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Wyszukujesz frazę "Zhang, He" wg kryterium: Autor


Tytuł:
A mechanism reliability analysis method considering environmental influence and failure modes’ correlation : a case study of rifle automaton
Autorzy:
Fang, Yi-chuan
Wang, Yong-juan
Sha, Jin-long
Gu, Tong-guang
Zhang, He
Powiązania:
https://bibliotekanauki.pl/articles/24200826.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
mechanism reliability
environmental influence
failure modes’ correlation
copula function
Kaplan-Meier estimation
rifle automaton
Opis:
In order to overcome the challenge of quantifying the influence of environmental conditions and the coexistence of multiple failure modes involved in mechanism reliability modelling under different environments. In this paper, we propose a method for the analysis of mechanism reliability that takes into account the influence of environmental factors and failure modes’ correlation, quantifies the influence of environmental factors as the random distribution and degradation path of parameters, and derives the Copula description of failure mode correlation from the historical data of environmental experiments. On the basis of the discrete mechanism dynamics model, the output parameters of the characteristic points are calculated, and the failure rate of each failure mode is calculated based on the failure criterion and the performance margin theory. Additionally, the dynamic change pattern of the mechanism reliability is compared with the Kaplan-Meier estimation of the corresponding environmental test history data to assess the validity of the calculation results. The reliability modelling problem of a motion mechanism of an automatic rifle automaton in a high and low temperature environment is applied to the method, and the reliability calculation results are close to those of Kaplan-Meier estimation of the test history data, and all are within the upper and lower bounds given by the reliability boundary theory, demonstrating the method's validity.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 2; art. no. 166145
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternating current calibration method for Helmholtz coil constant based on orthogonal calculation principle
Autorzy:
Zhang, Kuankuan
Cao, Mingxing
He, Jian
Gong, Wenjie
Huang, Yunhua
Powiązania:
https://bibliotekanauki.pl/articles/27311758.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Helmholtz coils constant
alternating current method
induction voltage
orthogonal calculations
Opis:
The Helmholtz coil constant (ℎ) is a crucial standard in magnetic moment measurement devices for permanent magnet materials. To overcome the problem of low accuracy of the direct-current (DC) calibration method, this study used a constant sinusoidal current in the Helmholtz coil and measured the induced voltage of the detection coil with known coil turns and coil area. Subsequently, the ℎ was calculated. The noise signal deduction rate in the induction voltage of the detection coil was greater than 99%, its influence on the induction voltage is less than 0.005%, and the repeatability of the calibration results is 0.003% (1). The results reveal that the alternating current (AC) method and orthogonal calculation (OC) can accurately measure the valid values of the voltage signal under the influence of the spatial stray field during the calibration of ℎ.
Źródło:
Metrology and Measurement Systems; 2023, 30, 3; 549--561
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of ecological restoration patterns on runoff and sediment in an abandoned coal mine of Southern China
Autorzy:
Li, Hao
Chen, Wenbo
Zhang, Cheng
He, Lei
Liang, Haifen
Li, Haifeng
Liu, Dingpu
Powiązania:
https://bibliotekanauki.pl/articles/28407391.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
citrus fruit
soil conservation
vegetation
Jiangxi Province
ecological restoration
coal mine
owoce cytrusowe
ochrona gleby
wegetacja
Prowincja Jiangxi
renowacja ekologiczna
kopalnia węgla
Opis:
Evaluating the ecological economic benefits of different ecological restoration patterns in abandoned mines is important in ecological restoration study. Taking the abandoned coal mine in Luoshi Township of Fengcheng county, Jiangxi province, as a case, 4 different ecological restoration patterns (grapefruit with grass vegetation – Pattern I, pine with grass vegetation – Pattern II, grapefruit – Pattern III, and bare slope – Pattern IV) have been conducted to study the runoff and sediment yield under natural rainfall conditions. The results showed that the ecological restoration patterns and rainfall intensity can significantly affect runoff and sediment yield which increased as rainfall intensity increased: Pattern IV > Pattern III > Pattern II > Pattern I. For the optimal ecological restoration with Pattern I, the average runoff and sediment reduction was 59.01 and 77.1%, respectively, in all rainfall intensities. Multivariate analysis of variance (MANOVA) showed that runoff and sediment were significantly affected by ecological restoration pattern and rainfall intensity (P < 0.05). Correlation analysis of runoff and sediment yields indicated that the reduction effect on sediment yield increased with the decrease of runoff, and the relationships between runoff and sediment at different ecological restoration patterns could be fitted with a linear function. Moreover, the vegetation configuration that combines fruit farming with grass can be not only beneficial to control soil and water conservation but produce considerable economic and ecological benefits.
