scholarly journals Investigation on Direct Shear and Energy Dissipation Characteristics of Iron Tailings Powder Reinforced by Polypropylene Fiber

2019 ◽  
Vol 9 (23) ◽  
pp. 5098 ◽  
Author(s):  
Jiang ◽  
Lv ◽  
Wang ◽  
Li ◽  
Wang
Keyword(s):  
Mathematical Model ◽  
Energy Dissipation ◽  
Back Propagation ◽  
Polypropylene Fiber ◽  
Interfacial Strength ◽  
Distribution Model ◽  
Direct Shear ◽  
Test Results ◽  
Effective Measure ◽  
The Mathematical Model

Resource utilization of iron tailings powder is an effective measure to reduce the dam-break risk of an iron tailings reservoir. Adding polypropylene fiber to iron tailings powder can improve its shear performance. Direct shear tests were carried out on reinforced iron tailings powder with polypropylene fiber with dosages of 0%, 0.25%, 0.5%, 0.75%, and 1%, respectively. The normal stresses during the tests were 100, 200, 300, and 400 kPa, respectively. The test results show that with the increase of polypropylene fiber dosage, the cohesive force of iron tailings powder firstly increases and then decreases gradually, and the internal friction angle firstly decreases and then increases. The back propagation (BP)neural network was used to fit the shear force (F) and shear displacement (s) of the test to obtain the F-s function relationship that satisfies the accuracy. Based on the energy dissipation theory, the direct shear energy dissipation of polypropylene-fiber-reinforced iron tailings powder was calculated. The mathematical model of energy dissipation of fiber interfacial failure was derived by the fiber distribution model. The interfacial strength parameters of polypropylene fiber were calculated based on the direct shear test data and the mathematical model of fiber interfacial energy dissipation. The test results show that the addition of polypropylene fiber from the perspective of energy dissipation can improve the shear properties of iron tailings powder.

scholarly journals Shearing Performance of Lime-Reinforced Iron Tailing Powder Based on Energy Dissipation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ping Jiang ◽  
Lingqi Qiu ◽  
Na Li ◽  
Wei Wang ◽  
Aizhao Zhou ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Resource Utilization ◽  
Shear Failure ◽  
Back Propagation ◽  
Direct Shear ◽  
Effective Measure ◽  
Accuracy Requirement ◽  
Direct Shear Tests ◽  
Neural Network Algorithm ◽  
Shear Energy

The resource utilization of iron tailing powder is an effective measure to reduce the risk of tailing stacking. Based on the research findings on lime soil, a method for using lime to strengthen iron tailing powder was proposed. F-s curves and c and φ values of iron tailing powder with 0%, 2%, 4%, 8%, and 10% lime were obtained through direct shear tests. The back propagation (BP) neural network algorithm was used to fit the F-s curve, and the fitting equation that met the accuracy requirement was obtained. Based on the energy dissipation theory, the shear failure energy dissipation of iron tailing powder with different lime doses was achieved in the form of definite integrals under different normal stresses of 100 kPa, 200 kPa, 300 kPa, and 400 kPa, respectively. It was concluded that the addition of lime could increase the shear energy dissipation of iron tailing powder. The shear energy dissipation of iron tailing powder first increased and then decreased with the increase in lime dose. The maximum value was reached with 4% lime, and the energy dissipation increased linearly with increasing normal stress. In this study, the shear performance of lime-reinforced iron tailing powder was studied through the direct shear test combined with the energy dissipation theory, providing a theoretical basis for the resource utilization of iron tailing powder.

scholarly journals Comparison of Mechanical Properties of Fiber-Reinforced Sand under Triaxial Compression and Direct Shear

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Reza Noorzad ◽  
Seyed Taher Ghoreyshi Zarinkolaei
Keyword(s):  
Shear Strength ◽  
Axial Strain ◽  
Triaxial Compression ◽  
Polypropylene Fiber ◽  
Triaxial Tests ◽  
Direct Shear ◽  
Test Results ◽  
Peak Reduction ◽  
Shear Tests ◽  
Direct Shear Tests

