scholarly journals Performance Analysis of Natural γ-Ray Coal Seam Thickness Sensor and Its Application in Automatic Adjustment of Shearer’s Arms

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zengfu Yang ◽  
Zengcai Wang ◽  
Ming Yan
Keyword(s):  
Mathematical Model ◽  
Coal Seam ◽  
Seam Thickness ◽  
Mining Machine ◽  
Practical Advantage ◽  
Rock Interface ◽  
Coal Rock ◽  
Coal Seam Thickness ◽  
The Mathematical Model ◽  
The Relationship

The technology of coal-rock interface recognition is the core of realizing the automatic heightening technology of shearer’s rocker. Only by accurately and quickly identifying the interface of coal and rock can we realize the fully automatic control of shearer. As the only one used in the actual detection of coal mining machine drum cutting coal seam after the thickness of the remaining coal seam detection method, natural γ-ray has a very practical advantage. Based on the relationship between the attenuation of the natural γ-ray passing through the coal seam and the thickness of the coal seam, the mathematical model of the attenuation of the natural γ-ray penetrating coal seam is established. By comparing the attenuation intensity of γ-ray with or without brackets, it is verified that the hydraulic girders will absorb some natural γ-rays. Finally, this paper uses the ground simulation experiment and the field experiment to verify the correctness of the mathematical model and finally develop the natural γ-ray seam thickness sensor. The sensor has the function of indicating the thickness of the coal seam, measuring the natural γ-ray intensity, and storing and processing the data.

Study and Application of Seismic Attributes on Coal Seam Thickness Prediction

2011 ◽  
Vol 138-139 ◽  
pp. 492-497
Author(s):  
Chong Hui Suo ◽  
Suo Liang Chang ◽  
Shi Mi Peng ◽  
Ru Tai Duan
Keyword(s):  
Coal Seam ◽  
Seismic Attributes ◽  
Regression Method ◽  
Seam Thickness ◽  
Thickness Prediction ◽  
Single Attribute ◽  
Proportional Relationship ◽  
Nonlinear Regression Method ◽  
Coal Seam Thickness ◽  
The Relationship

Seismic wave contain more information about the sediments. The seismic attributes has some relationship with the coal seam thickness. Through analysis of the wedge-shaped coal seam’s seismic attributes, when the seam thickness is less than the tuning thickness, there is proportional relationship between the amplitude value and seam thickness; while the apparent time difference between the wave peak and trough is not sensitive. When the coal seam thickness is above the tuning thickness, the conclusion is opposite. As a result, it’s difficult to predict the coal seam thickness only by using one single attribute. Therefore, we use the nonlinear-regression method to analyze the relationship between the seam thickness and both attributes, and get a method to predict the coal seam thickness. With the method we predict the coal seam thickness in a coal mine and get a perfect result.

scholarly journals Mathematical model of the cracking process in the coal-rock massif under hydrodynamic impact

2019 ◽  
Vol 109 ◽  
pp. 00111
Author(s):  
Vasyl Vlasenko ◽  
Kateryna Dudlia ◽  
Maryna Kyrychenko
Keyword(s):  
Mathematical Model ◽  
Coal Seam ◽  
Rock Massif ◽  
Inverse Filtering ◽  
Fluid Filtration ◽  
Hydrodynamic Impact ◽  
Coal Rock ◽  
Cracking Process ◽  
Power And Energy ◽  
The Mathematical Model

The physics of hydrodynamic impact (HDI) is in the softening of the coal seam due to the generation of alternation stress in it. Stress is carried out due to injection and discharge of fluid into the coal seam in the filtration mode. The mathematical model of the processes occurring in the coal massif under HDI was developed. The model allows to determine the nature of the coal destruction in forward and inverse filtering of fluid in the massif. Cracking in the process of fluid filtration is achieved while simultaneously fulfilling two criteria: power and energy.

scholarly journals Mechanical Properties of Rock–Coal–Rock Composites at Different Inclined Coal Seam Thicknesses

2022 ◽  
Vol 9 ◽  
Author(s):  
Bo Ma ◽  
Feng Wang ◽  
Hongyang Liu ◽  
Dawei Yin ◽  
Zhiguo Xia
Keyword(s):  
Mechanical Properties ◽  
Coal Seam ◽  
Failure Modes ◽  
Peak Stress ◽  
Confining Pressure ◽  
Seam Thickness ◽  
Peak Strain ◽  
Confining Pressures ◽  
Coal Rock ◽  
Coal Seam Thickness

