bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of “Green” Energy in Russia
Authors: Batenin V. M. , Zaichenko V. M. , Chernyavsky A. A.
Published: April 2024

The article presents the main factors influencing the country’s transition to a “green” energy, as opposed to the energy, the development of which is accompanied by large-scale environmental pollution, as well as the accumulation of a significant amount of production and consumption waste. The results of comparative calculations of the main parameters for traditional and non-traditional power plants for the conditions of Russia are considered. The comparison was made for nuclear power plants, thermal power plants operating on coal and on natural gas; hydroelectric power station; as well as network wind farms and solar power plants – without accumulation. It is shown that a promising direction in the construction of wind and solar power plants, as well as other generating facilities based on RES, is to cover the own energy needs of various enterprises and organizations. The proposed direction of energy development is promising and economically beneficial also due to the fact that biomass in our country is one of the most common types of renewable energy sources. About 48% of the world’s peat reserves and 23–24% of timber are concentrated in Russia, as well as huge amounts of agricultural waste. The article proposes effective technical solutions in the field of energy use of biomass. It is shown that for Russia a promising direction for the modernization of the existing energy supply system is the combined use of various types of renewable energy sources and local bioenergy resources that complement each other and provide guaranteed energy supply to consumers while minimizing the required investments.
Application of Search Algorithms in Determining of Fault Location on Overhead Power Lines According to the Emergency Mode Parameters
Authors: Kulikov A. L. , Ilyushin P. V. , Loskutov A. A.
Published: April 2024

Identification of fault locations (FL) on overhead power lines (OHPL) in the shortest possible time allows to reduce the time for shutting down OHPL in case of damage. This helps to improve the reliability of power systems. FL devices on OHPL according to the emergency mode parameters (EMP) are widely used, as they have a lower cost. However, they have a larger error than FL devices that record traveling wave processes. Most of the well-known algorithms for FL on OHPL by EMP assume a uniform distribution of resistivity along the OHPL. In real conditions, this is not the case. Application of these algorithms in FL devices on OHPL with inhomogeneities leads to significant errors in calculating the distance to the fault location. The authors proposed the use of search algorithms for u-nconstrained one-dimensional optimization to increase the speed of implementation of iterative procedures in FL devices on OHPL by EMP. The authors have developed recommendations for choosing optimization criteria, as well as options for implementing computational procedures. Using the example of a two-sided FL on OHPL, it is shown that the use of search algorithms can significantly (from tens to hundreds of times) reduce the number of steps of the computational iterative procedure. The implementation of search algorithms is possible in the software of typical relay protection and automation terminals, without their hardware upgrade.
Vapor Bubble Growth in a Superheated Liquid (Pressure Blocking Effect)
Authors: Zudin Yu. В. , Urtenov D. S.
Published: April 2024

The vapor bubble growth problem in a superheated liquid is considered. The Stefan number in the metastable region us evaluated. The asymptotics of the “thermal explosion” is investigated in the framework of the energy thermal scheme. The “pressure blocking” effect is show to occur if the Stefan numbers exceeds 1. An analytical solution is obtained for the bubble growth law in a liquid with energy spinodal temperature. A numerical study of butane bubble growth in the near-spinodal region is performed. A comparison of the solution with the experimental results on the boiling of a butane drop is given.
Multi-Agent Dynamic Model of the Multi-Criteria Information Interaction of Structural Elements of a Self-Organizing Data Transmission Network of a Ground-Air Monitoring System
Authors: Borodin V. V. , Kletskov D. A. , Timoshenko A. V. , Shchevtsov V. A.
Published: April 2024

An analytical model of the interaction of information between the structural elements of a monitoring system is presented, taking into account the dynamics of information exchange during its decentralized functioning based on a multi-agent approach within the framework of formation of a coalition of subscriber terminals. The relevance of the development of this model is due to the complexity and spatial distribution of modern information systems. The scientific novelty of the considered model lies in the study of a variety of strategies for managing the subscriber terminals (agents) of a decentralized transmission network, given in a logical-linguistic and set-theoretic form, analytical expressions for indicators of reciprocity and cognitive dissonance, which arise from the impact of destructive factors on the structural elements of a multi-level network of data transmission. The application of the developed model, in contrast to existing ones, makes it possible to study data-transmission networks of this type in terms of the stability of information interaction between structural elements at different time intervals in the absence of a single control center.
Solution of Problems According to Precedent in Knowledge Bases of Tactical Onboard Intelligent Systems During the Mission Phases of a Moving Object
Authors: Fedunov B E.
Published: April 2024

The solution of the problem according to precedent is possible if the experience of solving similar problems (precedents) is accumulated. Subject-independent structures of the experimental knowledge matrix containing information on precedents and the procedural knowledge matrix used to solve the problem are presented. An example of a solution based on the precedent of a problem that arose onboard a passenger aircraft in the situation “Aircraft takeoff after an interrupted run on the runway—the task “Where to fly after takeoff?” is given.”
Organization of the Control Subsystem in Real-Time Computing Systems
Authors: Furugyan M. G.
Published: April 2024

