bluuebunny/crossref_metadata_2025 huggingface dataset:
The application of virtual reality and augmented reality technology in the field of Education
Authors: Liyuan Liu
Published: December 2020

With the continuous development of modern information technology and the increasing level of science and technology, virtual reality and augmented reality as a new technology have been widely used in many industries, and play a positive role. This paper focuses on the differences and educational characteristics between virtual reality and augmented reality technology, analyzes the application of virtual reality and augmented reality technology in the field of education, and puts forward its own views for reference.
Heterogeneous remote-sensing image matching method based on deep learning
Authors: Hou Huitai , Xu Qing , Lan Chaozhen , Cui Zhixiang , Qin Jianqi , Wang Lianxia
Published: December 2020

In this paper, a deep learning matching method is proposed to address the difficulty in matching heterogeneous remote sensing images, which is caused by their differences in imaging modes, time phases, and resolutions. A heterogeneous image is inputted into the convolutional neural network (CNN) to extract deep features and, then, a graph neural network (GNN) is used for matching. Finally, correct matching points are retained while ensuring the effective elimination of mismatches. The algorithm adopted in this study was tested using multiple sets of heterogeneous remote-sensing images and compared with D2-Net+NN+RANSAC and Superpoint+SuperGlue algorithms. The results show that the algorithm used in this study possesses strong adaptability and robustness and is an optimal algorithm for the robust matching of remote-sensing images with different sources and large differences.
A User Mobility-Based Rate Adaptation Approach for Dynamic HTTP Streaming
Authors: Chen Renkang , Li Zeping , Yang Huawei , Xue Yangshang
Published: December 2020

It is common for users to use smartphones to watch streaming videos when they are walking, taking a bus, or taking a subway. However, the current streaming rate adaptation algorithms are mostly based on the available network throughput or the player buffer occupancy, and the user mobility state is less considered. In order to improve the user experience quality under the mobile streaming media, we propose a user mobility-based rate adaptation approach, which classifies the user mobility state using the random forests algorithm and adopts different rate decision under different mobility states. The experimental results show that compared with popular approaches, our approach reduces the re-buffer events by 24% on average, and reduces the data traffic consumption by 19% on average.
Analysis Nonlinear mechanical characteristics analysis of a UAV landing gear shock absorber
Authors: Lu Jianmin , Nie Wenzhong , Ma Yajian , Li Xiaoxuan
Published: December 2020

Shock absorber of landing gear can reduce landing overload and vibration. Under different working conditions, the shock absorber structure is easy to produce stress and strain changes. This paper takes a kind of spring shock absorber as the research object. The single factor method is used to analyze the mechanical characteristics of the shock absorber under different compression stroke and landing deflection angle. The simulation calculation is carried out by ANSYS Workbench software. The simulation results show that: with the increase of the compression stroke of the shock absorber, the contact pressure and stress between the piston and the outer cylinder as well as between the piston rod and the lower cover will also increase. With the increase of the land deflection angle, the contact pressure between the structures will also increase. When the contact pressure is too high, the shock absorber will be stuck. It is easy to cause shock absorber failure. The results of this study can provide guidance for structural optimization design of shock absorber.
Real-time tracing FPGA circuit system of the virtual signals from thermal motion simulations in optical tweezers
Authors: Hu Zhanming , Han Xiang , Chen Zhijie , Xiong Wei , Chen Xinlin , Xiao Guangzong , Yang Kaiyong , Luo Hui
Published: December 2020

Optically trapped nanospheres are demonstrated capable of atto-Newton force sensing, where its experiment need to control the modulation voltages of the laser power according to the positions of the trapped nanosphere in high speed. In this paper, position fluctuations of the trapping nanospheres due to thermal motions are simulated using Monte-Carlo method and finite difference method. Equal-scale amplified transformations of those position sequences are generated as the discrete voltage signal of the virtual position detector. A high-speed digital incremental PID(Proportion-Integration-Differentiation) control system is developed by a low-cost FPGA circuit system, which can generate feedback voltage signals correspondingly. The responsive signal frequency is up to 1MHz with a time delay of 0.3μs and quite high amplitude stability. It is validated to integrate the virtual position detector and the PID feedback system into a low-cost semi-physical system, which can test various feedback cooling mechanisms for the complex systems of optical tweezers in vacuum. It will be a further step relative to the pure simulations in digital computers and provide references for the development of optical tweezers in vacuum.
Experimental study on curing of bisphenol A epoxy resin
Authors: Chun-wen Wang , Qin Zhang , Xin-long Chang , Kuan Hu , You-hong Zhang , Renli Ma
Published: December 2020

