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The article dwells upon the possibility to assess quantitative evaluation of the level of articulatory skills. The rapidity and correct pronunciation of letter combinations, as well as the placement of verbal accents in the course of reading a coherent text, are subject to quantitative assessment. A procedure is proposed in which the subject reads aloud a standard text, and then a text, which includes a number of unfamiliar words (quasi-words). As a result, the subject’s pronunciation competence is estimated quantitatively (on a 100-point scale). The validity of the proposed procedure is checked by testing groups of subjects with varying levels of language training, as well as by data from a similar survey in Russian. Recommendations are given on the use of the procedure described. Besides, the experiment allowed us to point out the common mistakes made by the students. These mistakes concerned the rules of reading some letters and letter combinations, placing the primary and secondary stresses in polysyllabic words, as well as tertiary stresses in compound nouns. We considered both phonological mistakes which lead to misunderstanding, and non-phonological ones which distort words and make them difficult to understand in the process of communication.

At present, an actual trend in the development of fuel and energy complexes in a number of countries is the diversification of generation via the involvement of local types of solid fuel. In this case, thermochemical processing of fuel is often carried out in a fluidized state. A significant proportion of dispersed fuels cannot be transferred to a state of stable fluidization. The solution in such cases is to create a fluidized bed of inert carrier, into which particles of the target fuel component are then introduced. In this work, a computational and experimental study of the fluidization of inert bulk material (haydite granules) was carried out. The key purpose of the work was to develop a mathematical model for the formation of a fluidized bed, which makes it possible to calculate the process based on its local characteristics, as well as to identify the model parameters and test it using experiment data. During the study the problems of developing a numerical method for calculating the distribution of velocities and concentrations along the height of the apparatus were solved, parametric identification of the proposed mathematical model was carried out, and empirical verification of the modeling results was carried out. The mathematical apparatus of the theory of Markov chains was used as the mathematical basis for constructing the model. The data from our own laboratory full-scale experiment were used to identify the parameters of the model and verify it. A comparison of calculated and experimental data showed the high predictive efficiency of the model for the given granulometric composition of the fluidizing product. The results of the laboratory full-scale experiments also showed a significant evolution of the granulometric composition of haydite granules during their long-term stay in a fluidized bed, which requires a separate study, as well as the introduction of appropriate amendments to the mathematical model for its further improvement.

Accurate and reliable measurements of the total solar radiation flux make it possible to evaluate the efficiency of using stand-alone photovaltaic systems in various meteorological conditions. These measurements allow more accurately predict in time the energy production volume, accumulator and capacitive storage devices parameters and the payback period. Research purpose was to study the possibility of creating a photoelectric sensor and a method of uninterrupted measurement based on this sensor which allows to measure total solar radiation flux including its direct, diffused and reflected components simultaneously. The photovaltaic sensor with bifacial photosensitivity was manufactured and applied, which is low-inertia comparing to traditional thermoelectric pyranometers, and its spectral sensitivity is quite close to the same parameter of photovoltaic power supply system. It creates the possibility to estimate the insolation level capable to be completely converted into electrical energy without an ineffective heat-generating long-wavelength part of the solar spectrum. A laboratory measuring stand was made to test the sensor's operability. Modeling and experiments’ the sensor parameters were carried out and confirmed its operability. The bifacial photosensitivity sensor allows to control simultaneously direct, diffused and reflected from the earth's surface components of solar radiation, what gives more complete information about the energy potential of the photovoltaic power supply system location.

Purpose: Describe the surgical technique and experience using the LSZ growing system in skeletally immature patients for two–stage surgical treatment of adolescent idiopathic scoliosis (AIS). Methods: Eleven skeletally immature patients who underwent two-stage surgical treatment of AIS in our center were retrospectively analyzed. Patients initially treated with the LSZ growing system were observed for an average of 40.5 months (range 23–64 months) and for 4 years after planned replacement of the LSZ growing system with a standard pedicle screw system. Results: The average preoperative angle of the main thoracic curve was 64.55 ± 3.21°, and that of the lumbar curve was 46 ± 5.52°. After instrumentation using the LSZ growing system, the thoracic curve was corrected to 17.63 ± 5.14°, and the lumbar curve to 9.2 ± 5.45°. The correction percentages were 72.52 ± 8.35 and 80.59 ± 10.77, respectively. After planned replacement of the LSZ system with a pedicle screw system, the angle of the thoracic curve changed to 11.45 ± 4.84°, and the lumbar curve to 6.4 ± 4.72°. The percentages of final correction were 82,1 ± 7,91 and 85,64 ± 5,47, respectively. The difference in the “LSZ growth coefficient” was 0.063 ± 0.037, which indicates continued growth of the spine along the instrumented region. None of the patients had neurological or infectious complications. Conclusion: Our study demonstrates the safety and effectiveness of 2-stage treatment of AIS using the LSZ system, which allows for spine growth during the period between stages.