The problem of the optimal arrangement of control modules in a real-time computing system is considered. This problem is formulated as a minimax problem. Various structures of the graph of the partial execution order of applied modules are studied: a sequential chain, several independent sequential chains, a tree oriented from the root to the leaves, a tree oriented from the leaves to the root, and an arbitrary graph without cycles. Algorithms for constructing the optimal arrangement of control modules are developed.
Comparison of Methods of Organization and Management Efficiency in Dynamic Models of Cournot Oligopoly
Authors: Korolev A. V. , Kotova M. A. , Ugolnitsky G. A.
Published: April 2024

Nash and Stackelberg equilibria and cooperative solutions for dynamic game-theoretic Cournot oligopoly models in normal form with inhomogeneous agents are found analytically. Cooperative game-theoretic Cournot oligopoly models of three persons in the form of the von Neumann–Morgenstern and Gromova–Petrosyan characteristic functions are studied, including the calculation of the Shapley vector. A comparative analysis of the payoffs of agents, according to the solutions obtained, is carried out for games in normal form and in the form of a characteristic function.
Method of Forming a Regular Triangular Tethered Constellation of Microsatellites with Considering Their Motion Relative to the Centers of Mass
Authors: Zabolotnov Yu. M. , Chen Sh.
Published: April 2024

The process of formation of a rotating tethered constellation of microsatellites in the form of a regular triangle is considered. A combined control method for deploying the system using tether tension control and thrusters is proposed. Two models are used to substantiate the proposed control method. The first model is obtained by the Lagrange method and is intended for constructing a nominal group formation program. In this model, microsatellites are considered as mass points and tethers are inextensible mechanical bonds. The second model is developed to assess the possibility of implementing a nominal control program, since it takes into account the extensibility of tethers, simulates the operation of cable release mechanisms, and takes into account the motion of microsatellites relative to their centers of mass on which the direction of low thrust forces depends. The equations of the spatial motion of the constellation, corresponding to the second model, are written in a fixed geocentric coordinate system and make it possible to estimate the effect of the static and inertial asymmetry of microsatellites on their motion relative to the center of mass. The results of numerical calculations are presented, confirming the possibility of using the proposed control method for the formation of a tethered constellation in the form of a regular triangle, rotating at the constant given angular velocity in its final state.
Postflight Recovery of the Rotational Motion of a Small Space Vehicle from Solar Sensor Information
Authors: Belokonov I. V. , Lomaka I. A.
Published: April 2024

The use of the developed technology for solving inverse problems of parametric identification of the rotational motion of a spacecraft (SC) based on the accumulated sample of measurements of various compositions is expanded. On the example of processing telemetry data (measuring the direction vector to the Sun) of the BugSat-1 small spacecraft (SSC), the possibility of determining not only the characteristics of rotational motion but also its inertia coefficient is demonstrated. The rotational motion is determined based on the data obtained for five time intervals from January to May 2022, during which BugSat-1 made an uncontrolled movement around the direction vector toward the Sun. This type of motion does not allow applying traditional approaches to determine the dynamics of its rotation. In the process of data processing, a simplified model of the rotation of a SSC is used. At the same time, the initial conditions of rotational motion are estimated—the angular velocity vector and orientation angles, which made it possible to draw a conclusion about the precessional motion of a SSC. Using the analytical model of a regular precession, it is possible to estimate the inertia coefficient of a SSC. The results of flight information processing are presented and the errors of the obtained results are estimated.
Optimization of the Risk Functional to Control the Composition and Structure of a Heterogenous Grouping of Detection Sensors in Three-Dimensional Space
Authors: Dyukov V. A. , Kazantsev A. M. , Makushev I. Yu. , Putilin M. S. , Timoshenko A. V.
Published: April 2024

The steady growth in the scale and dynamics of the use of aerial weapons in the course of various conflicts necessitates the formulation and solution of the problems of building realistic systems to detect them. It should be noted that the priorities in the development of detection sensors is changing from solving problems to improve their characteristics to optimization and adaptability in controlling them. As an object, a heterogeneous grouping of sensors, which solves the problem of detecting a moving airborne object, is considered. The subject is the methodology for constructing control models for heterogeneous detection sensors. Based on the analysis of the antagonistic interaction of a heterogeneous grouping and airborne objects, as well as the processes of their functioning, a geometric approach to solve the problem of detecting a moving object (MO) is proposed, which uses an adapted and improved risk functional as one of the possible indicators for the further synthesis of the control algorithms. The practical effectiveness of the application of this functionality is substantiated and compared with other performance indicators through simulation modeling.
Comparison of Parallel Implementations of the Branch-and-Bound Method for Shared Memory Systems
Authors: Gorchakov A. Yu. , Posypkin M. A.
Published: April 2024

Four parallel algorithms are considered that implement the branch-and-bound method (BnB) for solving problems of finding a global minimum. The algorithms are designed for computing systems with shared memory. The BnB is based on two basic operations: branching and eliminating. To implement the elimination operation, interval arithmetic is used, which for real intervals defines operations similar to ordinary arithmetic. The main difference between the algorithms lies in the different implementation of storing the list of subproblems. In the process of testing on a representative set of test problems, the speed of the algorithms, their scalability, and their resistance to search anomalies are investigated.
Operational Absolutely Optimal Dynamic Control of the Stochastic Differential Plant’s State by Its Output
Authors: Rudenko E. A.
Published: April 2024

