bluuebunny/crossref_metadata_2025 huggingface dataset:
A Fast-Dynamic Response Control Strategy for Power Supply Unit of SAR Satellites
Authors: Zhang Xiaofeng , Li Haijin , Li Jiannong , Zang Jie , Gu Yu , Zhang Donglai
Published: December 2020

For the power supply of spacecraft, the dynamic response is a key requirement for converters. Especially for power supplies of SAR or other pulse power supplies, the transient of load is fast and the output current is high, it is very difficult to guarantee the output voltage in the required range. The ECSS-E_ST-20C has provided a standard for the power quality of power supply for spacecraft. In this paper, a fast-dynamic response control strategy for buck converters is proposed. The proposed strategy does not increase the output capacitance, and increases the dynamic response of the converter. In the proposed strategy, the linear control and non-linear control are combined. The linear control operates in the steady state, while the non-linear control operates in the transit state. Finally, the proposed strategy is verified by simulations and experiments.
Single Rotary Valve Engine Design
Authors: Deng Baoqing , Deng Zhenyu , Gao Yuezhen , Liang Dingkai , Deng Mengqi
Published: December 2020

This paper presents a new type of rotary valve engine, and discusses the basic mechanism and working principle of the machine. We design the combustion chamber structure and the cooling lubrication mode, calculate the compression ratio of the machine, design the gas distribution phase, and analyze the ventilation passing ability. It is summarized that the machine has the advantages of simple structure, few parts and strong ventilation capacity.
Research and Analysis on Cold Start of Fuel Cell Bus in Low Temperature Environment
Authors: Wei Changhe , Wang Chao , Li Dan , Wei Wenbo , Zhou Hui
Published: December 2020

Based on the characteristics of the components of the fuel cell bus, and on the premise of satisfying the best matching of fuel cell system, power cell system, driving system and transmission system, the purging control strategy of fuel cell system is designed. Taking the fuel cell system as the control variable, the conditions of the cold start heating energy source switching and the target temperature of the fuel cell system starting are determined by the total energy demand and the power cell energy. The integrated thermal management system and the purging control strategy of the fuel cell system proposed in this paper can meet the needs of the fast start of the fuel cell bus at -30°C. Through the energy compensation in the low temperature environment, the scheme can provide the heating energy needed for the start-up of the fuel cell system in time and meet the requirements of constant heating power of the fuel cell. The experimental results show that the output power of the fuel cell is from 42% to 75% of the rated power, and the waste heat utilization accounts for 32% - 100% of the total power.
Simulation Analysis of Vibration and Noise Characteristics of High Voltage Shunt Reactor Based on Multi-physical Field Coupling
Authors: Huang Qinqing , Zhang Jing , Fan Songhai , Zhang Zongxi , Luo Chuanxian
Published: December 2020

In order to study the vibration characteristics of the high-voltage shunt reactor, a finite element model of the single-phase reactor was established based on the analysis of the vibration mechanism of the reactor body, by using COMSOL multi-physical field coupling simulation software. The magnetic flux density distribution of reactor core, windings, stress distribution and vibration displacement of iron core were analysed by simulation. The sound pressure distribution of the iron core was analysed based on the pressure sound field model. The results indicate that the magnetostrictive effect of the iron core reactor, the electromagnetic attraction between the iron core cakes and the ampere force on the winding are the main factors for its vibration. In addition, the reactor vibration to be mainly concentrated at the core air gap. The results obtained by multi-physics simulation are basically consistent with the measured data, which verifies the effectiveness of the simulation method. The conclusions can provide theoretical basis for the analysis and monitoring of reactor vibration and noise.
Establishing an Intelligent Laundry Drying Rack Using System Innovation Theory
Authors: Lin Ying-Hsiang , Lee Yin-Ching , Chang Chia-Pao
Published: December 2020

Laundry drying is a daily chore that every family endures. In Taiwan it is worse as the available area is limited, urban areas are densely populated, the winters are wet, and thunderstorms often occur on summer afternoons. Improving on the traditional laundry drying rack could make it an indispensable part of modern life improving the quality of life for everyone. This study uses TRIZ to improve the traditional bamboo design. First, this study collects and analyses literature related to the traditional bamboo design. Second, it then utilizes a contradiction matrix, 39 engineering parameters, and 40 invention principles in TRIZ to find the places that need to be improved and subsequently improves them. Finally, an intelligent laundry drying rack was created using sensors to detect light and rain. These synchronously trigger the control circuit, and drive the motor, so that the laundry is smoothly moved inside from outside, making laundry drying more convenient and safer.
Research on Fault Location in Distribution Network Based on Fast Fault Transfer Arc Extinguishing Device
Authors: Xinyu Zhang , Yu Nie , Yanan Wang , Dan Zhao , Wei Du , Zimo Zheng
Published: December 2020

