نتایج جستجو برای: hard rocks

تعداد نتایج: 168880  

Journal: :IOP Conference Series: Earth and Environmental Science 2021

Journal: :نشریه دانشکده فنی 0
سید حسن بصیری

the conventional tunneling procedures for example drilling, charging, blasting, loading and supporting, are highly developed. new tunneling machines have recently come into operation and others are under construction or development. impactors are used in large numbers in the coal mining industry. face-heading machines are successfully used in new tunneling procedures in both soft and medium-har...

Journal: :International Journal of the Society of Materials Engineering for Resources 2014

2012

Pure beryllium (Be) is a hard grey metal, the lightest of all metals, and can be found in mineral rocks, coal, soil, and volcanic dust and natural waters. It is lighter than aluminium yet three times as strong as steel. Beryllium compounds are commercially mined, and refined beryllium is used in a wide range of manufactured products and industries including ceramics, mirrors, special metal allo...

2001
L. Mishnaevsky

In this chapter possibilities of the improvement of drilling tool efficiency on the basis of the analysis of mechanisms of rock destruction and some methods of the information theory are considered. Physical mechanisms of destruction of hard and plastic rocks under different conditions of mechanical loading are reviewed. Some physical effects which allow to improve the efficiency of rock drilli...

2007
M. Akram M. Z. A. Bakar

Nine rock types including Sandstone, Limestone, Siltstone, Dolomite and Marl collected from six different rock formations of the Salt Range area of Pakistan were tested to evaluate the correlations between the uniaxial compressive strength and the corresponding values of the point load index. Two hundred rock cores were drilled and used for the uniaxial compressive strength and point load index...

2015
Adriana Alagna Tomás Vega Fernández Giovanni D Anna Carlo Magliola Salvatore Mazzola Fabio Badalamenti

In the last decades the growing awareness of the ecological importance of seagrass meadows has prompted increasing efforts to protect existing beds and restore degraded habitats. An in-depth knowledge of factors acting as major drivers of propagule settlement and recruitment is required in order to understand patterns of seagrass colonization and recovery and to inform appropriate management an...

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