AbstractThis research investigates the behavior of sand reinforced with polypropylene fiber. To do this, 40 direct shear tests and 40 triaxial tests were performed on the coastal beaches of Babolsar, a city in the North of Iran. The effect of parameters such as fiber content, length of fiber and normal or confining pressure on the behavior of Babolsar sand have been studied. In this study, four various fiber contents (0, 0.25, 0.5 and 1 percent), three different lengths of fiber (6, 12 and 18 mm) and four normal or confining pressures (50, 100, 200 and 400 kPa) have been employed. The test results show that fiber inclusion has a significant effect on the behavior of sand. In both direct shear and triaxial tests, the addition of fibers improved shear strength parameters (C, '), increased peak shear strength and axial strain at failure, and also limited the amount of post-peak reduction in shear resistance. The comparison of the test results revealed that due to better fiber orientation toward the direction of principal tensile strain in triaxial test as compared to direct shear tests, the fiber efficiency and its effect on soil behavior is much more significant in triaxial specimens.

FPGA-Based Design of P-Detection 1-Persistent CSMA Control System

2014 ◽  
Vol 602-605 ◽  
pp. 933-936 ◽  
Author(s):  
Zheng Gang Liu ◽  
Hong Wei Ding ◽  
Jia Long Xiong ◽  
Qian Lin Liu ◽  
Xiao Hui Ma
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
System Performance ◽  
Communication Protocol ◽  
Test Results ◽  
Fpga Design ◽  
Simulation Results ◽  
Communication Control ◽  
The Mathematical Model ◽  
Waveform Simulation

In this paper, we propose P-detection and 1-Persistent CSMA/CA protocol. Using average cycle method, we established the mathematical model of the protocol. Through derivation, we obtain the throughput expression of this protocol. Simulation results show that this protocol improves the throughput and it is effective to enhance the system performance. Using this protocol, we completed the FPGA design of communication control system in WSN. The product passed waveform simulation and it is downloaded to the DB2 platform. Test results confirm the throughput of system has been increased, achieving the improvement of communication protocol for WSN.

Rotation of Two-Temperature Generalized Thermoelastic Half-Space Subjected to Thermal Shock and Without Energy Dissipation

2017 ◽  
Vol 14 (1) ◽  
pp. 529-535
Author(s):  
Eman A. N Al-Lehaibi
Keyword(s):  
Mathematical Model ◽  
Energy Dissipation ◽  
Mechanical Load ◽  
Generalized Thermoelasticity ◽  
Laplace Transforms ◽  
Temperature Parameter ◽  
Without Energy Dissipation ◽  
The Impact ◽  
The Mathematical Model ◽  
Two Temperature

In this work, a mathematical model for the thermoelastic medium with constant elastic parameters in the context of two-temperature generalized thermoelasticity without energy dissipation has been constructed. The governing equations of the mathematical model will be taken when the medium is quiescent first. Laplace transforms techniques will be used to get the general solution for any set of boundary conditions. The solution will be obtained for a particular model when the medium is subjected to a thermal load by using stat-space approach. The inversion of the Laplace transforms will be calculated numerically and after that we’ll present the results graphically with some comparisons to study the impact of thermal or mechanical load on the speed of progress of mechanical and thermal waves through the medium. Also, to studying the effect of the two-temperature parameter rotation parameter on all the studied field.

scholarly journals Mathematical Modelling of Acetaminophen Release in HPC/PAAm Hydrogel: Synthesis and Application

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Abigail M. Díaz-Guerrero ◽  
Claudia A. Castillo-Miranda ◽  
Carlos F. Castro-Guerrero ◽  
Hernán Peraza-Vázquez ◽  
Ana B. Morales-Cepeda ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Mathematical Modelling ◽  
Phosphate Buffer Solution ◽  
Absolute Error ◽  
Programming Algorithm ◽  
Test Results ◽  
Buffer Solution ◽  
Drug Molecules ◽  
Hydrogel Synthesis ◽  
The Mathematical Model

