bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue analysis of concrete structures using AI with the introduction of fractal corrosion detection
Authors: Donenko V , Donenko I , Bobrakov A , Kulik M , Ivanenko D
Published: February 2024

The article is devoted to the study of fatigue of concrete structures using modern artificial intelligence technologies. The main attention is paid to the use of machine vision for the fractal analysis of reinforced concrete structures. The article presents models optimized for operation in machine vision conditions, which makes it possible to detect signs of corrosion and fatigue with high accuracy and speed. A feature of the presented method is the use of a unique method of infinite fractal discrimination, which allows you to analyze the concrete structure in detail at the micro level. This method reveals unique features and heterogeneities in the structure of the material, which contributes to a more accurate prediction of its behavior under various influences. The application of this approach can become revolutionary in the field of diagnostics and maintenance of infrastructure facilities.
Analysis of the current density and electrolyte composition influence on the quality of micro-arc coatings
Authors: Pecherskaya E A , Li Qiang , Zhurina A E , Golubkov P E , Shepeleva J V
Published: February 2024

The results of an experimental study of oxide coatings obtained using an automated system developed by the authors in the anode-cathode mode at a ratio of the anode current to the cathode current equal to 1, at low current (0.125 A or 0.25 A) with different electrolyte composition are presented. An analysis of the dependence of the quality of the obtained coatings on the molding curves, which characterize the change in the electrical voltage on the samples depending on the time of their processing was made. It has been established that with increasing current density, the process is more intense, microdischarges begin to burn earlier, and, in general, the coating quality increases. However, at too high current densities (50 A/dm2), it is undesirable to carry out micro-arc oxidation treatment due to an increase in the coating roughness. In particular, it is expedient to use the results obtained for quality control of the technological mode under production conditions: the coating has inadequate quality if the molding curve has a distorted shape. The results obtained have been tested in the implementation of the method of formation by microarc oxidation of oxide coatings with specified properties.
To the theory of dimensional quantization in crystals in the Kane approximation
Authors: Ya Rasulov R , Rasulov V R , Eshboltayev I M , Kuchkarov M , Urinova K K
Published: February 2024

The microscopic mechanism of size quantization of the conduction band and valence band of semiconductors of cubic and tetrahedral symmetry has been theoretically studied in the Kane approximation. It is shown that the matrix Schrödinger equation obtained on the basis of the Kane model cannot be solved analytically for a potential well of an arbitrary profile. Therefore, expressions for the energy spectrum are obtained depending on the two-dimensional wave vector directed along the interface of the heterostructure for various cases that differ in the range of current carrier energy values.
Dimensional quantization in InSb and GaAs in three-zone model
Authors: Ya Rasulov R , Rasulov V R , Akhmedov B B , Muminov I A , Urinova K K
Published: February 2024

Various cases of size quantization in narrow-gap crystals of cubic or tetrahedral symmetry in the three-band Kane approximation are analyzed. Expressions for the energy spectrum depending on the two-dimensional wave vector are obtained for two different cases, differing in the range of current carrier energy values. The size-quantized energy spectrum of electrons in the conduction band and holes in the subband of light holes in InSb and GaAs semiconductors is analyzed in the three-band Kane model.
Fuzzy system of automatic tuning of electromagnetic excitation system of vibration-frequency liquid density meter
Authors: Huseynov T K , Abdulova N A , Huseymov T T , Hashimova A R , Shirinova A Y
Published: February 2024

A fuzzy system for setting the location of electromagnetic exciter of vibration-frequency density meter is presented, taking into account the possible nonlinearities of the object. This paper proposes a system and algorithm for tuning the location of electromagnetic exciter of vibration-frequency density meter using fuzzy set theory. The use of fuzzy control methods allowed us to obtain a system for tuning the location of the electromagnetic exciter of the vibration-frequency density meter without the use of cumbersome computational procedures characteristic of the classical control method.
Photocatalytic activity of ZnO-Zn nanoparticles after nanosilver covering and annealing
Authors: Gerasimov A S , Balezin M E , Ilves V G , Sokovnin S Yu
Published: February 2024

The research evaluated the photocatalytic activity (PCA) of zinc oxide nanoparticles (NPs) produced by pulsed electron beam evaporation (PEBE). The ability of NPs to accelerate the photodegradation of methyl violet dye under UV exposure was considered. The paper presents an analysis of changes in catalytic activity after annealing and coating with nanosilver of the studied samples. It has been shown that as the annealing temperature increases, the PCA increases, especially for doped particles. The highest catalytic ability was shown by doped NPs ZnO-Zn+Ag annealed at a temperature of 400 °C. This sample allowed to increase the photodegradation of the organic dye by more than 6.5 times compared to the control.
Investigation of the inlet useful temperature difference effect on the distribution of hydrodynamic characteristics of the vapor-liquid flow inside the falling-film evaporator heating tube designed for a nitric acid solutions evaporation
Authors: Khomyakov A P , Gushshamova V N , Mordanov S V , Khomyakova T V , Vlasova E A
Published: February 2024

