bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification and recognition of online hand-written alphabets using Machine Learning Methods
Authors: Popli R , Kansal I , Garg A , Goyal N , Garg K
Published: January 2021

The hand-written alphabet recognition and classification plays an important role in pattern recognition, computer vision as well as image processing. In last few decades, a plethora of applications based on this area are developed such as sign identification, multi lingual learning systems etc. This paper classifies samples of hand-written alphabets into different classes using various machine learning methods. The challenging factor in hand written alphabets recognition lie in variations of style, shape and size of the letters. In this paper a simplified and accurate methodology is proposed based upon engineered features which are evaluated and tested using MatLab tool in comparison to other existing methods. The proposed system achieves a substantial amount of accuracy of 98% as compared to the state of the art approaches.
Comparative Analysis of Detection of Email Spam With the Aid of Machine Learning Approaches
Authors: Madhavan Mangena Venu , Pande Sagar , Umekar Pooja , Mahore Tushar , Kalyankar Dhiraj
Published: January 2021

Over the past few decades, Technology has gained a rapid pace in its development making communication easier. Considering several modes of communication, E-mails(Electronic mails) are the best means for both informal and formal conversations. Some also use e-mails to store and share important information in the form of text, images, documents, etc. between people using electronic devices. Besides, some people improperly use this means of communication by sending useless or unwanted e-mails in bulk i.e., spammed emails which could result in disproportionate usage of memory in the mailbox. There are many suggested approaches in practice that could identify spam emails from the mailbox using machine learning methods. This paper mainly deals with the comparative analysis of detecting Spam Emails by various machine learning methodologies along with the proposed methodology. Considering various evaluation metrics such as Accuracy, Error, Evaluation time, Efficiency, and so on for the evaluation of models. This document draws the contrast on strengths, drawbacks, and limitations of some of the existing techniques that use the approaches of machine learning to detect spam emails. The machine learning method is further resourceful than the acquaintance approach of engineering which does not involve the specifications of any instructions. Considering various evaluation metrics such as Accuracy, Error, Evaluation time, Efficiency, and so on for the evaluation of models. The various accuracies obtained in this framework are KNN – 96.20%, Naïve Bayes – 99.46%, SVM – 96.90, Rough Sets Classifiers – 97.42%.
Twitter Sentiment Analysis Using Deep Learning
Authors: Neha  , Gupta Hritik , Pande Sagar , Khamparia Aditya , Bhagat Vaishali , Karale Nikhil
Published: January 2021

It is well established that the tweet sentiment analysis is still focused on conventional messages, such as film reviews and product reviews, while significant improvement has been made as deep learning becomes widespread, and comprehensive data sets are accessible for training (far from just emoticons and hashtags). Nevertheless, prior opinion analysis experiments typically performed on tweets, i.e. only two forms of global polarities (i.e. optimistic and negative) occur with their work/validation/test data sets. What is more, systems’ judgments are not actively aligned with the specified appraisal objects. In this paper, we have discussed some deep learning approaches for twitter sentiment analysis. We also trained our model using CNN and RNN to get some good accuracy results.
Dental cavity Classification of using Convolutional Neural Network
Authors: Sonavane Apurva , Yadav Rohit , Khamparia Aditya
Published: January 2021

Dental and Oral diseases are very common diseases and half of the world population suffers from it. Due to poverty or unhygienic practices, these diseases are common, and it is estimated that 5% of total medical expenditure in the world is on oral diseases. In this paper, we have focused on detecting cavities. Recent developments Machine Learning and Artificial Intelligence have helped a lot in medical science. Due to these algorithms, diagnosis and treatment of diseases can be done efficiently. To detect dental cavities different imaging modalities are used by doctors, however, in this paper we have used visual images of teeth’s and applied deep convolution neural network(CNN) to classify the teeth into caries or non-caries. We have used the images from the Kaggle dataset, and after tuning our model we were able to achieve 71.43% accuracy.
Extraction and Summarization of Reviews using Lexicon based Approach
Authors: Sheikh A A , Arif T , Malik M B , Bhat S I
Published: January 2021

Online service providers have enabled users to freely comment in the form of review on an online items. These large scale of reviews contains valuable information and poses the need of automatic summarization. In this paper the extraction and summarization of reviews expressed by customers on Samsung mobiles has been carried out. The proposed approach extracts the Samsung reviews using custom build scraper from Flipkart and classify them as positive, negative and neutral using Lexicon based approach (SentiWordNet).
Optimized Sequential model for Plant Recognition in Keras
Authors: Aggarwal Shilpi , Bhatia Madhulika , Madaan Rosy , Pandey Hari Mohan
Published: January 2021

