نتایج جستجو برای: middle coal
تعداد نتایج: 186550 فیلتر نتایج به سال:
canister desorption is a widely used technique to measure the gas content of coal. the gas content data, when normalized to volume/weight and multiplied by coal seam mass, is used to estimate the gas in place in an area around the cored hole. however, the gas content and the percentage of each constituent are likely to be influenced by trapped air in the canister at the time of the coal enclosu...
Coal fires have been found to be a serious problem worldwide in coal mining reserves. Coal fires burn valuable coal reserves and lead to severe environmental degradation of the region. Moreover, coal fires can result in massive surface displacements due to the reduction in volume of the burning coal and can cause thermal effects in the adjacent rock mass particularly cracks and fissures. The Wu...
Coal fires cause severe environmental and economic problems worldwide. In the current paper we analyse the potential of the experimental bi-spectral infrared detection (BIRD) small satellite to register coal fire related spectral radiances and we present BIRD data acquired over two coal fire areas in Northern China. Based on field observations of coal fires in the investigated areas, we visuall...
Coal ash, generated from coal combustion, is composed of small particles containing metals and other elements, such as metalloids. Coal ash is stored in open-air impoundments, frequently near communities. The objective of this study was to evaluate the prevalence of health and sleep problems in children living near coal ash and compare these prevalences to children not living near coal ash. In ...
Disabilities of coal miners due to black-lung decease morbidities are rather high (up to 10 men per 1 million tons of mined coal). Besides that, dangerous to health biological activity is also proper to various carbon nanoparticles. The analysis of relationships between coal miner morbidities, biological activities of coals and bibliographical data has shown that: activity of coals is mainly de...
Stricter emissions requirements on coal-fired power plants together with low natural gas prices have contributed to a recent decline in the use of coal for electricity generation in the United States. Faced with a shrinking domestic market, many coal companies are taking advantage of a growing coal export market. As a result, U.S. coal exports hit an all-time high in 2012, fueled largely by dem...
OBJECTIVE To evaluate the component of coal responsible for coal workers' pneumoconiosis (CWP). METHODS A literature search of PubMED was conducted to address studies that have evaluated the risk of CWP based on the components of coal. RESULTS The risk of CWP (CWP) depends on the concentration and duration of exposure to coal dust. Epidemiology studies have shown inverse links between CWP a...
Mercury emissions from coal-fired electric generating utilities are a major uncontrolled source of mercury in the environment. This mercury may be contributing to serious health problems in segments of our society. The USGS is compiling information on mercury in coal that may be useful in developing strategies for reducing mercury emissions from coal use. The USGS coal-quality database contains...
Coal is a highly variable fuel, which ranges from high heating-value anthracite through various forms of bituminous coal to intermediates in coal formation, viz. lignite and peat. Each of these types of fuel can contain different levels of moisture, non-combustible inorganic material (ash), sulfur, and sometimes significant levels of other impurities, e.g. arsenic, fluorine, lead and mercury. R...
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