A comprehensive understanding of the mechanical properties of coal and rock sections is necessary for interpreting the deformation and failure modes of such underground sections and for evaluating the potential dynamic hazards. However, most studies have focused on horizontal coal–rock composites and the mechanical properties of inclined coal–rock composites have not been considered. To explore the influence of different confining pressures and inclined coal seam thicknesses on the mechanical properties and failure characteristics of rock–coal–rock (RCR) composites, a numerical model based on the particle flow code was used to perform simulations on five inclined RCR composites at different confining pressures. The results show that the mechanical properties and failure characteristics of the RCR composites are affected considerably by the inclined coal seam thickness and the confining pressure. (1) When the inclined coal seam thickness is constant, the elasticity modulus of the inclined RCR composite increases nonlinearly with the confining pressure at first, and then remains constant. At the same confining pressure, the elasticity modulus of the inclined RCR composite decreases nonlinearly with the inclined coal seam thickness. (2) When the confining pressure is constant, the peak stress of the inclined RCR composite decreases with the increase of the inclined coal seam thickness. When the inclined coal seam thickness is constant, the peak stress increases with the confining pressure. (3) As the inclined coal seam thickness increases, the peak strain of the inclined RCR composite first decreases rapidly, and then remains constant when there is no confining pressure. When the confining pressure is between 5 and 20 MPa, the peak strain of the inclined RCR composite gradually increases. (4) In the absence of confining pressure, there are few microcracks in the rock at an inclined coal seam thickness of 10 mm, whereas all the other cracks are in the coal section. When the confining pressure ranges between 5 and 20 MPa, the failure modes of the RCR composite can be divided into Y- and X-types.

Temperature Influence on Performance of Oxidation Ponds

1991 ◽  
Vol 24 (5) ◽  
pp. 85-96 ◽  
Author(s):  
Qingliang Zhao ◽  
Zijie Zhang
Keyword(s):  
Mathematical Model ◽  
Temperature Influence ◽  
Field Scale ◽  
Experiment Data ◽  
Computer Technique ◽  
Oxidation Pond ◽  
Optimum Model ◽  
Oxidation Ponds ◽  
The Mathematical Model ◽  
The Relationship

By means of simulated tests of a laboratory–scale oxidation pond model, the relationship between BOD5 and temperature fluctuation was researched. Mathematical modelling for the pond's performance and K1determination were systematically described. The calculation of T–K1–CeCe/Ci) was complex but the problem was solved by utilizing computer technique in the paper, and the mathematical model which could best simulate experiment data was developed. On the basis of experiment results,the concept of plug–ratio–coefficient is also presented. Finally the optimum model recommended here was verified with the field–scale pond data.

scholarly journals Cutting Mechanical Study of Pick Cutting Coal Seams with Coal and Rock Interface

2021 ◽  
Author(s):  
Chenxu Luo ◽  
Junbei Qaio
Keyword(s):  
Compressive Strength ◽  
Coal Seam ◽  
Mechanical Model ◽  
Impact Load ◽  
Strength Analysis ◽  
Strength Condition ◽  
Rock Interface ◽  
Coal Rock ◽  
Rotary Cutting ◽  
Mining Coal

Abstract Shearer provide an effect solution for mining coal, and the cutting performance of pick largely accouts for the ability of a shearer and mining performance. We conducted pick cutting coal experiments in different seam forms on the coal and rock cutting teasted. According to the rotary cutting mechanical model of single pick cutting coal seam, combined with the strength condition of coal seam and coal-rock interface, the rotary cutting mechanical model of pick cutting coal seam with coal-rock interface is established. The stress strain and strength condition of the area in and around the interface are analyzed based on the coal-rock interface crushing theory, which provides basis for further research on the cutting mechanical model of single pick crossing the coal-rock interface. According to the analysis on the ampulitude domain, the phenomenon that force increment between the pick cutting rock and uniform coal seam linearly increases with the increase of compressive strength difference between coal seam and coal-rock interface, and the load fluctuation keep a positive correlation with the compressive strength. Analysis on the signals of the pick cutting coal seam with coal and rock interface at different conditions shows that some basic properties of the cutting load changes over times. In addition, the coal seam with coal-rock interface appears larger impact load and other time-domain characteristics.

scholarly journals METHODS OF FORMULATING AND SOLVING OPTIMIZATION PROBLEMS OF CUTTING LOGS OF LARGE SIZE BY BAR-SAWING METHOD WITH CUTTING OUT ONE BAR AND FIVE PAIRS OF SIDE EDGING BOARDS WITH SUBSEQUENT SAWING LUMBER FOR EDGED BOARDS