In the distribution network equipped with fast fault transfer arc extinguishing device, after a single-phase grounding fault occurs, the fault phase bus is quickly grounded to realize arc extinguishing. At the same time, the traveling wave signal generated during the grounding process of the fault phase bus can realize fault location. The traveling wave signal is subjected to phase-mode transformation, and the time difference of the zero-mode component mutation detected twice at the exit of the fault line is to be recorded. This time difference is the time which it takes for the zero-mode component to go to and fro once between the bus and the fault point. And then the fault distance can be calculated based on it. The integration of arc extinguishing and fault location is realized. The AT P simulation software is used to realize the fault simulation of distribution network. And the accuracy and feasibility of the proposed fault location method are verified.
Single-phase-to-ground fault model analysis of arc suppression coil grounding system in distribution network
Authors: Xinyu Zhang , Yu Nie , Chuanzong Zhao , Wei Du , Yanan Wang , Zimo ZHENG
Published: December 2020

Start your abstract here…The short-circuit fault type of China’s medium-voltage distribution network is 80% single-phase ground fault. Since the non-effective grounding system can continue to operate for 1∼2 hours after single-phase-to-ground fault, the analysis of the single-phase-to-ground fault model is very necessary for the arc-suppression coil grounding mode in distribution network. In this paper, by establishing a single-phase ground fault model of the distribution network with arc-suppression coil grounding method, it is theoretically analysed that is the different transition resistances in metallic grounding, high-resistance grounding and intermediate state, and use ATP/EMTP simulation to analyse the fault occurrence, the change and difference of the current waveform on the fault line and the normal line as well as the arc suppression coil. It is concluded that when the single-phase ground fault occurs in the distribution network under the grounding mode of the arc suppression coil, no matter how the transition resistance changes, the current direction of the fault line and the normal line (when the predetermined reference direction is the bus flowing to lines) is reversed, but the difference between the fault current and the normal current is weakened with the change of the transition resistance, so different faults models should be used for different grounding resistances to analyse the transient currents of normal and fault lines on the zero sequence circuit model.
Testing the decoupling theorem with IBM quantum computer
Authors: Li Xinying
Published: December 2020

Decoupling is a well-studied phenomenon in the theory of quantum information: the correlation between two systems - possibly in the form of entanglement - disappears almost entirely when one undergoes a random unitary evolution. Previous studies have proven the mathematical formulas and general conditions for decoupling two systems. The aim of this work is to observe the effectiveness of a real-world implementation of the decoupling scheme with the IBM quantum computer. In particular, we apply Clifford circuits to the systems in initial state and observe how correlation varies with respect to different circuit lengths. A significant trend was discovered, according to the mathematical theorems: the correlation between the systems decreases as the size of Clifford circuit increases. This observation shows that the decoupling theorem can be implemented effectively with the IBM quantum computer. Under a global perspective, this work is intended to provide a result in support of the fundamental task of laying the groundwork for the development of a reliable quantum computing architecture.
Review on land management and ecological natural restoration evaluation
Authors: Hao DONG , Yi ZHANG , Zhongwu LI , Chao JIANG , Jiaze LI , Liting WANG
Published: December 2020

Many lands will be destroyed due to construction, development and utilization, thus losing the function of Ecological Environment Service. In 2019, the state put forward the strategy of ecological civilization and green development, the idea of Life Community of mountains, rivers, forests, forests, fields, lakes and grasses, etc.. This paper first introduces the foreign experience of land renovation and ecological natural restoration, and puts forward the evaluation angle of land renovation and ecological natural restoration. From the key issues of governance and rehabilitation, such as the prerequisite elements, cost-benefit analysis, value judgment and adaptability principle, we draw lessons from foreign research cases, constructing the path and strategy of land renovation and ecological natural restoration suited to China’s national conditions. The research provides the feasible measurement standard and the scientific basis for the enterprise and the government.
Analysis of the influence of vertical sound field distribution on acoustic testing in shallow sea environment
Authors: Wang Xiaofeng , Meng Zhaoran , Liu Bo
Published: December 2020

The vertical sound field distribution in shallow seas is similar to the standing wave field, and the single-frequency sound source will have antinodes and nodes in the vertical direction. Therefore, the acoustic test system will have a greater impact on the test results when the acoustic test system is placed at different depths. In this paper, the fast field method is used to solve the spatial sound field distribution of the single-frequency line spectrum and the one-third octave broadband spectrum. The calculation results of the sound source fixed depth receiving point at a certain depth are given, and the different sound velocity gradients and acoustics are analyzed. The impact of the test system receiving depth changes on the sound field strength has certain engineering guiding significance for the actual underwater acoustic test.
Investigation on the influence of thermophysical properties of working fluid on heat extraction from hot dry rock
Authors: Wang Yuanming , Zhang Jinxu , Liu Xueling , Wang Jiansheng
Published: December 2020