. Currently, there is a tendency to diversify the generation of heat and electricity and to improve solid fuel technologies. These trends actualize the search for mathematical tools for describing and predicting the operation of apparatuses with a fluidized bed of dispersed fuel materials. However, since the mechanics of heterogeneous media (and dispersed media in particular) is to a certain extent in its infancy in relation to the mathematical foundations of modeling, it is often difficult to predict the operation of equipment. In particular, the poor quality of mathematical basis does not allow predicting the fields of concentrations and velocities of the phases of the fluidized bed, although this knowledge serves as the fundamental basis for calculating heat and mass transfer and chemical processes. In the present work, a computational and experimental study of the local hydromechanical characteristics of a monodisperse fluidized bed has been carried out. The mathematical apparatus of the theory of Markov chains was used as a basis for modeling. The tasks were solved in a one-dimensional formulation, which implied the division of the bed in height into cells of small but finite sizes. Fluidized bed phase distributions were described by state vectors whose evolution was controlled by transition probability matrices. The elements of these matrices were matched to the physical parameters of the processes. The model was verified by comparing the calculated predictions with the data of a full-scale experiment conducted as part of the study, aimed at measuring the local velocities of the gas phase inside the fluidized bed. The experimental data with a good accuracy for engineering calculations were described by the proposed model, which makes it possible to consider it as a reliable scientific basis for the computer method for calculating installations using the fluidization technique.

These days, strict requirements to aeronautical equipment are imposed to enhance reliability, durability, and environmental compatibility. Aeronautical equipment operation reliability depends not only on its structural and technologic abilities, but also on the fact how aviation oils, fuels and technical fluid meet quality requirements during operation. During the aircraft engine operation, oils are subjected to the thermal impact. As a consequence, their properties and composition change which can affect the engine operation, on the whole. The most promising means of improving thermal resistance of aviation oils is developing new ones and improving available oil compositions. Therefore, it is feasible to analyze the kinetic properties of the oil thermal conversion which will make it possible to predict their resistance within the extensive temperature range. The paper investigates thermal decomposition kinetics of aviation oils MS-8P, TN-98 and TN-600 used on different types of aircraft in civil aviation of the Republic of Belarus by the method of a thermo-gravimetric analysis. The composition of oil samples has been researched into by IR spectroscopy, chromatography-mass spectroscopy methods. A comparative analysis of research results of new oils and oils drained from aircraft engines indicates that even under insignificant overheat during the operation, a change in the hydrocarbon composition occurs, and the hydrocarbon content of basic types varies to some extent. The oil thermolysis research reveals that potential overheat after engine shutdown complies with the temperatures at which the decomposition commences. Thermal conversion products of oil carbohydrates will contribute to the defect formation in friction subunits. As a result of test data processing of thermal conversion of aviation oils MS-8P, TN-98, TN-600, the principles of their decomposition as well as macrokinetic parameters, allowing us to precisely evaluate the effect of oils operation temperature conditions on their conversion rate, have been specified. It is essential while simulating the aircraft engine operation and predicting variations of oil quality properties during their operation.

The purpose of this study is to investigate collective dynamics of coupled communities that evolve according to the population game «Battle of the Sexes». A separate community includes two interacting populations of players of opposite sex, where each player has one of two possible competing behavior strategies. It is necessary to determine the possibility of mutual synchronization of oscillations in the number of players adhering to a particular strategy, build a synchronization region, and also evaluate the dependence of the properties of oscillations on the coupling strength. Methods. In this paper, we study the system of evolutionary games «Battle of the Sexes» interacting through migration. To simulate the evolutionary game dynamics we make use of the stochastic Moran process, as well as the Monte Carlo method to sample game trajectories. Mutual synchronization is defined by the appropriately generalized criteria of frequency and phase locking. Results. It is shown that the system of coupled evolutionary games «Battle of the Sexes» demonstrates mutual synchronization of oscillations under sufficiently strong coupling. In particular, oscillation frequencies of two communities get adjusted to each other and begin to coincide at some interaction parameter, while the oscillations themselves become almost identical. A similar result was also observed for an ensemble of more than two communities. Conclusion. The dependence of the average frequencies of community oscillations on the coupling strength was determined, the adjustment of oscillations with an increase in the coupling strength was demonstrated, thereby showing the possibility of mutual synchronization in the model of coupled evolutionary games «Battle of the Sexes». The region of frequency synchronization was numerically found.

