نتایج جستجو برای: coal mine design

تعداد نتایج: 1008939  

2007
DAOLIANG LI

Abandoned coal mine spoils can result in severe pollution and have aesthetic on the local environment. A range of reclamation techniques is available for substrate but only through the use of vegetation to stabilize coal mine spoils can complete long-term rehabilitation be achieved. Experimentation has been undertaken at coal mine sites to attempt to elucidate and overcome limitations to vegeta...

2012
H L Zhao

The pipeline network of coalmine has the characteristics of widespread distribution and complex structure. It is difficult to detect abnormalities in time by manual when the faults occurred, which often lead to reduction in production. In this paper, a monitoring system is developed to monitor the operating conditions of the pipeline network in real-time. The system has abilities to dynamic mon...

Journal: :American journal of industrial medicine 1970
N S Seixas T G Robins M D Attfield L H Moulton

Underground U.S. coal miners were studied cross-sectionally for the association of respirable coal mine dust exposure with pulmonary function and symptoms of airways obstruction. The study group included 1,185 miners participating in Round 4 of the National Study of Coal Workers' Pneumoconiosis who had started mining in or after 1970 when comprehensive exposure regulations first came into effec...

Journal: :Journal of the Mining and Metallurgical Institute of Japan 1971

2010
Thomas F. Tomb John P. Seiler

In 1991 the Mine Safety and Health Administration conducted a special program to assess occupational exposures to respirable coal mine dust in underground coal mines. Priority was given to longwall mining operations, mines with a history ofhaving a problem controlling dust to the applicable standard, and a representative number of all other mines. Measurements were obtained on approximately 720...

2015
Hongxia Li Hongxi Di Shuicheng Tian Jian Li

The aim of this study is research the impact of management level's charismatic leadership style on miners' unsafe behavior by using the questionnaires on charismatic leadership style, safety attitude and the miners' unsafe behavior measurement to investigate 200 employees in Shen Dong Company. The research results suggest that management level's charismatic leadership style have very important ...

2017
Andrea Brock Alexander Dunlap

The German Rhineland is home to the world's largest opencast lignite coal mine and human-made hole e the Hambach mine. Over the last seven years, RWE, the mine operator, has faced an increase in militant resistance, culminating in the occupation of the Hambacher Forest and acts of civil disobedience and sabotage. The mine provides a European case study to examine the repressive techniques deplo...

Journal: :IJCNS 2011
Yanjing Sun Beibei Zhang

To overcome the frequency-selective fading of ultra wide band (UWB) caused by the multi-path propagation in complicated environment of coal mines, an underground wireless communication system of UWB based on multi-band orthogonal frequency division multiplexing (MB-OFDM) for coal mine is presented. Independent angle impulse response is used to build up revised channel model for underground tunn...

Journal: :JCM 2015
Ming Li

— An average Transmitted-Reference (TR) receiver scheme based on orthogonal codes is proposed for improving the bit error rate (BER) performance and the transmitting rate of Ultra-wideband (UWB) TR receiver systems in coal mine. Orthogonal codes are used for modulating the reference pulses and the data pulses in each frame of every bit. Since the orthogonality of the two codes, the inter-pulse...

2015
Hong Yu Xuezhen Cheng Maoyong Cao Xiaohang Gao

In view of the coal dust concentration measurement elements, the measurement pollution environment will reduce the measurement accuracy. The paper proposes a soft measurement method of mine dust concentration based on the K-RBF neural network theory. It takes the electrostatic signal as the measurement signal and extracts the short-term energy, RMS and rectification value of the electrostatic s...

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