bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of semiconductor nanostructures in an argon arc
Authors: Timerkaev B. A. , Kaleeva A. A. , Petrova O. A. , Suleymanov R. M. , Sorokina A. R. , Ibragimov I. S. , Saifutdinov A. I. 
Published: April 2021

Abstract
In this paper, the synthesis of semiconductor spherical nanostructures is carried out by the plasma-chemical method. The sizes of the obtained nanospheres range from 100 nm to 1 mm. These structures are open on one side, have thin walls with a thickness of several nanometers, which end with “tentacles” with a diameter of several nanometers. Since the synthesis involved three elements of the fourth group of the periodic table (germanium, silicon, carbon), it has not yet been possible to determine the crystal structure of the obtained samples. All three elements are present on the surface of the sample in atomic percentages Ge-2.5%, Si-8%, C-55%. In addition to these elements, oxygen is also present in the spectrum.
Production of silicon coatings by plasma-arc method
Authors: Kaleeva A.A. , Timerkaev B.A. , Petrova O.A. , Shamsutdinov R.S. , Dautov I.G , Mastygin A.V. 
Published: April 2021

Abstract
Silicon coatings consisting of micro and nanopores were obtained by plasma-arc method. An experimental setup was assembled for the synthesis of nanostructures. A number of experiments on the synthesis of silicon nanostructures with changes in parameters such as current, voltage, and pressure in a vacuum chamber were carried out. In the experiments, a molybdenum cathode was used as a substrate for the deposition of silicon nanostructures. Atomic silicon evaporated from the anode. The experiments were carried out in an argon medium at a pressure of about 500 Torus. The current in the experiments is about 8 A, and the voltage is within 80 V. The resulting coatings with silicon nanostructures will increase the active surface area by several tens of times.
In search of optimal mode of plasma polishing of surface of agricultural machinery parts when using a discharge with liquid cathode
Authors: Tazmeev B K , Tsybulevsky V V , Tazmeev G K 
Published: April 2021

Abstract
The process of plasma polishing using a gas discharge with liquid electrolyte cathode was studied. The search for optimal modes was carried out by the method of multi-dimensional experiment. The heat flux density and interelectrode distance were considered as the main factors.
The influence of a supersonic flow of gas at glow discharge
Authors: Shamsutdinov R S , Timerkaev B A 
Published: April 2021

Abstract
Experiments have been carried out to study the effect of a supersonic gas flow on a transverse glow discharge in the case when the supersonic gas outflow enters the region of Faraday dark space, i.e. the positive column ends before reaching the supersonic jet. And also in the case when the supersonic outflow of gas falls into the region of the positive column. It is established that the organization of the supersonic flow changes the glow pattern of the glow discharge, creating a spatial inhomogeneity in the interelectrode space.
Features of the process of laser welding of cast iron with steel
Authors: Zvezdin V V , Rakhimov R R , Khisamutdinov R M , Portnov S M , Saubanov R R 
Published: April 2021

Abstract
The article presents the results of research on laser welding of cast iron with steel on a robotic laser technological complex. A system of technical vision for precision focusing of laser radiation on the joint of welded elements is presented, which provides control of the movement of the laser beam along the welded joint and adjustment of the radiation power, depending on the temperature of the joint. The welding process is carried out in a protective atmosphere of inert gases. Rough guidance of the beam is carried out by the robotic complex until the point “start of welding” falls into the field of view of the technical vision system, which is built into the process head. Precision positioning of the beam focus on the seam is provided by turning the focusing lens to a certain angle by a piezo actuator. The results of metallographic studies of the welded seam of cast iron and steel are presented.
Development of a Thermographic Vibratory Test Bench for Predictive Maintenance in Asynchronous Motors
Authors: Vilchez K , Perez E , Coaquira C , Hernandez J , Carmona J 
Published: April 2021

Abstract
The predictive philosophy contributes to improving productivity, reducing system failures and reducing unplanned downtime in a non-invasive way to the machine, for which the test bench is based on the German standard VDI2221, using mathematical models to select the materials and the design of the final prototype. The development of the project consists of applying vibration analysis, thermographic analysis and the quality of energy in which each measurement and the correlation that exist between them is shown; in addition, the inverse Fourier transform was used to demonstrate the amplitude and frequency ranges according to the theoretical equation proposed in the Matlab program, it can also be seen the higher order vibrations of 22.1 is located at the same critical point of the SP7 measurement with a temperature of 34.6 ° C and an emissivity of 0.95, likewise the Power quality measurements are within the allowable limits according to ISO 50001; On the other hand, this analysis made it possible to determine the existence of a positive linear correlation between thermography and vibration analyzes with a correlation coefficient equal to 0.828.
Wear Mechanism and Failure Analysis of A High-speed Train Hydraulic Damper Using CFD Approach
Authors: Wang Wenlin , Huang Bao , Zhou Zirong , Du Jianming 
Published: April 2021