Taking the bisphenol A epoxy resin system as the research object, the thermal curing and microwave curing experiments were carried out. The relationship between the curing degree and the hardness of the product after thermal curing and microwave curing was analyzed. The thermally cured product and microwave cured product were tested for tensile properties and infrared spectroscopy respectively. The results show that there is a positive correlation between the degree of curing of the product and the surface hardness. Compared with thermal curing, microwave curing can save 50% of the time, and the microwave cured product does not generate a new structure. The tensile strength of the microwave cured product is about that of thermal curing. 88% of the tensile strength of the product.
Design of Decoupling Fuzzy Logic Controller for Quadrotor UAV
Authors: Huang Chao
Published: December 2020

This article first briefly introduces the quadrotor UAV model based on the Newton-Euler method, including kinematics model, dynamic model and force and moment model, and then proposes a decoupling fuzzy controller, which can effectively decouple the position and the orientation of the quadrotor UAV, i.e., the inner loop uses the input and output linearization method to control orientation, and the outer loop uses a fuzzy logic controller to control the position of the quadrotor UAV. Finally, we use Matlab to model the quadrotor UAV and design the decoupling fuzzy controller to control the quadrotor UAV. The results show that the tracking performance is good, which proves the feasibility of the controller algorithm.
Multi-objective Optimization Design for Battery Pack of Electric Vehicle Based on Neural Network of Radial Basis Function (RBF)
Authors: Li Yuefag
Published: December 2020

As a carrier of EV batteries, battery pack is a key component that ensures stability, safety, and reliability of energy system for power batteries. In order to complete the requirement of light weight for EV, the battery pack shall have light weight as much as possible while meeting structural strength. This paper uses an Surrogate Models algorithm based on RBF neural network to solve the problem of multi-objective optimization for battery pack. It can be observed from LsDyna simulation results that the battery pack has declined 17.62% in mass and 30.78% in maximum deformation. Therefore, the proposed structure optimization model of battery pack hereof provides an effective design and optimization method for battery pack.
Mathematical-physical modeling for analytical calculation of multilevel pulse-width modulations
Authors: Pabón Fernandez L D , Caicedo Peñaranda E A , Diaz Rodríguez J L , Pardo Garcia A
Published: December 2020

Currently there is a great interest from the electronic physical point of view in reducing losses and optimizing the harmonic content of power converters. Especially of the multilevel ones that have great advantages since they can work with low commutations. That is why, this paper proposes and verifies a methodology for the development of equations for the analytical calculation of the effective value and the total harmonic distortion of step and Pulse width modulations type multilevel. The equations are obtained by analysis in the frequency domain using Fourier theory. A generalized mathematical expression is obtained as a function of the switching angles, which is theoretically verified by comparing the calculated with the expression and the MATLAB fast Fourier transform algorithm. These equations allow the modification of the upper limit of calculation of the series, a characteristic that can be used to determine a vector of commutation angles with the minimum value of harmonic distortion for a range of harmonics.
Cold production from a metallic salt and low temperature sources
Authors: Noriega Sánchez C J , Afanador García N , Guerrero Gómez G
Published: December 2020

Chemisorption cooling is a type of technology that facilitates energy saving and produces less environment impact than that produced by vapor compression cooling systems. The advantages or disadvantages of these systems can be explored from mathematical models through which the impact of different working pairs as well as construction and operating parameters on these cooling systems can be described. In this sense, the impact of design variables on performance coefficient of a chemisorption refrigeration system that uses sodium bromide and ammonia as working pairs are evaluated from a mathematical model that describes the heat transfer into the system. The results indicate that the cycle time affects favorably the coefficient of performance as well as the apparent specific density of the sorbent and the reactor radius. Although the coefficient of performance values is low when compared to vapor compression cooling systems, the system can be operated by low temperature thermal sources, found in thermal solar collectors or flue gases, and it can increase the energy efficiency of industrial or residential applications.
Data processing from electrical signals acquired by an E-nose system used for quality control of cocoa
Authors: Florez A , Durán C , Carrillo J
Published: December 2020

This research consists of the implementation of different pattern recognition methods applied to discriminate and classify the physical signals (electrical) acquired by an artificial electronic nose system composed of a gas sensor array of 10 units coupled with a data acquisition board that were used to perform a sensor chamber that receives the electrical information from volatile organic compounds generated by cacao beans. A concentration chamber for samples conditioning of fermented beans was used and the samples were fermented around 72 and 144 hours while the cacao samples infected with monilia were over-fermented. For obtaining the temperature inside of the sensor chamber, a digital temperature sensor was implemented by using a Peltier Cell mechanism which was controlled through a classical algorithm. At the design stage, a data acquisition system composed of an Arduino card and a graphical interface made in LabView was developed for data storing, controlling, and signals monitoring. For the electrical signals treatment and data analysis, two pattern recognition models were applied by using Python software where two signals pre-processing methods such as Euclidean normalization and Roboust Scaling were used afterward with data processing techniques as principal component analysis and clusters analysis, obtaining a 96.51% of variance in the two first components.
Speed estimation of the three-phase induction motor with Volts/Hertz control using artificial intelligence techniques
Authors: Salamanca J E , Diaz Rodriguez J L , Pardo Garcia A
Published: December 2020