High pressure hydraulic fracturing is a safe and environment-friendly method for the utilization of hot dry rock. In present work, the heat transfer characteristics of water and helium in hot dry rock are probed with numerical simulation. The results show that reducing the injection temperature, increasing the pressure difference between the injection well and producing well, can increase the heat extraction rate and the total heat extraction. Furthermore, under the condition of same pressure difference and injection temperature, the heat extraction rate of helium is greater than that of water, which indicates that helium is more suitable for hot dry rock heat extraction.
Effect of Local Radiant Heating on Thermal Comfort in Cold Environment
Authors: Yanyan Huang , Ping Jiang
Published: December 2020

In cold environment, local radiant heating can improve thermal comfort. In this paper, the local radiant heating equipment was used to heat subjects’ ankles and backs separately at an ambient temperature of 12.5°C and 14.5°C, with the radiant power of 200W, 300W and 500W. The number of subjects was 20.The subjects’ thermal comfort changes were collected through a subjective questionnaire. The results show that local radiant heating can improve human thermal comfort. The effect of radiant heat source located on the back of human body is better than that on ankle. Local radiant heating in cold environment has energy saving effect.
Vegetation of the summit of the natural monument “Mount Beshtau” (Stavropol Krai, Russia)
Authors: Dutova Z V
Published: December 2020

The characteristics of steppe meadows with subalpine elements of the top of the natural monument “Mount Beshtau” are given with a list of measures for their protection. The Mount Beshtau is the highest of the laccolithic mountains of the Caucasian Mineral Waters (the Central Caucasus). The mountain broad-leaved forests, meadow steppes, steppes and steppe meadows with subalpine elements, characterized by a pronounced altitudinal zonation, are the main types of vegetation in the region. Five vegetation formations were identified on the top of the mountain, based on the ecological-phytocenotic approach. Calamagrosteta arundinaceae and Brachypodieta pinnati formations were considered to belong to steppe meadows with subalpine elements. These plant communities require a compliance with nature conservation measures determined by the status of a natural monument, and this may be named as an ultimate condition for their conservation. In this regard, it seems necessary to increase the environmental awareness, as well as to ban totally the access with quad bikes and uncontrolled visiting the top of the mountain.
Manifestation of altitudinal differentiation of climatopes and phytocoenoses on the slopes of the Maly Yamantau Ridge (South Ural Nature Reserve, Russia)
Authors: Gorichev Yu P
Published: December 2020

The altitudinal variability in the vegetation structure was studied for the Maly Yamantau Ridge (Ural Mountains, Russia). Previously, a number of original assumptions regarding the peculiarities of the altitudinal differentiation of forest formations in the region of deciduous-dark coniferous forests of the Southern Urals have been made, and a generalized scheme of altitudinal differentiation of climatopes and forest formations in this area has been presented. The study aims to search for the ways of manifestation of general patterns of altitudinal differentiation of forest formations on a particular mountain range. The Maly Yamantau Ridge was considered as a model area, since its vegetation has been studied in detail. A network of sample sites, serving as the markers of climatopes, was set in primary and secondary phytocoenoses. In general, the primary broadleaf and dark coniferous phytocoenoses may serve as the reliable markers of altitudinal belts and their climatopes. Secondary phytocoenoses blur the manifestation of altitudinal differentiation of the climatopes. The altitudinal ranges occupied by climatopes on the slopes of the Maly Yamantau Ridge have been defined. The altitude spectrum of climatopes and forest formations is pronounced much on the western slope of the ridge; on the southern slope, it is not expressed.
Ecological-coenotic structure of the pine forest flora at the southern margin of the geographical range of Pinus sylvestris L
Authors: Kin N O , Senator S A
Published: December 2020

The ecological-coenotic structure of pine forest flora was compared at the southern margin of the geographical range of Pinus sylvestris. The Usmansky and Khrenovsky (Voronezh and Lipetsk regions), Krasnosamarsky and Buzuluksky (Samara and Orenburg regions) pine forests were investigated. The species diversity of vascular plants in the studied forests included also the alien and introduced species. The coenotic structure reflects the zonal location of the pine forests and their current state. The zonal coenoses are resistant for the penetration of alien species. The meadow component brings the most number of species into the plant diversity of the pine forests (23.3-25.2%). The pine forests, located in forest-steppe zone (Usmansky and Khrenovsky), are characterized by high species diversity of the forest and pine-forest component (20.4% and 20.2%), while in Buzuluksky and Krasnosamarsky pine forests, located in the steppe zone, it is significantly lower (19.6% and 15.7%, respectively). Meantime, the steppe component is more pronounced in the pine forests located in the steppe zone of the Trans-Volga Region (Buzuluksky, 21.9%, and Krasnosamarsky, 24.8%), while in forest-steppe pine forests Khrenovsky and Usmansky, it is quite lower, 16.4% and 15.5%, respectively. In the Usmansky pine forest, every third alien species of vascular plants is of cultural origin (escapee), in Khrenovsky and Buzuluksky, every fourth, and in Krasnosamarsky, every fifth species.
Changes in species richness of vascular plants under climate and solar radiation in the Middle Volga River region (Russia)
Authors: Sharaya L S , Shary P A , Ivanova A V , Kostina N V , Rozenberg G S
Published: December 2020