The problem of synthesizing the average-optimal control law for a dynamic plant subject to random disturbances, if its state variables are measured partially or with random errors, is considered. Using the method of a posteriori sufficient coordinates (SCs), the complexity of constructing the well-known interval-optimal Mortensen controller is described and a much simpler algorithm for finding its operational-optimal analog is obtained. The new controller does not require the solution of the corresponding Bellman equation in inverse time, since it is optimal in the sense of a time-varying criterion. This makes it possible to disregard information about the future behavior of the object and reduces the procedure for finding the dependence of a control on sufficient coordinates to direct-time integration of the Fokker–Planck–Kolmogorov equation and to solving a problem of parametric nonlinear programming. The application of the obtained algorithm is demonstrated by the example of a linear-quadratic-Gaussian problem, as a result of which a new operational version of the well-known separation theorem is formulated. It represents a stochastic control device as a combination of a linear Kalman–Bucy filter and a linear operational-optimal positional controller. The latter differs from the traditional interval-optimal controller by the well-known gain and does not require the solution of the corresponding matrix Riccati equation in inverse time
Synthesis of Robust Linear Stationary Dynamic Systems Based on Improvement of the Controllability and Observability of the Computational Model of the Object
Authors: Abbyasov A. M. , Anisimov A. A. , Tararykin S. V.
Published: April 2024

An iterative method is developed for the synthesis of control systems of low parametric sensitivity with dynamic (polynomial) controllers, at each step of which singular numbers of controllability and observability gramians are intentionally changed, and a precontroller is formed that transforms the structure of the computational model of an object to increase its controllability and observability, taking into account the available opportunities and limitations. The method of polynomial modal control calculates the parameters of the main controller and evaluates the robust properties of the synthesized system in the given intervals of variation of the internal parameters.
Speed of Performance of a Group of Controlled Objects
Authors: Bortakovskii A. S.
Published: April 2024

The problem of the speed of performance (speed, performance) of a group of controlled objects is considered, the initial state of each of which is given, and the final state is selected from a fixed set of possible terminal states (targets). For each object, it is required to assign a target and find the control that ensures that the group simultaneously reaches all the selected targets in the shortest time. Since the speed-optimal controls of individual objects do not solve the problem of group speed, the so-called minimally delayed trajectories are used. A technique for solving the problem is developed, which includes an algorithm for solving the minimax assignment problem and a procedure for using the optimal and minimally delayed trajectories. The problem of the speed of a group of objects, whose planar motion is represented by Markov–Dubins trajectories, is solved.
Number of Solutions for Some Special Logical Analysis Problems of Integer Data
Authors: Djukova A. P. , Djukova E. V.
Published: April 2024

In the class of discrete enumeration problems, an important place belongs to the problems of searching for frequently and infrequently occurring elements in integer data. Questions on the effectiveness of such a search are directly related to the study of the metric (quantitative) properties of sets of frequent and infrequent elements. It is assumed that the initial data are presented in the form of an integer matrix, whose rows are descriptions of the studied objects in the given system of the numerical characteristics of these objects, called attributes. The case is considered when each attribute takes values from the set {0,1,...k-1}, k2. Asymptotic estimates for the typical number of special, frequent fragments of object descriptions, called correct fragments, and estimates for the typical length of such a fragment are given. We also present new results concerning the study of the metric properties of the minimal infrequent fragments of descriptions of objects.
Models and Algorithms for Multiagent Hierarchical Routing with Time Windows
Authors: Kozlova M. G. , Lemtyuzhnikova D. V. , Luk’yanenko V. A. , Makarov O. O.
Published: April 2024

The problem of modeling real logistics systems arranged in a hierarchical manner is considered. Clusters of lower level consumers are formed that meet the time window (TW) constraints for each consumer and the cluster as a whole. In each such cluster, a traveling salesman’s route is constructed and the vertex closest to the central node, which is the vertex of reloading goods from heavy vehicles (Vs) to light Vs serving consumer clusters, is selected. The transshipment vertices, in turn, are combined into higher level traveling salesmen’s routes, taking into account TWs for routes of this level. The software implementation is tested on well-known networks. The technique is applicable for the synthesis of the central distribution center and system distribution centers of the lower level, as well as for calculating the required number of vehicles (agents).
Oscillations of a Wind Power Plant with Several Moving Masses Using the Galloping Effect
Authors: Lokshin B. Ya. , Selyutskiy Yu. D.
Published: April 2024