Źródło:
Environment Protection Engineering; 2023, 49, 4; 29--44
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of the nonlinear behaviour of deep-sea mooring polyester fibre ropes
Autorzy:
Zhang, He
Zeng, Ji
Jin, Bowen
Chou, Chiate
Li, Hangyu
Dong, Hailei
Powiązania:
https://bibliotekanauki.pl/articles/34611198.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
polyester fibre ropes
static stiffness
creep coefficient
long-term cyclic loads
dynamic stiffness
Opis:
Mooring ropes are essential components of ships and offshore floating structures and they are subjected to cyclic axial loads. This study investigates the evolution of the full-cycle stiffness of fibre polyester ropes under long-term static and dynamic loading. First, the static stiffness characteristics of the ropes, including the rope elongation properties at different stages, shrinkage rates, and creep coefficients after an idle period, are examined under static loads; an empirical formula for static stiffness is established. Second, the dynamic stiffness characteristics of the ropes are investigated under cyclic loads that are typical of platform production operations. The stabilities of the structure under different tensions are compared; the effects of mean tension, tension amplitude, and load cycle on the dynamic stiffness of the ropes are analysed and an empirical formula is established to predict the dynamic stiffness during the engineering design phase. The results of this study can be helpful for the rational design of deep-sea taut-leg mooring systems because they present the evolution of the full-cycle stiffness characteristics of mooring ropes.
Źródło:
Polish Maritime Research; 2023, 3; 153-162
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frequency control of voltage sourced converter-based multi-terminal direct current interconnected system based on virtual synchronous generator
Autorzy:
Li, Congshan
Zhang, Xiaowei
He, Ping
Zhen, Zikai
Zhao, Kefeng
Powiązania:
https://bibliotekanauki.pl/articles/27309962.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
adaptive droop control
power margin
VSG
virtual synchronous generator
Opis:
In response to the inability of the flexible DC transmission system connected to the AC grid under conventional control strategies to provide inertia to the system as well as to participate in frequency regulation, a virtual synchronous generator (VSG) control strategy is proposed for a voltage source converter (VSC)-based multi-terminal high-voltage direct current (VSC-MTDC) interconnection system. First, the virtual controller module is designed by coupling AC frequency and active power through virtual inertia control, so that the VSC-MTDC system can provide inertia response for AC grid frequency. Second, by introducing the power margin of the converter station into the droop coefficient, the unbalanced power on the DC side is reasonably allocated to reduce the overshoot of the DC voltage in the regulation process. Finally, the power regulation capability of the normal AC system is used to provide power support to the fault end system, reducing frequency deviations and enabling inter-regional resource complementation. The simulation model of the three-terminal flexible DC grid is built in PSCAD/EMTDC, and the effectiveness of the proposed control strategy is verified by comparing the conventional control strategy and the additional frequency control strategy.
Źródło:
Archives of Electrical Engineering; 2023, 72, 4; 971--986
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on optimization method of flotation kinetic model based on molybdenite particle size effect
Autorzy:
Wan, He
An, Yanni
Qu, Juanping
Zhang, Chonghui
Xue, Jiwei
Wang, Sen
Bu, Xianzhong
Powiązania:
https://bibliotekanauki.pl/articles/24085892.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle size effect
molybdenite
mathematical model
method of correction
Opis:
Flotation kinetic models can be applied to describe the flotation process and to predict mineral recoveries. However, the size composition of the target minerals in the feed ore fluctuates considerably, resulting in insufficient accuracy with flotation kinetic models. There have been many studies that focus on the investigation of flotation kinetics with different particle sizes, while the optimization methods for flotation kinetic models based on particle size effects have not been reported. In this paper, flotation tests, optical microscope observations, and particle size analysis were used to identify the reasons for the decrease in accuracy of the flotation kinetic model due to changes in the composition of molybdenite particle size. Additionally, an optimization method for the flotation kinetic model was developed based on the particle size effect. The test results show that the accuracy of the flotation kinetic model for fixed particle size minerals is very high, but the predicted results for flotation recoveries of different particle size mineral mixtures have large deviations. The poor accuracy might be due to the autogenous carrier effect caused by the particle size composition fluctuating considerably. The optimization method for the flotation kinetic model is based on the particle size effect. The model can accurately describe the flotation process of molybdenite with different size compositions of molybdenite and predict the flotation recovery of molybdenite.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 163004
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comprehensive Analysis of Metal Deformation Law Based on Numerical Simulation of Cold Rolling Process
