bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of different geosynthetic reinforcement materials on transmitted pressure under dynamic machine foundation
Authors: Karim H H , Samueel Z W , Hussein M A 
Published: February 2021

AbstractThe present study has been carried out to study experimentally the contact pressure transmitted of dynamic machine foundation on unreinforced and reinforced multi-layered sandy soil (medium-dense sand MD). The relative density of the first layer was 50% corresponding to medium sand soil, while the relative density of the second layer was 85% corresponding to dense sand soil. The tests have been carried out on 8 models. The amplitude of the applied harmonic load was 0.25 ton and 2 ton with a frequency of 0.5 Hz. For each load amplitude, models of sand were tested in two cases reinforced and unreinforced models. Three types of reinforcements were used at 0.5B depth where B is the width of the square foundation. Analyzing the dynamic behavior of tested soil samples and presenting of some concluded remarks were done.
Analyzing and Predicating PH value in Nature Rubber Solidification Process Using Multiple Regression Method
Authors: Sun Zhongrui , Wang Bingbing , Zhang Fan , Liao Lusheng , Deng Weiguo , Zhang Yuan 
Published: February 2021

Abstract
Acid coagulation is the most common process in nature rubber(NR) processing and the acid concentration in latex is a key factor that will decide the quality of processed rubber. In order to invalid the change of PH value processed with acid concentration on latex clots, a group division experiment is designed to obtain the data of PH value, smell and color in latex clots under different solidification time, mode, and temperature. Then a multiple regression model based on Statistical Product and Service Solutions (SPSS) is used to analyse and predicate the PH value in different conditions. The result shows that predication method can have a good result and the average relative error of PH value is 4.60%.
Ultrasonic manipulation of cells for alleviating the clogging of extrusion-based bioprinting nozzles
Authors: Shao M H , Cui B , Zheng T F , Wang C H 
Published: February 2021

Abstract
Extrusion-based bioprinting is one of the most common biomanufacturing methods. The bioink composed of biomaterials and living cells is extruded into cylindrical filaments. The filaments are deposited on the substrate and stacked layer by layer to form a three-dimensional structure. During the extrusion process, the ink tends to accumulate at the nozzle, which clogs the nozzle and increases extrusion pressure, resulting in the decrease of cell survival rate. Here, we propose a method of using ultrasound to manipulate cells to assist the bioprinting process, which can alleviate nozzle clogging. The ceramic piezoelectric plate(PZT) is used to drive the nozzle to generate structural resonance, and the ultrasonic standing wave generated by the vibration make the cells/particles in the ink gather at the center of the nozzle, thereby reducing the risk of clogging of the nozzle. In this paper, we first analyze the mechanism of the standing wave generated in the cylindrical elastic nozzle and drive the cells to move under the PZT drive, and then use the finite element software to simulate the standing wave drive process. The results show that this method can be solved by a simple and low-cost device. The results indicate that this method has the possibility of using simple and low-cost equipment to solve the problem of nozzle clogging in bioprinting.
Casting process of gate valve steel based on ProCAST simulation
Authors: Qin Shanpeng , Lv Peng , Li Sirun , Li Yongcun 
Published: February 2021

Abstract
The sand casting process of 18CrNiMo7-6 gate valve casting was designed in this paper. The molding and core making methods of castings are sodium silicate CO2 method and self hardening cold box method respectively. The technological parameters of the casting were determined. The middle pouring system and top riser were designed. Using software to draw the assembly and 3D entity of gate valve casting. ProCAST simulation software is used to realize the numerical simulation task of the gate valve casting process. Shrinkage and porosity are the main research objects. It is found that the defects mainly appear in the thick part of the casting and the flange through the simulation experiment feedback parameters. In this paper, from the point of view of reducing and avoiding defects, the casting process is improved and improved. Finally, according to the experimental results, S2 (with chill) is determined as the final scheme.
Research and evaluation of the measurement uncertainty with the comparator
Authors: Hu Chang’an , Li Jiangang , Ouyang Hongmei , Luo Shutong , Lv Fei , Cai Dongyan 
Published: February 2021