There are huge varieties of floras in the world. Lots of varieties of species are beneficial to the human’s life. Plant recognition is a very important task to segregate the huge amount of floras which belong to various categories. Various researchers have applied different approaches to recognize the plant family. Deep learning is a subset of machine learning. This is one of the accepted technologies that automatically extracts features, processes them and yields the best results. Keras is a widely used deep learning framework which is employed in this work. Five different plant species are chosen as samples among the Indian species, namely OcimumTenuiflorum, Sansevieriatrifasciata, Chlorophytumcomosum, Azadirachtaindica, Aloe Vera. These samples are rich in oxygen. From these samples the features like shape, color, texture, corners are extracted. One hot encoding is also applied onto the target values to optimize the results of recognition. The extracted features are fed into the sequential keras model which recognizes the plant species. The accuracy of the training set is 100 percent and the testing set is 96.7percent. Confusion matrix is drawn to show the correctly classified and misclassified samples.
Potato Plant Leaves Disease Detection and Classification using Machine Learning Methodologies
Authors: Singh Aditi , Kaur Harjeet
Published: January 2021

Agriculture is one of the essential sectors for the survival of humankind. At the same time, digitalization touching across all the fields that became easier to handle various difficult tasks. Adapting technology as well as digitalization is very crucial for the field of agriculture to benefit the farmer as well as the consumer. Due to adopting technology and regular monitoring, one can able to identify the diseases at the very initial stages and those can be eradicated to obtain a better yield of the crop. In this document, a methodology was proposed for the detection as well as the classification of diseases that occur for the potato plants. For this scenario, the openly accessible, standard, and reliable data set was considered which was popularly known as Plant Village Dataset. For the process of image segmentation, the K-means methodology was considered, for the feature extraction purpose, the gray level co-occurrence matrix concept was utilized, and for the classification purpose, the multi-class support vector machine methodology was utilized. The proposed methodology able to attain an accuracy of 95.99%.
Improving the lubricating properties of transmission oils by activating the processes of boundary films formation
Authors: Ponomarenko A G , Boiko T G , Bicherov A A , Bicherov A V , Shiryaeva T A , Kulemzin D V
Published: January 2021

The properties of the boundary lubricating films determine the performance of friction units, which is most important in the event of a loss of lubricant. It has been found that when sunflower oil is added to mineral transmission oil, strong boundary layers are formed during friction. These layers reduce wear and friction. Vegetable oils with the lowest iodine value have the best antiwear properties. The additional introduction of the product of the interaction of rosin with copper (II) hydroxide into the transmission oil makes it possible to form lubricating structured layers that improve the tribotechnical properties.
Design technique of highly efficient technological processes for preparation of polymeric composite parts for adhesive bonding
Authors: Tamarkin M A , Tishchenko E E , Murugova E V , Kozulko N V
Published: January 2021

This paper presents the results of technological machining of polymer composite parts with the flexible flap wheels for further adhesive bonding. The peculiarities of polymer composite materials and their application field are revealed. Constructions that use polymer composite material parts are described.

The article identifies the process of gluing parts made of polymer composites, as well as features of ensuring the strength of the adhesive joint after mechanical processing of bonded parts.

Methodology of modes processing selection and structural-geometric tool parameters for the processing of surface parts under the adhesive bonding is elaborated. Theoretical studies of processing the polymer composite parts with the help of flap wheels are conducted. The surface roughness model is developed. A considerable amount of experimental research has been carried out. The tools for machining and cutting modes are selected. The strength of the glue connection of the details processed by the flap wheels is examined. To compare the durability of the received glue connections and the combinations executed according to the factory technology, the reference surfaces of the samples used at comparative control of quality sanding are investigated. The theoretical and experimental results are compared. Their high convergence is established. The adequacy of the theoretical dependence in compliance with the Fisher criterion is checked. Effective methodology for designing highly efficient technological processes tested in industrial conditions is presented. It allowed to reduce the processing time in more than 2 times, while providing the high strength adhesive bonds.
Improvement of friction units limiting the durability of mechanical systems
Authors: Demyanov Aleksey , Demyanov Alexander , Pavlova Irina , Pavlitskiy Boris
Published: January 2021

The efficiency and competitiveness of transport, other things being equal, directly depends on improving the safety of the transportation process, which in turn depends on the actual technical condition and durability of the rolling stock. To solve problems of this type, it is proposed a set of solutions is proposed that increases the durability of especially critical friction units that affect the safety of operation of technical systems used in loading and unloading and transport processes. The proposed solutions are characterized by manufacturability, low resource consumption and versatility.
Simulation of Oscillation Frequency Effects on Complex Shape Part Milling
Authors: Yamnikov A S , Bogomolov M N
Published: January 2021