Hydrogels are commonly used as Drug Delivery Systems (DDS) as patches due to its ability to store drug molecules within their structures. The release can be activated under certain stimuli, such as temperature and pH. In this paper, the mathematical modelling of acetaminophen release in hydroxypropyl cellulose with polyacrylamide (HPC/PAAm) is reported. The HPC/PAAm gel was synthesized in proportions of 25/75 wt% and was characterized by FTIR, DSC, optical microscopy, SEM, and TGA, with and without acetaminophen. The release tests were performed for hypothermic, normal, and febrile human body conditions, at 35, 37, and 39°C, respectively, on two release media: water and phosphate buffer solution. In order to describe the release of acetaminophen in HPC/PAAm gel, a genetic programming algorithm was used to accomplish Multigene Symbolic Regression (MSR). Characterization results showed that the drug was crystallized on the surface of the HPC/PAAm gel. Release test results showed that several simultaneous processes occurred in the acetaminophen diffusion phenomenon. A unique mathematical model was obtained by MSR. This model was able to describe the release of acetaminophen in HPC/PAAm gel with high values of R2 and adjusted R2 and to simulate the drug release at times beyond the end of the experiment. High values of R2 and low values of Coefficient of Variation (CV), Root-Mean-Square Error (RMSE), and Mean Absolute Error (MAE) were obtained from the comparison between the simulated and the experimental data. This allows to conclude that the mathematical model is reliable to represent and simulate the acetaminophen release in HPC/PAAm gel at 35, 37, and 39°C.

Shape and Flatness in Thin Strip Rolling

1972 ◽  
Vol 94 (4) ◽  
pp. 1113-1123 ◽  
Author(s):  
H. W. O’Connor ◽  
A. S. Weinstein
Keyword(s):  
Mathematical Model ◽  
Work Roll ◽  
Thin Strip ◽  
Test Results ◽  
Considerable Influence ◽  
Strip Rolling ◽  
Roll Bending ◽  
Strip Shape ◽  
Mill Stand ◽  
The Mathematical Model

The paper describes measurements of lateral flow of material which took place during cold rolling thin strip. This sideways flow is shown to have a considerable influence of the final flatness of the strip. A mathematical model of a rolling mill stand is described, which includes a calculation allowing for sideways flow of material. Parameter studies are made using the mathematical model, which show the influence of crowns, tensions, back-up and work roll bending on the resultant strip shape. A comparison is made between results predicted by the model and test results obtained on a production mill.

Study on the Electrolysis Expansion of Carbon Cathode in [K3AlF6/Na3AlF6]-AlF3-Al2O3 Low Temperature Melts

2013 ◽  
Vol 749 ◽  
pp. 633-642
Author(s):  
Zhao Fang ◽  
Peng Fei Xu ◽  
Jian Xu ◽  
Lin Bo Li ◽  
Jun Zhu
Keyword(s):  
Mathematical Model ◽  
Low Temperature ◽  
Alkali Metal ◽  
Test Results ◽  
Carbon Cathode ◽  
The Mathematical Model ◽  
Good Agreement

Electrolysis expansion of carbon cathodes due to alkali metal penetration in [K3AlF6/Na3AlF6]-AlF3-Al2O3 melts was tested. Effect of ampere density and superheating temperature on the electrolysis expansion was studied. A mathematical model was got to numerically describe electrolysis expansion performance of carbon cathode. The results indicated that K and Na penetrate into carbon cathode from outside to inside. Ampere density and superheating temperature had a great effect on the electrolysis expansion of carbon cathode. With the superheating temperature increasing from 10 to 50, electrolysis expansion increased from 1.41% to 2.10% gradually. With the ampere density increasing, the increase trend of electrolysis expansion was not linear. When ampere density was lower than 0.4A / cm2 and greater than 0.7A / cm2, cathode electrolysis expansion obviously increased with the increase of ampere density. Meanwhile, cathode electrolysis expansion tended to be constant as the ampere density changed at the range of 0.4A / cm2 to 0.7A / cm2.The results of the mathematical model in this study had a good agreement with the test results. This model would be helpful to accurately describe the anti-penetration performance of K and Na on the carbon cathode.

scholarly journals Mathematical Modeling and Mechanism of VUV Photodegradation of H2S in the Absence of O2