We present the results of mathematical modeling of effect of inlet useful temperature difference on the vapor- liquid flow in the heat exchange tube of a vertical evaporating film apparatus, which is designed for evaporation of nitric acid solutions. Distributions obtained along the heat exchange tube length of local values of the: mass flow rate of the fluid and secondary steam, the velocity of the fluid film, the velocity of the secondary steam, the Reynolds criterion of the liquid and vapor phases, the absolute pressure depending on the values of this useful temperature difference. The study was carried out using numerical simulation. To study the effect of the initial useful temperature difference on the hydrodynamics of the vapor-liquid flow, the vertical evaporator equipped with the tube ø38x3 mm and length of L = 4 m was adopted. The linear nature of the distribution of hydrodynamic parameters along the length of the heat exchange tube is established. The absolute pressure in the tube space decreases along the heating tube due to pressure drop. The limiting factor in reducing the absolute pressure is the friction losses of the secondary vapor on the solution film surface. A decrease in the pressure in the tube space leads to decrease in the boiling point of the solution. This leads to increase useful temperature. This has a positive effect on the evaporation efficiency The obtained data should be used in the design of evaporation plants, which are designed for evaporation of nitric acid solutions.
Physical and mechanical modeling of shaping pneumatic formwork by bicubic splines
Authors: Yadgarov Uktam , Akhmedov Yunus , Asadov Shukhrat , Badiev Makhmud
Published: February 2024

The article deals with the hierarchical design structure, consisting of four stages of the stress state of pneumatic shells. The main tasks of designing and constructing pneumatic formworks during the construction of thin-walled architectural shells are considered. The introduction of pneumatic formwork into architectural and construction practice has a significant impact on the ability of the architect, builder and designer in the search for new and more advanced forms, as well as the builder in translating the creative ideas of the architect into steel and modern concrete. Thanks to the flexibility and elasticity of the material, it allows the construction of curvilinear spatial shells of a new elastic quality level. The proposed geometric model makes it possible to obtain a variety of software as well as the formation of a discrete-point frame of a finite shape by bicubic splines, which provides a predetermined accuracy for solving subsequent software design and construction problems.
Study of dynamics of the turning process in pneumechanical spinning in the presence of false torsion
Authors: Sayidmuradov Mirzokhid , Khudayberdiyev Abdukarim , Abdullajonov Nosirjon
Published: February 2024

The paper presents the results of a study of the dynamics of the process of torsion of yarn of pneumomechanical spinning in the presence of false torsion. Dynamic mathematical models of the process of torsion of yarn of pneumomechanical spinning in the presence of false torsion in unsteady modes of starting and stopping the forming-twisting device are constructed. By now, the question of yarn twisting in a transient mode of operation in rotor spinning remains unexplored. We have here made an attempt to fill the indicated gap by constructing mathematical models of a forming-twisting device during torsion. In connection with the above-mentioned problem arises to systematize the accumulated information on new methods of forming yarn and constructions of forming and torque devices, to clarify a number of questions of theory and technology, and also to classify methods of forming yarn. The main direction of development of new methods of yarn formation remains the improvement of the high-speed modes of the working organs and, above all, of the forming and turning devices, which raises a number of important problems of both technological and structural nature.
Computational approach based on use of multilayer neural networks in classification of rail line states
Authors: Tarasova Anna E , Tarasov Evgeny M , Zolkin Alexander L , Pestin Vyacheslav A , Bityutskiy Alexey S
Published: February 2024

The article considers the issue of classification of the states of rail lines using multilayer neural networks. It is shown that with significant external disturbing influences, the most promising direction is the retraining of classification models using neural networks. The representativeness of the sample is proposed to be realized by applying the scaling of informative features. It is proposed to minimize classification errors by gradient optimization methods. In the work during classification of rail lines states by neural networks, at the first stage, artificial classes of states are formed. At the second stage, the classification of states by the trained neural network is considered, classification errors are identified. On the basis of these errors the network is retrained until acceptable results are obtained. The article presents neuron learning algorithms: Hebb’s algorithm, error backpropagation method (for training a multilayer neural network), Konohen’s, Hopfield’s, Hamming’s algorithm and network. In the presented revision of the classification model, the correction is carried out according to the Widrow-Hoff algorithm.
Solutions to the problem of differential games with electric oscillations by finite difference methods
Authors: Mamatov Mashrabjon
Published: February 2024

The article deals with the issues of electromagnetic processes from the point of view of application technology. The problem of voltage normalization in lines in the presence of opposing external forces is studied. The process of realizing the solution of this problem is based on the introduction of a mathematical model of electromagnetic processes occurring in lines as a continuous differential pursuit game described by hyperbolic equations. The finite difference method transforms the continuous pursuit problem into a discrete game. Sufficient conditions are obtained getting into neighbourhood. And with the help of a well-known a priori estimate for the difference between the solutions of a continuous differential and the corresponding discrete game, sufficient conditions are obtained for the possibility of completing the pursuit of a continuous game. A pursuer outputs terminal set, which is voltage normalization.
Using numerical simulation to analyze the strength properties of the developed demountable body of a trolley
Authors: Peshkov R A , Tretyakov P A , Fedorov A V , Kuplevatsky D V , Mineev A V
Published: February 2024