The study shows that auto-oscillations occur even at low-speed turning. The paper includes a literature review revealing the reasons for machining vibrations. It is difficult to analytically describe the physical processes in the cutting area, so we used simulation. Moreover, milling is the most difficult process to describe and research. The variable magnitudes/directions of the cutting forces resulting in extra auto-oscillations make the analysis even more complex. It is shown that reducing the cutting speed leads to lower vibrations, and to lower output, higher rigidity, and damping capacity. It is important to know the natural frequency of the workpiece to choose the right cutting mode. The finite element method and SoldWorks CAD models were used for simulating the complex shape part dynamic behavior. We found out that the workpiece natural frequency is 6.5 times higher than the forced oscillation frequency.
Surface Layer Formation at Dynamic Combined Exposure by Two-Component Electrode
Authors: Boldyrev A I , Kuzovkin A V , Boldyrev A A , Padurets A A
Published: January 2021

This article is devoted to the study of workpieces surface layer state, resulting from dynamic exposure of a two-component electrode with imposition of electric field. The objects considered in the work are details with complex profile. Such parts are used in aviation, rocket and space technology and in oil and gas industry. They include impellers and flow part of turbopump bodies, augers, blade wheels, which have areas of variable curvature with limited tool access to treatment area. The authors show that mixture in combined process of two-component processing media from current-carrying granules and conductive liquid medium supplied at high speed to the treatment area, provides the required quality of surface layer due to the combined dynamic exposures on the material being treated. The parameters combination of electric field and kinetic energy of conductive granules allows you to control the magnitude and depth of material hardened layer in treatment area. Experimental studies have shown the increase in resource and durability of critical assemblies for aerospace equipment and oil and gas apparatus.
Technological provision for vibration cleaning of products in preparing them for disposal
Authors: Lebedev V A , Ivanov V V , Vesnin V , Basenko G V , Pastuchov F A , Sanamyan G V
Published: January 2021

The article discusses one of the main stages of products’ preparation for disposal, providing for their cleaning from contamination; it is shown that the most promising methods of cleaning treatment are the mechanochemical cleaning methods based on the use of a different vibration spectrum of the processing substance. Depending on the nature of contamination, the material and shape of the processed parts, the conditions of vibration cleaning (mode, working environment, washing and dissolving liquids) can be varied. Based on the studies carried out, it has been established that the vibration cleaning of the surface depends directly on the work of the influence force on contamination which, in turn, depends on the dynamic activity of the particles of the working environment and the gravitational activity of the process fluid. An energy condition and calculated dependencies are proposed that can be used in the development of vibration cleaning technology for specified contaminants and product materials when solving a specific applied problem, as well as developing and optimizing the vibration cleaning process for products, describing and justifying the influence of mechanochemical phenomena on the intensification of the cleaning process in order to identify technical and economic effect from the use of vibration processing method.
Assessment of the mechanical properties of welded joints after wave strain hardening
Authors: Kirichek A V , Barinov S V , Silantyev S A , Aborkin A V , Yashin A V
Published: January 2021

The purpose of this work is to establish the relationship between the modes of wave strain hardening (WSH) and changes in the ultimate strength, microhardness, impact strength of welded joints. The need for these studies is associated with the prevention of destruction of welded joints with the help of their subsequent WSH. The uniqueness of the WSH method lies in the wave loading of the processed material by shock pulses with a given duty cycle, energy and duration. This makes it possible to increase microhardness and form compressive residual stresses at a depth of more than 10 mm, which makes the use of the method promising for increasing the strength of welded seams. These studies have not previously been conducted. Materials 10XCHД, 30XГCA and 40X were taken as objects of research, from which important welded products are often made in industry. As a result of the research, based on the conditions for increasing the strength of welded joints of the selected materials, rational modes of strengthening and the direction of processing have been determined.
Regularities of technological inheritance in the categories of loading programs
Authors: Blumenstein V Yu , Krechetov A A
Published: January 2021

The paper presents an approach to describing technological inheritance as a pattern of changing loading programs under the influence of the loading history of the metal of the surface layer at the previous stages of processing. The loading program represents the regularity of the accumulation of deformation under conditions of a change in the stress state in the process of deformation and determines the regularities of the accumulation of metal damage during the processing and operation of the product. The proposed approach makes it possible to assess the accumulation of deformation and damage to the metal of the surface layer at all stages of the product life cycle.
High-speed pneumomechanical drive of the executive movements of machine mechanisms
Authors: Prikhodko S P , Sidorenko V S , Kharchenko A N , Grishchenko V I
Published: January 2021

This paper presents a technical solution for a high-speed positional pneumatic actuator of the executive movements of technological equipment, and also developed a mathematical and computer model. The method of solving the differential equation in the SiminTech program is used. The result is an oscillogram of transient processes. The resulting models allow for dynamic analysis of pneumo-mechanical systems. This article presents graphs constructed in the computer program SimInTech, the dependence of the angular velocity and angular displacement on time. A mathematical model is written that is confirmed by a computational experiment.
Design of control laws for rotary inverted pendulum based on LQR and Lyapunov function
Authors: Nguyen C X , Tran Th Tr , Pham Th X , Le K M
Published: January 2021