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Jian-hui Xu ◽  
Bin-bin Ding ◽  
Xiao-mei Lv ◽  
Shan-hong Lan ◽  
Chao-lin Li ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Retention Time ◽  
Gas Flow ◽  
Flow Distribution ◽  
Calculation Model ◽  
Point Of View ◽  
Distribution Model ◽  
Balance Model ◽  
Photodegradation Rate ◽  
The Mathematical Model

The existence of H2S has limited the biogas energy promotion. The traditional photodegradation of H2S is usually conducted in the presence of O2, yet this is unsuitable for biogas desulfurization which should be avoided. Therefore, the ultraviolet degradation of H2S in the absence of O2 was investigated for the first time in the present study from a mathematical point of view. Light wavelength and intensity applied were 185 nm and 2.16 × 10−12 Einstein/cm2·s, respectively. Firstly, the mathematical model of H2S photodegradation was established with MATLAB software, including the gas flow distribution model and radiation model of photoreactor, kinetics model, mass balance model, and calculation model of the degradation rate. Then, the influence of the initial H2S concentration and gas retention time on the photodegradation rate were studied, for verification of the mathematical model. Results indicated that the photodegradation rate decreased with the increase in initial H2S concentration, and the maximum photodegradation rate reached 62.8% under initial concentration of 3 mg/m3. In addition, the photodegradation rate of H2S increased with the increase in retention time. The experimental results were in good accordance with the modeling results, indicating the feasibility of the mathematical model to simulate the photodegradation of H2S. Finally, the intermediate products were simulated and results showed that the main photodegradation products were found to be H2 and elemental S, and concentrations of the two main products were close and agreed well with the reaction stoichiometric coefficients. Moreover, the concentration of free radicals of H• and SH• was rather low.

Thermodynamic analysis of the rotary tooth compressor

2002 ◽  
Vol 216 (4) ◽  
pp. 321-327 ◽  
Author(s):  
X Peng ◽  
Z Xing ◽  
L Li ◽  
P Shu
Keyword(s):  
Mathematical Model ◽  
Experimental Test ◽  
Power Loss ◽  
Gas Flow ◽  
Analytical Study ◽  
Test Results ◽  
Gas Leakage ◽  
Efficient Alternative ◽  
The Mathematical Model ◽  
Thermodynamic Processes

The Roots blower has no built-in compression and therefore is not efficient when it discharges gases at pressures substantially higher than at suction. The rotary tooth compressor, which includes built-in compression, has been proposed as a more efficient alternative. This paper describes an analytical study of the rotary tooth compressor. A mathematical model has been constructed to simulate the thermodynamic processes within it and hence predict its performance. The model allows for gas leakage as well as the main gas flow into and out of the working chamber. The estimated performance has been compared with experimental test results. The mathematical model was thereby validated. Further analyses were then carried out, using the validated mathematical model, to determine the magnitude of power and capacity losses in the machine. It is shown that the rotary tooth compressor is more efficient than the Roots blower at pressure ratios greater than about 1.4. Loss in capacity is most affected by gas leakage, and the main cause of loss in adiabatic efficiency is the power loss associated with high gas velocities during discharge.

Study on Computer Simulation for Car Handling Dynamics with 8 DOF

2013 ◽  
Vol 655-657 ◽  
pp. 1136-1140
Author(s):  
Peng Zhang ◽  
Le He ◽  
Xu Tao Liu ◽  
Qun Sheng Xia
Keyword(s):  
Mathematical Model ◽  
Load Transfer ◽  
Normal Load ◽  
Lateral Acceleration ◽  
Test Results ◽  
Double Lane Change ◽  
Vehicle Test ◽  
The Mathematical Model ◽  
Real Vehicle ◽  
Good Agreement

A mathematical model of eight degrees freedom was built up with considering the normal load transfer due to the presence of the longitudinal, lateral acceleration for a vehicle under braking in turn condition. And the simulation model based on the mathematical model was eatablished by means of MATLAB/Simulink software. The comparison between simulation results and real vehicle test results under the snow pavement double-lane change condition is in good agreement. It can be concluded that the 8DOF vehicle dynamics model of this study is acceptable and valid.

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