Specially protected natural conservation areas in the Middle Volga River region serve to preserve both rare and endangered species and the entire biotic complex, including typical floristic communities of vascular plants. We have identified 25 sites, 100 km2 each, where the flora is represented in full the most. We studied the relationships between the general species richness (SR) and the richness of particular life forms (LF) of vascular plants with climate and relief using multiple regression methods. Our study shows that the special function of March precipitation is the factor that influences the most the spatial change of the SR and LF. When increasing the precipitation in the model by only 1 mm, this leads to a decrease in the number of species by 7.1%. Winter precipitation and temperature are important factors as well; together they are responsible for 70-82% of the SR variation. These close links made it possible to develop the maps of the species richness of the study area. The SR model did not include solar radiation, one of the most important environmental factors, as a significant predictor. This factor was omitted due to the analysis of the number of species of particular LF, which showed the maximum illumination of the slopes as a highly significant factor for number of them. The two dominant LFs (hemicryptophytes and therophytes), which account for 73% of the total number of species, depend oppositely on the illumination. This fact indicates a decrease in competition between LFs due to their separation in space, since hemicryptophytes, in contrast to therophytes, predominate on well-illuminated slopes. In addition, opposite LF responses lead to omitting of illumination factor from the SR model for all species in the region.
Monetary valuation of rare plant species in the specially protected natural areas by example of the Samara Region (Russia)
Authors: Rozenberg A G , Kudinova G E , Kostina N V , Kuznetsova R S , Aristova M A , Ivanova A V
Published: December 2020

The approaches of assessing the ecosystem services are little implemented in Russia and are being developed recently at the regional level. Earlier, particular components of ecosystem services in the Samara Region have been evaluated. Here, an algorithm for monetary valuation of particular ecosystem services of specially protected natural areas is presented based on the data on rare and endangered plant species using the example of the Red List of the Samara Region. In total, 281 species of vascular plants have been analyzed, taking into account their spatial distribution in 27 municipal districts of the Samara Region. The ecosystem services were evaluated according to the formulas that took into account several parameters: (1) share of the area of specially protected natural areas; (2) number of tree and shrub species; (3) number of herbaceous plant species; (4) cost estimates; (4) expert assessments in the form of correction factors taking into account special value of relict and endemic species. The lower limit of the monetary value of ecosystem services, estimated by the only specially protected plant species, exceeds 50 million rubles. We suggest using this methodology for evaluating the ecosystem services in other territories, which will probably help to ensure the conservation and sustainable use of natural capital and natural ecosystems.
Environmental impact assessment of electromagnetic fields near to the specially protected natural areas on the example of Samara region of Russia
Authors: Vasilyev A V
Published: December 2020

Impact of physical pollutions (electromagnetic fields, noise, vibration, ionization etc.) is increasing every year and may cause significant discomfort and health damage of inhabitants of urban territories and of specially protected natural areas. Peculiarities of negative influence of electromagnetic fields to the man’s health and to environment are considered. Russian approaches to environmental impact assessment of electromagnetic fields of urban territories are discussed. It is pointed out that during environmental impact assessment it is necessary to undertake a complex of steps: identification of the most intensive sources of physical pollutions, calculations and measurements of physical pollutions propagation to the nearest living territories and of it impact to the workers of industrial enterprises, estimation of results of calculations and measurements, mapping of physical pollutions, development and implementation of measures to reduce negative impact of physical pollutions. Experience of realization of suggested approaches to environmental impact assessment of electromagnetic fields of territories are discussed on the example of Samara Region of Russia.
Influence of the water discharge of the Kuibyshev reservoir on the dynamics of the ecosystem of the Seredysh and Bakhilovsky islands, the Volga River, Russia
Authors: Bespalova K V , Selezneva A V , Seleznev V A
Published: December 2020