Abstract
To evaluate wear-induced hydraulic damper failures, wear mechanism of a Chinese CRH train hydraulic damper by invaded dust and sand particles under vibration conditions is firstly analysed, CFD modelling of the working chamber of the damper is then carried out and fluid dynamics analysis of the damper under different vibration speed input conditions is performed. The CFD results demonstrate that under wear conditions both the fluid discharge speed and produced pressure would drop significantly, the maximum fluid discharge speed and pressure are far smaller than that under non-wear conditions, the damping force would have a maximum decrease of 62.3%. The wear mechanism, CFD model established and analysis results obtained in this study can be used for further railway hydraulic damper evaluation and optimal designs.
A Multi-error Measurement Method for Workpiece of Vertical Machine Tool
Authors: Wang Xiaoming , Wan Daowen , Liu Yongmeng , Wang Dawei , Cao Zifei , Wang Junfeng , Sun Chuanzhi , Zhou Dong , Chen Xue , Ma Hongliang 
Published: April 2021

Abstract
This paper proposes a method of multi-error separation for online monitoring of machine tool workpieces based on a single sensor with three rotation. Firstly, the multiple error sources what include roundness error, spindle radial rotation error and eccentric error are identified in the measured data of the sensor. Then, a multi-error separation model is established based on error sources. And the accurate separation of each error is realized through theoretical derivation. At the same time, an experimental system is set up to further verify the effectiveness and accuracy of the model.
Design of the New Locking Mechanism of Lock-iron Deflection Type and Dynamic Simulation
Authors: Yan-fu SUN , Jian-yu ZHU , Sheng-Jie CI 
Published: April 2021

Abstract
Rotary rigid locking mechanism It has the characteristics of reliable function, simple structure and it can shoot more powerful cartridge. Hence, it is universally utilized in the gun family which was developed independently by China. At present, the research level of rifle weapon locking mechanism structure has been significantly improved, but the research on dynamics simulation is still relatively few. To improve the research on the dynamics of the locking mechanism. Established the 3D model based on UG and selected locking block as the research object, established the dynamics differential equation of the locking mechanism through the dynamics analysis and make simulation on the model by using the ADAMS. The results show that the locking mechanism can be completed the unlock within 0.5 minute and lock within 1 minute, the motion characteristics of the recoil and reentry proved that the locking mechanism is coordinated, and the locking is reliable and went well. Dynamics differential equation of the locking mechanism of lock-iron deflection type provides a certain theoretical basis for the design of the automatic weapon locking mechanism.
A Health Monitoring Method of Machine Tool Spindle Based on Multi-domain Analysis and Convolutional Neural Network
Authors: Wang Xiaoming , Wan Daowen , Liu Yongmeng , Wang Dawei , Cao Zifei , Wang Junfeng , Sun Chuanzhi , Zhou Dong , Chen Xue , Ma Hongliang 
Published: April 2021

Abstract
This paper presents a method for monitoring machine tool spindle health based on multi-domain analysis and convolutional neural network. By extracting the characteristics of data from time domain, frequency domain and time frequency domain, the data information is fully excavated automatically. Meanwhile, Convolutional neural network is used to realize fault diagnosis and classification. As a result, the fault classification results reveal high accuracy by datasheet. It proves that the method in this paper which has strong practicability and application value.
Mechanical Displacement for 3D Printers’ Parts Using FEM as Inverse Engineering Method in Honduras
Authors: Luis Ordoñez Avila Jose , Elena Perdomo Maria , Yanire Rivas Bejarano Mildred , Luis Ordoñez Fernández Jose 
Published: April 2021

Abstract
Plastics industry is growing day by day; the new techniques generated by the fourth industrial revolution, such as additive manufacturing (AM) or better known as 3D printing, make the design and production of plastic products available to all. The aim of this research aims to explore the application of reverse engineering in improving the mechanical displacement in AM. The method used in this paper was the finite element analysis (FEM) applying it to different 3D printing parameters with a grid infill. Then the multiple line regression (MLR) was implemented to determine parameters relation. Finally, the simplex method to improve the parameters to decrease the mechanical displacement in AM. Reverse engineering process for parts that use 0.2 as shell wall and 25% of grid infill can have acceptable mechanical performance to be used in different applications.
Nonlinear Responds of Lamb Waves in Plate Structure with Micro-Crack Using Frequency-Mixing Technique
Authors: Zhan Zaifu , Wang Fuping , Zheng Yang , Wang Zhe , Huang Songling , Li Xincheng , Wang Shen 
Published: April 2021

