Study and Application on a New Type of Rapid Determination Model of Gas Content

2014 ◽  
Vol 962-965 ◽  
pp. 1201-1204
Author(s):  
Xiao Hua Jin ◽  
Bei Fang Gu ◽  
San Feng Bai ◽  
Xin Yao Guo ◽  
Ming Gang Luo
Keyword(s):  
Linear Regression ◽  
Coal Seam ◽  
Rapid Determination ◽  
Gas Content ◽  
Characteristic Parameters ◽  
Accuracy Rate ◽  
Theoretical Derivation ◽  
Residual Amount ◽  
New Type

Against the problem of calculating gas content rapidly, this article studied the desorption characteristics of coal by measuring the characteristic parameters of coal in the laboratory. With the actually measured amount of desorption and the desorption rule of the coal within the first 30min, through theoretical derivation and Multiple Linear Regression, the gas content desorbs within the first 120min and the residual amount after a 120min of coal desorption is studied and confirmed Based on the rapid determination model of gas content in the coal seam is established, and the new model is verified, whose accuracy rate reaches above 85%. If relevant electronic equipments were made, this method would be able to give a result within 40min, thereby realizing the rapid determination of gas content in the coal seam within the gas belt.

A method of rapid determination of gas pressure in a coal seam based on the advantages of gas spherical flow field

2017 ◽  
Vol 45 ◽  
pp. 502-510 ◽  
Author(s):  
Chaojie Wang ◽  
Shengqiang Yang ◽  
Chenglin Jiang ◽  
Dingding Yang ◽  
Chaojie Zhang ◽  
...  
Keyword(s):  
Flow Field ◽  
Coal Seam ◽  
Rapid Determination ◽  
Gas Pressure

scholarly journals Calculation of permeability coefficient of coal seam under rapid measurement conditions

2019 ◽  
Vol 136 ◽  
pp. 04004
Author(s):  
Manzheng Yang ◽  
Bingrui Li ◽  
Shubo Li
Keyword(s):  
Coal Seam ◽  
Permeability Coefficient ◽  
Integral Transformation ◽  
Gas Permeability ◽  
Rapid Determination ◽  
Flow State ◽  
Time Curve ◽  
Pressure Time ◽  
The Relationship

In order to achieve rapid determination of coal seam permeability, the calculation method of coal seam permeability coefficient was studied. Based on the Darcy's law in the flow of gas in the coal seam, the relationship equation between the gas pressure of the borehole and the gas permeability coefficient of the coal seam is established under the radial unsteady flow state. The gas permeability coefficient of the coal seam is obtained by coordinate transformation and integral transformation. Solve the expression. The analysis and verification of the field measured data show that the expression of the analytical solution of the coal seam permeability coefficient is consistent with the variation of the borehole pressure-time curve, which can provide a theoretical basis for the rapid determination of coal seam permeability.

scholarly journals Estimation of Gas Loss in Methodology for Determining Methane Content of Coal Seams

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 982
Author(s):  
Nikodem Szlązak ◽  
Dariusz Obracaj ◽  
Marek Korzec
Keyword(s):  
Coal Seam ◽  
Coal Sample ◽  
Uniform Method ◽  
Methane Content ◽  
Gas Content ◽  
National Standard ◽  
Desorption Rate ◽  
Coal Seams ◽  
Gas Loss

The determination of natural gas content in coal seams is essential to safe mining activities and to estimate gas resources. It is used to estimate methane emissions into workings, which is very important when using preventive measures of methane ignition and explosion. Methane content in a coal seam is mostly determined using a direct method. However, a problem with estimation of gas loss during collecting a sample in a mine occurs in each method. That gas loss is estimated using different procedures. In the Polish mining industry, methane content in a coal seam is mostly determined during roadway advancing faces in coal seams. The differences in procedures for determining methane content in coal in various laboratories gave rise to starting research into developing a new method. This article presents results of study of gas loss unification for the determination of methane content in coal seams. The research focused mainly on determining a uniform method for estimating gas loss using the early adsorption diffusion process. The method of coal sample saturation with methane was used to measure gas desorption rate. Saturation pressures of samples were determined for coal seams in the Upper-Silesian Coal Basin. The analysis of desorption results allowed to determine the dependence between methane content in a coal sample and the initial methane content in a coal seam. It was concluded that the desorption rate was highest within two minutes. For the procedure of coal sampling, gas loss was determined at 12% of both desorbed and residual gases. The presented research results gave rise to developing a uniform method for determining gas content used in Polish coal mining. The method was accepted as the national standard. Methodology using a new gas loss estimation procedure allows for achieving relatively fast results of the determination of methane content in coal seams, which is very important, especially in gassy mines.