Abstract
As a kind of portable three-coordinate, the comparator is playing an more and more important role in precision industry measurement. Therefore, it is of great scientific significance and obvious socioeconomic benefits to carry out the research of comparator. This paper was based on rich experience with the institute in the field of the geometric measurement technology for a long time. And the measurement uncertainty of the instrument has been researched. The uncertainty of the diameter indication error is U=1.2μm k=2, the uncertainty of roundness indication error is U=1.4μm k=2, the uncertainty of sphere-center distance error is U=1.5μm+7.2×10−6
L k=2 L:m, and the uncertainty of length indication error is U=1.2μm+1.5×10−6
L k=2 L:m.
Research on 3D Printing layered Algorithm based on FDM Technology
Authors: Jia Hongwei , Xu Wei 
Published: February 2021

Abstract
Fused deposition forming (FDM) is the most mature 3D printing technology, which has been widely used in many fields of our daily life, science and technology, and economic development.In the molding process of the model, how to choose the appropriate layering method has become the key point to improve the precision and efficiency of 3D printing. Based on adaptive layered algorithm was studied, using three-dimensional modeling software of entity modeling, the introduction of the z axis curve contour curve is determined, and then segment, find out each section contour tangent to the curve, calculated the contour tangent with the model the Angle between the positive direction, an analysis model of layer thickness;The lamination thickness of the model is calculated by using probability statistics, summation superposition and other mathematical methods.Practice has proved that the adaptive layering method is clear in process and simple in calculation, which reduces the workload of layering to a certain extent and improves the precision and efficiency of 3D printing molding.
Simulation Analysis of Influencing Factors of High Pressure Phase Transformation in Single Crystal Germanium Ductile Cutting
Authors: long Bi Jiao , Shi Guang feng , Jiang Fei , Shi Guo quan , Xia Ming qiang 
Published: February 2021

Abstract
The high-pressure phase Ge-II of germanium has similar metal cutting characteristics. In single-point diamond turning, in order to maximize the high phase transition zone of germanium, that is easily to make ductile cutting realized. The single factor test method is used to simulate the ultra-precision turning process under different machining process parameters and tool geometric parameters. Through the calculation of the area of the high-pressure phase change zone in the simulation results and the description of the cutting temperature change law, the influence law of different process parameters and tool geometry parameters on the evolution of the phase change zone is obtained, which provides a useful reference for the choice of turning test parameters.
A Flexible Resistive Strain Sensor Based on Mixed Carbon Nanomaterials
Authors: Chen Yucheng , Zhang Peng , Zhang Jian , Huang Liangsong 
Published: February 2021

Abstract
With the development of flexible electronic technology, flexible strain sensors are playing an increasingly important role in human motion detection and medical health. It is still an important research topic to consider the sensitivity and stability of flexible strain sensors in practical applications. This work describes a new type of flexible resistive strain sensor that uses a new and simple method to embed sensitive materials on the surface of a flexible substrate. The flexible strain sensor has both excellent stability and good flexibility. The sensor has a gauge factor of 5.875 in the strain range of 0-5%, and a gauge factor of 4.252 in the strain range of 10%-120%. The sensor remains stable over 1000 repetitions. The sensor can be used to detect human movements, including large-scale movements of human limbs and small-scale bending of finger joints. Because of its simple manufacturing process and excellent characteristics, it has shown great potential in medical health and smart wearable devices.
Design and Analysis on Mixed Line Welding Fixture for Light vehicle
Authors: Shu-guang SUN , Meng WANG 
Published: February 2021

Abstract
The existing welding has some defects that can only be used for a single type of vehicle body and cannot apply to mixed line welding for several vehicle types. According to the structure characteristics and normalization design requirements of body welding fixture, the existing four light vehicle body structure parameters, clamping fixture and welding process requirements are analysed, so that a modular fixture which is suitable for four kinds of light vehicle body with mixed line repair welding is designed, which includes flexible clamp concrete, pressure control system, the single-chip microcomputer control, and mixed line of three kinds of switch control method.
The natural properties analysis of a power turret gear system based on the varying mesh stiffness
Authors: Xu Lijiao , Zhou Pan , Zang Liguo 
Published: February 2021

Abstract
As the time-varying contact stiffness is one of the most important nonlinear factors, which not only has great influence on dynamic properties, but also on the natural properties. In this paper, the natural properties of a power turret gear system were studied based on varying stiffness. The influence was concluded by natural frequencies.
Ultrasound-assisted 3D printing platform and method capable of flexibly adjusting layer thickness and rotation angle
Authors: Wang Z Y , Cui B , Zheng T F 
Published: February 2021

Abstract
The technology of arranging particles by ultrasound has matured. In recent years, this technology has been used as a basis for arranging particles in a photocurable resin for stereolithography (SL). In order to process the resin doped with particles to obtain a variety of particle arrangement patterns, most of the previous work chose to use different polygonal containers to obtain single-layer fiber angles. In this adjustment mode, the selectivity of the fiber angle is very poor, usually 45°, 90° and other common angles. In this work, we designed and manufactured a new ultrasound-assisted 3D printing platform that can flexibly adjust the thickness of the sandwich and the rotation angle of the sandwich. We will introduce the basic working principle and matching usage of the device, and show some basic print samples.
A simple way to achieve black-and-white designs in topology optimization
Authors: Xing Jian , Qie Longfei 
Published: February 2021

Abstract
In order to obtain crisp black-and-white designs, it is vital to use filtering techniques in density-based topology optimization. However, the applying of filters result in a large number of gray transition zones between the solid and void phases in the final designs. To solve this problem, a dynamic parameter tuning method is proposed in this paper. With the approach, the filter radius can be dynamically adjusted during the optimization process, thereby suppressing the gray elements in the final designs. The proposed method is tested by the classic MBB beam problems. The experimental results show that the proposed method can effectively inhibit the appearance of gray transition areas in the optimization results.
Numerical research on the effect of aircraft leading-edge curvature on bird strike resistance
Authors: Su K , Bai R X , Bai H S 
Published: February 2021

Abstract
With development of aviation industry, bird strike becomes great threat to flight safety. Numerical study has attracted widely attention due to high-cost experimental test. In this paper, Smooth Particle Hydrodynamic (SPH) couple with Lagrangian method is taken to study on the effect of both material and aircraft leading-edge curvature on bird strike resistance. Simulation result shows that fiber-metal material structure can offer greater impacting stiffness than aviation aluminum alloy materials. Besides, appropriate reduction of the curvature radius on the top of skin of leading-edge is beneficial to improve the structural stiffness, however, when curvature radius is too small, the impact resistance of the structure becomes worse due to matrix damage of material. The work in this paper may provide reference for the design of leading-edge structure.
Research on wheat modeling method based on EDEM
Authors: Chen Song , Cao Shukun , Gao KuiZeng , Cao WenLong , Cui Shoubo , Ma Jianzhong 
Published: February 2021

Abstract
Based on the actual shape of the wheat, the size of 50 wheat grains was measured, and the average value was used to construct a three-dimensional map. Then, the sphere of 0.2mm is filled automatically in the API of discrete element software, and the model is compared with the filling model included in the software. The method of bottomless cylinder stacking angle is used to simulate and compare with the actual experiment. The results show that, compared with the actual test results, the error of API automatic filling model and manual filling model is 3.08% and 14.00% respectively. This result proves that the model of API automatic filling is closer to the wheat grain in real life.
Optimal design of structure parameters of coaxial powder feeding nozzle for laser cladding
Authors: Su Peng , Li Hu , Yang Jianyu , Huang Dong 
Published: February 2021