This paper deals with the design and development of a prototype for speed estimation of a three-phase squirrel cage induction motor using Volts/Hertz control. The speed estimation was using an embedded electronic device with an adaptive neuro-fuzzy inference system. In this way, it is expected to increase the reliability of the rotor speed measurement. For the estimation, the currents and voltages that feed the induction motor were taken as input data to training an adaptive neuro-fuzzy inference system. Additionally, a Volts/Hertz control technique was used to test the operation of the estimator at different operating speeds, comparing the estimation with a speed sensor coupled to the machine shaft. The estimation was supported on a Raspberry Pi 3B hardware. The algorithms were developed using Simulink, which allows a graphical block interface that facilitates the understanding of the system. For the power stage, a multilevel converter was developed, thus, ensures a low total harmonic distortion.
Study on the Integration of Flue Gas Waste Heat Desulfurization and Dust Removal in Civilian Coal-fired Heating Furnace
Authors: Zhou Gang , Zheng Haorun , Zhu Xiaopeng , Liu Yuemei
Published: December 2020

To put the policy of civil coal governance environment, the clean and efficient use of technology and civilian cainuanlu practical application within consideration, this paper designed a set of flue gas desulfurization dust removal integration of recovery of waste heat from flue gas treatment system, in order to achieve the recovery of waste heat of flue gas and reduce cainuanlu particulate matter and sulfur dioxide emissions. The flue gas treatment system mainly used the structure of the spiral coil heating and stainless steel tube, and will recovery the smoke waste heat ; There are three dust removal processes: the strainer mesh filtration of the entire unit, adsorption of modified activated coke and water spray cleaning; Desulfurization part was designed to operate the easy drawer cabinet structure, using the modified adsorption properties of activated coke processing SO2 in flue gas. The experimental results show that the processing system of dust removal and desulfurization efficiency is at 80%.
Wellbore Stability Mechanism and Countermeasures of Igneous Formations in Shunbei Oilfield
Authors: Zhong Wenjian , Yu Yang , Liu Jingtao , Li Shaoan
Published: December 2020

Shunbei oilfield is located in the Midwest of Tarim Basin. Since 2018 many wells in the block have encountered broken formation, directional wells wellbore collapsed seriously, resulting drilling sidewells, with a huge loss of drilling costs. The influencing factors of igneous formation stability include internal and external factors. The internal cause refers to the formation instability caused by the strength anisotropy and strong in-situ stress nonuniformity of igneous formation. The external cause refers to various factors that cause the change of the external environment of the formation caused by drilling engineering, including the physical and chemical interaction between the drilling fluid and the formation, well trajectory and mechanical disturbance of the drilling string, etc. Based on the analysis of the influencing factors of wellbore stability in igneous rock, the technical countermeasures of wellbore stability in igneous rock formation are put forward and field tests are carried out. In the Permian fractured formation of Shunbei oil field,the idea of “prevention first, combination of prevention and blocking” is adhered to the first principles. Low density and low viscosity drilling fluid with low displacement is adopted to prevent the occurrence of lost circulation. The wellbore of the igneous rock intrusion in santamu formation of Ordovician is easy to collapse. By adopting special sealing structure and strengthening plugging and anti-collapse, combined with slurry plugging and well washing and refining engineering measures, the safe drilling of the igneous rock can be ensured.
Research Status of Spinel LiMn2O4 Cathode Materials for Lithium Ion Batteries
Authors: Zhang Yaqing , Xie Hongyan , Jin Huixin , Zhang Qiang , Li Yezhu , Li Xiaohui , Li Kaifeng , Bao Chongjun
Published: December 2020

As a new type of green power system, lithium ion battery has been widely developed in the field of new energy. Lithium manganese oxide has become a hot topic due to its low price, safety and pollution-free properties. In this paper, the research progress of positive electrode material LiMn2O4 for lithium ion batteries in recent years is reviewed, in addition, the structural properties, synthesis methods, existing problems and modification aspects of the material are described.
Blockchain Technology Enables Fixed Assets Investment Statistics
Authors: Wen Fan , Ma Lei , Qian Xiao , Song Hongfang , Weng Geping , Jiang Hao , Cui Qinyue
Published: December 2020

Blockchain technology is a kind of decentralized transaction and data management technology, which has been extended to many economic and social fields, such as digital finance, Internet of things, intelligent manufacturing, supply chain management, digital asset trading and other economic and social fields, but the application of statistical work is still less. The current investment statistics business of Power Grid Companies involves multi-department collaboration and multi-level interactions. There are uneven data maintenance and low data quality among various business departments. The statistics majors and the basic data providing departments and the statistical data reporting units are both at the upper and lower levels. There are varying degrees of “mutual trust issues”. According to the characteristics of blockchain Smart Contract, consensus mechanism and linked storage structure, multi-party sharing of data on the chain and higher credibility, this paper explores how to integrate the technical characteristics of blockchain with the investment statistics business, and change the business model of investment statistics.
Research on strip pressure relief drainage technology in deep coal roadway
Authors: Sun Luanluan , Wang ZHonghua
Published: December 2020

