نتایج جستجو برای: coal mining
تعداد نتایج: 114364 فیلتر نتایج به سال:
in the present study, an investigation was carried out on parvadeh coal mine in tabas, iran, to survey the effect of fractures on unusual methane gas emission in coal mines. this coal mine was chosen for investigating because of its high methane gas content in the coal body and available data from sensors in desired locations. gas concentration monitoring programs were carried out at the mine s...
The Appalachian region of USA hosts diverse forests and abundant high-quality coal reserves. Surface mining methods are often used for coal extraction. Because common reclamation methods in past years have not restored forest vegetation, surface mining has created a diverse land base. Although some mined lands have been placed into managed uses, most have not. Little is known about the extent a...
Cancer incidence and mortality rates are high in West Virginia compared to the rest of the United States of America. Previous research has suggested that exposure to activities of the coal mining industry may contribute to elevated cancer mortality, although exposure measures have been limited. This study tests alternative specifications of exposure to mining activity to determine whether a mea...
There are many sources trough which the soil get enriched and contaminated with REEs. The determination of REEs in environmental samples has been limited because of the lack of sensitive analytical techniques. Soil samples were collected from four sites including open cast coal mine, natural coal burning, coal washery and control in the coal field located in Dhanbad, India. Total concentrations...
This paper constructs a forecasting model for coal mining water inrush from the floor through the analysis and careful study of the mechanism of water inrush in coal mining and the Self-Adaptive Evolutionary Extreme Learning Machine (SaE-ELM) which obtains self-learning, generalization performance and speediness is used. In SaE-ELM, the network hidden node parameters are optimized by the self-a...
The most important determinant of whether there is a radon problem is the presence of uranium and radium in the bedrock and overburden. As the permeability of the ground controls the ease with which radon can be transported, any cavity that exists underground has the potential to accumulate elevated levels of radon. Buildings built upon the ground surface have the potential to draw in ground ga...
the first step in mining activities is rock excavation in both mine development and production. constant pressure for cost reduction and creating an improved/safe work environment for personnel has naturally resulted in increased use of mechanical excavation systems in many mining operations. also, mechanical excavation and mining is more compatible with automation, meaning possibility of reduc...
The pooling problem is a nonconvex nonlinear programming problem (NLP) with applications in the refining and petrochemical industries, but also the coal mining industry. The problem can be stated as follows: given a set of raw material suppliers (inputs) and qualities of the supplies, find a cost-minimising way of blending these raw materials in intermediate pools and outputs so as to satisfy r...
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