The state of the ecosystem of the protected islands Seredysh and Bakhilovsky (former Shalyga) is significantly affected by the water consumption in the power site of the Zhigulevskaya Dam. The 62-year dataset was analyzed to study the patterns of temporal variability of water discharge from the filling of the Kuibyshev Reservoir to the present. Long-term variability of the water discharge is due to climatic conditions in the Volga River basin, it follows to some extent the 22-year cycle of solar activity. Natural seasonal variability of the water discharge is altered by regulation at the Zhigulevskaya Dam, especially under unfavorable conditions for the formation of the water flow. The periods of low-water, high-water and medium water content were defined in regard to the annual water consumption. The low-water period lasted 19 years from 1958 to 1976, the high water period, 20 years from 1977 to 1998, and the period of medium water availability, 23 years from 1999 through 2019. Extreme high-water and low-water years, which had an adverse effect on the functioning of the islands’ ecosystem, were calculated using the empirical data on the water flow rate. During the spring flood of extremely high-water years, the water level in the reservoir increased sharply, so a part of the island was flooded. In the summer dry season of extremely dry years, the water level decreased, so the island area increased due to the shore retreat and appearing of sandbanks around the island. The negative impact of the water discharge on the ecological state of the islands may increase if the rules for regulating the water flow at the Zhigulevskaya Dam are violated.
Computer modeling of a non-stationary regime of distribution of the wastewater of Togliatti city in the coastal zone of the Bakhilovsky Island of the Middle Volga Integrated Biosphere Reserve (Saratov Reservoir, the Volga River, Russia)
Authors: Rakhuba A V
Published: December 2020

The formation of the pollution zones in the coastal water area of the Bakhilovsky Island belonging to the Middle Volga Integrated Biosphere Reserve was examined under the influence of a large source of wastewater discharge from the Togliatti city taking into account different phases of the daily flow regime of the Saratov Reservoir (the Volga River, Russia). Numerical simulation methods were used to calculate the flow fields and the transfer of the wastewater lenses at various water flow rates at the Zhigulevsk hydroelectric complex. Three typical scenarios for regulating water discharge were calculated: at night, during the day, and during the regulating releases. According to model calculations, the maximum pollution zone is formed in the area of wastewater discharge and in the vicinity of the Bakhilovsky Island during long-lasting regulating releases in the summer-autumn low-water period. The maps of the sewage plume distribution were developed, and vulnerable zones were defined for subsequent environmental monitoring of the water quality in the water area surrounding the protected island.
Current Carrying Characteristics of Energy-Saving and Loss-Reducing Conductor Joint
Authors: Lin Haofan , Ma YiLi , Jin YongTao , Yang Liming , Li Te , Yang Yong
Published: December 2020

The loss of submarine cable is an important problem in the process of design and manufacture. In this paper, the technology of the energy-saving and loss reducing conductor joint was introduced. The current carrying capacity test of energy-saving and loss-reducing conductor was carried out. At the same time, the same current was applied to the common stranded conductor and the energy-saving loss-reducing conductor, and the heat loss of the conductor under the same test environment was compared. The experimental results showed that at the connection of outgoing terminal and connecting pipe, the contact resistance of the layer insulated conductor was greatly reduced after depainting treatment. Meanwhile, the temperature of thermocouple after paint removal was obviously reduced in the current carrying capacity test. Compared with bare copper single wire stranded conductor, laminated enamelled insulated stranded conductor could reduce the power loss.
Generalized Prediction of Commercial Buildings Cooling and Heating Load Based on Machine Learning Technology
Authors: Liu Jianing , Zeng Kaiweng , Wang Haizhu , Du Bin , Tang Yufeng
Published: December 2020

Factors such as building area, materials, light transmittance, and housing orientation have significant effects on cold and heat loads of commercial buildings. Accurate prediction of cold and heat loads based on the characteristics of the building can provide a reliable data basis for power grid dispatch. In order to quantitatively study the influence of the commercial building factors on the cooling and heating load, this paper collected the load of 768 buildings in a certain area on a typical day in spring and the relative density, surface area, room orientation, and light transmission area of the building group. This paper uses typical machine learning methods such as random forest, extra random tree, bagging, and deep neural network to perform regression modeling on the data. Finally, three models with the best effects are selected for blending to obtain the final building cooling and heating load prediction model. In preset 156 test cases, the mean square error of the model for heat load prediction is 0.201 and the mean square error of cooling load forecast is 2.56. The blending model reduces the error to a smaller range and reduces the phenomenon of data overfitting.
Analysis of Affirming the Height of Weir Based on Fish Swimming Performance in Mountain River
Authors: Lei Hua , Aiju You , Kaiping Xu
Published: December 2020

The weir group has been great negative impact on fish migration, and there is no corresponding construction standard for the height of weir which may destroy fish migration. In this study, the discharge in extreme velocity of the local fish and submerged conditions of the weir was taken as a limitation of the height of the weir group in mountain area. Taking Majin River as an example, the height of weir was analyzed aiming for the local fish to get over the weir in migration period with one-dimensional hydrodynamics model. The results showed that the fish cannot pass through all weirs at a specific discharge with current weir height, by reducing the height of the weir, the discharge met to fish migration can be reduced, and different weirs required different heights to be reduced. The fish can pass through all weirs at a limited discharge with the weir heights reduced. This method provides a calculation method for determining the height of weir in mountain river.
A Study on the Path of Building Hefei as a Green Development City
Authors: Fang Tao , Sun Qian-qian
Published: December 2020