Aiming at the characteristics of coal and gas outburst disasters in Jianxin Coal Mine, based on the compound energy mechanism of coal roadway outburst in deep mining and the distribution law of the roadway surrounding rock fracture zone, the pre-drilling pressure relief floor rock roadway and the cross-bed borehole drainage coal road way g as a r e p r o pos ed. Regi o n al anti-outburst measures have been applied in engineering. The application shows that this technical measure can greatly improve the permeability of the coal seam and the effect of pressure relief extraction, and ensure the safe and rapid excavation of coal roadways.
Ecological and biological adaptations of the hemiparasite Odontites luteus (L.) Clairv. (Orobanchaceae) on the territory of the conservation stow “Levadki” Oak Grove (Russia)
Authors: Prosiannikova I , Bodko D
Published: December 2020

The abundance of Odontites luteus (L.) Clairv (Orobanchaceae) was studied on the territory of the conservation stow “Levadki” Oak Grove (Russia). The average species abundance was 11.75 ind./m2 on the study area during the growing season. The phenological phases of the plant hemiparasite were studied, the indicators of seed productivity and the efficiency of its fruit formation were examined. O. luteus, being an annual plant, forms a significant number of flowers and fruits within a single specimen (the average number of seeds is 1,930). The specific affinity of the semi-parasite to the host plants has been studied.
Adjustments to the method for assessing the phytosozological status of the specially protected natural areas
Authors: Saxonov S V , Senator S A , Koneva N V
Published: December 2020

The study determines the criteria, allow quantifying the phytosozological (conservation) status of the specially protected natural areas. We distinguished 10 such criteria that reflect the diversity of vegetation cover and allow assessing the necessity of conservation for the specially protected natural areas. Among them: (1) the degree of the study of the vegetation cover, assessed by the number of published literature sources; (2) a reference (demonstration) value, an integral indicator that considers, on the one hand, the typicalness (reference value), on the other hand, the uniqueness of the vegetation cover. The following points must be taken into consideration: the presence of relict and endemic species of plants and plant communities in the study area; classical territories (relevés) of the first descriptions of taxa and syntaxa new to science; the diversity (in terms of numbers) of landscapes and types of vegetation, or plant associations; (3) the area of the territory, estimated according to reference materials; (4) man-impact tolerance of the vegetation cover, based on generally accepted concepts of primary, secondary (demutation) successions and the climax theory; (5) coenotic diversity, evaluated by the presence of the vegetation types or the number of studied plant associations; (6) general species diversity of the vascular plants, quantified by the number of registered species of vascular plants; (7) the number of species included in the federal Red List; (8) the number of species included in the regional Red List; (9) the degree of transformation of the natural territorial complex (landscape) assessed by the state of conservation of indigenous vegetation and disturbance of the lithogenous basis; (10) the restoration potential estimated by the ability (intensity) of the vegetation cover to recover after the anthropogenic load has been removed. Phytosozological status is an integrative indicator reflecting the current degree of conservation of the vegetation cover and the probability of its existence in near future. The conservation status is determined by simple arithmetic addition of the criterion points in accordance to the suggested original scheme.
Karst Lakes of Mari Chodra National Park: stratification and vertical distribution of phototrophic plankton
Authors: Yu Gorbunov M , Umanskaya M V
Published: December 2020

The characteristics of micro-scale vertical heterogeneity of physicochemical parameters, photosynthetic pigments’ content and populations of phototrophic microbial plankton in four karst lakes of the Mari-Chodra NP (rep. Mari El), the Bolshoy Kichier, Cherny Kichier, Shungaldan and the Blue Oxbow, are presented on the basis of summer surveys of 2006, 2007 and 2009. According to our data, two lakes, Shungaldan and Cherny Kichier are, meromictic waterbodies of crenogenic type; the Lake Bolshoy Kichier is holomictic with stable summer stratification and anoxic hypolimnion. The Lake Blue Oxbow occupies an intermediate position, and, apparently, is irregularly mixing. The physicochemical conditions and composition of the phototrophic plankton communities of the chemocline zone of the two previously studied lakes, Bolshoy and Cherny Kichier, have remained stable over the past 20-35 years. Significant development of anoxygenic phototrophic bacteria was found in two lakes in which data on their development were previously absent. In the bacterial plates of meromictic lakes, the concentration of bacteriochlorophyll d, the pigment of green phototrophic bacteria, reaches some mg per liter.
A Unified Interface Library Open-IES-Sim Platform
Authors: Qiu Jun , Wang Rongli , Fang Yunhui , Ge Kailiang , Zhang Li , Xu Boya , Zhou Suyang , Zhou Ying
Published: December 2020