One of the safest types of public transport is the metro, which is actively developing in many countries. Despite a number of advantages, the construction of metro tunnels is a rather labor-intensive process, which involves complex technical equipment in the form of tunnel boring complexes. Tunnel boring complexes include locomotives that perform the functions of hauling away rock using trolley with removable body. Trolley differs from their usual characteristics - in weight, dimensions, as well as the component composition of individual systems, in particular the compressed-air braking system. The article is devoted to the analysis of the parameters of the stress-strain state of one of the main load-bearing elements of a trolley- the casing. As a result of the analysis, design loading cases were selected, the most loaded parts of the body were determined, recommendations were formed for choosing the optimal material thickness of various elements and increasing the load-bearing capacity of the body.
Enhancing MPI remote memory access model for distributed-memory systems through one-sided broadcast implementation
Authors: Abuelsoud M M , Kogutenko A A , Naveen
Published: February 2024

Efficiently processing vast and expanding data volumes is a pressing challenge. Traditional high-performance computers, utilizing distributed-memory architecture and a message-passing model, grapple with synchronization issues, hampering their ability to keep up with the growing demands. Remote Memory Access (RMA), often referred to as one-sided MPI communications, offers a solution by allowing a process to directly access another process’s memory, eliminating the need for message exchange and significantly boosting performance. Unfortunately, the existing MPI RMA standard lacks a collective operation interface, limiting efficiency. To overcome this constraint, we introduce an algorithm design that enables efficient parallelizable collective operations within the RMA framework. Our study focuses primarily on the advantages of collective operations, using the broadcast algorithm as a case study. Our implementations surpass traditional methods, highlighting the promising potential of this technique, as indicated by initial performance tests.
Method for changing the redundancy of sequential concatenated code
Authors: Sidorenko Alexander A
Published: February 2024

During the operation of information transmission systems errors occur in the transmitted data due to the influence of various negative factors. To correct errors the codes are currently used that can withstand both single and multiple errors. From the point of view of the ability to correct multiple errors, concatenated codes are highly efficient. When constructing a sequential concatenated code, coding is carried out first by the external, then by the internal code. A significant disadvantage of such coding is a significant increase in redundancy. It is proposed to regulate redundancy by encoding with the internal code only a certain part of the bits from the output of the external code encoder. The study showed the effectiveness of this method, which made it possible to change the parameters of the cascade code within a wide range. A method was proposed and tested to increase the corrective ability of selective coding by multiplying symbols decoded by an external code by coefficients that are different for symbols that have and have not been encoded by an internal code. Decoding of the external code was carried out according to the Viterbi algorithm. The performance of the proposed method has been confirmed experimentally.
On the issue of designing and creation of a composite grinding wheels of increased productivity for rails treatment
Authors: Maksimov I S , Galanskiy S A , Zolkin A L , Bogdanov M.R. , Matvievskaya T B
Published: February 2024

The article discusses the technological aspects of the development and design of composite modified wheels used in the mechanical treatment of railway rails. It allows to increase the productivity of treatment and tool durability. An increase in the physical and mechanical features of the shard of abrasive wheels can be achieved by modifying the binder component in the composition of the ceramic charge mixture with a nanomodifier such as carbon tubes. As a result of the modification of the abrasive composition of the charge mixture, it was possible to achieve an effective performance of railway rails treatment without a significant loss in the durability of the composite grinding wheel.
Registration of melting temperature at phase boundaries in melting powder mixtures
Authors: Smykova Polina , Ishkov Aleksey , Katasonov Alexander , Dzjasheev Abdul-Mudalif , Sokolova Viktoriia , Zagidullin Ramil , Akhmetshin Stanislav
Published: February 2024

An integral constituent of the induction surfacing process for parts hardening pertains to the thermal treatment of rigid alloy particulates and the flux contained within the surfacing amalgam. This scholarly exposition delineates the outcomes of a comprehensive investigation, oriented towards the quantification and simulation of thermal gradients at interphase boundaries within intricate amalgamations of melting and thermosetting powdery substrates. In order to monitor the thermal dynamics during induction surfacing, the application of the CA-microthermocouple methodology and the thermal indication technique utilizing self-propagating SHS-process compositions is posited. The study encompasses both computational simulations and the resolution of the unsteady-state heat conduction problem within the chosen model of composite contacting materials. The devised methodologies for the intricate tracking of thermal profiles during induction surfacing offer the capability to ascertain the temperatures at which the surfacing amalgam and its individual constituents undergo liquefaction, in conjunction with the temperature gradient exhibited by the surface of the targeted component. This facet holds marked significance in the context of optimizing the hardening regimen and ensuring the requisite attributes of the amalgamated materials post-fusion. The outcomes of this research bear practical relevance in industrial applications, wherein enhancements to the caliber and dependability of hardened components are sought, simultaneously facilitating the curtailment of production overheads.
Composite biofilm chitosan-microcrystalline cellulose for tomato preservation
Authors: Doan Trang Tran Y , Dzung Ha Thi , Huong Ta Thi , Quynh Pham Huong
Published: February 2024