With “improving quality, reducing total amounts and preventing risks” as the mainline, Hefei adheres to ecological priority and the concept of symbiosis between cities and lakes, accelerates the transition towards green production methods, lifestyles and consumption patterns, and strides into a beautiful Hefei where “all lands are green, all waters are lucid, all seasons are scented with flowers and all places are resonant with singing birds”. This paper analyses the unique measures taken by Hefei for green development. On the basis of reviewing the main achievements and problems of Hefei’s green development, it proposes suggestions for reducing the excessive consumption of resources, comprehensively promoting industrial upgrading, disseminating ecological culture, strengthening the rule of law, environmental protection and eco-governance, and pushing forward the continuous improvement of ecological and environmental quality, so as to provide the decision-making basis for building Hefei as a green development demonstration city which realizes comprehensive, coordinated and sustainable development on economic, social and ecological aspects.
Research of Ti-6Al-4V titanium alloy welded joints made by electron beam welding, designed for operation in cryogenic conditions
Authors: Kovalev S V , Portnykh A I , Aslamova V Y
Published: December 2020

The article is based on realization of metallographic research in order to prove quality and following application of welded joint with the changed construction of coupling edges for details made of titanium alloy Ti-6Al-4V. The welded joint has been gained by electron beam welding. The expertise of macro- and microstructures has been realized, the hardness has been changed and testing of mechanical qualities under room and reduced temperature has been realized. The conclusion of possibility of application electron beam welding for welded joints of titanium spherical tanks is based on the research.
Production technology for polymeric composite materials by additive manufacturing methods
Authors: Egorov S A , Tarasova T V , Terekhina S M
Published: December 2020

Additive manufacturing methods make it possible to create complex geometry parts, that cannot be produced by conventional methods. For manufacture of the products, composite polymeric materials can be used, both disperse-filled and filled with short or continuous fibers. Recently, more and more attention has been paid to reinforcing plastics with natural fibers. The study of the manufacturing process of a polymeric composite material filled with continuous natural fibers by the fused filament fabrication is presented
Extruder for the production of metal-polymer filament for additive technologies
Authors: Roshchupkin S I , Golovin V I , Kolesov A G , Tarakhovskiy A Yu
Published: December 2020

In the process of performing the work, an extruder was designed for the manufacture of metal-polymer filament for additive technologies, of sufficient power, characterized in that it has a cooled screw, which allows to reduce the forces for mixing the mass, as well as a tungsten carbide coating, which has high wear resistance. The extruder will be loaded with a pre-prepared mixture consisting of polymer and metal powder.
The parameters values choice for the preliminary thermo mechanical effects on polymeric materials before machining
Authors: Erenkov O Yu , Lopushanskii I Ya , Yavorskii D O
Published: December 2020

In this paper the commonality of the destruction and materials cutting processes is substantiated. The use of preliminary mechanical and thermal effects on polymer composite materials is justified on the base on the provisions of the materials fracture kinetic concept. The ranges of the parameters values for thermal and mechanical effects on polymer composite materials are scientifically sound. Experimental studies of the polymeric materials deformation and fracture processes under uniaxial tension were carried out in order to select rational values of the preliminary mechanical stresses. It has been experimentally proved that the most weakened structure of the material is retained for 5-20 minutes for fluoroplastic and caprolon after preliminary loading. And the rest time between the deformation steps for thermosets such as getinaks and textolite does not affect the formation and change in the material strength.
Improving the accuracy of axisymmetric parts by applying controlled heat treatment
Authors: Drachev O I , Bobrowskii A V , Tisenko V N
Published: December 2020

The article discusses the technology of thermal power treatment of long, non-rigid parts of the “shaft” type. The design of the device for thermal-power deformation of the shaft and the principle of its operation are given. The device is equipped with a three-circuit automatic control system. The control system allows you to control the forces for axial deformation and the temperature of heating and cooling. The developed technology allows us to solve the problem of maintaining the straightness of the shaft during operation.
The wheels for final processing of parts
Authors: Dimov Yu , Podashev D
Published: December 2020

Microrelief characteristics of elastic abrasive wheel and parameters of its interaction with processed surface are studied (depth of penetration and quantity of penetrated grains). The received equitations of mathematical expectation of average depth of penetration of cutting logs and number of grains of elastic wheel being in contact allow to generate mathematical models of material removal and formation of parameters of roughness of the processed surface.
Rolling of a cylinder on the deformable surface with account of viscous lubricant
Authors: Zavyalov Oleg
Published: December 2020