In the future, integrated functions and energy internet will become the direction of smart energy development. This puts forward requirements for power flow calculation and simulation of combined heat and power supply and unified modeling. Due to the complexity of the tespy heat network equipment model, the lack of node modeling corresponding to the power flow calculation model brings difficulties to the simulation modeling of the unified power and power flow calculation. Therefore, it is necessary to unify the interface of thermal network and power flow calculation model. Based on the tespy and pandapower libraries, this paper unifies the interface functions of heat network and power grid power flow calculation modeling, constructs a unified interface library Open-IES-Sim platform and builds a coupled power flow calculation process method and corresponding visualization results display program. The corresponding open source example is given. It is convenient for the future use of scientific research workers who need thermal and electrical coupling modeling and the demonstration research in education and teaching.
A CMAQ-based Study on Evaluation of Achievements of Measures on Ozone Pollution Prevention and Control in Summer 2017 in Chengdu
Authors: Liu Hefan , Deng Ye , Lu Chengwei , Zhang Xin , Yang Xinyue , Song Danlin , Tan Qinwen
Published: December 2020

Ozone Pollution is one of the major difficulties in improving the air quality of Chengdu. In 2017, on the basis of research findings including a mass of observation data, meteorological data and numerical simulation data of air quality on the localized ozone and its precursors in Chengdu, Chengdu Environmental Protection Bureau drew up and implemented 2017 Chengdu Ozone Pollution Prevention and Control Action Program (OPCAP). This study elaborated on the specific measures of OPCAP and the subject of implementation of the said measures, and based on the localization of CMAQ parameters, conducted scientific evaluation on the achievement of OPCAP implementation. The research findings are set forth as follows: OPCAP made pollutants reduced to a large extent, for example, the industrial emissions of VOCs and NOx were reduced by 8600 tons and 2150 tons, respectively. Compared to the corresponding period of last year, in August 2017, meteorological change made O3max, PM10, PM2.5, NO2 and CO reduced by 34.9%, 24.2%, 23.9%, 16.6% and 6.0%, respectively. After a series of measures including OPCAP were taken, O3_8h max was reduced by 6∼10μg/m3 in most areas of Chengdu. Under equal meteorological conditions in August 2017, OPCAP made O3_8h max in the downtown of Chengdu reduced by 3.67% on average, and the concentration of NO2, SO2, PM10, PM2.5 and CO was reduced by 25.00%, 11.11%, 19.59%, 19.63% and 5.32% on a monthly average basis. As shown above, it can be seen that OPCAP worked on ozone pollution prevention and treatment. The technologies adopted in and the findings of this study may provide technological guidance on the mid-term and long-term ozone pollution prevention and treatment.
Research on UAV Aided Earthquake Emergency System
Authors: Zhao Jie , Yang Wenjing , Wang Feijian , Zhang Congcong
Published: December 2020

As a hot technology in the industry, UAV can play a role in all aspects of earthquake emergency system. In view of the scene of earthquake emergency, according to the characteristics and latest development of UAV, combined with its application in various kinds of natural disasters in recent years, it discusses the design of UAV aided earthquake emergency system. The UAV aerial image processing subsystem focuses on the disaster condition collection, earthquake intensity evaluation and thematic map production after the earthquake. The UAV on-site rescue subsystem focuses on the materials transportation after the earthquake, personnel searching and rescuing, and command and dispatching. The tethered UAV emergency communication subsystem mainly provides emergency communication support after the earthquake. The UAV image return subsystem is designed to deliver images of disaster areas to headquarters and the public, so that they can have an intuitive and vivid understanding of the disaster situation, rescue force deployment and rescue progress in the disaster areas.
Intelligent diagnostics and control of 3D printing processes by electric arc surfacing of workpieces made of cold-resistant materials on a CNC machine using machine learning approaches and neuromorphic calculations
Authors: Shatagin Dmitrii , Kabaldin Yuri , Anosov Maksim , Colchin Pavel
Published: December 2020

The article discusses a method for diagnosing and optimizing the dynamic state of an electric arc during 3D printing of workpieces from cold-resistant materials on a CNC machine within the framework of a cyber-physical system. The possibility of applying nonlinear dynamics methods to assess the stability of the 3D printing process and artificial neural processes for classifying and optimizing the parameters of the dynamic state of the 3D printing process is shown. Experimental studies of the cold resistance obtained by 3D printing of 09G2S steel samples were carried out taking into account the choice of optimal modes.
Application of additive technologies for manufacturing a wear-resistant steel pipe outlet
Authors: Sedykh L V , Albul S V , Efremov D B , Sukhorukova M A
Published: December 2020