Single phase CuCoMgAl-layered hydroxides were obtained by making fine adjustment to their composition through changing the (Co + Cu)/Mg = 0.5; 1; 2; 3 and Co/Cu = 0.5; 1; 2 ratios. The rise of Co/Cu in systems contributed to the increase in their thermal stability. CuCoMgAl-catalysts showed high selectivity of carbonyl group hydrogenation in furfural and 5-hydroxymethylfurfural. In furfural hydrogenation, the selectivity to furfuryl alcohol was more than 99%, and in 5-hydroxymethylfurfural hydrogenation, the selectivity to 2,5-hydroxymethyl furfural was 95%. The surface of the samples with different Co/Cu after calcination and reduction was the same and had a «core-shell» structure (TEM). «Core» consisted of Cu and Co metallic particles. «Shell» consisted of CuCoMgAlOx mixed no-stoichiometric spinel oxides. There was no sintering or change in size of the metallic particles after the reaction. For the sample with Co/Cu = 1, their phase composition after reaction remained unchangeable. The increase of Co/Cu led to the formation of an X-ray amorphous phase after the reaction. This suggests the decrease in structural stability of this sample. The obtained results prove the prospects of using bimetallic CoCu-systems for hydrogenation of furan aldehydes, and opens up new directions for further research and improvement.

This study introduces an empirical equation allowing to estimate an uncertainty of area-averaged snow depth on the Aldegondabreen Glacier, computed from standard snow surveys and made by an avalanche probe or by similar equipment. The two-decade history of the ongoing mass-balance monitoring program on this glacier shows that the methodology of field work on snow-measuring survey varies somewhat from year to year: the number and location of measurement points change. To identify and quantify long-term trends and variations in snow cover, it is crucial to assess the inter-comparability of the data in the obtained measurement series. The proposed equation was intended to solve this task basing on the collected data only, allowing to estimate the uncertainty even retrospectively. To build this equation, we applied a bootstrap statistical approach to the results of snow surveys carried out in Svalbard in 2015–2021. After interpolating the field measurements, obtained rasters were sampled sequentially with different numbers of points, simulating the real snow survey. The points were initially located in a form of a quasiregular grid and then randomly shifted between the iterations. After a thousand simulations for each number of points, the standard deviations were calculated relative to the “true” values, derived from corresponding rasters. These standard deviations, which we admit to be a random error of the area-averaged snow depth value, expectedly decrease with the number of sampling points and increase with the coefficient of variation ( ). The well-known index indirectly characterizes the irregularity of snow cover. After approximating the bootstrap results, the authors derived an equation that yields a relative error. The equation includes only two predictors which are the probing density per area unit and the , which potentially allows using it for the other glaciers. However, the universality of the empirically obtained coefficients is debatable, since they may vary due toa glacier size, its morphology and other parameters.

Introduction. In the modern period there is a dynamic introduction of information technology in all spheres of social life. Scientific and applied achievements concerning the development of IT began to be actively used for the rehabilitation of people who became disabled, including those with problems with the musculoskeletal system, muscle atrophy, loss of hearing, vision, etc. Theoretical analysis. Advances in scientific and technological progress, especially in medicine, biomedicine, genetics, bioengineering, mathematics, programming, psychophysiology and neurophysiology, alongside the use of information and communication technologies, are changing the quality of life of people who find themselves in extreme health situations. The “industry of smart devices” is developing, assisting people in restoring the functions of lost organs. The use of “smart” devices raises the problem of ensuring free will and mental privacy, respect for privacy, which is one of the manifestations of individual freedom. In this regard, there is a need for the development of scientific directions that study the legal support for the implementation of neuro-interfaces and other “smart devices”. Results. Emphasis is placed on advances in biomedicine, psychophysiology and neurophysiology and other sciences, which, in interaction with the possibilities of information and communication technologies, contribute to the return of people with disabilities to active and fulfilling life activities. While using “smart” devices, there is a problem of ensuring free will and mental privacy, respect for privacy, which is one of the manifestations of individual freedom. It is emphasized that in the future there will be a need to resolve the dilemma between the benefits that “smart devices” can provide for people and the equality of people. The use of these devices in the absence of objective requirements may lead to inequality between people, creating advantages not conditioned by the natural qualities for some of them. The author puts forward an idea of the need to address the issue of qualification of the actions of those who hacked the neuro-interfaces, which caused death or additional harm to the person who uses it.

