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...

To improve the coal permeability and outburst prevention, coal seam water injection and a series of outburst prevention measures were tested in outburst coal mines. These methods have become important technologies used for coal and gas outburst prevention and control by increasing the external moisture of coal or decreasing the stress of coal seam and changing the coal pore structure and gas de...

The article describes the research of coal and gas outburst prediction technology and the new problems they face in the modern mining. It also describes the superiority of neural network technology in dealing with complex geological conditions. It refers to the possibility and necessity of combination of the coal and gas outburst prediction and artificial neural networks, and other hightechnolo...

The Outburst can be defined as a sudden release of coal and rock accompanied by large quantities of gas into the underground coal mine workings which represents a major hazard in underground coal mines. Gas drainage has been proven to be successful in reducing outburst hazards by decreasing the in-situ gas pressure. One of aspect of gas drainage from coal seams is coal matrix volume changes. Cu...

Coal and gas outbursts have always been a serious threat to the safe and efficient mining of coal resources. Ground stress (especially the tectonic stress) has a notable effect on the occurrence and distribution of outbursts in the field practice. A numerical model considering the effect of coal gas was established to analyze the outburst danger from the perspective of stress conditions. To eva...

A thin coal seam mined as a protective coal seam above a gas outburst coal seam plays a central role in decreasing the degree of stress placed on a protected seam, thus increasing gas permeability levels and desorption capacities to dramatically eliminate gas outburst risk for the protected seam. However, when multiple layers of coal seams are present, stress-relieved gas from adjacent coal sea...

The coal and gas outburst is one of complex geological disasters and its prediction is influenced by a multiple of factors, such as coal gas, ground stress, physical and mechanical properties, and complex non-linear system, which cause the low prediction accuracy. It is a favorable scheme to use the nonlinear BP neural network for the prediction algorithm design. But, the traditional BP neural ...

Výpočet možnosti vzniku průtrže v dlouhých důlních dílech The article brings results of the evaluation of a possibility of coal and gas outburst origin on the basis of calculation of active forces that try to induce an outburst and passive forces that prevent an outburst from occurring. The analysis of outbursts from the Paskov Mine, Staříč plant, shows that decisive indicators, by which a pron...

A semi-analytic model of cluster cooling flows is presented. The model assumes that episodic nuclear activity followed by radiative cooling without mass-dropout cycles the cluster gas between a relatively homogeneous, nearly isothermal post-outburst state and a cuspy configuration in which a cooling catastrophe initiates the next nuclear outburst. Fitting the model to Chandra data for the Hydra...

Evolution of gas and dust distributions following a spatially and temporally localized comet outburst was calculated using a hybrid kinetic hydrodynamic method. It was found that a comet outburst resulted in significantly increased dust terminal velocities. As these higher terminal velocity values result in larger apex distances, therefore the outburst generates distinct dust envelopes in front...