The paper analyzes the problems of exploitation of pipe outlets for the oil and gas industry and describes the special design of the outlet’s vane, which allows to extend its service life. However, this special shape of the vane requires new manufacturing technologies. The paper lists the technical requirements for the finished model of the outlet and the method of its manufacture. Based on them, an analysis was carried out, and has been proposed the application of additive technologies for the manufacture of a steel pipe outlet with the vane, namely, the method of Selective Laser Melting (SLM). The advantages and particularities of the method’s application are described, as well as the stages of the manufacturing process for manufacturing an outlet with a special shape of the vane.
Study of FDM technology applications in the casting production of GTE details
Authors: Balyakin A V , Vdovin R A , Kyarimov R R
Published: December 2020

FDM is an additive manufacturing technology that can be effectively used to make investment casting models. This method is considered economical in a single production, since it does not require the manufacturing of expensive equipment. However, the roughness of models surface made by FDM printing is significantly lower than wax models obtained by traditional way - using metal and elastic silicone molds, that ultimately affects the roughness of castings. In this work, was studied the use of FDM printing technology for materials: REC CAST, PVA and Wax3D from company the “Filamentarno!”, used in molds to obtain models, as well as a combined method for wax models production. FDM printing technology is especially suitable for producing models with internal channels and cavities through the use of water-soluble support materials.
Formation of aluminum alloy parts with working internal cavities by selective laser melting
Authors: Voznesenskaya A A , Kochuev D A , Raznoschikov A S , Chkalov R V
Published: December 2020

The great difficulty in synthesizing parts by selective laser melting lies in the formation of high-quality internal surfaces of workpieces. High quality is understood as the absence of defects in the form of shells, pores, partially fused powder granules, forming a rough surface. This task is especially relevant when obtaining parts by selective laser melting of aluminum alloys powders. The main problem is the great complexity or impossibility of their mechanical post-processing. Thus, in the manufacture of parts with working internal cavities used for the flow of liquids and gases, the presence of defects is completely unacceptable. In this paper, we studied the formation of defects in the internal surfaces during the process of obtaining objects by selective laser melting, in particular, the sticking of granules of powder material on the formed surface under various processing conditions. Variable parameters were scanning speed and laser radiation power. Data on the behaviour of the growth of a multilayer object depending on the variable parameters are obtained. The groups of samples of different shapes obtained under different melting conditions are considered.
Efficiency of applying advanced electromagnetic pulse processing when turning polymer composite materials
Authors: Erenkov O Yu , Lopushanskii I Ya , Yavorskii D O
Published: December 2020

The new approach to high-performance turning of polymeric composite materials is presented in this paper. The approach essence is a combination of a conventional work pieces turning with simultaneous irradiation by nanosecond electromagnetic pulses. As a result the changes of studied material structure occur that lead to technological softening the work pieces surface layer. It has been experimentally proved that irradiation of the studied materials with nanosecond electromagnetic pulses for 5 and 10 minutes leads to a noticeable decrease in the strength and hardness of all samples. On the basis of the experimental data the new turning methods for polymer composite materials and the device for its implementation have been developed and patented. Analysis of the experimental studies data allows us to conclude that such approach leads to decreasing in cutting force during work pieces subsequent turning and, therefore to increasing in the process productivity, for example, due to increasing cutting speed or size of the removed allowance.
Technology of extending operational life of multifaceted disposable plates
Authors: Nosov N V , Balakirov S N
Published: December 2020

The article presents the results of the development of MDP remanufacturing technique. The problem statement is related to the improvement of durability, strength and performance properties of MDP. Remanufacturing technique of plates provides the development of the process scheme for the resharpening of MDP along the front surface and application of TiN wear-resistant coatings. The optimal geometry of the restored tool, the sharpening scheme, the characteristics of grinding wheels and cutting modes are selected. The coating technology, scheme and surface cleaning modes are developed, and the coating quality parameters are determined. Technical and economic analysis of the efficiency is carried out.
Perfection of the methodology for calculating the keyway broach through the experimental data of photomechanics
Authors: Zhed O , Kozochkin M , Kazymaeva K
Published: December 2020

In work by the method of photomechanics, the stress-strain state of the models of the keyway broach is evaluated. Models are made of optically sensitive organic glass of E2 grade. The aim of the research is to improve the method of calculating the keyway broach based on experimental data obtained by the photomechanics method. The effect of the radius of the transitional fillet on the stress concentration in the models of new and reconditioned keyway broaches is studied.
Determination of conditions ensuring maximum operability of replaceable hard-alloy cutting plates during blade processing
Authors: Artamonov E V , Tveryakov A M , Shtin A S
Published: December 2020

This study is devoted to the definition of conditions ensuring maximum operability of replaceable hard alloy cutting plates during blade processing of hard-to-process materials, with assessment of the possibility to use the tool of Russian production without loss of processing efficiency, as well as the possibility to implement adjustments of regime conditions in non-stop mode, using cloud services in enterprises with network structure, thus supporting the implementation of smart production and the fourth industrial revolution.
The use of laser radiation for cutting of blind grooves and small-sized through cuts in thin-walled cylindrical bodies
Authors: Ratmanov V A , Gavrilov G N , Marinin E A , Beltukov A S , Razheva K V
Published: December 2020