Abstract
Aiming at the problems of large powder gathering diameter, low powder utilization rate, easy clogging of the nozzle, poor cooling water system effect and unstable powder feeding effect existing in the existing nozzles, an improved laser cladding coaxial powder feeding nozzle with external shielding gas structure is optimally designed. The response surface method and the BP neural network optimized by genetic algorithm are used to optimize the nozzle structure parameter combination. After the nozzle structure parameter combination is determined, the external shielding gas structure parameter range is determined according to the nozzle structure parameter combination. The unsupported laser cladding coaxial powder feeding nozzle is made of photosensitive resin material, and the powder feeding effect is verified. The optimized nozzle is measured for the powder converging point, powder converging diameter and powder utilization rate, which verifies the validity of the simulation results.
Solutal convection in a horizontal porous layer with clogging at a high solute concentration
Authors: Maryshev Boris S , Klimenko Lyudmila S 
Published: February 2021

Abstract
The authors study the transport of solute particles in a horizontal layer of a porous medium taking into account the clogging process for a wide range of solute concentrations. On the basis of the most popular and experimentally confirmed MIM model with saturation of the immobile phase, a closed equation system describing such transport is derived. The concentration dependence of porosity is described within the Kozeny-Carman model. The criteria for the transition to the popular model of weak clogging, when the solute concentration is significantly lower than the porosity of the medium, are considered. It is shown that the basic state for the model does not correspond to the classical linear distribution of mobile solute. The convective instability of horizontal seepage with respect to two dimensional perturbations is studied. The critical curves in the space of problem parameters are obtained.
Wave-like concentration profiles of a diamagnetic admixture in a cholesteric liquid crystal
Authors: Sokolchik D P , Makarov D V 
Published: February 2021

Abstract
The behavior of the orientation structure of a suspension of diamagnetic particles based on a cholesteric liquid crystal in an external magnetic field is theoretically studied. The effects of magnetic segregation and rigid homeotropic coupling between the liquid crystal matrix and admixture diamagnetic particles are taken into account. Within the framework of the continuum approach, a system of equations for the orientation equilibrium of the suspension was obtained using standard variational procedures. In the limit of weak magnetic fields, analytical dependences describing the behavior of the director vector field and the distribution of the admixture concentration along the suspension helix are obtained. A significant influence of the anisotropy parameter of the diamagnetic susceptibility subsystems on the wave-like concentration profiles in the suspension was revealed.
Numerical investigation of double-diffusive convection at vibrations
Authors: Kozlov Nikolai 
Published: February 2021

Abstract
The problem of convection in a rectangular vertical cell, located in the gravity field and under the action of high-frequency vertical vibrations, is solved using the direct numerical simulation. At the initial moment of time, the system is formed by two horizontal layers of miscible liquids: the lower (heavy) layer is an aqueous solution of sodium chloride, while the upper one is a sugar solution. A two-dimensional formulation is considered; ANSYS Fluent software package is used as a solver. The impermeability and no-slip conditions are satisfied at the cell boundaries. As a result of the difference in the diffusion coefficients of dissolved species, layers with unstable stratification are formed over time near the contact zone. This leads to the onset of convection in the form of thin ascending and descending fingers. The vibrations, on average, lead to a decrease in the growth rate of fingers and the velocity of convection. In the case of relatively high vibrational overloads, a more regular convective structure forms in the diffusion layer leading to a more pronounced mixing of fluids.
Experimental and numerical study of acoustic pressure distribution in a sonochemical reactor
Authors: Kuchinskiy M O , Lyubimova T P , Rybkin K A , Fattalov O O , Klimenko L S 
Published: February 2021

Abstract
In this work, it is shown numerically in COMSOL Multiphysics and experimentally that a change in the NaCl concentration in water significantly affects the distribution of acoustic pressure in a laboratory sonochemical reactor. Thus, in distilled water under the action of ultrasound, two areas of increased pressure were ob-served, one of which was located directly above the ultrasound source, and the second was near the surface of the liquid, this effect is associated with the reflection of sound waves from the surface of the liquid. With the increase in the salt content, the maximum value of the acoustic pressure in the liquid decreases, which is associated with the dependence of the acoustic impedance of the liquid on the salt concentration and the peculiarities of the dynamics of vapor-gas bubbles in such solutions.
Oscillatory dynamics of two liquids interface in straight narrow gap
Authors: Vlasova O , Kozlov V 
Published: February 2021

Abstract
Oscillatory dynamics of the liquid-liquid interface in a straight slot channel is studied experimentally. We use fluids with a large difference in viscosity and similar densities. The experimental conditions are chosen in such a way that the oscillating motion of a low-viscosity liquid is inviscid, and the oscillating motion of viscous liquid obeys Darcy’s law. At the beginning of the experiment, the interface is oriented perpendicular to the channel axis. It is found that the interface takes a shape of a symmetric hill curved towards a viscous liquid under liquid oscillations. The equilibrium interface shape (the hill height) is determined by the amplitude of the interface oscillations.
Gravity level influence on the onset and nonlinear regimes of a binary mixture convection in rectangular cavity heated from below
Authors: Rushinskaya K S , Lyubimova T P , Zubova N A 
Published: February 2021

Abstract
In this paper we present the results of numerical simulation of nonlinear convection regimes of a NaCl aqueous solution heated from below. The calculations are carried out for square and horizontally elongated rectangular cavities, both in the approximation of a constant thermal diffusion coefficient and in case of taking into account its temperature dependence. Other transport coefficients are considered as constant. We observe the local and integral characteristics of the realized flows at constant and variable thermal diffusion coefficients in the conditions of the Earth and reduced gravity.
Modeling optoelectronic converting structures using the ZEMAX software package
Authors: Bushuev A. S , Zolotov A. N , Firsov I. V , Efremov I. M 
Published: February 2021

Abstract
The paper is devoted to the study of the possibility of constructing a digital conversion on new optoelectronic principles that will expand the frequency range of the conversion, as well as increase the bit conversion, thereby improving accuracy. The basic configuration options of radiating elements in digital-to-analog conversion systems are considered. Simulation was carried out using the ZEMAX software package. The dependence of the conversion of an input digital signal into an analog signal at a photodetector is investigated.
Forming microstructures of certain transparency on thin titanium films by laser thermochemical method
Authors: Nguyen Q.D. , Shakhno E.A. , Sinev D.A. , Zakoldaev R.A. , Veiko V.P. 
Published: February 2021

Abstract
Controllable transparency level is the key parameter for production of the grayscale masks for the aims of submicron photolithography. In this work, we have developed an analytical model to predict transparency dependencies of the irradiated areas on thin titanium films during laser oxidative treatment. This allows controlling final optical properties of submicron recorded areas by tuning the parameters of laser fluences, initial film thicknesses, and laser wavelengths in the wide ranges. Modelling results were confirmed by experimental investigation and can be used to optimize the recording process by the preliminary planning the required levels of transparency and necessary laser treatment parameters.
Tunable near infrared laser
Authors: Putilov A.G. , Antipov A.A. , Shepelev A.E. , Arakelian S.M. 
Published: February 2021

Abstract
The article introduces a tunable NIR laser. The tuning process realizes by the dispersion elements placed inside the resonator. Energy parameters depending on the laser operating mode are presented. The possibility of smooth tuning of the fundamental lasing wavelength depending on the rotation parameters of the dispersion element is shown.
Ablative laser processing of titanium surface in n-hexane
Authors: Kochuev D.A. , Chkalov R.V. , Chkalova D.G. 
Published: February 2021

Abstract
The work is devoted to the problem of high-spherical powders synthesis by the method of laser ablation processing of refractory metals. An investigation of interaction of ultrashort laser pulses with titanium in an n-hexane medium has been carried out. The dependence of granules size and dispersion of synthesized micro- and nanoparticles on the parameters and processing conditions, namely, laser radiation energy, scanning speed, working medium and pressure is shown.