Autorzy:
Yan, Zhu-Wen
Wang, Bao-Sheng
Bu, He-Nan
Li, Hao
Hong, Lei
Zhang, Dian-Hua
Powiązania:
https://bibliotekanauki.pl/articles/2106570.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
3D elastic-plastic FEM
work roll deflection
lateral thickness
flatness regulation effect
rolling pressure
Opis:
Through taking the cold rolling process as the research object, the three-dimensional finite element model of the strip rolling process is established by using ANSYS/LS-DYNA software. The actual rolling product data has strong consistency with the finite element simulation results. The rolling process is dynamically simulated, and the distribution curves of important rolling parameters such as equivalent stress, control efficiency coefficient, transverse rolling pressure, lateral thickness and work roll deflection is obtained. Based on summarizing the influence of rolling parameters on rolling deformation, the research results of this paper can play an important role in the actual rolling process control. The research results have certain guiding significance for the development and optimization of the rolling control system.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 2; 623--635
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Drying shrinkage and creep properties of self-compacting concrete with expansive agent and viscosity modified admixture
Autorzy:
Liu, He
Duan, Guangchao
Zhang, Jingyi
Powiązania:
https://bibliotekanauki.pl/articles/2174047.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beton samozagęszczalny
środek ekspansywny
UEA
domieszka o zmodyfikowanej lepkości
pełzanie
skurcz suszenia
self-compacting concrete
expansive agent
viscosity modified admixture
creep
drying shrinkage
Opis:
Self-Compacting Concrete (SCC) has been widely used in the filling layer of high-speed railways. The quality of the filling layer directly affects the durability, comfort, and safety of the track system. In this study, shrinkage characteristics and the creep behavior of SCC were investigated by compressive creep tests and shrinkage tests. They were performed on specimens with different loading levels with a calcium sulfoaluminate-based expansive agent (UEA) and viscosity modified admixture (VMA). Furthermore, based on the scanning electron microscope (SEM) morphology of hydration products and X-ray diffraction (XRD) analysis, the influence of admixtures on microstructure and mineral phases of SCC was analyzed.The results show that when concretes were loaded with the same stress level, the main factor influencing creep of SCC was the quantity and microstructure of amorphism and hydration crystal. The XRD and SEM result showed that UEA andVMAmake the creep and shrinkage of SCC reduce obviously as the cementitious system grow many crystals in hydration products. The creep of NC was less than SCC with identical compressive strength. At the same time, the addition of UEA can improve the ability to resist drying shrinkage.
Źródło:
Archives of Civil Engineering; 2022, 68, 3; 539--551
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the oxygen-containing functional group on the adsorption of hydrocarbon oily collectors on coal surfaces
Autorzy:
Wan, He
Hu, Xianglin
Luukkanen, Saija
Qu, Juanping
Zhang, Chonghui
Xue, Jiwei
Li, Hui
Yang, Wei
Yang, Shenghong
Bu, Xianzhong
Powiązania:
https://bibliotekanauki.pl/articles/2146920.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
oxygen-containing functional groups
hydrocarbon oily collectors
molecular dynamics simulation
coal surfaces
adsorption
Opis:
The oxygen-containing functional groups (OCFG) on the coal surface affect the adsorption effect of hydrocarbon oily collectors (HOC). An investigation of the interaction between the HOC and OCFG in the absence and presence of water is conducive to understanding the effect of OCFG type on the adsorption of HOC on the coal surface. In this paper, FTIR analysis was used to analyze the OCFG type of coal surface. The adsorption behavior of HOC on different OCFG surfaces was investigated using molecular dynamics simulation. The results indicated the presence of OCFG such as -OH, -COOH, -C=O, and -COCH3 on the coal surface. In conditions without water, the effect of OCFG on HOC adsorption capability follows the order -COOH > -C=O > -OH > -COCH3. In an aqueous solution, the effect of OCFG on HOC adsorption capability follows the order -C=O>-COCH3>-OH>-COOH. Moreover, the hydrophilicity of OCFG is the key factor that affects the adsorption effect of HOC. In other words, the adsorption effect of HOC on the coal surface in an aqueous solution does not depend on the strength of the interaction between the OCFG and HOC in the absence of water, but on the hydrophilicity of the OCFG. The -COOH and -OH on the coal surface are not conducive to the adsorption of HOC onto the coal surface. Masking the -COOH and -OH of the coal surface is beneficial in improving the coal flotation performance with HOC as a collector.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 149937
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exposure to particulate matter 2.5 leading to lung microbiome disorder and the alleviation effect of Auricularia auricular-judae polysaccharide
Autorzy:
Zhang, Yanshu
He, Bin
Wu, Lei
Mi, Xiaoyi
Zhang, Lijin
Li, Shuang
Wang, Jian
Yu, Xiaoyu
Powiązania:
https://bibliotekanauki.pl/articles/2152971.pdf
Data publikacji:
2022
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
PM 2.5
inflammatory damage
lung injury
BALF