The issues of optimization of technological parameters of laser treatment of radio engineering products for the formation of narrow through cuts and blind grooves at shell spheres are considered. The laser marker not performing such operations is used as the main technological equipment. The possibilities of a laser marker for getting narrow through cuts are shown in the paper. The modes of getting cuts at the samples made of D16T, 12Cr18Ni10Ti and steel 45 are selected and optimized.
The problem of capsule manufacturing for hot isostatic pressing
Authors: Zhilin P L , Gavrilov G N , Ryabtsev A D , Bazhenov E O
Published: December 2020

The article deals with new materials, problems of manufacturing capsules for gas-sealing, the use of various types of welding to improve productivity and improve the quality of welds.
Kinematics of ultrasonic processing
Authors: Rakhimyanov Kharis , Gileta Viktor , Samul Artem
Published: December 2020

The paper considers the kinematics of ultrasonic finishing processing with implementing the vibrations tangentially to the surface machined. The investigations are conducted on determining the main kinematic parameters of the method mentioned and their influence on the character of the tool trace on the machined part surface. The mathematical description of the motion trajectory of the deforming tool on the processed surface is presented. Its analysis allows us to find out the main principles of the formed trajectories and their relative location as well as the possibilities of increasing the processing efficiency.
Determination of the maximum grain width in fractions of grinding powders obtained by screening on test sieves
Authors: Nosenko V A , Aleksandrov A A
Published: December 2020

The article outlines the results of the study of the maximum and minimum grain width of black silicon carbide grinding powders with F60 grain size produced by Volzhsky Abrasive Plant, JSC, dispersed by fractions on test sieves. Grinding powders were sieved on a vibration stand in accordance with ISO 9284. Test sieves with the ISO 3310-1 cell size and tolerances were installed in the RO-TAP machine. The grain width was measured using electronic photos of the horizontal projection profile obtained by optical microscopy. Electronic images of grains were processed in specialized software. In each sample, at least 750 grains were measured, selected by quartering. It was found that the grinding powder made of black silicon carbide with a grain size of F60 meets the requirements of GOST R 52381 for grain composition. Visual inspection of the horizontal grain projection profiles showed that the grains are able to pass through the sieve cell, taking into account their possible orientation along the diagonal of the cell. The conditional pass-through size of the grain width in all fractions corresponds to the diagonal of the maximum average cell size of the upper sieve, taking into account the tolerance. The conditional non-passable size of the grain width corresponds to the lower limit of the average size of the cells of the lower sieve, taking into account the tolerance.
Analysis of geometrical parameters of hot-rolled rolling
Authors: Belskiy S M , Pimenov V A , Shkarin A N
Published: December 2020

The shape of cross-sectional profile is the most important characteristic of the quality of hot rolled steel, because it is accurately reproduced after subsequent cold rolling and thereby has a significant effect on the flatness of cold rolled strips. Traditional method to evaluating the accuracy of cross-sectional profile by geometric dimensions is the least squares approximation of hot-rolled strip thickness by second order polynomial. A number of parameters that characterize the macro-features of hot-rolled strips’ profile are found from the obtained second order parabola coefficients; this is wedge, convexity, displacement, coefficient of determination and the recently introduced saddle-shape coefficient, showing the presence of edge thickenings. Edge thickenings are formed due to wear of the work rolls in the areas corresponding to the edges of the rolled strips. An analysis of the existing geometrical parameters of the cross-sectional profile of the hot-rolled strips showed that with their help in some cases it is practically impossible to predict the flatness of cold-rolled strips. Analysis of the flatness of cold-rolled strips has identified four specific classes of cross-sectional profiles of hot rolled strips that have a significant effect on the shape of cold-rolled strips, and three of them negatively affect the flatness of cold rolled strips. Profiles with a concave middle and (or) near-edge areas lead to waviness, pike-shaped profiles cause warping.
Improving the accuracy of deep hole machining by diamond honing process in 41Cr4 steel parts
Authors: Dzhemilov Eshreb , Uysal Alper
Published: December 2020

This study presents the results of accuracy parameters during the machining of deep holes by diamond honing process in 41Cr4 steel parts. It was clarified that the use of diamond honing stones in the developed tool design helps to correct the geometric parameters of the hole obtained in the preliminary machining operations. The experiments showed that diamond honing is a productive process and provides high accuracy for the formation of roundness and straightness of deep holes in comparison with the internal grinding.
Influence of various types of spherocorundum on the performance of grinding wheels
Authors: Korotkov Vitaliy
Published: December 2020

