نتایج جستجو برای: eastern alborz coal mines

تعداد نتایج: 124213  

Journal: :The Science of the total environment 2002
Bin He Lina Liang Guibin Jiang

The contents of arsenic and selenium in 33 coals collected from the main coal mines in northeastern, northern and eastern China were determined by flow injection-hydride generation and non-dispersion atomic fluorescence spectrometry (HGAFS). The concentrations of As in the northeast region are relatively higher with the values > 100 microg g(-1); in the east they are lower with values < 100 mic...

Journal: :Journal of the Air & Waste Management Association 2000
D A Kirchgessner S D Piccot S S Masemore

Past efforts to estimate methane emissions from underground mines, surface mines, and other coal mine operations have been hampered, to different degrees, by a lack of direct emissions data. Direct measurements have been completely unavailable for several important coal mining operations. A primary goal of this study was to collect new methane emissions measurements and other data for the most ...

Abbas Esmaeilnia Shirvani Hossein Ghafourian

Coal with low ash content has an important role in the coal and steel industry. There are different methods to measure the ash content. The conventional method which is used in most coal mines of Iran, is to burn the coal and measure the remaining ash. A new method has been recently developed at Nuclear Research Center (NRC) of Iran, Which works on the basis of the absorption of the dual en...

Journal: :Radiation protection dosimetry 2017
Fu-Dong Liu Zi-Qiang Pan Sen-Lin Liu Ling Chen Lu Chen Chun-Hong Wang

Due to the improvement of production technology and the adjustment of energy structure, as well as the town-ownership and private-ownership coal mines (TPCM) were closed or merged by national policy, the number of underground miner has changed comparing with 2004 in China, so collective dose and normalization collective dose in different type of coal mine should be changed at the same time. In ...

Journal: :زمین شناسی اقتصادی 0
طاهره ربانی نادر تقی پور رضا اهری پور

introduction maceral is a term to introduce organic components visible under a microscope (stopes, 1935). the physical and chemical characteristics of macerals such as elemental composition, moisture content, hardness, density and petrographic characteristics differ. the differences in the physical and chemical characteristics of macerals are reflected in their industrial behavior.(parkash, 198...

2016
D. Lynas

Studies conducted on surface coal mining equipment have identified whole-body vibration as a significant hazard. Operators of underground mobile equipment, particularly shuttle cars and transport vehicles, are likely to be exposed to significant levels of whole-body vibration. To date, measuring whole-body vibration from underground mining mobile equipment has been difficult due to the strict g...

2010
Eileen Birch

In a previous study, the efficacy of commercial and prototype impactors for sampling diesel particulate matter (DPM) in coal mines was investigated. Laboratory and field samples were collected on quartz-fiber filters and analyzed for organic and elemental carbon. Coal dust contributed a minimal amount of elemental carbon when commercial cascade impactors and prototype impactors, designed by the...

Journal: :International journal of environmental health research 2010
Yilan Liao Jinfeng Wang Jilei Wu Luke Driskell Wuyi Wang Ting Zhang Gu Xue Xiaoying Zheng

Shanxi province in northern China has one of the highest reported prevalence rates of neural tube defects (NTDs) in the world. The current study selected Heshun, the county with the highest rate of NTDs in Shanxi, as a study area and tested whether residence in a coal mining area was a contributing factor. A NTD cluster was detected in an area within 6 km of the coal mines for almost every year...

2001

ational statistics on coal-mining productivity show that—except during the 1970s—coal mines have become steadily more efficient. More coal is removed per hour of work, causing a drop in both mining costs and coal prices. However, a new Energy Laboratory study suggests that those national statistics do not tell the whole story. When the researchers analyzed productivity data for more than ninete...

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...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید