bluuebunny/crossref_metadata_2025_split huggingface dataset:
Convection of Viscoplastic Fluid in Square Cavity Heated from the Sidewalls
Authors: Lyubimova T P , Kazimardanov M G 
Published: June 2021

Abstract
The paper is devoted to the numerical study of two-dimensional convective motion of a viscoplastic fluid in a closed region under lateral heating. The problem is solved numerically using the ANSYS Fluent software. The Bulkeley-Herschel model describing viscoplastic behavior was chosen as a non-Newtonian fluid model. Under certain rheological parameters, this model is reduced to a Newtonian fluid model, the behavior of which is also investigated as a limit case. Based on the results of the calculations, the dependence of the maximum value of the stream function in the cavity on the Rayleigh number is plotted and the evolution of the unyielded zones with an increase in the Rayleigh number is traced. The threshold value of the Rayleigh number, at which a sharp growth of the flow intensity is observed, has been determined. The calculated threshold value of the Rayleigh number for the Bulkley-Herschel liquid was found to be very close to the threshold value of the Rayleigh number at which the flow of the Bingham liquid arises, which was obtained analytically.
Convection of a Binary Mixture with Thermal Diffusion Coefficient That Depends on Temperature
Authors: Lyubimova T P , Rushinskaya K S , Zubova N A 
Published: June 2021

Abstract
In this paper we present the results of numerical simulation of nonlinear regimes of a NaCl aqueous solution in a square cavity with rigid and impermeable for substance boundaries. The vertical boundaries are thermally insulated, there are different constant temperatures on horizontal ones, it corresponds to the heat from below. The calculations are carried out within the non-stationary approach, with using of Boussinesq approximation and taking into account the polynomial dependence of the thermal diffusion coefficient on temperature. According to experimental data, the sign of thermal diffusion coefficient of the mixture under study changes at a temperature 285.4 K. In this work we consider a temperature range such that the sign of the thermal diffusion coefficient changes inside the simulated region. Other transport coefficients factors are considered as constant. The calculations were carried out for the cases of Earth and reduced gravity. A comparison is made with the case of the thermal diffusion coefficient constant value, which is negative at the considered average temperature.
Numerical Modeling the Effect of Static Indentation on the Rate and the Fatigue Crack Growth Trajectory
Authors: Matvienko Yu G , Razumovskii I A , Fedorov A A 
Published: June 2021

Abstract
The results of numerical modeling (in ANSYS) are presented, concerning the effect of the local residual stress field in the vicinity of the crack tip on the fatigue crack growth rate and change of the crack trajectory. Static indentation by a spherical indenter is considered as a method for creating a residual stress field. In this case, the point (or points) of indentation can be located both symmetrically relative to the line of initial crack orientation and with an offset. It is shown that the fatigue crack can grow in the direction opposite to its initial orientation. This effect can be employed to control the fatigue crack growth trajectory.
Analytical and Numerical Study of Biaxial Bending on VHCF Testing Machine
Authors: Nikitin A D , Stratula B A 
Published: June 2021

Abstract
Modern VHCF testing regimes are studied. A new loading scheme applicable to a piezoelectric fatigue testing machine is proposed. The scheme is studied analytically and numerically. The analytical part comprises the calculation of the specimen’s geometry to operate correctly on the VHCF testing machine, as well as the specimen’s stress-strain state calculation during an experiment in order to determine the one’s durability. A model based on a kinetic damage equation is introduced. This model is used in the numerical experiment. The behavior of a finite-element specimen in a fatigue experiment is calculated from the beginning up to the stage of active crack growth.
Study of Heat and Mass Transfer in Ventilation Shafts of Deep Mines in the Case of Airflow Reverse
Authors: Olkhovskiy D V , Kuzminykh E G , Zaitsev A V , Semin M A 
Published: June 2021

Abstract
This article presents the results of a simulation of conjugate heat transfer between cold air and warm shaft lining during airflow reverse at a hard rock mine. A comparison of the numerical results with collected experimental data was carried out. A significant discrepancy between the two was revealed, indicating that not all heat sources and additional air heating mechanisms were taken into account in the simulation. Possible reasons for the discrepancy are discussed and the most probable reasons are identified for further study. A quantitative assessment of the possible factors considered is carried out. Further tasks for research are determined.
Influence of a Liquid on the Deformation Behavior of Porous Nickel and Titanium under Compression
Authors: Panfilov Gleb P , Zaytsev Dmitry , Panfilov Peter , Kiseev Valery 
Published: June 2021

Abstract
The deformation behavior of capillary porous (CP) Ni and CP Ti is examined under uniaxial compression in air, water, and ethanol. CP metals contained inert liquids such as H20 and C2H5OH are used as the heat pipes’ active elements in space applications. The samples for mechanical testing were isostatic compacting and vacuum annealing (porosity of 60%). Uniaxial compression tests were carried out in the air, water, and ethanol in Shimadzu AG-50K XD (traverse rate 0.1 mm/min). It was shown that CP Ni and CP Ti exhibit the ductile deformation behavior in all cases, which is inherent to Ni and Ti. The ethanol environment induces the increase of the compression strength and the total deformation in both materials compared to deformation behavior in air and water. Therefore, a heat pipe’s failure containing CP Ni and CP Ti matrixes and ethanol as the working body is caused rather by manufacturing defects, but not the structural materials’ intrinsic properties.
Four approaches for description of stochastic systems with small and finite inertia
Authors: Permyakova E V , Klimenko L S , Tyulkina I V , Goldobin D S 
Published: June 2021

Abstract
We analyse for approaches to elimination of a fast variable, which are applicable for systems like passive Brownian particles: (i) moment formalism, (ii) corresponding cumulant formalism, (iii) Hermite function basis, (iv) formal ‘cumulants’ for the Hermit function basis. The accuracy and its strong order are assessed. The applicability and performance of two first approaches are also demonstrated for active Brownian particles.
Dynamics of Magnetic Fluid Cylinder in Inhomogeneous Magnetic Field
Authors: Shel’deshova E V , Polunin V M , Churaev A A , Ryapolov P A 
Published: June 2021

Abstract
The dynamics of some magnetic fluid (MF) samples of various concentrations filling the tube horizontally and held by a field of a magnetic axial system made based on unipolar permanent rare-earth ring magnets were studied. The magnetic field of an “axial” magnetic system of MSO was studied, as well as the dependence of the system oscillation frequency on the length of the MF cylinder. An original method for determining MF magnetization is proposed and applied to the obtained data. Magnetization was determined for three magnetic fluid samples. The results obtained by the developed method are comparable to the magnetization values obtained by the ballistic method. The developed and presented technique of a dynamic experiment with measuring oscillations frequency of the “MF column suspended in a strong and inhomogeneous magnetic field” system involves the creation of a new absolute method for determining saturation magnetization and can be useful for studying magnetophoresis and aggregation processes of magnetic nanoparticles. This technique is used to study the degree of elastomagnetic consistency parameters over time.
Forecast of the Surface Tilt Based on the Monitoring Data of Settlement of a Group of Buildings
Authors: Tsvetkov R V , Glot I O , Epin V V , Shardakov I N , Shestakov A P 
Published: June 2021

Abstract
This paper presents the results of long-term monitoring of ground subsidence above flooded mining. To assess the change in the shape of ground surface, the data obtained by monitoring the settlement of the foundation of a large group of buildings were used. The control of the slope was carried out using automated hydrostatic level systems mounted on the foundations of 40 buildings located in this area. The accumulated data on the long-term evolution of the tilt were processed using the methods of statistical analysis of non-stationary time series. Choice of forecast model was made based on a comparison of forecast and real monitoring data. A forecast based on 5-year monitoring data predicts that the observed deformation processes in the rock massif will not change over the next 2 years.
Experimental Study of Steady Flows in Centrifuged Immiscible Liquids in Rotating Horizontal Cylinder
Authors: Vlasova O A , Karpunin I E , Kozlov N V 
Published: June 2021

Abstract
The steady time-averaged flows in a rotating system of immiscible fluids are studied experimentally. The fluids fill a horizontal cylindrical container and are brought into a centrifuged state, when a less dense fluid forms a cylindrical core, and a denser fluid is distributed in the form of a coaxial layer. Under the action of the gravity field, the core is steadily displaced along the radius in such a way that its axis is oriented parallel to the container axis and remains stationary in the laboratory frame of reference. In the frame rotating with the container, the core and the fluid surrounding it oscillate. This leads to the generation of a steady flow in the form of differential rotation of the fluid with respect to the container. To study the structure of the flow, light-scattering tracers of neutral buoyancy are added to the liquid. The flow rate is calculated from their displacement. Measurements show that at the interface, from the side of the external fluid, a Stokes boundary layer is formed, at the boundaries of which a tangential discontinuity of the averaged velocity is formed.
Approximation of Heat Dissipation-Crack Rate Curve for Fatigue Crack in Stainless Steel
Authors: Vshivkov A , Iziumova A , Prokhorov A , Mybassarova V , Plekhov O 
Published: June 2021

Abstract
The experimental and theoretical analysis of thermodynamical peculiarities of heat flux at the fatigue crack tip during its propagation was made in presented work. The goal is to elucidate the relation between heat flow at the crack tip and kinetic of fatigue crack propagation for different loading conditions. The plane specimens with notch made from stainless steel (AISI 304) were studied. There were two types of specimens for uniaxial loading and one type for biaxial loading. A heat dissipation during fatigue crack propagation was measured by simultaneous use of contact and noncontact techniques. The samples were subject to cyclic loading with constant stress amplitude and different biaxial coefficients. The functional dependence between crack propagation and heat flow at the crack tip was received by experiment measurement and analytical calculation. This relation depends on only type of material and righty for all fracture mode.
Research of Ionic, Molecular and Cellular Mechanisms for Formation of Electric Impedance in Biological Fluids and Tissues
Authors: Zuev A L , Shakirov N N , Sudakov A I , Ju Mishlanov V 
Published: June 2021

AbstractContemporary medicine applies the analysis of molecular composition and physicochemical properties of biological fluids as one of the main tools for diagnostics and control over body state and behaviour of pathological processes. However, most laboratory diagnostics methods (such as biochemical, enzyme-linked immunosorbent assay, etc.) are too expensive and time-consuming. They demand the availability of well-equipped laboratories, complex equipment, scarce and expensive reactants and materials and the highly skilled medical staff. Compared to them, bioimpedansometry is an incomparably simpler and cheaper method of laboratory research, becoming increasingly popular for diagnosing internal diseases. In the current research the main physical factors responsible for bioelectrical impedance variations in some conductive intracellular and extracellular biological fluids with different protein molecules, cell components and microbes were studied experimentally. The original laboratory impedance meter was developed for investigation of blood or interstitial biological fluids as well as condensates composition in orderto determine the concentration of organic substances in them and the rate of biochemical and immune reactions.
Features of modeling multiphase media in problems of electromagnetic generation of flows
Authors: Kolesnichenko I , Losev G , Eltishchev V , Mamykin A 
Published: June 2021

Abstract
The study of the electromagnetic force acting on a medium with inhomogeneous electrical conductivity has been carried out. The electrical conductivity changes abruptly which simulates the liquid–solid interface during the crystallization of a pure metal. The electromagnetic force is created by a traveling field inductor with one of the most demanded in metallurgy construction. The results showed a significant dependence of the electromagnetic force on the position of the interface with respect to the inductor. Consequently in the mathematical modeling of the directional crystallization process under the influence of an electromagnetic force created by an inductor of this type it is necessary during the movement of the interface, either to do the calculation of the electrodynamic part of the problem anew or to use the method of canonical domains.
3D Instability of a Toroidal Flow in the Liquid Partially Covered by a Solid Film
Authors: Demin V A , Petukhov M I , Shmyrova A I 
Published: June 2021

Abstract
The structure of a steady radial thermocapillary flow from the local heat source in cylindrical geometry has been studied numerically. The up boundary of the liquid was partially covered by the stationary film of an insoluble surfactant, pushed to the wall of the cavity. The calculations are fulfilled on the base of interfacial hydrodynamics equations by using mathematical package “Comsol Multiphysics”. It is shown that the effect of a radial flow symmetry breakdown appears as a result of convective instability, so that the initial poloidal rotation of the liquid transforms into the azimuthal plane. The system of inclined steady volumetric vortices is formed under the film of surfactant. The inclination angle of the plane of rotation in dependence on the intensity of radial thermocapillary flow is studied. It is shown that the azimuthal vorticity can be regulated by the power of point-heat source and by free surface area. The increase of heating intensity leads to the growth of the azimuthal vorticity. Thus, the initially radially symmetric toroidal flow is divided into two parts with the origination of vortices in the azimuthal plane under the film.
Application of Diagram Image Classification Based on PCBMER
Authors: Wang Ruixiang 
Published: June 2021

Abstract
Nowadays, in order to express data more clearly and accurately, data visualization has become a wave of the times. In this context, due to the different types and quantities of data stored in computer systems, different forms of data visualization can be seen in web pages, demonstration slides and papers. However, in many cases, we can’t directly obtain the underlying data, so the classification of chart images becomes very important. Only with the classification technology of chart images can we understand it more intuitively and deal with it more concretely, such as generating new charts according to the extracted data. Using depth learning technology to classify chart images is now a very popular way. In the field of image classification, convolution neural network (CNN) is the most widely used technology in depth learning, not only because of its high accuracy, but also because it encapsulates the process of feature extraction. At the same time, using the software architecture of PCBMER framework to design application programs can maintain high stability of the system. From the experimental results, this new technology is feasible, and the architecture can be further optimized to make the results more accurate.
Research on Colour Modelling and Detecting System Based on Computer Big Data
Authors: Pei Xia , Zhang Li 
Published: June 2021

AbstractThrough the statistics and analysis of the three colour components of dynamic background pixels in RGB space, the paper found that the difference between the three components fluctuates in a narrow area. Based on this fact, it proposes RGB colour based on computer big data Background modelling method of component statistics. This method fully considers the correlation of the three colour components of RGB, and the foreground detection process is faster. Experimental results show that compared with other colour invariant methods, this algorithm can more accurately reduce the computational complexity, time consumption and memory consumption of foreground detection.
Image Enhancement and Improvement Algorithm Based on Esrgan Singal Frame Remote Sensing Image
Authors: Yang Zhiwei , Wang Yunyan 
Published: June 2021

Abstract
Traditional spline interpolation algorithm for reconstruction of visual effects are not good, based on Super Resolution against Network (Super - Resolution Generative Adversarial Network, SRGAN) edge character to deal with such problems as imperfect, using a generated based on the enhanced Super Resolution against Network to improve the Resolution of ordinary optical remote sensing images, the first Network generated by high Resolution data sets to train (G network), then lower Resolution test data model test, The test results and real results are put into the discrimination network (D network) to get the adversarial loss, and then the generated network is modified according to the adversarial loss. The superiority of the network is improved by introducing dense residuals to SRGAN, modifying the judgment object of the discriminator to be relatively real, and using the eigenvalue before activation to improve the perceived loss. The desert, farmland, forest and mountain data were tested on AID data set, and the algorithm in this paper could obtain the recomposition of the real image more closely. Compared with SRResNet and SRGAN algorithms, PSNR improved by about 4.0db and SSIM improved by about 0.14. This method improves the feature comprehensiveness by increasing the network fineness degree, and USES the modified perception loss to get the brightness closer to the real image, which is beneficial to improve the quality of single frame remote sensing image.
Study and simulation of heterodyne optical phase-locked loop for inter-satellite laser interferometer
Authors: Liu Shaokun , Zhong Xingwang 
Published: June 2021

Abstract
Coherent transmission of optical signal is an important module of inter-satellite laser interferometer. Through heterodyne optical phase-locking technology, the coherent transmission of laser signals from the master spacecraft can be achieved. And in the case of ensuring the stability of the local laser frequency, amplifying of the optical output power is realized. This article introduces and analyzes the principle, modeling and simulation of heterodyne optical phase-locking technology, which provides a reference for the realization of laser signal’s coherent transmission from slave satellite.
Face fatigue detection method based on convolution neural network
Authors: Song Yibing , Wang Qiang , Zhai Yantao , Tai Qiang 
Published: June 2021

AbstractIn order to monitor the fatigue state of the face, a state detection algorithm based on a variety of facial fatigue parameters is proposed. Firstly, convolution neural network is used to enhance the edge information of eyes and mouth for accurate positioning. Then, a rotation invariant LBP pyramid feature is used to describe the eyes, and a linear SVM classifier is trained to distinguish the open and closed state of eyes. The open and closed state of mouth is judged according to the open area and aspect ratio of mouth. At the same time, the vertical movement of eyes is counted Determine changes in head position. Finally, based on the state of eyes and mouth and the position of head, four fatigue parameters which can describe the state are calculated, and the final fatigue state is obtained by convolution neural network. The experimental results show that the detection and state discrimination algorithms have high accuracy.
Study of Flame Detection based on Improved YOLOv4
Authors: Cao Chengzhi , Tan Xiaoyu , Huang Xinyi , Zhang Yongjun , Luo Zehao 
Published: June 2021

Abstract
In some complex circumstances, the detection of conflagration mostly depends on smog detectors, which have lots of limitations in precision, efficiency and safety. If we make full use of object detection algorithms to detect the flame in industries, it will benefit people’s safety obviously. Among all kinds of object detection algorithms, YOLO series play a very significant role. In this paper, we propose an improving strategy on YOLOv4 to enhance its precision based on multi-scale feature maps. Firstly, we create flame datasets including almost 4000 high-resolution flame pictures. Secondly, some improvements on feature extraction network are made to detect smaller objects. Finally, the total algorithm are trained and tested on our datasets for about 400 epochs. The result show that the method can generate high quality on flame detection in a great number of situations.
Foreign Object Detection Algorithm Based on Multi-scale Convolutional Network
Authors: Zheng Jiexin , Chen Ye , Zhang Hong , Liu Dan 
Published: June 2021

Abstract
In order to detect foreign matter invading the track and prevent the intrusion of foreign matter from causing railway safety accidents, the detection algorithm of foreign matter intrusion on the track is studied. Aiming at the problem that the rail transit scene is complex and the obstacle scale changes in the acquired image information, this research proposes a multi-scale target detection algorithm based on the YOLO (you only look once) algorithm. First, an adaptive feature fusion module is designed to make the feature maps used for detection have strong semantic information at various scales; then, a new loss function is designed to alleviate the problem of uneven sample distribution and optimize the training process. Experiments show that the algorithm has obvious advantages in multi-scale detection, which not only improves the accuracy of target detection, especially the accuracy of small targets, but also does not significantly increase the inference time and the amount of parameters, and has high real-time performance.
Image Denoising Algorithm Based on Generative Adversarial Network
Authors: Liu Gaoyuan , Zhong Guangyuan , Zhao Huiqi 
Published: June 2021

Abstract
Image denoising is an important research direction of image restoration. With the increasing requirements of image quality, image denoising has been widely concerned by scholars at home and abroad. This paper studies the problem of noise image denoising, using improved sparse representation algorithm and deep learning technology to denoise the noise image. In this paper, a de-noising model based on generative countermeasure network is proposed. The residual algorithm and dense connection are added to the network layer of learning image noise information features. At the same time, the discriminator is trained to judge whether the generated image is true or false, so as to avoid boundary blur while de-noising. Zero filling convolution is used to ensure the consistency of input and output characteristic dimensions of each layer. The output of network model is image noise information. Simulation results show that the algorithm has good denoising performance.