Study on the Residual Coal Distribution and the Improving Measures

2014 ◽  
Vol 556-562 ◽  
pp. 822-825
Author(s):  
He Bing Luan
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Production System ◽  
Recovery Rate ◽  
Distribution Characteristics ◽  
The Core ◽  
Residual Coal ◽  
Core Problem

The core problem of fully mechanized top-coal caving technology is to accurately grasp residual coal distribution characteristics and improve the recovery rate to the highest possible. Based on the top-caving working site in some coal mine, combined with the numerical simulation on the residual coal in end roadway, the distribution of residual coal is analyzed. Corresponding improvements on the production system have been proved to be efficient for recovering the residual coal.

Effect Analysis of Nitrogen Injection on the Variation of “Oxidation Zone” in Coal Mine Gob Based on Numerical Simulation

2016 ◽  
Vol 9 (1) ◽  
pp. 47-54
Author(s):  
Jing Shen ◽  
Mingran Chang
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Heat Dissipation ◽  
Spontaneous Combustion ◽  
Oxidation Zone ◽  
Effect Analysis ◽  
Mine Fire ◽  
Nitrogen Injection ◽  
The Difference ◽  
Residual Coal

One of the main reasons for coal mine fire is spontaneous combustion of residual coal in gob. As the difference of compaction degree of coal and rock, the underground gob can be considered as a porous medium and divided into “three zones” in accordance with the criteria. The “three zones” are “heat dissipation zone”, “oxidation zone” and “choking zone”, respectively. Temperature programming experiments are taken and numerical simulation with obtained experimental data is utilized to analyze the distribution of “three zones” in this paper. Different width and depth of “oxidation zone” are obtained when the inlet air velocity is changed. As the nitrogen injection has inhibition effect on spontaneous combustion of residual coal in gob, nitrogen is injected into the gob. The widths of “oxidation zone” are compared before and after nitrogen injection. And ultimately the optimum location and volume of nitrogen injection are found out.

scholarly journals Instability Analysis and Reinforcement Support Technology of Coal-Rock Interbed Roadway in Gaojiazhuang Coal Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chaolin Liu ◽  
Guohua Zhang
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Distribution Characteristics ◽  
Control Effect ◽  
Ultrasonic Detection ◽  
Wide Range ◽  
Surrounding Rock Deformation

In order to effectively solve a series of problems such as the difficulty of coal and rock interbed roadway support in Gaojiazhuang Coal Mine and get a scientific and reasonable optimization scheme of surrounding rock support, theoretical analysis, numerical simulation, ultrasonic detection, field-effect test, and other means are adopted to analyze the instability of coal and rock interbed roadway. The results show that the interbedded roadway has weak interbedded cementation, and its ore pressure is more intense due to the influence of its interbedded weak structural plane. Based on Mohr’s strength envelope principle, it is proposed that horizontal stress is the main factor that causes a wide range of shear displacement, penetration crack, and surrounding rock failure of the roof of this kind of roadway. Through the finite element numerical simulation analysis, the deformation and failure law, stress distribution characteristics, and failure area distribution characteristics of coal and rock interbedding roadway surrounding rock are theoretically revealed, and the control effect of different support schemes on roadway surrounding rock deformation is greatly different. Based on the ultrasonic detection technology, it is proved that the roadway side failure has strong zoning characteristics, and the failure range and stress distribution range of the surrounding rock of the belt roadway in the 2103 working face of Gaojiazhuang Coal Mine are detected. Finally, the coupling strengthening support scheme combining prestressed anchor cable and bolt is proposed. The engineering application and the observation of surrounding rock deformation show that the reinforced support technology can effectively enhance the stability of the surrounding rock of the interbed roadway in Gaojiazhuang Coal Mine, and it has a good reference for the surrounding rock conditions of this kind of roadway.

In a word, I’ve been there

2019 ◽  
pp. 246-256
Author(s):  
A. K. Zholkovsky
Keyword(s):  
The State ◽  
Female Characters ◽  
Political Situation ◽  
The Core ◽  
The Relationship ◽  
Core Problem ◽  
Typical Solution

In his article, A. Zholkovsky discusses the contemporary detective mini-series Otlichnitsa [A Straight-A Student], which mentions O. Mandelstam’s poem for children A Galosh [Kalosha]: more than a fleeting mention, this poem prompts the characters and viewers alike to solve the mystery of its authorship. According to the show’s plot, the fact that Mandelstam penned the poem surfaces when one of the female characters confesses her involvement in his arrest. Examining this episode, Zholkovsky seeks structural parallels with the show in V. Aksyonov’s Overstocked Packaging Barrels [Zatovarennaya bochkotara] and even in B. Pasternak’s Doctor Zhivago [Doktor Zhivago]: in each of those, a member of the Soviet intelligentsia who has developed a real fascination with some unique but unattainable object is shocked to realize that the establishment have long enjoyed this exotic object without restrictions. We observe, therefore, a typical solution to the core problem of the Soviet, and more broadly, Russian cultural-political situation: the relationship between the intelligentsia and the state, and the resolution is not a confrontation, but reconciliation.