In this paper, a new technique for synthesizing control laws of stabilizing rotary inverted pendulum is proposed. The key of the proposed method is combination of linear quadratic regulator (LQR) method and Lyapunov function such that the control system can achieve higher performance. The Lyapunov function-based methods guarantee the globally approximate stability; however, they face to the difficulty of constructing an effective Lyapunov function. On the other hand, the LQR-based methods have been shown the ability to achieve high performance only if the control system has a weak nonlinearity and/or operate around equilibrium point. Combining them may partially deal with their limitations. The effectiveness of the proposed method is examined by experiments on the rotary inverted pendulum and compared with the LQR method. The results show that the proposed method has achieved a better performance.
The design of a quasi-time optimal cascade controller for ball and beam system
Authors: Nguyen C X , Phan H Ng , Hoang L D , Tran H Ng
Published: January 2021

In this paper, a methodology for designing quasi-time optimal cascade controller for ball and beam system is presented and the result is compared with LQR method as well as implemented on real system. Ball and beam system is a highly non-linear system, its parameters are difficult to estimate accurately and easily affect by disturbance. In designed method, a mathematical model describing the system is built, including a motor that creates a rotation of beam and is divided into two subsystems when synthesizing the cascade controller for the system. The first floor is the beam subsystem with the output is the angle as the set value for the second floor, which is ball subsystem. The controller is synthesized for each subsystem based on the quasi-time optimal control. The advantage of this method is the synthesizing control law with non-linear system. The simulation results show the effectiveness of the proposed design.
Two-dimensional plan source, vortex and vortex source
Authors: Kokhanenko V N , Burtseva O A , Alexandrova M S
Published: January 2021

Modern hydraulic structures require highly reliable water-supply channels, free-flow pipes and open spillways. Therefore, they must be built with considering dynamic properties of the affecting flow. The theory of one-dimensional open flows cannot answer many questions raised by the hydraulic engineering practice. Hence, this paper considers two-dimensional graphical open flows, with separate particular models following from the general theory, important for designing couplings, curves in more complex constructions (two different channels) required in hydraulic engineering (Hydraulics technical structures) (HTS). And the more such models are obtained, the more opportunities will appear for scientists and designers to synthesize more complex structures required in HTS.

This study identifies three elements, and three simplest models of two-dimensional graphic open water flows similar to flat models: a source, a vortex and a vortex source. The number of such individual models will continue to increase and expand the range of possibilities for designing more complex water technical objects (WTO).

The models are obtained analytically from solving the system of two-dimensional graphical open potential water flows in the plane of the velocity hodograph. The elementary construction of each model includes an analytical solution for the potential function and the stream function.

The paper considers the problem of determining the parameters of a two-dimensional graphical open water flow at any point in the flow: a source, a vortex, a vortex source. The practical significance of the models lies in the possibility to use the results by the designers of hydraulic structures both at the first stage of solving problems and at the subsequent ones, with flow resistance forces taken into account.

The study also represents the transition method from the plane of the flow velocity hodograph to the flow diagram by integrating the models in the plane of the velocity hodograph from the condition of the connection between the considered planes.
Alignment the controlled trajectories of the machine’s executive elements with the properties of the cutting system
Authors: Zakovorotny V L , Gvindjiliya V E
Published: January 2021

The article considers the task of alignment of trajectories of machine executive elements set by CNC-system with evolutionarily changing properties of the cutting process in such a way that minimize the wear intensity. Consequently not position optimizes in the space of the technological regimes but its trajectories are harmonized with changes of the properties of the manufacturing process. The definition of trajectories is considered from the point of view of synergetic mutually agreed interaction of external control and internal dynamic of the cutting system.

The study of alignment is performed on the basis of constructing mathematical models of a controlled dynamic system and performing digital experiments for a cutting system, the parameters of which and tool wear depend on the phase trajectory of the power of irreversible energy transformations in the cutting zone. Based on the research, new directions for improving the efficiency of cutting processes on CNC machines are proposed, which allow increasing the productivity of the cutting process without changing the requirements for the quality of manufacturing parts.
RETRACTED: Composite antifriction coating modified with copper complex and fluoropolymer
Authors: Shcherbakov I N
Published: January 2021

A composite antifriction coating modified with copper complex and fluoropolymer has been developed. Studies were carried out on the effect of modifiers on obtaining a solid lubricating coating of a certain thickness, depending on the heat treatment modes, and measurements of friction and adhesion coefficient were carried out. This coating can be used in friction units of machines and mechanisms operating in an air environment with frequent cyclic loads, temperature drops, as well as in vacuum. On the basis of experimental data, the optimal structure of the composite coating components has been developed.
Efficiency analysis using complex ultrasonic vibrations in electroacoustic spraying of axial cutting tools
Authors: Kudryshev S B , Naumenko V A , Zakalyuzhnyy A A
Published: January 2021