microbiome disorder
AAP
Opis:
Objectives The aim of the paper is to explore the role of lung microbiome disorder in lung tissue injury induced by exposure to particulate matter with a maximum diameter of 2.5 μm (PM2.5) and the alleviation effect of auricularia auricular-judae polysaccharide (AAP). Material and Methods Sprague Dawley rats were given PM2.5 suspension at a dose of 20 mg/l twice a week for 8 weeks. Then, 100 mg/kg or 200 mg/kg of AAP was administered to the rats after PM2.5 exposure. The bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at the end of the experiment. The BALF was meant to detect changes in lung microbiome by 16S sequences and cluster analysis, with the application of the principal component analysis and the partial least squares discriminant analysis. The levels of interferon-γ (IFN-γ), and interleukin (IL)-4, IL-8, and IL-10 in lung tissue were detected by the enzyme-linked immunosorbent assay method. The pathological changes in lung tissue were observed by hematoxylin and eosin staining. Results After PM2.5 exposure, the alveolar septum was widened, and the structures of alveolar walls were destroyed. There was inflammatory cells infiltration in the alveolar space and the interstitial space. Alpha diversity in BALF showed that the Chao1, ACE, Simpson, and Shannon values were increased, and the lung microbiome analysis revealed that the relative abundance of Firmicutes and Clostridium increased, while the relative abundance of Bacteroidetes and Akkermansia decreased. The contents of IFN-γ and IL-8 in lung tissue increased while the content of IL-10 decreased. After the administration of AAP, the alveolar structure damage was alleviated, and the interstitial hemorrhage, edema, and inflammatory cells infiltration were reduced. The Chao1 and ACE values decreased, and the taxonomic abundance values of Akkermansia were much higher. Simultaneously, the contents of IFN-γ, IL-4, and IL-8 decreased, and the content of IL-10 increased. Conclusions It was found that PM2.5 resulted in lung microbiome disorder, which might lead to the inflammation of lung tissue. It was also revealed that AAP could alleviate the inflammatory damage of lung tissue induced by PM2.5.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2022, 35, 6; 651-664
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free vibration and buckling analysis of composite laminated shells using the refined zigzag theory
Autorzy:
Zhang, Haibo
Gao, Yihang
He, Dan
Yang, Wanli
Powiązania:
https://bibliotekanauki.pl/articles/2104757.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
composite
shell
buckling
free vibration
refined zigzag theory
Opis:
In this study, a new composite laminated shell model is proposed for free vibration and stability analysis based on the refined zigzag theory (RZT). In contrast to the published shell models based on the first-order shear deformation theory (FSDT), piecewise-linear zigzag functions are utilized to provide a more realistic representation of deformation states of a transverse shear-flexible shell. In the present formulation, the governing equations and boundary conditions of composite laminated shells are established by d’Alembert’s principle to obtain natural frequencies and critical buckling loadings. In order to evaluate the effectiveness and performance of the present new model for composite laminated shells, examples of free vibration and buckling analysis are carried out for cylindrical and spherical shells involving different lamination schemes and design parameters. The results are compared with the three dimensional (3D) exact, first-order and some high-order solutions in the literature. Numerical results show that the present model not only has high accuracy but also has superior computational efficiency in comparison with high-order models, such that it may show a great potential in engineering applications.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 435--448
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical trapping forces of focused circular partially coherent beams on Rayleigh particles
Autorzy:
Yu, Chaoqun
Chen, Fuchang
Zeng, Jun
Huang, Cheng
He, Zhimin
Lin, Huichuan
Zhang, Yongtao
Chen, Ziyang
Pu, Jixiong
Powiązania:
https://bibliotekanauki.pl/articles/2172861.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tight focusing
radially polarized
circular partially coherent
spherical aberration
optical trapping force
Opis:
The optical trapping forces of tightly-focused radially polarized circular partially coherent beams on Rayleigh particles are theoretically investigated. Numerical calculations are performed to study the optical trapping forces on Rayleigh particles for different initial coherent length of the incident circular partially coherent beams. The results show that the magnitude of the gradient force decreases with the reduction of the initial coherent length of the focused radially polarized circular partially coherent beams, while the balanced position (i.e., the position where the optical trapping forces becomes zero) stays constant. Moreover, the focused spot gradually elongates along the optical axis with the reduction of the initial coherent length, and the axial gradient force on Rayleigh particles also decreases gradually with the reduction of the intensity gradient in axial direction. As there exists an spherical aberrant in the focusing optical system, the focal spot in the direction of the optical axis becomes trumpet-shaped, and the optical trapping forces on Rayleigh particles change as well.