Abstract
Lamb waves have huge potential in non-destructive testing. Its nonlinear responses provide a promising method to detect micro-cracks. This work mainly analyses nonlinear responses of two Lamb waves with different frequencies in plate structure with micro-cracks. The interaction between ultrasound and two types of cracks with different lengths, widths, angles and number was performed using finite element simulations. From the results, it is shown that frequency-mixing technique is sensitive to the micro-cracks. Also, different parameters of cracks have different relationships with sum-frequency harmonic amplitudes. These relationships provide basic support for quantitative evaluation of cracks.
Research on a Passenger Aircraft Flight Control System Gain Scheduler Design
Authors: Guo Wei 
Published: April 2021

Abstract
This paper employs the mathematical model of a passenger aircraft for the purpose of designing longitudinal flight control law to satisfy handling qualities assessment. Aircraft Rate Command Attitude Hold (RCAH) controllers are designed at the specific equilibrium points in the flight envelope by means of a state space pole placement design procedure. The handling qualities assessment of the aircraft is presented, based on which the gain scheduler is designed. The existing criteria are employed to assess the handling qualities of the aircraft augmented by the gain scheduler, including the Control Anticipation Parameter (CAP) and Neal and Smith. The augmented aircraft performs satisfactorily and meets the requirement of handling qualities.
Simulations and Ground Experiments of Interior Noise for Space Station Module
Authors: Yang Jiang , Feng Gousong , Wang Dong , Zhang Jungang , Li Xinming , Liu Chuang 
Published: April 2021

Abstract
China Space Station (CSS) module is currently under construction. Considering astronauts will be working and living on orbit for several months, a comfortable acoustic environment in manned space station must be provided. This paper investigates the interior noise effects for CSS using two typical vibro-acoustic analysis methods, that is, coupled finite element/finite element method (FE/FEM) and statistical energy analysis (SEA) method. The simulation models are validated through ground experiments by the noise test for space station simulation module. The combination of the above two methods can well predict the acoustic levels for both low and high frequencies. A ground experiment scheme for interior noise of space station module is also proposed on the basis of its noise characteristics. Sound power equivalent method is utilized to simulate a single noise source and multi-input multi-output (MIMO) closed-loop control method is employed for multiple noise sources. It is shown that the sound field simulation results are in perfect agreement with the simulation requirements of noise sources.
Modelling and Experimental Validation of the Dynamic Damping Characteristics of A High-speed Train Hydraulic Damper
Authors: Fan Youquan , Zhu Shan , Wu Yongming , Wang Wenlin 
Published: April 2021

Abstract
Aiming to understand the effects of damper parameter on vehicle system dynamics in the context of railway vehicle system design, a full parametric damper model, which includes the complete valve system dynamics, the dynamic force equilibrium equation, the flow continuity equation, the flow losses model and the comprehensive stiffness model, is established in this work. Both numerical simulation using the established damper model and bench test of dynamic performance of the damper are carried out, the comparison shows that the maximum relative error between simulation and bench test is only 2.6%, in addition, the rates of asymmetry are near and both small. Therefore, the simulation result agrees well with the test result, the established full parameter damper model is validated, the model would be accurate in predicting damper parameter effects in further high-speed train dynamics research and vehicle design.
Thermal Performance of Vapour Chamber in Different Tilting Configurations for Battery Liquid Cooling System
Authors: Li Weiping , Li Longjian , Cui Wenzhi , Guo Mengting 
Published: April 2021

Abstract
Vapour chamber is a planar heat pipe and has been widely used in the thermal management of electronic device. In this work, a grooved aluminium vapour chamber was presented with a one-through cooling plate to develop a simplified and practicable battery liquid cooling system. The impact of filling ratio and tilting configuration on the thermal performance of vapour chamber was experimentally investigated. The results showed that the thermal resistance of the vapour chamber increased gradually with the increase in filling ratio, and there was a deterioration of the heat transfer in tilting configuration. However, the vapour chamber at 20% filling ratio had a better performance at positive tilting angle configuration compared with that at negative tilting angle configuration. Moreover, the temperature distribution of the heating surface is fairly uniform with the application of the vapour chamber. Despite the temperature rise of the cooling water in the cooling plate up to 3.8ºC, the minimum temperature difference of the heating surface could be kept within 1 ºC and the minimum thermal resistance could be kept within 0.075ºC/W. The results indicate that the temperature difference of the heating surface can be suppressed through the heat and mass transport of phases inside the vapour chamber.
Numerical and Experimental Analysis of Subsonic and Transonic Base Pressure
Authors: Xiaobing Wang , Binhua He , Hong Zhang , Zhongliang Zhao , Yuping Li , Jianzhong Chen 
Published: April 2021