The article considers the electric spark intensification doping methods by using ultrasonic vibrations to obtain the method of electroacoustic deposition. The ultrasonic vibrations use in the deposition process is possible due to the use of an acoustic system at the end of which a naturally swirled waveguide is used. To analyze the waveguide oscillation amplitude dependence on the frequency, the article presents analytically obtained dependences of the longitudinal and torsional components of vibrations. The obtained results reliability of theoretical studies is confirmed by the good convergence of the theoretical and calculated frequency response resonant peaks. The electroacoustic deposition effectiveness method is confirmed by experimental studies of maintaining the hardened drills performance. The experimental data analysis showed a 2-4 fold increase in the total durability period of hardened drills.
Numerical solution of mathematical physics problems by the collocation method
Authors: Shcherbakova E E , Knyazev S Yu
Published: January 2021

A modified collocation method for the numerical solving boundary value problems of mathematical physics is proposed. The irregular arrangement of collocation nodes in the problem solving domain can sharply increase the accuracy of the numerical solution by improving the quality of the linear algebraic equations system, to which the solved boundary value problem leads. Various basis functions systems are considered. The proposed method allows one to obtain an approximate solution of boundary value problems for a wide range of linear and nonlinear elliptic, parabolic and wave equations in an analytical form. This numerical method makes it possible to significantly expand the application field of traditional numerical methods when solving applied problems for modelling fields of various physical natures, described by linear and nonlinear equations of mathematical physics. The developed method is used to solve a quantum-mechanical problem for a hydrogen molecule ion. The results obtained in this work show the high potentialities of the complete collocation method, which are based on the universality of the method and high accuracy of numerical solutions. The energy of the ion ground state calculated with the minimum number of collocation nodes differs from the experimentally obtained value by 13%.
Simulation of pneumatic actuator position system for long stroke mounting movements
Authors: Sidorenko V S , Korotych D A , Grishenko V I , Kharchenko A N
Published: January 2021

The creation of new equipment and technical means for the implementation of promising processes and technologies is largely determined by the level of development of mechanical engineering. The most important requirements for technological equipment are an increase in work processes, flexibility and adaptability, automation, implementation of complex algorithms of executive movements. The mechanisms of executive movements ensure the operation of transporting, fixing and other target mechanisms, this largely determines the quality and efficiency of processing processes. Positional actuators have existing technical solutions. However, to a greater extent they relate to linear movements realized by rod cylinders, this does not allow adapting the results of existing research to the development of long-stroke positional movements. In the course of this work, an assessment was made of the existing types of drives and a displacement and position measurement sensors. The proposed positional pneumatic scheme allows solving the problem of positioning long-stroke displacements, its mathematical and computer models were built, and dynamic analysis and conclusions were made.
Combined pneumatic drive of the rotary-dividing mechanism of the revolver head
Authors: Dolgov G A , Sidorenko V S , Grishenko V I , Kharchenko A N
Published: January 2021

Currently, the use of a positional combined drive in metal-cutting equipment must have a high-precision ability to process new materials, the design of workpieces and parts; ensure the technical and environmental safety of personnel, etc. All these requirements must be met by CNC machines to produce competitive products in the market criteria. Metal cutting equipment due to its high cost has led to the need to use a single power source for multiple work movements. To increase the productivity of the machine, it is necessary to use a combined two-motor positional pneumatic drive. This increases the total production time. reduce the main time (by automating two movements: rapid supply of the workpiece to the processing center, and reduce the auxiliary time (automating the installation of the workpiece and removing the part, reducing the path of movement of the tool), reduce the time for equipment changeover (using digital display and software control). The section “research results” presents the results of mathematical modeling based on a computer model implemented in the SimInTech software package. The graphs of pressure dependences in the piston and rod cavities of the pneumatic cylinder, speed and displacement of the pneumatic cylinder are obtained.
Optimization of dynamically loaded nonlinear technical systems
Authors: Shapovalov V V , Kharlamov P V , Gorin S L , Mischinenko V B , Kornienko R A , Zinovev V E
Published: January 2021

Modeling and simulation technologies play an important role in the operation, diagnosis of the current state and prediction of changes in various mechanical systems. The most effective approach for the study of nonlinear friction systems is the use of the method of physical and mathematical modeling, which is based on the construction of a mathematical model of a quasi-linear subsystem of a machine or mechanism and the creation of a physical model of a substantially nonlinear friction subsystem. Fundamentally new approaches have been developed to solve the problems of optimization, increasing the efficiency and competitiveness of non-linear technical systems using the example of the wheel-rail tribosystem. Proposed technology of metal cladding of locomotive wheel band and implementation of anisotropy of friction coupling provide significant increase of efficiency of “wheel-rail” tribosystem.
Schemes of high-voltage rectifiers as part of dust removal electric gates
Authors: Yurov A A , Minkin M S , Kuimov D N
Published: January 2021

