the formation of a canted structure was determined. In the Hartree-Fock approximation, the model parameters were found for which the canted spiral structure is the ground magnetic state. When taking into account the correlation effects in the slave boson approach, no region of a stable canted state was found. Possible reasons for the differences in the results obtained by different approximations are discussed. In future, the method can be generalized for the calculations of canted spiral states with and without taking into account strong electron correlations on any crystal lattice with a layered nature of interaction.
Keywords: Hubbard model, Hartree-Fock approximation, spiral magnetism, antiferromagnetism, strongly-correlated systems.

DOI: https://doi.org/10.15350/17270529.2023.3.37


14. Marina A. Shumilova, Nikita E. Suksin. Technology of the Waste Disposal Process Containing Organic Components. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 3, pp. 425-433. Download

Because of the activities of oil industry enterprises, large volumes of waste are generated, which are disposed into special depressions in the ground with the formation of oil sludge. Currently, thermal, chemical, physico-chemical, biological, and combined methods of processing and disposal of oil sludge are used. The experience of the practical application of these processing methods has shown that the most promising ways of oil sludge disposal are complex processing methods. In terms of the volume of polluted water per unit of output, dairy industry enterprises occupy one of the leading places. Wastewater treatment is carried out by a combination of several methods: mechanical, chemical, physico-chemical, biological and wastewater disinfection methods. Taking into account the general approaches in wastewater treatment, the aim of the work was to develop a universal module for the neutralization of hazardous organic industrial waste consisting of stable oil-water and water-fat emulsions. Earlier it has been found that when solutions of iron vitriol and bleach are introduced into the water-oil emulsion of the company Udmurtneft-Drilling, its coagulation occurs with the simultaneous formation of gypsum, which facilitates the filtration of the resulting sediment. In the variant of the decomposition of the water-fat emulsion of wastewater of the company "Molprom", a solution of aluminum sulfate was added as a coagulant until a flake-like precipitate was formed. The procedure for the disposal of water-oil and water-fat emulsions consists of similar stages, which makes it possible to develop a scheme of a universal technological module for the neutralization of hazardous industrial organic waste. Water after biological purification can be sent to the collector of household sewage or to the post-treatment facilities. Compacted sediment after thermal neutralization processes can be used as a commercial product, for example, for the production of building materials.
Keywords: oil-water emulsion, oil sludge, water-fat emulsion, processing methods, utilization, universal technological module, technological scheme.

DOI: https://doi.org/10.15350/17270529.2023.3.38