A friction unit describing in this article consists of an absolute solid cylinder and a deformable surface. The cylinder rolls on the surface. The viscous liquid is applied to the surface as a lubricant. The surface is getting deformed if the cylinder is rolling under the load. This article demonstrates that if the cylinder is rolling without load, a locally thin layer of lubricant is formed between the surface and the cylinder. When the cylinder is rolling on the surface, the surface is deforming by the load. A thin layer of lubricant between the cylinder and the surface also exists. Moreover, the presence of a layer of the lubricant leads to an increase of an impact area and to a decrease in the load per surface unit. The distribution of pressure in the thin layer of liquid is calculated. The presence of the layer of viscous incompressible liquid in a cylinder-surface pair leads to an increase of a contact area and more even pressure distribution over the surface. As a result, the measures of pressure on the surface is significantly reduced. The rolling cylinder makes less pressure than it is calculated in statics.
The Investigation of lengthwise rolling on a stub mandrel by the use of a computer simulation
Authors: Pavlov D A , Erpalov M V
Published: December 2020

Lengthwise rolling of pipes on a stub mandrel is one of the most common pipe rolling methods. An urgent problem of the process of lengthwise rolling of pipes on a stub mandrel is the increased wall thickness variation in rough pipes caused by the flow of metal into the groove tapers and the formation of stripes during the rolling process. Therefore, an important direction is the study of the inhomogeneity of the metal flow in the deformation zone during the rolling process. To evaluate the wall thickness variation during the rolling process, a dimensionless parameter was introduced, which is the ratio of the average wall thickness variation in the groove tapers to the average wall thickness at the groove tops. The article presents the results of a study of the influence of mandrel calibration on the wall thickness variation and the tendency to form defects on the inner surface. With the use of computer simulation made for structural alloyed steel AISI-4140, the shape change of the pipe is investigated. Based on the studies, practical recommendations are formulated when choosing the calibration of the mandrel during lengthwise rolling on a stub mandrel, providing increased accuracy of pipes and reducing the level of defects.
Development of a sophisticated tool for processing parts with an involute profile
Authors: Ryazantsev Alexander , Shirokozhuhova Anna , Evchenko Irina
Published: December 2020

The article presents main parts of a modern propulsion system with liquid rocket engines. The critical parameters that affect the turbo-pump unit performance, as well as main methods of manufacturing gears in mechanical engineering, are shown. Standard and complex-profile tools used for machining parts with an involute profile are considered. Features of designing and manufacturing of complex cutting tools are revealed. Problems in the design of gear cutter used for gear machining are shown. The dependence of the gear cutter external diameter on the profile of the manufactured part is revealed. The mechanism and mathematical calculation of the tool profile adjustment are presented, taking into account the actual geometric dimensions of the manufactured part. The tool parameters that provide the specified critical parameters of parts with an involute profile are indicated. The proposed method of adjusting the geometric dimensions of a complex-shaped tool allows you to adjust and modify the final made gear cutters, which eliminates material and labor resources for the new expensive tool production.
An approach to complex model ECGA for the stable and unstable grinding conditions
Authors: Alsigar Masar , Pereverzev Pavel , Almawash Aziz , Alkadhim Mohamed
Published: December 2020

In this article dedicated to the mathematical solution and analytical methods to identify the causes of low efficiency and productivity range limits of grinding machine. A major point of the paper is the development of an optimal cycles in the external cylindrical grinding with axial feed ECGA. A Classification of mathematical programming models MPM and algorithms provides general tools for engineering design optimization of grinding cycles with two feeds at radial and axial feed under different conditions of non-stochastic programming in the multi-stage zone. A related model for formation of radius on basis of experiments and calculations with a simultaneous feed to assure quality control of designing and production of grinding.
Application of the group scheme of cutting when processing coarse-grain cogwheels
Authors: Artamonov E V , Kireev V V , Zyryanov V A
Published: December 2020

Today between the leading countries of the world there were difficult foreign policy relations. In the conditions of constant sanctions and refusal of delivery of various goods to the Russian Federation there is a question of creation of products of an own type in the conditions of import substitution. Against the background of these events in the Russian Federation the State program which has to give an impetus of the machine-building industry was developed and implemented and strengthen its influence in the world market. In particular, the large tool enterprises of Russia passed to developments of own designs of the metal-cutting tool for the machine-building industry. Now the perspective and effective tool can be considered assembly as its advantages were repeatedly proved by the leading Russian researchers [1-7].
Rapid assessment of adhesion of paint coatings by digital image analysis
Authors: Antonova N M , Khaustova E Yu , Nebrat A A , Puzanova A S
Published: December 2020

A program is developed that allows to numerically assess the area of defects in protective coatings by analyzing digital images of surfaces. The program is implemented in Microsoft Visual Studio programming environment. The possibility of estimating the area of flaking of the paint coating from the base layer (%) and determining the adhesion in points, in accordance with the cross-cut test method in the context of paint production is shown. The created program does not require a large computing power of the computer and can reduce the time to obtain calculation results for one plate with a coating from 20 minutes to 1-2 seconds. An example of using the developed program for calculating the area of metal surface areas with different chemical composition is given.
Structure and properties control of carbon alloys cast blanks produced by aluminothermic method with following heat treatment
Authors: Predein V V , Komarov O N , Zhilin S G
Published: December 2020