The problem of controlling emissions of dust fractions from various types of technological machines and containers during the production and transportation of bulk materials in the construction and metallurgical industries is quite urgent, due to the need to ensure environmental protection. The development of an energy efficient and inexpensive air filtration system can be an optimal solution to this problem. An important part of this system is the power supply. Measures aimed at increasing load characteristics of circuits of high-voltage rectifiers as a source of high DC voltage of negative polarity of dust collecting electric locks are considered in this work.
Structure, phase composition and properties of borowolframed coating on steel 20 after microarc chemical heat treatment
Authors: Davidyan L V , Dombrovskii Yu M
Published: January 2021

The results of the research devoted to the study of structure, phase composition, micro hardness and wear resistance of the borowolframed coating on steel 20, that was obtained by the method of microarc chemical heat treatment, are presented. With the help of microrentgenospectral analysis, it was found that during microarc borowolframing, both grain-boundary and trans crystallite diffusion of boron, carbon and tungsten occurs, which avoided the formation of brittle carboborid eutectics along the boundaries of plastic grains of the layer base. X-ray phase analysis in the diffusion coating found iron and tungsten borides Fe2B and W2B5, tungsten carbide WC, boron nitride BN and iron intermetallic with tungsten Fe7W6. The micro hardness of the borovolframed layer was 12-13 GPa. The wear rate of the borowolframed samples is reduced by 4.4 times in comparison with steel 20 in the initial structural state.
Evaluation of wear resistance of boron-containing layers on steel 20 after microarc surface alloying
Authors: Davidyan L V , Dombrovskii Yu M , Chumachenko G V , Balinskaya M V , Asten T B
Published: January 2021

The evaluation results of abrasive wear resistance on a friction machine K4-B of boron-containing coatings on steel samples are presented in this paper. It was obtained with the method of microarc chemical heat treatment from coatings. Samples of steel 20 with a diameter 4 mm and a length 30 mm were tested after microarc borating, borovanadium treatment, boro-molybdenation and borochromization. It was identified that after borating with microarc heating, the wear rate decreases by 3.04 times in comparison with the wear rate of the reference - steel 20 in the initial structural state. Microarc multicomponent saturation, when borides, carbides, and more complex substances that contain chromium, molybdenum or vanadium were found in the diffusion layer, significantly reduces the wear rate of steel products up to 4.4 times in comparison with the initial state.
The effect of the selective laser melting mode on second phases precipitation in 316L steel during subsequent heat treatment
Authors: Popkova D S , Ruslanov I M , Zhilyakov A Y , Belikov S V
Published: January 2021

The object of the study was 316L steel obtained by the method of selective laser melting (SLM). The structure of 316L steel was investigated after different SLM modes. The effect of different SLM modes on the second phases precipitation after heat treatment was studied. It is revealed that the fraction of precipitates of the χ-phase correlates with the energy density of the laser beam during SLM.
Identification of the second phases formed in VDM® alloy C-4
Authors: Pyrin D V , Popkova D S , Zhilyakov A Y , Belikov S V
Published: January 2021

The electrochemical extraction of the second phase in the VDM® alloy C-4 alloy has been studied by transmission and scanning microscopy, as well as by X-ray phase analysis. It was found that annealing, which consists in heating up to 850 °C with further holding for 32 hours and cooling in a furnace, leads to the precipitation of a second phase in VDM® alloy C-4 alloy. It can lead to embrittlement and a general decrease in the corrosion resistance of the alloy. The precipitation of the anode deposit (the second phase in the samples of the VDM® alloy C-4 alloy after annealing) and its identification was carried out by the methods indicated above.
Preliminary study of distribution of mechanical properties and mineral density by depth of liquid saturated carious dentine
Authors: Sadyrin E V , Mitrin B I , Yogina D V , Swain M V
Published: January 2021

Fissure caries in a form of brown spot lesion is a serious problem for patients. Having passed the dentine-enamel junction, cariogenic bacteria cause demineralization of dentine in its vicinity. Over time, the area of demineralization spreads deeper towards the pulp of the tooth, creating a gradient of strength characteristics in dentine. The aim of this work was to determine the mechanical properties and mineral density in the direction from the dentine-enamel junction to the dental pulp using nanoindentation and X-ray computed microtomography. The results can be used as control ones for the further research of remineralization techniques used in clinical practice.
Phase Diagram of Nanoparticles of Palladium-Platinum Alloys
Authors: Aref`eva L P , Dolgachev Yu V
Published: January 2021