The demand for packaging has caused a surge in non-biodegradable plastic waste. To tackle this issue, biofilms provide a safe and effective alternative for packaging and preservation. This research focused on combining chitosan and microcrystalline cellulose (MCC) to produce composite biofilms to preserve fresh fruits. The study involved adding varying quantities of MCC, ranging from 0g to 11g, to chitosan using a glycerol plasticizer. The results showed that adding MCC reduced the adhesion of the chitosan-based film, resulting in a more intact film. The surface morphology of the film showed uniform dispersion of MCC particles. The water adsorption and solubility of the MCC-added films increased while biodegradability decreased. The best biofilm for preservation application was the chitosan film supplemented with 3g of MCC. This film helped limit weight loss, vitamin C content, total acid content, and soluble solids loss in tomatoes during storage. Essentially, the chitosan-MCC film helped to reduce water evaporation, respiration, metabolism with the external environment, and penetration of microorganisms on tomatoes, thus extending their shelf life.
Localized modes in platinum aluminides
Authors: Cherednichenko A I , Bebikhov Y V , Semenov A S , Starostenkov M D , Korznikova E A , Rakhmatullina Z G , Zakharov P V
Published: February 2024

Platinum aluminides have the prospect of being used as both functional and structural materials for a range of scientific and technical tasks. They possess unique properties that make them effective catalysts. The dynamics of the crystal lattice play an important role in the manifestation of these properties. In this study, an analysis of the density of phonon states of crystals and the possibility of the existence of localized lattice vibrations in Al and Pt alloys is conducted using atomistic modeling. The following compounds are considered: AlPt, Al2Pt, Al3Pt, AlPt2, Al3Pt5, AlPt3 (four types of lattices). The calculated phonon spectra allow for the assessment of the possibility of the existence of nonlinear localized modes in the forbidden zone of the spectrum, if it is present. It is shown that a number of crystals within the framework of the considered formalism and interatomic potential can have a forbidden zone. This condition, together with the nonlinearity of the bonds, ensures the existence of highly-amplitude localized modes in the following compounds: AlPt3, AlPt3(1), AlPt3(2), AlPt3(3). It is also established that in the Al3Pt5 alloy, the existence of prolonged high-amplitude excitations on the Al atom is possible.
Memristor effect in an amorphous garnet ferrite film Y1.8Bi1.2Fe3.5Ga1.5O12
Authors: Sitnikov M N , Kharkov A M , Zelenov F V , Nikitinskiy O S , Voronova E G , Cheremnykh N A
Published: February 2024

Amorphous films of yttrium bismuth ferrite garnet were obtained by thermal evaporation. Morphological and elemental analysis was carried out using an electron microscope. The IR spectra of the precursors and the amorphous film were measured. Measurements of theI-U characteristics were carried out in different electric fields and in the temperature range of 80-450K. The hysteresis of the I-U characteristic and the difference between high-resistance and low-resistance resistance by an order of magnitude at voltages of hundreds of microvolts were found.
Aluminizing of the EP33 alloy by hot-dipping
Authors: Kulevich V P , Bogdanov A I , Shmorgun V G
Published: February 2024

The features of hot-dip aluminizing of the EP33 alloy were studied and the structure transformation of the resulting coating during high-temperature treatment was investigated. Aluminizing the EP33 alloy leads to the formation of a continuous 120 μm thick coating, consisting of an aluminum matrix with the Cr2Al13 intermetallic compound inclusions and a continuous layer of FeAl3 intermetallic compound along the boundary with the substrate. Heat treatment of the aluminized alloy at 1100 °C ensures the formation of a layered coating structure. The phase composition of the coating from the surface to the substrate changes in the following sequence: FeAl(Ni,Cr,Ti,Mo) → FeAl(Ni,Cr,Ti,Mo)+Ni(Fe,Cr,Al,Ti,Mo) → FeAl(Ni,Cr,Ti,Mo)+Fe(Al,Ni,Cr,Ti,Mo).
Improving the physical, mechanical and operational characteristics of cast internal combustion engine pistons made of aluminum alloy using secondary charge
Authors: Kovalev I V , Kovalev D I , Voroshilova A A , Gofman P M , Yu Sergeev I , Efa S G
Published: February 2024

