Based on the measurements, the optimal mixture is determined as substituting natural sand with 30% mass ratio of mining tailings, which enables structures achieve a favorable buildability and a relatively high mechanical strength.
The study is based on a comprehensive analysis of factors affecting the displacement factor, such as mechanical properties of the cover rock, the ratio of mining depth to seam thickness, dip angle of the coal seam and the thickness of loose layer.
Historically, the ratio of underground mining to open-pit mining has been approximately even, but as usable deposits close to the surface become scarcer, underground mining will probably increase.
However it could also be due to nonspecific cationic bundling and subsequent stabilization of MinD polymers (see, e.g., [29]), or to nonspecific aggregation (see, e.g., [30]) of MinD and/or MinE leading to reduced ratios of MinE to MinD participating in the subcellular Min oscillation.
Thus, in order to improve energy efficiency and ensure the security of energy supply, China must increase the beneficiation ratio of run-of-mine coal.
In this plan, it is clearly pointed out that the beneficiation ratio of run-of-mine coal will be improved to more than 70%% till 2017 and apparently, a lot of continued efforts must be made to achieve this goal.
After adjustment, the stomach-cancer Standardized Mortality Ratios (SMRs) for the aggregate of mining towns were 92 for men and 104 for women.
Under panel and pillar mining, the final surface subsidence factor (the ratio of maximum surface subsidence to the mining height) is generally less than 0.1, with surface subsidence being well controlled and surface buildings being protected.
To determine the optimal step length (the minimal value by which the regularization parameter must be decreased in order for the active set to change), we need to solve a similar problem, this time involving the ratio of two separate frequent itemset mining optimization problems.
The ratio of the number of subtrees mined by EVOMINER to the number of subtrees mined by MFSTMINER is maximum for support values f=.75 and f=.95, thus, MFSTMINER is fastest with respect to EVOMINER in these cases.
The filling ratio of <100%% has been confirmed by practices of mining with backfill in different countries (Gandhe et al. 2005).