We consider a chain of several bodies that can move translationally along a horizontal line. The neighboring bodies are connected to each other by springs. One end of the chain is fixed, and on the other there is a body, which is a rectangular parallelepiped of a square section. The system is placed in a horizontal stationary medium flow perpendicular to the specified straight line. Under the assumption that the flow affects only the parallelepiped, the dynamics of this system are studied as a potential working element of an oscillatory wind power plant using the galloping effect. For a different number of bodies in a chain, different values of flow velocity and external load, periodic regimes in the system are studied. It is shown, in particular, that an increase in the number of bodies in a chain makes it possible to increase the maximum power that can be obtained using the device and to reduce the critical speed at which oscillations occur. A scheme for regulating the load resistance is proposed, aimed at ensuring the transition to an oscillatory mode with maximum power.
On the Theory of Individual Atmospheric Vortices: an Example of the Subtropical Anticyclone Evolution
Authors: Kislov A. V. , Zheleznova I. V. , Mukhartova Yu. V. , Nesviatipaska A. I.
Published: April 2024

The physics of individual atmospheric vortices is far from clear, despite the fact that modern hydrodynamic models reliably reproduce them. In this paper, we develop the theory of vortices that stably exist for a long time in a certain region. Their structure is characterized by the first (dominant) empirical orthogonal function (EOF, NOF), and the dynamics is determined by the coefficient at a given mode y1(t), for which an ordinary differential equation is obtained based on the vorticity budget equation. The residual between the explicitly resolved terms is compensated by the parameterization, which is based on taking into account the effects of the second and subsequent modes of the EOF expansion. It is shown that it consists of Gaussian noise and a non-random component, which can be approximated using a cubic function of y1(t). To test the developed technique, we used modeling of the vorticity behavior describing the dynamics of the most stable vortex among all existing in the Earth’s atmosphere—the subtropical (Hawaiian) anticyclone. ERA5 reanalysis data were used for the work. The proposed approach to the analysis of integral vortex structures is supposed to be used to evaluate various circulation systems, identify factors affecting their dynamics in different regions, and study extreme hydrometeorological events associated with long-lived vortexes.
Statistical and Model Estimates of the Relationship between Characteristics of Atmospheric Tornadoes
Authors: Mokhov I. I.
Published: April 2024

Based on the observational data, statistical estimates of the relationship between different characteristics of atmospheric tornadoes were received. Statistically significant estimates of the power-law relationship of the tornado path length and path width were obtained. Specific features are noted for different ranges of path length and path width of intense atmospheric vortices. A simple model is proposed to explain the noted power-law, including the root, dependence of the tornado path length on path width.
Clouds and Turbulence Theory: Peculiar Self-Similarity, 4/3 Fractal Exponent and Invariants
Authors: Golitsyn G. S. , Chkhetiani O. G. , Vazaeva N. V.
Published: April 2024

In 1982 Lovejoy has published an illustration to Mandelbrot proposal how to characterize the area-perimeter ratio of complicated planar forms and it was found that exponent \(\beta \) for the satellite- and radar-determined cloud and rain areas of such a fractal is 1.35 close to 4/3. Later on it was notified that the same exponent was found also for noctilucent clouds. Such a value might be related to classic turbulence theory of 1941. This text demonstrates this relation using two basic papers by Kolmogorov and Obukhov. The role of prefractal multipliers is revealed, they form a couple of the peculiar invariants for cloud fields and a non-dimensional self-similarity numbers for these fields of sizes \(1 - {{10}^{6}}\,\,{\text{k}}{{{\text{m}}}^{2}}.\) The peculiarity is in their dimensional dependence and in the presence of few invariants, not usual invariants in cloud forms. Further research on random walk of a fluid particle in the 6D phase-space may lead to new discoveries.
About Acoustic and Electromagnetic Radiation of the Charged Droplet
Authors: Grigoryev A. I. , Kolbneva N. Yu. , Shiryaeva S. O.
Published: April 2024

Theoretical methods of classical mathematical physics investigate the acoustic and electromagnetic radiation generated by capillary oscillations of a charged drop of an ideal uncompressible electroconductive fluid in an ideal nonconductive medium. The radiations discussed are found in first-order analytical asymptotic calculations of smallness by the dimensionless amplitude of droplet oscillations. Analytical expressions were found for the intensity of acoustic and electromagnetic radiation, which differ by several orders of magnitude and fall on different frequency bands. Acoustic radiation from liquid-droplet systems of natural origin: fogs, clouds, smogs – falls on the ultrasonic frequency range, but acoustic radiation from large raindrops goes in the area of audible sound. Electromagnetic radiation from liquid-droplet systems of natural origin goes at frequencies from tenths of megahertz to megahertz units.
Submeso Wave-Like Structures in the Atmospheric Boundary Layer and Their Parameters Measured with the Help of Sodar in Moscow Region
Authors: Zaitseva D. V. , Kallistratova M. A. , Luyluykin V. S. , Kouznetsov R. D. , Kuznetsov D. D. , Vazaeva N. V.
Published: April 2024

