نتایج جستجو برای: mine

تعداد نتایج: 23787  

2011
Shanhua Yao Xianliang Wu

The propagation environment of electromagnetic waves in mine tunnels is confined areas. The mine tunnel is regard as wave-guide which contains kinds of un-beneficial medium, the field formulas of different polarization waves were presented based on Marcatili method, and field prediction of horizontal and vertical polarization waves were simulated. The results showed that propagation effect of v...

2017
Lin Yu Zhen Zhang Xiao Huang Binquan Jiao Dongwei Li

Copper mine tailings are the residual products after the purification of precious copper from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper mine tailings for preparation of geopolymer. This paper studies the enhancement of the cementitious activity of copper mine tailings in geopolymer system. First, copper mine tailings are activat...

Journal: :JCP 2011
Jinxue Sui Li Yang Zhilin Zhu Hui Fang Zhen Hua

The mine ventilation optimization and airflow control are the mine ventilation system's two important aspects, good ventilation optimization design can deliver fresh air to establish good work environment and provide a scientific and reliable basis to prevent disaster. Based on the air distribution request of the mine ventilation network, carries on the optimized computation to the mine ventila...

Journal: :journal of mining and environment 2011
j. gholamnejad a.r. mojahedfar

the determination of the ultimate pit limit (upl) is the first step in the open pit mine planning process. in this stage that parts of the mineral deposit that are economic to mine are determined. there are several mathematical, heuristic and meta-heuristic algorithms to determine upl. the optimization criterion in these algorithms is maximization of the total profit whilst satisfying the...

2002
Philip A. Smith

Two seams at the Tab-Simco abandoned underground coal mine site in southern Illinois were mined intermittently from the 1890’s until 1955, and later surface mined. The stripping operations resulted in several break-ins into the old underground works which were later buried by mine spoil. The resulting mine pool in the lower of the two seams has been producing an average of ~150 m per day of aci...

Journal: :Environmental monitoring and assessment 2013
Jens Søndergaard

This study investigated dispersion and bioaccumulation of mining-related elements from an open-pit olivine mine at Seqi in Southwest Greenland (64° N) using lichens (Flavocetraria nivalis), seaweeds (Fucus vesiculosus), mussels (Mytilus edulis) and fish (Myoxocephalus scorpius). The mine operated between 2005 and 2009, and samples were taken every year within a monitoring area 0-17 km from the ...

2017

We propose a simple generalization of the Brennan-Schwartz approach to real option valuation of a mining project that incorporates disaster risk using a Poisson point process to model arrivals. Using techniques from the field of robust performance analysis, we are able to calculate upper and lower bounds over all the probability models within a certain distance from the original model. We sugge...

2006
Ludwik Zawisza Jan Macuda

Hodnotenie nebezpečnosti banských plynov v uzavretej čiernouhoľnej bani „Niwka-Modrzejów” Closing of hard coal mines, especially stopping the process of mine water pumping, results in a reconstruction of the Carboniferous water-bearing horizon, leading to the intensification of gas flux to the near-surface zone („piston effect”). Stopping the fans considerably enhances the movement of mine gase...

2001
Christopher Raphael Stuart Geman

We demonstrate a three stage procedure for mine detection. The rst phase locates plausible candidates through a series of hypothesis tests. The second state nds the globally optimal convex set containing each candidate using \coarse-tone" dynamic programming. The third stage re nes the mine shape estimates using the knowledge contained in a mine-shape library.

Journal: :Journal of bacteriology 2000
S L Rowland X Fu M A Sayed Y Zhang W R Cook L I Rothfield

Escherichia coli cells contain potential division sites at midcell and adjacent to the cell poles. Selection of the correct division site at midcell is controlled by three proteins: MinC, MinD, and MinE. It has previously been shown (D. Raskin and P. de Boer, Cell 91:685-694, 1997) that MinE-Gfp localizes to the midcell site in an MinD-dependent manner. We use here Gfp-MinD to show that MinD as...

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