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...

Navigation canals are used for transport purposes. In order to allow safe navigation the water level should be kept in a certain range around the Normal Navigation Level (NNL). The water level is disturbed by known and unknown inputs, like tributaries, municipal water flows, rain, etc. Some of these inputs can be used to control the water level. If the geometry requires it, canal reaches are co...

In the early 1980’s, the world steel market collapsed. Since the almost exclusive use of ironore is in steel production, many iron-ore mines had to be shut down. We divide the major iron-ore producing countries into groups based on the threat of closure faced by iron-ore mines in the respective country. In countries where mines faced no threat of closure, the iron-ore industry had little or no ...

Abstract This study was conducted to determine the content of mercury in flowing river around small-scale gold mines. Mining wastes from run mining are dumped into watersheds and potentially contaminate water sediment watershed near area. We analyzed characteristics waste result compared with quality standards (Environment Minister Decision No.202 2004 Government Regulation No.82 2001) standard...

The origin of this report lies in the very interesting discussions with Chal-lamel of the CGES at Ecole des Mines de Paris and with Hugues Mounier of Ecole des Mines de Nantes.

We show that the Minesweeper game is PP-hard, when the object is to locate all mines with the highest probability. When the probability of locating all mines may be infinitesimal, the Minesweeper game is even PSPACE-complete. In our construction, the player can reveal a boolean circuit in polynomial time, after guessing an initial square with no surrounding mines, a guess that has 99 percent pr...

background and purpose: multiple sclerosis (ms) is a disease determined by the interaction of genetic and environmental factors. metals are suspected of being involved in ms. there is not any epidemiologic study about mines and ms. the purpose of this study was to determine ms prevalence according to mines in kerman province. methods: this cross-sectional study was conducted on 932 patients in ...

Concentrations of total Hg, Hg (II), and methylmercury were measured in stream-sediment, stream-water, and fish collected downstream from abandoned mercury mines in southwestern Alaska to evaluate environmental effects to surrounding ecosystems. These mines are found in a broad belt covering several tens of thousands of square kilometers, primarily in the Kuskokwim River basin. Mercury ore is d...

During World War II (1939–1945), German forces placed approximately 1.4 million landmines along the Danish west coast as part of the West Atlantic Wall. After the war, manual clearance and the use of tanks with rollers operated by former German soldiers under Danish and British command removed the majority of these mines. While the boundary of each minefield was known in the area of Skallingen,...