Development and Application of the Coal Mine Safety Production System Based on GIS

2012 ◽  
Vol 14 (4) ◽  
pp. 454-459
Author(s):  
Xiaobo XU ◽  
Hualing WU ◽  
Jianqiang WANG ◽  
Shengping WANG
Keyword(s):  
Coal Mine ◽  
Production System ◽  
Mine Safety ◽  
Coal Mine Safety ◽  
Safety Production

Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Seam ◽  
Coal Mine ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Seam Mining

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.

PERANCANGAN IDENTITAS VISUAL REBRANDING CITRA PERUSAHAAN CEMARA CERAMICS (DESIGN OF CEMARA CERAMICS VISUAL REBRANDING IDENTITY)

2021 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Anak Agung Ngurah Gede Marhendra ◽  
Agung Eko Budiwaspada ◽  
Sangayu Ketut Laksemi Nilotama
Keyword(s):  
Design Thinking ◽  
Corporate Identity ◽  
Corporate Image ◽  
Visual Design ◽  
Stage Design ◽  
The Core ◽  
Visual Identity ◽  
The Creation ◽  
Strategy Design ◽  
Core Problem

<p>Abstract Design of Cemara Ceramics Visual Rebranding Identity aims to produce a concept strategy and visual rebranding of the Cemara Ceramics company and produce a Cemara Ceramics rebranding visual identity design in order to encourage the creation of a new identity image. The method in this design uses a 5-stage Design Thinking approach, namely Empathize, Define, Ideate, Prototype and Test. The result achieved is the design of the new Cemara Ceramics corporate identity. With the use of the design thinking method in this research, various problems related to the company image of Cemara Ceramics can be found. The core problem obtained is how to design a strategy and concept of visual identity rebranding to encourage the creation of a new corporate image of Cemara Ceramics.</p><p>Keywords: visual rebranding identity, concept strategy, design thinking</p><p>Abstrak Perancangan Identitas Visual Rebranding Citra Perusahaan Cemara Ceramics ini bertujuan untuk menghasilkan strategi konsep dan visual rebranding perusahaan Cemara Ceramics serta menghasilkan rancangan identitas visual rebranding Cemara Ceramics dalam rangka mendorong terciptanya citra identitas yang baru. Metode dalam perancangan ini menggunakan pendekatan 5 tahapan Design Thinking yaitu Empathize, Define, Ideate, Prototype dan Test. Hasil yang dicapai yaitu rancangan corporate identity Cemara Ceramics yang baru. Dengan adanya penggunaan metode design thinking pada penelitian ini dapat menemukan berbagai permasalahan terkait citra perusahaan Cemara Ceramics. Permasalahan inti yang didapat yaitu mengenai bagaimana merancang strategi dan konsep identitas visual rebranding untuk mendorong terciptanya citra baru perusahaan Cemara Ceramics.</p><p>Kata kunci: identitas visual rebranding, strategi konsep dan visual, design thinking</p>

Numerical Simulation of the Stress Field of Thick 7B04 Aluminum Alloy Board during Continuous Manufacture Procedure

2007 ◽  
Vol 127 ◽  
pp. 259-264
Author(s):  
Hong Yuan Fang ◽  
Cheng Iei Fan
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Stress Concentration ◽  
Stress Field ◽  
Solution Treatment ◽  
Simulation Method ◽  
The Core ◽  
Manufacturing Procedure ◽  
Continuous Manufacture ◽  
Simulation Results

Numerical simulation method is employed in the article to analyze the stress field of thick 7B04 aluminum alloy board during manufacturing procedure of solution treatment, calendaring and stretching. The simulation results show that the surface of the board endures compressive stress while the core segment endures tensile stress, and the distribution of the stress is very inhomogeneous. The calendaring procedure helps to decrease the stress and redistribute the stress uniformly, but it also leads to stress concentration at the two ends of the board, which engenders bad influence on the subsequent processing. The board deforms plastically when being stretched, thus the stress decreases greatly and is redistributed uniformly.

Measurement and numerical simulation of the stress relaxation zone on the roadway face in coal mine

2010 ◽  
pp. 481-484
Author(s):  
Nie Baisheng ◽  
Zhai Shengrui ◽  
Zhang Ruming ◽  
Jia Chuan ◽  
Zhang Jufeng
Keyword(s):  
Numerical Simulation ◽  
Stress Relaxation ◽  
Coal Mine ◽  
Relaxation Zone

scholarly journals Mind mapping as a tool of teaching English vocabulary at transport university

2021 ◽  
Vol 295 ◽  
pp. 05021
Author(s):  
Oksana Marunevich ◽  
Elmira Shefieva ◽  
Olga Bessarabova
Keyword(s):  
Educational Process ◽  
Control Group ◽  
Teaching English ◽  
Mind Mapping ◽  
New Words ◽  
The Core ◽  
Mind Maps ◽  
The Given ◽  
Core Problem ◽  
Experimental Group

The core problem of teaching English as a second language at transport university is students’ poor knowledge of vocabulary. Current solutions to the given problem such as providing word explanations and repetitive practices are ineffective. We strongly believe that the mindmapping technique proposed by Tony Buzan as a note-taking method is a novel, yet an extremely potent tool that aids students in enlarging their professional word stock by associating new vocabulary to their existing knowledge using colors, images, symbols, etc. As might have been expected, the findings of our study point towards the idea that the strong visual appeal of mind maps created by easy-to-use software boosted the educational process and helped students of the experimental group memorize more new words in contrast to students of the control group.

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