Melting and crystallization temperatures of mesoscopic metal particles have been calculated within the framework of thermodynamics of surface phenomena and the electron-statistical method, for which it is necessary to take into account the dimensional dependences of the surface and interphase energies. All estimates were carried out in the model of heterogeneous melting in the presence of a skin layer. Phase diagrams have been constructed for binary Pd-Pt nanoparticles with solid core linear dimensions of 5 and 8 nm and a skin layer thickness of 2 nm. The surface and interfacial energies, as well as their temperature and size dependences, were estimated by a modified electronic statistical method. A comparative analysis of the results obtained using different expressions for the size dependence of the specific heat of fusion of nanoparticles is carried out. It was found that the shape of the diagram has significant differences from the phase diagram for the bulk phases of the metals under consideration. The main reason for the difference is the melting-crystallization hysteresis and the appearance of a smooth maximum on the liquidus and solidus lines. The maximum on the lines of melting and crystallization temperatures can be explained by a more pronounced size dependence of the interfacial characteristics of platinum. In accordance with the criterion that determines the more surface-active component, it can be concluded that with a change in the melting point ratios of pure components and lower values of the surface energy of palladium, a core (Pd) - shell (Pt) structure will form in nanoparticles.
Investigation of the fracture structure of a composite material after bending test by atomic force microscopy
Authors: Duka V V , Aref`eva L P , Mitrin B I , Pustovoit V N
Published: January 2021

The paper presents the results of a study of the surface fracture tested for bending at negative temperatures of a ferrite-martensite composite (FMC) obtained on the basis of K 02704 structural hypoeutectoid steel by atomic force microscopy. Metallographic studies of the sample were carried out on longitudinal sections. Investigations of microstructures were performed on optical microscopes Metam RV-22 and Neophot-21. Impact bending tests were carried out in accordance with ISO 148-1:2016. The quantitative assessment of martensite was carried out using the digital imaging program and amounted to 30%. A three-dimensional image of the fracture of the sample surface was obtained by atomic force microscopy (Nanoeducator II) in the semi-contact mode. An AFM study of the fracture surface showed that the data of optical and atomic force microscopy are in agreement. The three-dimensional AFM image of the surface fracture and its profiles, extracted in different areas, as well as the roughness parameters, show the presence of a dual line structure in steel.
Microstructure and elemental composition of multicomponent systems based on silicon, titanium and zirconium oxides
Authors: Blinov A V , Jasnaja M A , Kravtsov A A , Gvozdenko A A , Raffa V V
Published: January 2021

The paper presents the results of studying the microstructure and elemental composition of multicomponent systems based on silicon, titanium and zirconium dioxides. These systems are of great practical interest for the medical, food, and microbiological industries due to their unique optical, photocatalytic, and bactericidal properties. Studies have shown that multicomponent systems based on silicon, titanium, and zirconium dioxides obtained by the solgel method have an amorphous structure, while the samples exhibit a deviation from stoichiometry towards an increase in the oxygen content, which is explained by the presence of oxo-, hydroxo-, and aqua complexes. The structure and shape of multicomponent oxide particles are determined by the component that prevails in the system. The presence of additional components and possible chemical interactions between them determines the process of nucleation, which, in turn, affects the polydispersity of the obtained samples.
DLC coatings for tribotechnical purposes: features of the structure and wear resistance
Authors: Kudryakov O V , Varavka V N , Kolesnikov I V , Novikov E S , Zabiyaka I Yu
Published: January 2021

The article presents the results of metal-physical and tribological studies of carbon thin films - diamond-like coatings (DLC), obtained by vacuum ion-plasma technology. The most interesting results are the gradient distribution of the ratio of carbon electronic configurations sp3/sp2 over the depth of the coating, obtained by the XPS method. The structure of such a coating, as it approaches the substrate, transforms from DLC to amorphous graphite (GLC). This feature manifests itself in the mechanism of coating wear during tribological tests. Its wear occurs by the abrasion mechanism, similar to high-strength rubbers.
Diagnostics of gradient strains field in polymer composite material with built-in fiber optic piezosensor
Authors: Pan’kov A A
Published: January 2021

Description of design, principles and functioning of distributed optical fiber piezoelectroluminescent (PEL) sensors embedded in polymer composite structures for refined monitoring of inhomogeneous “gradient” strains fields inside structures is given. The informative light signal occurs due to the mechanical-luminescent effect caused by the interaction of the piezoelectric and electroluminescent elements (sectors of layers) of the sensor. Monitoring are found as a result of digital processing of the information spectrum of the intensities of the integral light signal at the output from the optical fiber taking into account the known dependences of the light output intensity of the each j-th electroluminophore on electrical voltage applied thereto. Mathematical models have been developed, settings and problem solving scheme on finding numerical values of transfer information and control coefficients of PEL sensors are given, and results of numerical calculation of transfer coefficients of sensor for case of small values of gradients of diagnosing strains field are presented.
Modeling and analysis of functional characteristics of QD-InAs/GaAs heterointerface with multi-barrier layers
Authors: Blokhin E E , Irkha V A
Published: January 2021

