in advance longwall mining, the safety of mine network, production rate, and consequently, economic conditions of a mine are dependent on the stability conditions of gate roadways. the gate roadway stability is a function of two important factors: 1) characteristics of the excavation damaged zone (edz) above the gate roadway and 2) loading effect due to the caving zone (cz) above the longwall w...

In advance longwall mining, the safety of mine network, production rate, and consequently, economic conditions of a mine are dependent on the stability conditions of gate roadways. The gate roadway stability is a function of two important factors: 1) characteristics of the excavation damaged zone (EDZ) above the gate roadway and 2) loading effect due to the caving zone (CZ) above the longwall w...

Minor faults, subsidence columns, coal tunnels and gob are very important in coal mining because they can cause flooding accidents, broken coal beds, added fissures, and gas accumulation. All of these factors will increase coal mining risk. In addition, minor faults also affect the design of roadways. In this article, we have achieved satisfactory results in identifying minor faults, subsidence...

The Critical Zone (CZ) is the thin layer of the Earth’s terrestrial surface and near-surface environment that ranges from the top of the vegetation canopy to the bottom of the weathering zone and plays fundamental roles in sustaining life and humanity. The past few years have seen a number of Critical Zone Observatories (CZOs) being developed following the first CZOs established in the United S...

The shoot apical meristem (SAM) is a collection of stem cells that resides at the tip of each shoot and provides the cells of the shoot. It is divided into functional regions. The central zone (CZ) at the tip of the meristem is the domain of expression of the CLAVATA3 (CLV3) gene, encoding a putative ligand for a transmembrane receptor kinase, CLAVATA1, active in cells of the rib meristem (RM),...

In any cave mining method a horizontal slice of rock is mined out at the base of the block to be caved by drilling and blasting. Once a sufficiently large area has been mined continuous caving initiates and propagates through the block. High stress levels are set up in the abutment zone around the perimeter of the caving area that can affect tunnel stability to a distance of 20 metres from the ...

We evaluate the logarithmic derivative of the depth of the solar convective zone with respect to the logarithm of the radiative opacity, ∂ lnRCZ/∂ lnκ. We use this expression to show that the radiative opacity near the base of the solar convective zone (CZ) must be known to an accuracy of±0.6% in order to calculate the CZ depth to the accuracy of the helioseismological measurement, RCZ = (0.713...

In this paper we report on high efficiency screen-printed 4 cm solar cells fabricated on randomly textured float zone, magnetic Czochralski (MCz) and Ga-doped Cz silicon. A simple process involving POCl3 emitters, low frequency PECVD silicon nitride deposition, Al back contact print, Ag front grid print followed by co-firing of the contacts produced efficiencies of 19.0% on textured float zone,...

S U M M A R Y We present a semi-analytic iterative procedure for evaluating the 3-D deformation due to faults in an arbitrarily heterogeneous elastic half-space. Spatially variable elastic properties are modelled with equivalent body forces and equivalent surface traction in a ‘homogenized’ elastic medium. The displacement field is obtained in the Fourier domain using a semi-analytic Green func...