2017 ◽  
Vol 7 (1) ◽  
pp. 137-150
Author(s):  
Агапов ◽  
Aleksandr Agapov
Keyword(s):  
Mathematical Model ◽  
Objective Function ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Target Function ◽  
Cross Sectional ◽  
Optimization Task ◽  
Cutting Out ◽  
The Mathematical Model ◽  
The Relationship

For the first time the mathematical model of task optimization for this scheme of cutting logs, including the objective function and six equations of connection. The article discusses Pythagorean area of the logs. Therefore, the target function is represented as the sum of the cross-sectional areas of edging boards. Equation of the relationship represents the relationship of the diameter of the logs in the vertex end with the size of the resulting edging boards. This relationship is described through the use of the Pythagorean Theorem. Such a representation of the mathematical model of optimization task is considered a classic one. However, the solution of this mathematical model by the classic method is proved to be problematic. For the solution of the mathematical model we used the method of Lagrange multipliers. Solution algorithm to determine the optimal dimensions of the beams and side edging boards taking into account the width of cut is suggested. Using a numerical method, optimal dimensions of the beams and planks are determined, in which the objective function takes the maximum value. It turned out that with the increase of the width of the cut, thickness of the beam increases and the dimensions of the side edging boards reduce. Dimensions of the extreme side planks to increase the width of cut is reduced to a greater extent than the side boards, which are located closer to the center of the log. The algorithm for solving the optimization problem is recommended to use for calculation and preparation of sawing schedule in the design and operation of sawmill lines for timber production. When using the proposed algorithm for solving the optimization problem the output of lumber can be increased to 3-5 %.

Walking Stability Analysis of Multi-Legged Crablike Robot over Slope

2013 ◽  
Vol 572 ◽  
pp. 636-639
Author(s):  
Xi Chen ◽  
Gang Wang
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Stability Criterion ◽  
Stability Margin ◽  
Static Stability ◽  
Matlab Simulation ◽  
And Performance ◽  
The Stability ◽  
The Mathematical Model ◽  
The Relationship

This paper deals with the walking stability analysis of a multi-legged crablike robot over slope using normalized energy stability margin (NESM) method in order to develop a common stabilization description method and achieve robust locomotion for the robot over rough terrains. The robot is simplified with its static stability being described by NESM. The mathematical model of static stability margin is built so as to carry out the simulation of walking stability over slope for the crablike robot that walks in double tetrapod gait. As a consequence, the relationship between stability margin and the height of the robots centroid, as well as its inclination relative to the ground is calculated by the stability criterion. The success and performance of the stability criterion proposed is verified through MATLAB simulation and real-world experiments using multi-legged crablike robot.

Estimation of burnt coal seam thickness in central Borneo using JERS-1 SAR data

2003 ◽  
Vol 24 (4) ◽  
pp. 879-884 ◽  
Author(s):  
J. Tetuko S. S. ◽  
R. Tateishi ◽  
N. Takeuchi
Keyword(s):  
Coal Seam ◽  
Seam Thickness ◽  
Sar Data ◽  
Coal Seam Thickness

Design and Implementation of Digital Asthma Diagnosis System

2019 ◽  
Vol 14 (3) ◽  
pp. 1-15
Author(s):  
Qinghua Yao ◽  
Xiantao Yang
Keyword(s):  
Mathematical Model ◽  
Mutation Rate ◽  
Forced Expiratory Volume ◽  
Digital Signals ◽  
Respiratory Parameters ◽  
The Mathematical Model ◽  
The Relationship ◽  
Objective Indicators ◽  
Signal Conditioning Circuit

In this article, the MSP430F149 is the microcontroller (MCU), and a pressure sensor, MPX5100AP, is used to measure body measurement of maximal forced expiratory volume (FEV) and peak expiratory flow rate (PEFR). The two analog signals are processed by the signal conditioning circuit, and then the corresponding digital signals are acquired by the MCU. With the related operations of multiple respiratory parameters, a built-up time of respiration signal mutation rate values and the determination of the mutation rate, a mathematical model is built among FEV, PEFR and the rate of variation. The mathematical model of the system is analyzed, and the relationship between the detection results and the degree of airway obstruction is established. Finally, the patient's condition analysis results are given directly on the LCD, which provided the objective indicators for the medical treatment of the disease.

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