The article is devoted to improving the physical, mechanical and operational characteristics of cast internal combustion engine pistons made of aluminum alloy using secondary charge. The advantage of the proposed approach is that these parts are manufactured from any aluminum alloy using the remelting of failed internal combustion engine parts of the same name. The paper shows that while using a secondary charge in the form of remelting failed parts of the same name, the quality of cast products not only does not deteriorate, but, on the contrary, their physical and mechanical characteristics even increase. It should be noted that the high density of the alloy obtained from remelting failed pistons and the high degree of its modification confirmed the authors’ assumption that in this case refining and modification operations can be avoided. The presented approach using the remelting of failed parts makes it possible not only to save fresh charge materials, but also to preserve the chemical composition of the primary parts, and, consequently, the level of their physical, mechanical and operational characteristics.
Methods for increasing the cavitation and solid particle erosion resistance of 20GL and 30L steels based on their surface modification
Authors: Mednikov A F , Tkhabisimov A B , Zilova O S
Published: February 2024

The article presents the results of studies of cavitation and solid particle erosion resistance of samples of 20GL and 30L steels with various surface modification options based on nitriding and boriding processes. Tests for cavitation resistance were carried out according to the ASTM G134-17, and for solid particle erosion resistance - according to the ASTM G76-13. It was revealed that to increase wear resistance, the depth of modification of the considered steels should be at least 80 microns. Based on the totality of cavitation and solid particle erosion studies carried out, the best option for surface modification for 20GL steel is boriding, and for 30L steel nitriding.
Technology for obtaining VO2 films from the gas phase during thermal decomposition
Authors: Sharipov M Z , Urinov J , Kilichov J , Khadjayev M , Normakhmadov B
Published: February 2024

The paper considers the process of obtaining films of vanadium dioxide by the method of deposition of inorganic coatings and films from the vapor phase during the thermal decomposition of organometallic compounds. In recent years, there has been a growing interest in the practical use of organometallic compounds. This has led to the development of many devices that include various vapor deposition techniques. This technology is currently being used as the latest technology. The design of the technological installation for pyrometric film deposition is presented and the principle of operation is given. In the course of the study, film samples were obtained and experimental work was carried out. The results obtained are presented in the form of graphs.
Horizontal tank strength analysis considering nozzle loads and horizontal deviations
Authors: Zakirnichnaya M M , Rubtsov A V , Krivenkov I I , Ilyasov V R , Mustafina E R
Published: February 2024

When assessing the reliable and safe operation of technological equipment, and in particular, capacitive-type equipment, a fairly diverse number of methods are used. However, all current procedures do not sufficiently take into account the impact of certain factors on the forming stressed-deformed state of the object. Usually, when assessing the actual technical condition of an object, the level of defect of the object is determined, and appropriate calculations are carried out according to the criterion of the dominant damage mechanism. A significant impact on the stressed-deformed state of the shell structure can be exerted by the level of loads on process nozzles from the connection of process pipelines, as well as possible deviations during installation work. One of these deviations may be a deviation from the horizontal of the housing when installing supports on the foundation. Moreover, the combination of the action of the above factors can have a determining negative effect on the strength, and, accordingly, the operational reliability of the technical device. In the modern world, technological progress does not stand still and the consequence of this is the development of a fairly extensive number of software products that allow you to simulate possible individual scenarios for the development of unfavorable processes and predict the behavior of the object under the conditions under consideration. In this work, studies are carried out on the strength analysis of the horizontal tank, taking into account various values of loads on the nozzle of the body diameter, as well as taking into account the deviation of the tank body from horizontal.
Application of spring energy accumulators in forging and pressing equipment
Authors: Barashov N N , Shanygin S V , Kananadze S S
Published: February 2024

The development of forging and stamping production requires automation of various pressure treatment equipment. An important feature of the pressure treatment mechanisms is their inherent unsteady mode of operation, consisting of often alternating acceleration and deceleration, so the proportion of inertial loads is quite large. Such mechanisms are considered to be among the least efficient in terms of energy consumption parameters The low efficiency of the known designs is caused by the inability to exclude the influence of inertial forces on energy consumption and the speed of the equipment. The use of damping devices is not able to solve this problem, since they are designed to absorb a certain amount of energy and when the number of strokes per minute changes, they can cause an increase in dynamic loads.
Determination of optimal 3D printing modes for composite parts for reaching the set design-engineering parameters
Authors: Markanov I D , Vdovin R A , Goncharov E S , Firsin A O
Published: February 2024

This paper discusses properties of various 3D printing materials, namely, plastics, including polyamides, along with composite or engineering plastics with inclusions of carbon fiber and fiberglass. We selected an optimal sample printing mode and carried out experiments, following which we determined maximal loads for test composite materials, and linear shrinkage. As the result, we determined an optimal 3D printing mode for various structures of composite material parts with the purpose to reach the set design-engineering parameters.
Ultrasonic treatment for waste-water cleaning
Authors: Shakura V A , Titov G A , Morozova E A
Published: February 2024