The paper presents study of the parameters of wave-like structures based on the data of long-term continuous sodar monitoring of the atmospheric boundary layer (ABL). Submesoscale internal gravity waves (IGWs) of non-orographic origin trapped in a stably stratified ABL (SBL) are considered. Statistical data on the parameters of two classes of IGWs are presented: internal gravity-shear waves (IGSWs) of the Kelvin-Helmholtz billow (KHB) type and buoyancy waves (BW). Identification and classification of IGWs was carried out by the visual analysis of sodar echograms. The measurements carried out in the Moscow region were used. The seasonal and diurnal variability of the frequency of registration of waves of both classes were studied, the values of the parameters of the observed waves were analyzed, and the ranges and average values of these quantities were compared.
Seasonal Hydrodynamic Forecasts of INM-CM5 Model for Estimation of the Start of the Birch Pollen Season
Authors: Emelina S. V. , Khan V. M. , Semenov V. A. , Vorobyeva V. V. , Tarasevich M. A. , Volodin E. M.
Published: April 2024

The experimental seasonal forecasts of the INM-CM5 climate model were used as input data for the temperature-time phenological model of birch dusting. Within the framework of the joint model, a test technology was developed for seasonal forecasting of the timing of the beginning of birch dusting in the European territory of Russia. Verification of this technology on seasonal retrospective forecasts of the INM-CM5 model (1991–2019) showed an adequate reproduction of the birch dusting start dates calculated for the same period according to the ERA5 reanalysis. The mean systematic errors are ±2 days, and the spatial correlation coefficients are above +0.84. The forecasts of the date of dusting start in 2022, calculated from the experimental operational seasonal forecasts of the INM-CM5 model with a monthly lead-time and with a zero lead-time, are also evaluated. It is shown that the errors in forecasting the beginning of dusting are ±5–10 days, and the forecasts with a one-month lead-time have fewer errors. The obtained results allow us to conclude that the seasonal forecast of the surface temperature of the INM-CM5 model can be used as input information for the temperature-time phenological model for the operational forecast of the timing of the start of birch dusting in the European territory of Russia.
Analytical Models of the Interaction of Convection with Intercepting Layers in the Atmosphere
Authors: Ingel L. Kh.
Published: April 2024

The interaction of various forms of convection with stably stratified barrier layers in the atmosphere is theoretically investigated. Three different formulations of the problem are considered. 1) A linear problem with given perturbations of temperature and vertical velocity at the lower boundary of a stably stratified medium. 2) Penetration of an isolated turbulent thermal into such a medium. 3) Impact on the intercepting layer of an intense convective turbulent jet. Analytical solutions of the corresponding model problems are found. The possibility of connecting the considered models with signatures of intense convection, in particular, with dome-shaped protrusions above the anvil of a cumulonimbus cloud (or a cluster of a convective system), which represent the intrusion of a powerful updraft into a stably stratified medium, is discussed.
Analytical Model for the Generation of Vorticity Due to Inhomogeneous Friction on the Underlying Surface
Authors: Ingel L. Kh. , Makosko A. A.
Published: April 2024

In a number of recent publications, attention is drawn to the heterogeneity of the underlying surface as a factor that can contribute to the initiation and intensification of tornadoes. The paper proposes an analytical model for the generation of vorticity under the influence of horizontally inhomogeneous friction. The resulting vorticity is proportional to the background flow velocity and to the horizontal gradient of the drag coefficient transverse to this flow; dependence on other factors is relatively weak. Numerical estimates show the possibility of efficient vorticity generation.
On the Mechanism of Sulfur Dioxide Oxidation in Cloud Droplets
Authors: Yermakov A. N. , Aloyan A. E. , Arutyunyan V. O. , Pronchev G. B.
Published: April 2024

Data from field experiments on the dynamics of SO2 oxidation in cloud droplets are presented. The rapid oxidation of SO2 by molecular oxygen observed in experiments is attributed here to the catalytic action of a pair of manganese and iron ions in droplets. Their inhomogeneous effect by the drop-size distribution, attributed in experiments only to the leaching of ions of these metals from coarse particles of mineral dust is also due to the transition of the oxidation reaction into a branched mode. The results obtained indicate that the branched regime of catalytic oxidation of SO2 detected in cloud droplets should be considered as a new and significant source of sulfates in the atmosphere. This process must be taken into account when considering both the budget of sulfates in the global atmosphere and their impact on the climate.
Diapycnal Mixing and Double Diffusion over the Continental Slope in the Northern Sea of Japan in the Warm Half-Year
Authors: Stepanov D. V. , Ostrovskii A. G. , Lazaryuk A. Yu.
Published: April 2024

This study investigates double diffusion processes responsible for diapycnal mixing in the Primorye current in the northern Sea of Japan. The results of processing and analysis of a long time series of data from regular Aqualog-profiler measurements of thermohaline characteristics and current velocity over the continental slope between the horizons of 60 and 420 m from April to October 2015. Using the Osborne-Cox parameterization (1972) and Gregg’s (1989) parameterization, we estimated heat and salt diffusivities, as well as the buoyancy flux. To reveal the processes of double diffusion, the Turner angle was estimated. We estimated contributions of diffusive convection and salt fingers into the buoyancy flux. Due to double diffusion, the intense vertical mixing covered the layer from 80 to 170 m. From mid-spring to early May, diffusive convection penetrated to a horizon of 250 m, and then a process like salt fingers played a leading role. Shear instability caused by the weakly nonlinear interaction of internal waves prevailed in the underlying layers.
Seasonal Variations in Stratospheric Circulation and Interactions between the Troposphere and the Stratosphere
Authors: Perevedentsev Y. P. , Ismagilov N. V. , Mirsaeva N. A. , Guryanov V. V. , Nikolaev A. A. , Shantalinsky K. M.
Published: April 2024

