نتایج جستجو برای: hard rock pillar design

تعداد نتایج: 1132503  

Journal: :Circulation 2017

Journal: :Frontiers in Astronomy and Space Sciences 2023

The discovery that most of the prokaryotic diversity and biomass on Earth resides in deep subsurface, calls for an improved definition habitability, which should consider existence dark biospheres other planets moons Solar System beyond. “interior liquid water worlds” some ice with waterless surfaces has piqued wide astrobiological interest, but sporadic mentions possibility life subsurface roc...

Journal: :The practising midwife 1993
Natalia Suvorava Steven Richmond Neil Patel Brian Bell Hector Mesa

Developing small-molecule inhibitors against protein-protein interaction targets is among the most difficult challenges in contemporary drug discovery. Recent developments in our understanding of this problem, and in the knowledge and tools available to address it, give cause for renewed hope, but substantial challenges remain.

2016
Xiaoming Han Chenxu Luo Xingyu Han

In order to solve the bit front rake angle parameter selection problem of under different coal rock, it is proposed in polycrystalline diamond compact no core bit as the research object, and established a bit compact two-dimensional stress model of cutting teeth. The result shows that the front rake angle is the factor of cutting force and the drilling efficiency. Application of Solid Works sim...

2012
Karel FRYDRÝŠEK

This paper focuses on a numerical analysis of a hard rock (ore) disintegration process. A bit moves into the ore and subsequently disintegrates it. The disintegration (i.e. fracture of ore) is solved via a deterministic approach (FEM) and a probabilistic approach (FEM in combination with the SBRA Simulation-Based Reliability Assessment method, i.e. Monte Carlo simulations, stochastic inputs). T...

2000
Brian Asbury Jamal Rostami Levent Ozdemir

Over the last several decades mechanical mining machines have developed into highly productive, light weight, mobile machines which are able to economically mine many soft rock ore bodies. Due to the utilization of disc cutters Tunnel Boring Machines, with great mass and limited mobility, have developed the ability to cut the hardest rocks at high production rates. Technological advancements ha...

Journal: :The Journal of family practice 2000
P R Gross

A solution to get the problem off, have you found it? Really? What kind of solution do you resolve the problem? From what sources? Well, there are so many questions that we utter every day. No matter how you will get the solution, it will mean better. You can take the reference from some books. And the a rock and a hard place is one book that we really recommend you to read, to get more solutio...

2013
Roberto C. Medel-Morales

Nowadays there is a large number of tunneling projects in progress, mainly in Europe, both for roads and transport supplies. Performance prediction of tunnel boring machines (TBM) and the determination of some design parameters have become crucial, as they are critical elements in planning a project of mechanical excavation. In this paper we use the Discrete Element Method (DEM) to build models...

Journal: :int. journal of mining & geo-engineering 2012
nielen van der merwe

a brief background to the development of the rock engineering design process is given, showing that since the development of the science of mathematics, deterministic methods have been used to perform various calculations. the variability of rock properties and support characteristics have always been known. however, they were not explicitly used in design but compensated for by the use of a sa...

2013
H. Sawa

Mine fill is the material placed underground to fill the voids created by mining excavations. It provides overall large scale ground stabilization while allowing localized pillar recovery. In addition to providing a working floor or back, mine fill has the potential to reduce subsidence and minimize dilution. Mine fill is essential to cut and fill, benching and sublevel stoping mining methods. ...

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