scholarly journals Determination of Gas Content in Low Permeability and High Gas Coal Seam

2019 ◽  
Vol 384 ◽  
pp. 012058
Author(s):  
Jufeng Zhang ◽  
Fengfeng Yang ◽  
Wulin Lei ◽  
Tai Xu ◽  
Chao Zheng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Gas Content ◽  
Low Permeability ◽  
Gas Coal

A Study on the Outburst Threshold Value of Gas Content in Coal

2013 ◽  
Vol 295-298 ◽  
pp. 2855-2858
Author(s):  
Sheng Xue ◽  
Liang Yuan ◽  
Jun Xie ◽  
Yu Cang Wang
Keyword(s):  
Numerical Modelling ◽  
Coal Seam ◽  
Field Measurements ◽  
Threshold Value ◽  
Gas Content ◽  
Field Observations ◽  
Underground Coal Mining ◽  
Made In

An outburst of coal and gas is a major hazard in underground coal mining. It occurs when certain conditions of coal stress, strength and gassiness are met. Based mainly on field observations related to the conditions, a number of indices are used in prediction of the outburst. Some of the indices are considered to be inadequate, inappropriate or impractical in some coal seam conditions. Significant progresses have been made in development of the technologies over the last few years. One of the major achievements is an analytical method in determination of an outburst threshold value of the gas content in a coal seam. The method combines field measurements and numerical modelling. The method is illustrated in this paper in a case study for determination of the outburst threshold value of gas content for a coal seam.

Rapid Determination of Pentose and Hexose Sugars in Mixed Sugars by Multiple Linear Regression Calibration Method

2011 ◽  
Vol 145 ◽  
pp. 159-163
Author(s):  
Xiao Chen Liu ◽  
Ping Wang ◽  
Ying Long He ◽  
Yong Lei Kou ◽  
Biao Zhang ◽  
...  
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Rapid Determination ◽  
Calibration Method ◽  
Linear Regression Method ◽  
Regression Calibration ◽  
Mixed Sugars ◽  
Hexose Sugars ◽  
Pentose Sugar

This research provides an improvement for the method of Douglas to determine pentose and hexose sugars in mixed sugars. Specific absorption wave of 553 nm for pentose derivatives and 408 nm for hexose derivatives are selected for determination, and the interference from pentose sugar to hexose sugar is corrected with multiple linear regression method. The results show that the interference from pentose sugar is reduced greatly after multiple linear regression calibration; the error is lower than 5.0 %. The experimental results show a satisfying precision and accuracy, with a recovery range from 95.1 % to 106.8%. This method is suitable for simultaneously rapid determination of pentose and hexose sugars in practical application.

Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

1976 ◽  
Vol 34 ◽  
pp. 590-591
Author(s):  
T. Y. Tan ◽  
W. K. Tice
Keyword(s):  
Fast Neutron ◽  
Rapid Determination ◽  
Stacking Faults ◽  
Imaging Method ◽  
Large Reduction ◽  
Dislocation Loops ◽  
Fringe Spacing ◽  
Weak Beam ◽  
Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

Trial production of γ-type energy filtering TEM

1995 ◽  
Vol 53 ◽  
pp. 604-605
Author(s):  
Y. Taniguchi ◽  
E. Nakazawa ◽  
S. Taya
Keyword(s):  
Magnetic Energy ◽  
Electron Optics ◽  
Electron Microscopic ◽  
Mass Spectrometers ◽  
Ion Optics ◽  
Energy Filtering ◽  
New Information ◽  
New Type ◽  
Fringing Fields

Imaging energy filters can add new information to electron microscopic images with respect to energy-axis, so-called electron spectroscopic imaging (ESI). Recently, many good results have been reported using this imaging technique. ESI also allows high-contrast observation of unstained biological samples, becoming a trend of the field of morphology. We manufactured a new type of energy filter as a trial production. This energy filter consists of two magnets, and we call γ-filter since the trajectory of electrons shows ‘γ’-shape inside the filter. We evaluated the new energyγ-filter TEM with the γ-filter.Figure 1 shows schematic view of the electron optics of the γ-type energy filter. For the determination of the electron-optics of the γ-type energy filter, we used the TRIO (Third Order Ion Optics) program which has been developed for the design of high resolution mass spectrometers. The TRIO takes the extended fringing fields (EFF) into consideration. EFF makes it difficult to design magnetic energy filters with magnetic sector fields.

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