Based on the data of the ERA5 reanalysis, the dates of spring and autumn rearrangements of the stratospheric circulation on isobaric surfaces of 30, 20 and 10 gPa in the latitude zone of 30–90° C. in the period 1979–2020 were obtained. Of the 42 cases of spring restructuring, 10 belong to the early, 15 to the middle and 17 to the late. The spread in the dates of spring rearrangements on the surface of 10 hPa is 69 days. Most often, the spring restructuring of the circulation occurs from top to bottom, in some years, the delay of spring restructuring on the surface of 30 gPa relative to the surface of 10 gPa reaches 22–25 days. Autumn perestroika takes place from the bottom up and their terms at the 3 levels under consideration are close to each other. The relationship between the timing of the spring restructuring of the stratospheric circulation with solar activity and large sudden winter stratospheric warming is shown. Analysis of the fields of anomalies of daily temperature values and zonal wind velocity in the 1000-1 hPa layer in the period January-May showed their significant spatio-temporal difference in the case of early and late spring perestroika. Thus, foci of positive anomalies of temperature and wind speed are formed initially in the upper stratosphere, and then shifted from top to bottom. The interrelations between the layers of the atmosphere in different seasons are considered.
Variational Data Assimilation for Ocean Thermodynamics Model and Sensitivity of Marine Characteristics to Observation Errors
Authors: Shutyaev V. P. , Parmuzin E. I.
Published: April 2024

The methodology of variational assimilation of observational data for the restoration of the initial state and heat fluxes for the mathematical model of sea thermodynamics is presented. An algorithm is developed for estimating the sensitivity of a model solution to errors in observational data. Calculation of the gradient of the response function of the model solution is based on the use of the Hessian of the cost functional. The results of numerical experiments for the Black Sea dynamics model developed at INM RAS are presented.
ON THE SIGNIFICANCE OF SELECTING HYDROPHOBIZATION CONDITIONS FOR OBTAINING STABLE SUPERHYDROPHOBIC COATINGS
Authors: KUZINA E. A. , OMRAN F. SH. , EMELYANENKO A. M. , BOINOVICH L. B.
Published: April 2024

A method has been described for obtaining superhydrophobic coatings on the surfaces of tungsten and D16 aluminum alloy using nanosecond laser treatment followed by chemical deposition of fluorooxysilane from a vaporous phase. It has been shown by the examples of aluminum and tungsten that, in order to obtain chemically stable coatings, it is necessary to select sample preparation conditions for applying the hydrophobizer individually for each material. Varying the time of surface pretreatment with oxygen plasma makes it possible to controllably change the density of surface adsorption sites and control the chemical stability of the hydrophobizer layer and, hence, the coating as a whole. Superhydrophobic coatings with contact angles of larger than 170° have been obtained on the studied metals, with contact angles remaining preserved during a long-term continuous contact with aqueous media.
PECULIARITIES OF STRUCTURAL PHASE TRANSITIONS IN A SELF-ORGANIZING AOT/WATER/ISOPROPYL MYRISTATE SYSTEM UPON INTRODUCTION OF L-LYSINE
Authors: SAUTINA N. V. , GUBAIDULLIN A. T. , GALYAMETDINOV YU.  G.
Published: April 2024

New biocompatible microemulsion and liquid-crystalline sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/water/isopropyl myristate systems have been obtained for the delivery of drugs and physiologically active substances. A combination of dynamic light scattering and X-ray diffraction methods has been used to determine their structural and size characteristics. The Primus and SasView software packages have been employed to simulate the shape and arrangement of particles as depending on AOT content. It has been shown that, as the concentration of the surfactant increases, the shape of micelles varies from spherical to cylindrical, and, at high concentrations, a structural phase transition occurs with the formation of a liquid-crystalline phase. The influence of a model bioactive compound, L-lysine, on the size and structure of the system has been studied. It has been revealed that the addition of the amino acids to the samples leads to an increase in the microemulsion droplet size, and, in the case of the liquid-crystalline phase, to the disintegration of the hexagonal packing into individual cylinders. The results obtained can be useful for the analysis of the mechanisms of L-lysine release from the AOT/water/isopropyl myristate transport system.
LECITHIN MICROEMULSIONS WITH GAC OIL AND TURMERIC ESSENTIAL OIL
Authors: MURASHOVA N. M. , NGUYEN HUU  TUNG
Published: April 2024