Abstract
Base drag of space vehicles with large, truncated base usually forms a considerable component of overall drag. The base drag is usually difficult to be accurately predicted due to the intrinsic complexity of base flow. The subsonic and transonic base pressure characteristics were studied by large scale wind tunnel test and Reynolds-Averaged Navier-Stokes/Large Eddy Simulation (RANS/LES) hybrid numerical simulation. The test results show that interferences of both tail sting and ventral blade varies evidently with Mach numbers. The RANS/LES hybrid method was proved to be effective as the calculated time-average base pressure and base drag agree well with wind tunnel test, and detailed flow structures were successfully captured. The base flow pattern is complicated in sub- and transonic regime that either single support scheme is not sufficient to obtain an accurate measurement of base drag. Various support schemes and high precision numerical method are recommended in similar studies.
Experimental Investigations of the Flow through Slotted Wall in Transonic Wind Tunnel*
Authors: GUANGYUAN LIU , DAWEI LIU , QIUTING GUO 
Published: April 2021

Abstract
Experimental study of the flow through slotted wall was conducted in 0.6m transonic and supersonic wind tunnel. Transverse flow properties, such as flow angle, pressure, velocity components were measured using travelling probe, and distributions of Mach number, total pressure recovery were acquired for both empty tunnel and airfoil model cases. Shear layer thickness was calculated based on test results. Results showed that, transverse velocity from shear layer through slot into plenum chamber is approximately linear, and wall shear layer thickness was up to 3 to 4 times slot widths on slot center plane, and homogeneous boundary conditions were inaccurate.
Geotechnical Characterization and Applications of Riyadh Metro Tunnel Boring Machine Excavated Material (TBMEM)
Authors: Alnuaim Ahmed 
Published: April 2021

Abstract
The Riyadh city is witnessing one of the most significant infrastructure projects in its history. The 22.5 billion dollars and 180 km in total length Riyadh Metro project will be constructed using different tunnelling methods: 10 m diameter tunnel boring machine (TBM), cut and cover, and new Austrian tunnelling method (NATM). About 35 km will be constructed using 10 m diameter TBMs, which will produce approximately 2.8 million cubic meters of TBM excavated material (TBMEM). Transferring such an amount of material will cause a severe impact on the environment and traffic as it required many trucks to transport the material to a remote site. The comprehensive geotechnical characterization profile of the material was prepared in order to understand the performance of the material and identify the areas in which the material can be utilized. In addition, this paper will explore the potential of using TBMEM after being treated and mix with clean sand to enhance its geotechnical characteristics. Several potential areas to utilize the TBMEM will be presented. Furthermore, the project will investigate the applicability of TBMEM to be used as backfill material and to what extent the treatment should go to achieve a mixture that meets the standard requirements.
Installation of a heavy king pile using driving guidance
Authors: Beuße Jannik , Grabe Jürgen 
Published: April 2021

Abstract
Combined walls are built out of heavy king piles and lighter sheet piles to protect site jumps up to 30 m of quay walls. Few recommendations exist on how to install the king piles so that the sheet piles can absorb the deformations coming from the location slippage of the king piles. As such the installation process of king piles needs to be regulated. By measuring the installation process on a construction field in Rostock in Germany, the dynamical influence on the king pile’s position at the end was investigated. For that purpose, a large king pile with a length of about 30 m was equipped with acceleration, strain and inclination sensors. The driving guide and the installation machine were equipped with acceleration sensors as well. The data was saved with a frame rate of 200 kHz. Next to these analogical sensors the hole driving process is visually recorded by a high-speed camera and a drone. The movement of the king pile during driving derived from the measurement data and compared with the numerical video analyses. The influence of the driving guide was then analysed. Further, the end position of the king pile was measured with an inclinometer.
Modeling of Air Distribution in an Office Building Using Microperforated Textile Air Duct
Authors: Agafonova V V , Skibin A P , Volkov V Y 
Published: April 2021

Abstract
The article is devoted to improving the efficiency and efficiency of ventilation systems through the use of new types of air distribution devices. These include textile air ducts made of polyester. This material allows you to cut micro-holes of a given diameter on the surface of the air duct with a laser. The advantage of micro-perforated air ducts is the possibility of supplying supply air with micro-jets with a small pulse, which eliminates the possibility of drafts in the workplace. The results of experimental and theoretical studies of air distribution using textile air ducts are analyzed. It is concluded that there are no data on the study of the distribution of supply air using textile air ducts with microperforation. The results of comparative numerical modeling of air distribution in an office space with two supply air supply schemes are presented: traditionally, through supply grilles and through a microperforated textile air duct. The fields of temperature and air velocity distribution over the room height are obtained. It is concluded that the use of a microperforated textile air distribution device increases the efficiency of assimilation of heat surpluses in comparison with traditional air supply sources (ventilation grilles).