The effect of introducing filled spherocorundum and hollow spherocorundum into the composition of grinding wheels on epoxy resin on the grinding coefficient, cutting ability, constituent cutting forces, temperature and quality of treated surfaces during implementation of a flat grinding operation is investigated. It has been established that replacing 40% of abrasive grains of electrocorundum in grinding wheels with filled spherocorundum with the same chemical composition and grain size reduces tool wear by 42%. It was also found that replacing 40% of abrasive grains with a hollow spherocorundum of similar grain size leads to a decrease in heat generation during grinding by 25%, as well as a significant reduction in deformations of the processed material during processing, compared with grinding wheels without adding spherocorundum.
Quality control of parts which were manufactured from polymeric composite materials with hybrid matrix with the application of method of infrared thermography
Authors: Kosenko Ekaterina , Baurova Natalia , Zorin Vladimir
Published: December 2020

This article contains the description of different polymer composite materials (PCM) with different types of hybrid matrices. One of the components of PCM’s hybrid matrix is hardened as the other one stays in its viscoelastic condition. The following materials are chosen to serve as viscoelastic components of hybrid matrix: technical wax compound, anaerobic and organosilicone polymer materials. The use of viscoelastic materials allows the enhancement of PCM’s stress-strain properties. This article also contains: the destruction mechanism of polymer composite materials with different types of hybrid matrices; the quality control process of products made of polymer composite materials with different types of hybrid matrices; the localization method of hybrid matrix viscoelastic components by using infrared thermography during product molding process. The results of quality control are shown as thermograms.
The role of dispersed phase in the formation of Ni – CEC
Authors: Vodopyanova S V , Mingazova G G , Fomina R E , Sayfullin R S
Published: December 2020

Composite electrochemical coatings make it possible to successfully solve many practical problems of surface hardening of structural parts, tooling and restoration of their wear parts. One of the factors influencing the structure and properties of composite coatings is characteristics of the dispersed phase (nature, concentration, dispersion). This paper presents the results of studying activation of titanium carbide by heat treatment method, which contributed to an increase in the main characteristics of nickel electroreduction. Barium sulfate is a promising dispersed material for composite coatings. This powder can be obtained with any dispersion as a result of an exchange reaction. In this work investigates the effect on the particle size of barium sulfate deposition conditions (time of mixing and pouring of reagents). The optimum conditions for obtaining barium sulfate are determined. Both powders can be used as a dispersed phase to obtain composite coatings with a nickel matrix.
Basic concept of tribocrystalochemistry of composition antifriction coatings
Authors: Shcherbakov I N
Published: December 2020

The article considers a possibility of introducing a new term, ‘tribocrystallochemistry of composite antifriction coatings’, which can be used in scientific terminology to explain friction and wear processes, modeling processes in the chemical nanoconstitution of composite antifriction coatings, modifiers and surfaces in contact with a composite antifriction coating, as well as technological aspects of receiving composites. The developed concept is based on the scientific knowledge of crystal chemistry, tribology, physical chemistry, tribochemistry, materials science, as well as theoretical and experimental research of the author.
Investigation of the resistance of protective coatings to fouling by the mollusk Dreissena polymorpha
Authors: Kostin Vasiliy , Orlov Sergey , Kochetkov Vladimir , Sokolova Natalya
Published: December 2020

Fouling of hydraulic structures with a wide variety of organisms is a worldwide problem. Fouling organisms not only increase the load on technological equipment, but also contribute to the occurrence of bacterial corrosion, including symbiotic. One of the methods of prevention is the use of anti-fouling coatings. Universal anti-fouling coatings do not exist, since the mechanisms of fouling are different. The main ways to create coatings are a decrease in adhesion or the use of biocidal additives. The authors investigated the mechanisms of fouling of the mollusk Dreissena polymorpha in fresh water. For the prevention of mollusk fouling and symbiotic biocorrosion, we analyzed the results of experiments using epoxy coatings containing a biocidal additive (bottoms from aniline production). Based on the experiments, it was concluded that epoxy compositions with biocides for the prevention of fusion of zebra mussel are ineffective. More effective are coatings with low adhesive characteristics, for example, fluoroplastic, but difficult to apply and quite expensive.
Evaluation of the effectiveness of using solid lubricants to reduce the wear of the brushes of electric AC machines
Authors: Isotov A I , Isotov S A
Published: December 2020

The article aims to study the influence of the major solid lubricant powder materials on the wear of electric brushes of universal LNA grinders in the process of rotaprint lubrication of the brush sliding path. The lubricating effect of substances was evaluated by the loss of mass and height of the brush products. Based on the results, the authors have defined the two most effective powder lubricants - epimol and molybdenum disulfide. The authors have studied how these lubricants influence the switching quality. They have come the conclusion that a lubricating film of the two most effective lubricants does not cause to a deterioration in the performance of the electrical machines. The use of rotaprint deposition of epimol and molybdenum disulfide on the slip track reduces the wear effect of the G-33MI brushes by more than 3 times.