It has been shown that water-in-oil microemulsions in lecithin–oleic acid–Vaseline oil–vegetable oil–essential oil–water systems can be obtained using the oil of a tropical plant, gac (Momordica cochinchinensis), and turmeric essential oil (Curcuma longa). Water (at least 6.5 wt %) can be incorporated into the microemulsions at a lecithin concentration in the organic phase of 20 wt %, a Vaseline oil-to-gac oil ratio of 1 : 1 (weight/weight), and an oleic acid-to-lecithin molar ratio of 0.2–0.8. Depending on the contents of water and lecithin, the hydrodynamic diameter of microemulsion droplets ranges from 3 to 21 nm. FTIR spectroscopy has been employed to show that, for the microemulsion with W = 14, the fraction of bulk (free) water in the droplets is 36.5 mol %, the fraction of hydration water (bound to polar groups of the surfactants) is 55.0 mol %, and the fraction of water trapped between hydrocarbon chains is 8.5 mol %. Using the dialysis method and a water-soluble dye Rhodamine C as a model, it has been shown that the rate of its transfer from the microemulsion to the physiological solution is 15.4 × 10–3 g/(m2 h). Approximately 3.2% of the dye has been found to be released over 6 h, thus making it possible to develop controlled drug release systems.
SILVER-CONTAINING BICOMPONENT NANOPARTICLES: RELATIONSHIP BETWEEN MORPHOLOGY AND ELECTROKINETIC POTENTIAL
Authors: LERNER M. I. , BAKINA O. V. , KAZANTSEV S. O. , GLAZKOVA E. A. , SVAROVSKAYA N. V.
Published: April 2024

The chemical compositions, structures, and electrokinetic potentials have been studied for silvercontaining Janus-type ZnO/Ag nanoparticles, heterophase Cu/Ag nanoparticles with a uniform distribution of the components over a particle, and silver-decorated TiO2 nanoparticles. The nanoparticles have been obtained by the simultaneous electric explosion of two wires. The influence of nanoparticle surface structure on the isoelectric point position and electrokinetic potential values has been analyzed. The effect of silver localization on the electrokinetic characteristics of nanoparticles has been investigated. These characteristics have been compared with those of mechanical mixtures having the same mass ratios of the components.
Modification of the Stefan’s Rule for the Surface Tension Coefficients of Liquids
Authors: Sevryugin V. A. , Skirda V. D.
Published: April 2024

A modification of the “Stefan’s rule” for the surface tension coefficients of liquids has been proposed, with the modification consisting in choosing a liquid as a system of comparison with respect to its surface. An expression for the surface tension coefficients has been derived and employed to interpret their temperature dependences for a number of molecular liquids with different physicochemical properties.
ELECTROKINETIC TRANSPORT OF NON-NEWTONIAN FLUID THROUGH SOFT NANOCHANNEL WITH PH-RESPONSIVE AND PARTIALLY ION-PENETRABLE POLYMER LAYER
Authors: Kumar Deepak , Barman Bhanuman
Published: April 2024

The present article deals with the comprehensive parametric study on electroosmotic flow and transportation of ions through polymer grafted soft nanochannel containing non-Newtonian fluid. We consider the fully developed flow in a slit rectangular channel. The charged poly-electrolyte layer (PEL) carries a monovalent acidic ionizable group attached to a rigid wall. The ion partitioning effect is considered in our study, which arises from the difference in relative permittivity of the polyelectrolyte region and the bulk electrolyte. The non-linear Poisson−Boltzmann equation and the modified Cauchy momentum equation, which are coupled, are used to describe the mathematical model. The main objective of this analysis is to demonstrate the impact of bulk pH on the charge regulation of mono-ionic functional groups residing in PEL, the impact of flow behavior index and different electrohydrodynamic parameters, including EDL thickness, ion-partitioning parameter, the Debye−Hückel parameter, and softness parameters etc, on the overall flow modulation and selectivity parameter. This study is expected to constitute a significant step forward in the real-world continuum mathematical modelling of interfacial flow physics in the scenario of electrohydrodynamics in soft nanochannels.
Stability of a Magnetically Actuated Satellite towards the Sun on a Sun-Synchronous Orbit
Authors: Roldugin D. S.
Published: April 2024

Magnetically actuated satellite moving on a Sun-synchronous orbit is considered. The satellite maintains one axis attitude towards the Sun while rotating around this direction. Stabilization algorithm utilizes information about the required direction and rotation rate. Evolutionary equations are used to find equilibrium positions and analyze their stability. Conditions on the satellite inertia moments and control parameters are established for different equilibria, including the required motion. Numerical simulation with different disturbing sources is performed to verify stable equilibria existence.
Spectroradiometry of the Solar Corona on the RATAN-600
Authors: Bogod V. M. , Lebedev M. K. , Ovchinnikova N. E. , Ripak A. M. , Storozhenko A. A.
Published: April 2024