Purification of liquids from undesirable admixtures and malignant bacteria is one of the most important problems of the mankind. It is especially sharply appeared at the cleaning of sewage. At present in the most part of the world (in densely populated territories) there is a lack of pure fresh water. Industrial and domestic waste waters negatively influence on the ecological situation in stretches of fresh water. It is evident, that it is caused by the large quantity of insufficiently cleaned sewage, which constantly comes to rivers and ponds in the connection with functioning of the industrial enterprises and households. The presence of admixtures and malignant bacteria in different liquid food (beverages, acetic seasonings) decreases their consumer properties and can be harmful for people health. So there is no doubt of the development new methods of liquid purification. The article is devoted to the analysis of the problem of purification of domestic and industrial waters from pathogenic microorganisms, undesirable admixtures and malignant bacterium. It is considered existing industrial solutions and their disadvantages. The theoretical research of optimum ultrasonic influence modes providing maximum diffusion coefficient was performed and example of US apparatus was presented.
Modeling of radio monitoring systems on signals of short-wavelength adaptive radio communication systems
Authors: Khotamov A , Amonov A K , Nurmurodov J , Nizamov A , Khadjayev M , Xikmatov X X
Published: February 2024

The article describes the structure of a model that allows to evaluate the effectiveness of the radio monitoring system on the signals of flexible shortwave radio communication systems in adverse conditions of external interference. This model is characterized by the ability of modern short-range communication systems to establish radio communication and automate the processes of guaranteed transmission of information, adapt to the noise situation in the shortwave range, the organization of analog and digital communication networks.
Modeling non-linear loads for low-voltage electric grids
Authors: Platonova E V , Toropov A S , Kolovsky A V , Yu Shcherbachevich V
Published: February 2024

The authors performed the computer modeling of a power distribution grid section comprising a significant non-linear and asymmetric household and office load. The modeling was performed using the SimInTech software. The developed model was used to study the impacts that non-linear single-phase consumers (e.g. computers, printers, TV sets, microwave ovens, etc) have on the distortion of current and voltage curves in the grid and the formation of current in the transformer neutral. The authors demonstrate the dependency between the higher harmonic values of the phase and transformer neutral currents and the total non-linear consumer power, their share in the overall power substation load, and the distribution of non-linear consumer load across the substation feeders. To reduce the level of harmonic current components, the authors suggest using narrow-band passive higher harmonic filters. A computer model was developed for the simultaneous operation of a single-phase non-linear load and a four-link filter compensating device that comprises the filters set for the frequencies of the third, fifth, seventh, and ninth harmonics. The analysis of the non-sinusoidal operating modes of the grids with -harmonic filters connected showed that there is practically no current in the neutral while the distortion factors of the phase currents and grid voltage curves are at the minimum.
The comparative analysis of different two-wavelength laser altimeter versions for forest monitoring
Authors: Belov M L , Belov A M , Gorodnichev V A , Alkov S V , Shkarupilo A A
Published: February 2024

This study presents a capability analysis of the various options for the technical implementation of a two-wavelength laser altimeter for monitoring forests. The results of woodlands pieces identification statistical simulation for a neuronic net using experimentally measured spectral reflectance are presented. It is shown that the neuronic net provides a strong probability of correct identification when using information about the reflectivity and the height of woodlands pieces. Two wavelengths 532 and 1064 nm and the neuronic provide the probability of correct identification of green broad-leaved and needle-leaved trees understory, wetlands and ground vegetation of greater than 0.89 and the misidentification probability of lower than 0.055.
The influence of power on the intensity of working fluid heating in the hydraulic drive
Authors: Andreychikov I V , Ionova V A , Kolpakov I G , Sergeenkov A D , Troyakov K V
Published: February 2024

This paper discusses the influence of power on the intensity of working fluid heating in the hydraulic drive. The work considers methods and methods of maintaining thermal conditions in the hydraulic drive. Thermal balance scheme in hydraulic drive of self-propelled machines is considered. Calculation is also made for hydraulic drive of drilling machine. Based on the results of the calculation, a graph was drawn on the dependence of the intensity of pre-start heating of the working fluid on the power developed by the temperature control device.
The first plasma in a newly constructed linear device for plasma turbulence research
Authors: Yu Y. , Xiao C.Y. , Liu H. , Wang Z.H. , Zhou Y.X. , Zhao G.Y. , Xu M. , Nie L. , Yuan Z.H. , Zheng P.F.
Published: February 2024