The article is devoted to the problem of studying the functional characteristics of heterointerfaces with quantum dots InAs by methods of mathematical and simulation modeling. A solution to the problem in the form of a developed mathematical model of a structure with quantum dots InAs with two types of barrier layers GaAs and AlGaAs is proposed. It is shown that using the quasi-drift-diffusion model in combination with the solution of the Schrödinger equation in the potential well of a quantum dot, it is possible to construct the energy structure of the layer-by-layer heterointerface design with the possibility of modeling functional characteristics, in particular, the spectral dependence of the external quantum efficiency and the dark current-voltage characteristic.
Growth of zinc oxide nanostructures by mass transfer through a micro-sized vacuum zone in a temperature gradient field
Authors: Irkha V A , Blokhin E E
Published: January 2021

This paper presents the results of studies on the controlled production of ZnO nanostructures with specified physical properties. It has been shown experimentally that by using the mass transfer of a substance through a micro-sized vacuum zone in a temperature gradient field, it is possible to grow quasi-one-dimensional ZnO nanostructures stochastically or orderly located on a substrate. The density of deposition of quasi-one-dimensional ZnO nanostructures is determined depending on the substrate material. It was found that the resulting ZnO nanostructures have good crystal perfection and stoichiometric compositions, and also have pronounced piezoelectric properties.
Information system “Graded coatings”
Authors: Krenev L I , Sadyrin E V , Nikolaev A L , Litvinenko A N
Published: January 2021

Functionally graded coatings are widely used to protect structures and machine parts from damage caused by mechanical and thermal loads. The information system “Graded coatings” was developed to help the researchers to design such coatings and also for expanding of the availability of tools for calculating and analysing of experimental data. The system was constructed for interactive data preparation and multi-parametric analysis of the results of numerical-analytical solution of mixed boundary value problems of crack theory and theory of elasticity and thermoelasticity for continuously inhomogeneous coatings of complex structure
Application of FPGA technologies for modeling hydrophysical processes in reservoirs with complex bottom topography
Authors: Leontyev A L , Chumak M I , Nikitina A V , Chumak I V
Published: January 2021

The article is devoted to the development and research of methods for accelerating calculations and processing input data for mathematical modeling of hydrodynamic processes in reservoirs with complex bottom geometry. The mathematical model of hydrodynamics considers: microturbulent diffusion; the influence of salinity and temperature. To increase the speed of calculations, it is proposed to transfer part of the computational load to reconfigurable computing systems (RVS). The paper also proposes an algorithm for adding input data by analyzing the existing database of environmental data, which was successfully verified analytically. The practical significance of the work is that a hardware implementation of the IP core was proposed, which allows solving systems of linear algebraic equations that arise when sampling the model of hydrodynamics of the Caspian Sea. It is experimentally established that the resulting implementation is characterized by low power consumption and is capable of processing large-dimensional matrices. The prospects of using the proposed algorithm are determined.
Use of modern technologies in assessing the stability and vulnerability analysis of information technology systems
Authors: Leontyev A L , Chumak M I , Chumak I V
Published: January 2021

The paper is devoted to the study of the possibility of applying the main methods of assessing the reliability of information technology systems, including a review of existing developments in this field and analysis of the basic principles of testing systems. Special attention is paid to methods for evaluating the reliability of software. This paper describes the main steps that should be taken by an attacker in a cyber-attack. Methods of vulnerability detection using graph theory are considered and methods of their elimination are shown. The possibility of using neural networks for traffic analysis in order to detect signatures is considered. The mechanism of DDoS attacks is considered and the main mechanisms of protection against them are analyzed. Mechanisms for changing the topology of information technology systems through the use of graph theory were tested on decentralized systems and showed a significant increase in the system’s resistance to unauthorized access. Mechanisms to prevent DDoS attacks through the use of neural networks allowed real-time tracking of unwanted content and reduced the time required to update databases of malicious signatures.
Modelling the pollutants transport in the “air-water” system of a shallow water
Authors: Lyashchenko T V , Lyapunova I A , Chistyakov A E , Nikitina A V , Filina A A , Leontiev A L
Published: January 2021

The work is devoted to the spread processes mathematical modelling of impurities in a reservoir in areas located far from river runoff. An aerodynamic processes mathematical model is proposed that takes into account a variety factors: increased air humidity, variability of atmospheric pressure and temperature, etc. The model discretization was carried out taking into account the partial filling of the calculated cells, which made it possible to significantly reduce the error at the boundary. For the calibration and verification of the pollutants transport model, the expeditionary research data were used.