Modern studies of solar radio emission are complicated by continuous power amplification and multifrequency external interference, which often completely overlap important frequency ranges. Many topical problems in solar radio astronomy require large effective areas of radio telescopes, high frequency and time resolutions, accurate spatial measurements, and a large dynamic range. It becomes relevant to change the concept of receiving recording equipment. This paper deals with topical problems of the physics of the solar corona in combination with optimal methods of observation with large instruments. The features and difficulties of combining high parameters—dynamic, spatial, temporal, and frequency resolutions—are considered. The proposed solutions of the new-generation observation complex implement the possibilities of intelligent selection of registration conditions in a multioctave mode with multichannel over 8000 channels/GHz with temporary permission up to 8 ms/spectrum. A multiobject observation mode becomes available from powerful flaring objects to faint structures of various nature. High-speed data processing makes it possible to implement an online mode of interference elimination, which is based on a fast statistical analysis of the spectrum with the selection of non-Gaussian (interference) structures. Methods for high-speed analysis of large-volume data (the principal component analysis method) and their presentation to the user are proposed. Examples of the operation of the complex in the range of 1–3 GHz are given. The prospects of a new approach for multiobject radio astronomy observations in the implementation of the RATAN-600 tracking mode are considered: from recombination lines to wide-range spectra, from low-contrast fluctuations to fast changes in flares, etc.
The Effect of Products Released from the Structural Materials of a Spacecraft on the Optical Properties of Its Thermal Control Coatings
Authors: Chirov A. A. , Belyakova N. G.
Published: April 2024

In this paper, we report on our experimental findings regarding the release of easily condensing substances from certain structural materials utilized in spacecraft, and we evaluate the impact of thin condensate films on the integral optical coefficients of external thermal control coatings (TCCs) of spacecraft. To simulate the space environment and solar radiation, the experiments were conducted in a vacuum. We found that the flux densities of the components released from the materials’ surfaces reach 5.4 × 10–7 g cm–2 s–1 and exhibit an exponential decrease over time. Furthermore, thin condensate films with a thickness of 100 Å can significantly degrade the integral optical coefficients of TCCs by tens of percent. These effects can alter the heat balance of the spacecraft. The experimental research methods used in this study can be applied to a broad range of materials, and the results have implications for the design and construction of various types of spacecraft.
A Prototype of a Background Solar Wind Forecasting Service Based on MHD Modeling and WSA Boundary Conditions
Authors: Arutyunyan S. , Kodukov A. , Subbotin M. , Pavlov D.
Published: April 2024

A prototype service for MHD modeling of the calm solar wind and forecasting the speed and density of solar wind particles in interplanetary space, similar to the NOAA and ESA services, has been created. The service consists of an MHD simulator, a module for processing simulation results, and a web interface. The simulator is based on the implementation of the TVDLF method in the PLUTO package. The boundary conditions of the model (density, radial velocity, magnetic field, temperature) at a distance of 0.1 AU from the origin are obtained regularly from the corresponding NOAA service, in which they are calculated according to the WSA model based on the magnetograms of the GONG network. Two modes of boundary conditions are available: constant and daily. The simulations were carried out on a uniform grid in the range of 0.1–1.7 AU by distance (512 elements), –60°...+60° by latitude (60 elements), 0°–360° by longitude (180 elements). The calculated particle velocity and density maps are compared with the NOAA SWPC and NASA CCMC calculations under the same boundary conditions. A retrospective comparison of the resulting forecasts with data from direct measurements (OMNI) was carried out.
The Significance of Input Features for Domain Adaptation of Spacecraft Data
Authors: Karimov E. Z. , Myagkova I. N. , Shirokiy V. R. , Barinov O. G. , Dolenko S. A.
Published: April 2024

The problem of improving the neural network forecast of geomagnetic index Dst under conditions in which the input data for such a forecast are measured by two spacecraft, one of which is close to the end of its life cycle, and the data history of the other is not yet enough to construct a neural network forecast of the required quality. For an efficient transition from the data of one spacecraft to the data of another, it is necessary to use methods of domain adaptation. This paper tests and compares several data translation methods. Also, for each translated attribute, an optimal set of parameters for its translation were found, which further reduces the difference between domains. The paper shows that the use of domain adaptation methods with the selection of significant features can improve the forecast compared to the results of using untranslated data.
Propellant Influence on Electromagnetic Environment Generated by Stationary Plasma Thrusters
Authors: Plokhikh A. P. , Vazhenin N. A. , Merkurev D. V.
Published: April 2024

Possible aspects of violation of the functional safety of spacecraft in terms of electromagnetic compatibility with electric rocket thrusters in their work on alternative working substances are considered. The procedure of experimental determination of spectral–time characteristics of own electromagnetic radiation of laboratory model of stationary plasma thruster SPT-70 developed by the Research Institute of Applied Mechanics and Electrodynamics of the Moscow Aviation Institute is described. Measurements of noise emissions were carried out on a vacuum installation with a “radiotransparent” compartment and a shielded echo-free camera in the frequency range of 1–12 GHz for typical discharge capacities (600, 800, and 1000 W), vertical and horizontal polarization, and various working substances used (krypton and xenon). The conducted studies have allowed obtaining new comparative results of the assessment of spectral characteristics of SPT-70 radiation for standard modes and prospective working bodies within the orthogonal polarization bases. The new results should include information about the radiation characteristics of SPT-70 in the time area. It is shown that the transition from xenon to krypton retains the pulsed nature of the radiation of a stationary plasma thruster, leading not only to an increase in the amplitude of pulses, but also to an increase in the frequency of repetition of “bursts” and an increase in their duration, which requires additional measures to ensure electromagnetic compatibility in order to preserve the functional safety of the spacecraft.