The work is a natural continuation of the authors' earlier studies in the analysis of the conditions for the weak solvability of one-dimensional initial-boundary value problems with a space variable changing on a graph (network) in the direction of increasing the dimension $n$ ($n>1$) of the network-like domain of change of this variable. The first results in this direction (for $n = 3$) were obtained by one of the authors for the linearized Navier–Stokes system, later for a much more complex nonlinear Navier–Stokes system. The analysis was carried out in the classical way, using a priori estimates for the norms of weak solutions in Sobolev spaces of functions. In this study (for arbitrary $n>1$) another approach is proposed to obtain conditions for the weak solvability of linear initial-boundary value problems reduction of the original problem to a differential-difference system, the idea of which goes back to E. Rothe's method of semi-discretization of the initial-boundary value problem by temporary variable. A differential-difference system of equations with weighted parameters and its corresponding three-layer differential-difference scheme (a set of schemes) are considered. The resulting system is an analog of the initial-boundary value problem for a parabolic type equation with a space variable changing in a network-like domain of an n-dimensional Euclidean space. The main aim is to establish a domain of the range of weight parameters that guarantees the stability of the differential-difference scheme (continuity by the initial data of the problem), to obtain estimates for the operator norms of the weak solutions of the scheme, to construct a sequence of solutions for a differential-difference system that is weakly compact in its state space. The latter is an important element when using numerical methods of analysis of a wide class of applied multidimensional problems and constructing computational algorithms for finding approximations to their solutions. The results are applicable in applied optimization problems arising from modeling network processes of continuum transport with the help of the formalisms of differential-difference systems.

Introduction. The nature of problems and challenges that arise in the modern state involves rethinking its functions, tasks and approaches to their solution in order to respond in a timely manner and take effective action. The most important tool for this is the law – the main regulator of socio-economic relations. Theoretical analysis. The balance of interests of the individual person and society as a whole is constantly under the influence of objective and subjective factors. The state is forced to adapt to the changing situation, including due to the accumulation of unforeseen phenomena in the economy, social and spiritual spheres. The article focuses on some aspects of increasing the effectiveness of public administration in modern conditions, as well as unforeseen phenomena of multidirectional nature (the pandemic COVID-19, environmental and man-made disasters, sanctions effects, escalated political confrontation between Russia and Western countries). Results. Taken together, all aspects to which attention is drawn require the adoption of non-standard and prompt (quick) solutions, the consequence of which will be to counter emerging threats, ensuring security and balancing the interests of the individual, society and the state.

The transition of soils into fallow state has a significant impact on the accumulation and transformation of soil organic matter (SOM). However, the issue of SOM transformation as a result of soil transition to fallow state in cryolithozone conditions is insufficiently studied. The aim of this study is to investigate the molecular weight (MW) distribution of humic acids (HAs) isolated from soils of central Yakutia. Native, fallow and agricultural soils in the vicinity of Yakutsk city were studied. MW distributions of HA preparations were obtained on an AKTAbasic 10 UPS chromatographic system (Amersam Biosciences, Uppsala, Sweden) using a SuperdexTM 200 10/300 GL column (with cross-linked dextran gel, fractionation range for globular proteins 10–600 kDa). The data on the molecular-mass distribution of HAs of fallow and agricultural soils of Central Yakutia were obtained for the first time. According to the obtained data, it was found that the highest carbon content in the structure of HAs was observed in agricultural soils (52.56%), and is associated with soil cultivation and fertilizer application. Among the HAs of fallow soils, we note that those soils that are in the process of self-vegetation have a relatively high carbon content in the HAs (45.84%), but the highest content was observed in fallow soils used as hayfields (49.98%), indicating that the reinvolvement of agriculture in fallow soils leads to an increase in the carbon content of HAs. According to the data of the MW distribution of HAs, it was found that the highest content of a high MW fraction of HAs was recorded in native soil (18.8%); this is due to the early stages of humification and the low maturity of organic matter. The highest content of a low MW fraction of HAs was recorded in agricultural soil (73.3%); this is due to the formation of molecular complexes of a “secondary” nature, which are more stable in the environment than the primary transformation products of humification precursors. The molecular composition of the HAs of fallow soils in the process of self-overgrowing is characterized by values closer to the HAs of native soils, which indicates their transformation towards HAs of native soils. The obtained results indicate that the reinvolvement of fallow soils leads to the transformation of the molecular composition of HAs towards HAs of agricultural soils, and to an increase in the resistance of SOM to biodegradation.