Parameters of the first plasma in a newly built middle-size
multi-functional linear plasma device named LEAD (Linear
Experimental Advanced Device) were presented. The LEAD device is
built to serve as a multi-purpose laboratory plasma experiment
platform for various topics, including plasma turbulence,
plasma-material interaction, and other fundamental plasma
physics. This device is also useful for testing new diagnostic
systems. It will be complementary to the HL-2A/HL-3 tokamaks in
Southwestern Institute of Physics. The plasma was generated by a
large-area helicon plasma source with a multi-ring antenna driven by
a 13.56 MHz, 5 kW radio frequency (RF) power source. Argon plasma
parameters were measured by a Langmuir probe in different external
parameters including RF power, axial magnetic field, and neutral
pressure. The threshold power for helicon mode transition is
empirically confirmed to be 180 W. Steady-state argon plasma with a
density of higher than 1019 m-3 was generated when RF
power reached 3 kW. Plasma parameters are crucially influenced by
the axial magnetic field. With a weak magnetic field, the radial
density profile is Gaussian-like. However, with a stronger magnetic
field, shear and reversion of azimuthal rotation velocity reversion
appear, resulting in a hollow-shaped density profile. When further
increasing the magnetic field, plasma density
decreases. Steady-state plasma discharges were achieved under a wide
range of argon neutral pressure from 0.1 Pa to over 10 Pa. With
increasing neutral pressure, plasma density increases to its maximum
at 2.5 Pa and then drops, while electron temperature drops
monotonically.
Development of a cryogenic DC transformer using for the measurement of large current
Authors: Zhang Shuqing , Zhang Jingfeng , Liu Fang , Zhou Chao , Liu Huajun , Shi Yi , Xu Peng , Wang Chengtao , Xu Qingjin , Gao Peng
Published: February 2024

Superconducting transformer is a typical facility used for
inducing ultra-high current for large-scale scientific measurement
systems, such as SULTAN-facility at the Centre de Recherches en
Physique des Plasma (CRPP) in Switzerland, FRESCA-facility at CERN
in Switzerland etc. A new program has been launched at the Institute
of Plasma Physics, Chinese Academy of Sciences (ASIPP) to build a
new conductor test facility to investigate the transverse pressure
dependence of critical current of various superconducting cables
using a compact superconducting transformer and cryogenic
electromagnetic press systems. The superconducting transformer can
induce a secondary current up to 60 kA, at a background magnetic
field up to 15 T at 4.2 K. To measure the induced secondary
current at cryogenic temperature precisely, three types of NbTi
superconducting coils are designed based on the zero-flux principle
to characterize the variation of the measured current. In this
paper, the design principle of the cryogenic DC transformer and its
commissioning results in a preliminary prototype test device are
presented. The measurement results show achievements on accuracy of
±0.6% or less and nonlinearity of better than ±0.25%,
which demonstrates the feasibility of the cryogenic DC transformer
and provides a reliable technology for the secondary current
measurement of a 100 kA superconducting transformer used in the
program of Super-X test facility at ASIPP.
Picosecond programmable delay line using commercial components for precision timing signal alignment
Authors: Freeborn T.J. , Owings H.B. , Griffin S.J.
Published: February 2024

A picosecond precision programmable digital delay line with
10 ps average resolution and 200 ns range using low-cost,
commercially available integrated circuits (MC100EP195 and DS1023)
is presented. This design is integrated into an existing product
(AOG-110 from Microchip Technology Inc.) to facilitate alignment
between 1 PPS and 5 MHz output waveforms based on user
selected features (e.g. zero-crossings or peak amplitudes) for
precision-timing applications. The performance of this design is
experimentally validated using logarithmic stepped delays from
10 ps to 200 ns with a median deviation of 1.9% from the
ideal. The largest deviations are observed in the range from
10 ps to 100 ps, attributed to the non-linear behavior of the
MC100EP195 in the design. Overall, this design is a low-cost,
digital delay option that can be easily integrated into any
microcontroller based system and does not require additional complex
design revisions. Further, this highlights the increased range and
precision options available by cascading commercially available
digital delay line integrated circuits.
Impacts of terrestrial vegetation on surface ozone in China: from present to carbon neutrality
Authors: Lei Yadong , Yue Xu , Wang Zhili , Tian Chenguang , Zhou Hao , Liu Quan
Published: February 2024

Despite many efforts to control anthropogenic sources, high ambient ozone (O3) concentrations remain a serious air pollution problem in China. Terrestrial vegetation can remove surface O3 through dry deposition but also enhance surface O3 through biogenic volatile organic compound (BVOC) emissions. However, the net impacts of terrestrial vegetation on surface O3 remains unclear. Here, we perform simulations using a chemistry-vegetation coupled model to assess the impacts of terrestrial vegetation on surface daily maximum 8 h average (MDA8) O3 in China through biogeochemical processes, including BVOC emissions and stomatal uptake. The results show that vegetation biogeochemical processes increase summer mean surface MDA8 O3 by 1.3 ppb in the present day in China, with 3.7 ppb from BVOC emissions but −2.7 ppb from stomatal uptake. However, the enhanced summer mean surface MDA8 O3 from vegetation biogeochemical processes decreases from 5.4 to 2.7 ppb in the North China Plain (NCP), from 7.2 to 0.8 ppb in the Yangtze River Delta (YRD), from 8.7 to 1.8 ppb in the Sichuan Basin (SCB) and from 4.2 to 0.4 ppb in the Pearl River Delta by the period of carbon neutrality. Our study highlights that carbon neutrality-driven emission reductions can greatly mitigate the enhanced surface O3 related to terrestrial vegetation, though there is still a positive impact of terrestrial vegetation on surface O3 in some hotspots, including the NCP and the SCB.
Wear and friction behaviour of Cu-Gr-B4C composites and correlating to the topographical characteristics
Authors: Kumar Manish , Ankit  , Majhi Manas Ranjan , Chaturvedi R K
Published: February 2024