Źródło:
Optica Applicata; 2022, 52, 4; 575--583
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties of flash roasted products from low-grade refractory iron tailings and improvement method for their magnetic separation index
Autorzy:
Wan, He
Lu, Xianlu
Luukkanen, Saija
Qu, Juanping
Zhang, Chonghui
Chen, Yanxin
Bu, Xianzhong
Powiązania:
https://bibliotekanauki.pl/articles/2175437.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
roasted products
low-grade refractory iron tailings
magnetic separation
MLA
Opis:
The properties of flash-roasted products from low-grade refractory iron tailings (IGRIT) and the improved method for their magnetic separation index were investigated by the MLA, XRD, iron phase analysis, and magnetic separation test. The results show the siderite and hematite in the IGRIT have been converted to magnetic iron after the flash roasting treatment with a time of 3-5 s; magnetic iron in roasted products has a monomeric dissociation of 37.20%, and a 75−100% exposed area of contiguous bodies as rich intergrowth was 29.83%, and that a 32.97 poor intergrowth; moreover, magnetic iron is mainly associated with muscovite and quartz. It is also found that the regrindingmagnetic separation (1500 Oe) treatment of the middling was beneficial to obtain more qualified iron concentrate products. Therefore, roasted products magnetic separation process in the absence/ presence of the middling regrinding-magnetic separation treatment obtains an iron concentrate with 60.10%/ 60.12% iron grade and 72.04%/81.13% iron recovery. The iron concentrate from the magnetic separation process with middling regrinding-magnetic separation can have a 9% higher recovery than the process without middling regrinding-magnetic separation. The work is significant for helping to improve the utilization of IGRIT.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 156725
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rheological properties of paste for self-compacting concrete with admixtures
Autorzy:
Liu, He
Duan, Guangchao
Zhang, Jingyi
Yang, Yanhai
Powiązania:
https://bibliotekanauki.pl/articles/2174035.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beton samozagęszczalny
właściwości reologiczne
zagęszczenie
ścinanie
krytyczne naprężenie ścinające
lepkość minimalna
domieszka
self-compacting concrete
rheologic properties
shear thickening
critical shear stress
minimum viscosity
admixture
Opis:
The paste content in the self-compacting concrete is about 40% in unit volume. The rheological properties of paste directly determine the properties of self-compacting concrete. In this paper, the effect of silica fume (2, 3, 4, and 5%), limestone powder (5, 10 and 15%), and the viscosity modified admixture (2, 3, 4, 5, 6, and 7%) on the rheological properties were investigated. The effect of admixtures on shear thickening response was discussed based on the modified Bingham model. The results indicate that yield stress and plastic viscosity increased with increased silica fume and viscosity modified admixture replacement. The paste’s yield stress increases and then decreases with limestone powder replacement. The critical shear stress and minimum plastic viscosity are improved by silica fume and viscosity modifying admixture. The critical shear stress first increases and decreases as the limestone powder replacement increases. A reduction in the shear thickening response of paste was observed with silica fume and viscosity modified admixture replacement increase.
Źródło:
Archives of Civil Engineering; 2022, 68, 3; 585--599
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specified weight cutting system for irregular solid material based on 3D scanning
Autorzy:
He, Jiadong
Huang, Yafeng
Zang, Xiao
Zhang, Yajun
Powiązania:
https://bibliotekanauki.pl/articles/2173699.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
specified weight
3D scanning
reverse engineering
calculation algorithm
waga określona
skanowanie 3D
inżynieria odwrotna
algorytm obliczeniowy
Opis:
A specified weight-cutting system for irregular solid materials such as rubber is important for industrial engineering. Currently, the workers’ experience is used, which has low accuracy and efficiency. A specified weight cutting system for irregular solid material based on 3D scanning is proposed in this paper, which aims to overcome the inaccuracy and inefficiency of the manual cutting process. Firstly, the surface of the irregular solid material is scanned by a tracking 3D laser scanner, and a triangular mesh file is generated. Secondly, the defects of the 3D model are repaired by reverse engineering, and then the 3D model file of the irregular objects is generated. Finally, the cutting position of the specified weight solid material is calculated by the calculation algorithm in UG software. In short, this research creates a new method for processing data collected by the 3D scanner, by working jointly with multiple devices and software, facilitating the cutting of irregular solid materials with specified weights. Additionally, the system has the advantage of accuracy and efficiency over the experience of workers.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 5; art. no. e143108
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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