Casting production with aluminothermic method is one of the mainstream lines of production process designing and improvement in foundry practices. Cast blanks production methods based on thermite mixtures application provide economic benefits due to machinery and steel production plants waste (ferrous and non-ferrous chip scrap and scale) usage. Alloys resulting from exothermal reaction are used for cast blanks production. For minimization of expenses coming from power consumption, the oncoming cast blanks properties correction is conducted at initial stages to put them into operation immediately after production, which is achieved by adding fillers in charge materials to decrease reaction’s heating effect or by external heat supply. In some cases reaction’s high intensity and temperature lead to difficulties in final properties foreseeing therefore affecting the formation of repairable and irrepairable defects. Cast blanks with irrepairable defects are used as charge materials in further recasting in traditional melting units, which increases metal waste processing efficiency and non-wastefulness. Cast blanks with repairable defects are a subject to further processing. E.g., in case of chemical and structural inhomogeneity, high-rate internal stress, cast blanks are a subject to complex heat treatment, that allows bringing properties to the required level. Annealing is applied to achieve better homogeneity compared to as-cast condition. After heat treatment cast blanks contain granular pearlite or ferrite with various inclusions. It’s been established that high rates of alloying aluminium increase the high-carbon steels hardening temperature. After 1000°C hardening the samples have martensite structure with hardness index up to 628 HBW.
Monitoring system of hydro and wind power equipment based on intelligent measuring complexes and Neurodiagnostics
Authors: Komshin A S , Potapov K G , Syritsky A B , Fomin A E
Published: December 2020

The paper presents an analysis of the development of wind energy and hydropower in the Russian Federation. The analysis of modern approaches to the diagnosis of wind turbines in the world. The possibility of applying the phase-chronometric technology for renewable energy facilities wind turbines and hydraulic units is substantiating. An example of diagnosing wear during operation of gears and rolling bearings based on a phase-chronometric approach is giving. Multivariate mathematical modeling is presenting on the example of a hydraulic unit. An alternative approach to the application of measuring technologies to support the life cycle of hydropower and wind energy facilities using Neurodiagnostic systems is presented.
Current issues of the quality management system in mechanical engineering
Authors: Ostapenko M S , Loginova E V
Published: December 2020

In the modern world, the need to create high-quality goods and services and improve product quality comes to the fore. An effective method that many enterprises of the world have resorted to is the quality management system (QMS) in production. Implementation of QMS in the organizational processes requires both time and material costs and carries several problems that arise for managers. First, there is lack of interest on the part of management in QMS implementation process, which results in obstacles in the form of insufficient funding and staff resistance, as well as problems with staff motivation when introducing a new system and choosing a certification body. For the QMS implementation to bring the enterprise maximum effect, the manager needs to plan the implementation process in advance and develop actions to avoid these problems in the implementation process.
Experimental production of samples and prototype parts from titanium-polymer composite material
Authors: Nasonov F A , Akulinin A O , Morozov B B , Popova U A , Filatov A A
Published: December 2020

Work on the current topic of hybrid titanium-polymer composite materials (Ti-PCM) is continuing. After checking the technological feasibility of the two-stage process of manufacturing flat and single curvature of parts, work is carried out to optimize the composition, including through the introduction of elastic intermediate layers, the selection of the optimal parameters of the process.
Investigation of Technological Parameters for Machining Toroidal Section of Solid Ceramic End Mills
Authors: Grigoriev S N , Grechishnikov V A , Volosova M A , Jiang X , Pivkin P M
Published: December 2020

Solid ceramic mills are a promising technological solution for cutting heat-resistant materials. Although nanostructured cutting ceramics has a number of valuable physical and mechanical properties providing high operational performance of mills, it has low strength. The design of a solid ceramic mills is formed by smooth surfaces without stress concentrators to ensure operability and to reduce the probability of failure. The most important structural element of solid ceramic end mill is a helical groove with a negative rake angle needed to increase surface strength. This groove can be machined with standard grinding wheels of type 1A1 or 1V1. However, the application of grinding wheels of a standard shape requires the use of reduced cutting parameters to prevent chipping on the forming sections of the cutter. Chipping can be caused by too short length of the contact line and the stress concentration at the end point of the profile of the grinding wheel, which is typically fully responsible for shaping the front surface and its transition to the tooth back. In this paper, in order to increase the contact line, we develop a new approach to designing grinding wheels for machining helical grooves of solid mills and determining rational technological and operational parameters for there use. A new approach is developed based on the fundamental principles of analytical geometry and linear algebra, numerical methods and basic axioms of the shaping theory. In this study, we have identified the key relationships between parameters determining the position of the grinding wheel relative to the workpiece and the geometrical parameters of a solid ceramic mills. The developed approach allowing to determine the specific design of the grinding wheel, depending on the initial parameters of the mill and the trajectory of the axis of the wheel relative to the mill, was implemented in the MathCAD environment.