The mechanical and tribological characteristics are important in applications such as bearing linings, bushings, and electrical contacts. In the current experiment, copper-chromium matrix composites reinforced with graphite (Gr.)-boron carbide (B4C) [at 1.5, 3, and 4.5 wt%] were made using powder metallurgy (P/M) process. As reinforcements, equal amounts of Gr and B4C were utilized. The microstructural characteristics of the sintered composites have been investigated using analytical techniques such as EDS mapping analysis, x-ray diffraction, and scanning electron microscopy (SEM). The composites with a copper matrix displayed a homogeneous distribution of the reinforcement phase within the material. The pin-on-disc tribometer was used to conduct dry sliding wear tests with loads ranging from 10 to 40 N, sliding speeds of 1–3 m s−1, and fixed sliding distances of 2 km. The hardness is 97.3 HV with 3 wt% of each graphite and B4C reinforcement, which is 70.1% harder than pure copper (57.2 HV). It has been discovered that the wear rate and COF of composites decrease as the quantity of reinforcing rises—the composite with 4.5 wt% graphite and 4.5 wt% B4C exhibits the least amount of wear. The wear rate showed a rising trend with the applied load and sliding velocity across every material. The study of the deteriorated surface also reveals that delamination is the primary wear mechanism for pure Cu specimens. B4C and graphite-reinforced composites have been subjected to abrasives, oxidative and delamination wear modes.
RD-OCT net: hybrid learning system for automated diagnosis of macular diseases from OCT retinal images
Authors: Prabha A Jeya , Venkatesan C , Fathimal M Sameera , Nithiyanantham K K , Kirubha S P Angeline
Published: February 2024

Macular Edema is a leading cause of visual impairment and blindness in patients with ocular fundus diseases. Due to its non-invasive and high-resolution characteristics, optical coherence tomography (OCT) has been extensively utilized for the diagnosis of macular diseases. The manual detection of retinal diseases by clinicians is a laborious process, further complicated by the challenging identification of macular diseases. This difficulty arises from the significant pathological alterations occurring within the retinal layers, as well as the accumulation of fluid in the retina. Deep Learning neural networks are utilized for automatic detection of retinal diseases. This paper aims to propose a lightweight hybrid learning Retinal Disease OCT Net with a reduced number of trainable parameters and enable automatic classification of retinal diseases. A Hybrid Learning Retinal Disease OCT Net (RD-OCT) is utilized for the multiclass classification of major retinal diseases, namely neovascular age-related macular degeneration (nAMD), diabetic macular edema (DME), retinal vein occlusion (RVO), and normal retinal conditions. The diagnosis of retinal diseases is facilitated by the use of hybrid learning models and pre-trained deep learning models in the field of artificial intelligence. The Hybrid Learning RD-OCT Net provides better accuracy of 97.6% for nAMD, 98.08% for DME, 98% for RVO, and 97% for the Normal group. The respective area under the curve values were 0.99, 0.97, 1.0, and 0.99. The utilization of the RD-OCT model will be useful for ophthalmologists in the diagnosis of prevalent retinal diseases, due to the simplicity of the system and reduced number of trainable parameters.
Supervised and unsupervised learning of
(1+1)
-dimensional even-offspring branching annihilating random walks
Authors: Wang Yanyang , Li Wei , Liu Feiyi , Shen Jianmin
Published: February 2024

Machine learning (ML) of phase transitions (PTs) has gradually become an effective approach that enables us to explore the nature of various PTs more promptly in equilibrium and nonequilibrium systems. Unlike equilibrium systems, non-equilibrium systems display more complicated and diverse features because of the extra dimension of time, which is not readily tractable, both theoretically and numerically. The combination of ML and most renowned nonequilibrium model, directed percolation (DP), led to some significant findings. In this study, ML is applied to

(
1
+
1
)

-d, even offspring branching annihilating random walks (BAW), whose universality class is not DP-like. The supervised learning of

(
1
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1
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-d BAW via convolutional neural networks (CNN) results in a more accurate prediction of the critical point than the Monte Carlo (MC) simulation for the same system sizes. The dynamic exponent z and spatial correlation length correlation exponent

ν

⊥

were also measured and found to be consistent with their respective theoretical values. Furthermore, the unsupervised learning of

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1
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-d BAW via an autoencoder (AE) gives rise to a transition point, which is the same as the critical point. The latent layer of AE, through a single neuron, can be regarded as the order parameter of the system being properly re-scaled. Therefore, we believe that ML has exciting application prospects in reaction-diffusion systems such as BAW and DP.