Results 161 to 170 of about 902 (216)

Laboratory investigation on cooling effect of coarse rock layer and fine rock layer in permafrost regions

Cold Regions Science and Technology, 2004
Instability and failures of railway/roadway embankment are mainly caused by thaw settlement of permafrost in cold regions. To protect foundation soils beneath the embankment from thaw settlement is the primary construction principle. In the present study, the heat transfer characteristics of two cases of porous media were examined experimentally, with ...
Wenbing Yu, Yuanming Lai, Xuefu Zhang, Shujuan Zhang, Jiangzhang Xiao   +4 more
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DFIT Analysis and Interpretation in Layered Rocks

SPE Hydraulic Fracturing Technology Conference and Exhibition, 2020
Abstract Diagnostic fracture injection tests (DFITs) are often used to estimate formation properties such as closure stress, pore pressure, and matrix permeability. These estimations are typically based on analysis of pressure data assuming the closure of simple planar fractures in homogeneous reservoirs.
Shuang Zheng, Ripudaman Manchanda, HanYi Wang, Mukul Sharma   +3 more
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Patterns to ores in layered rocks

Economic Geology, 1960
Distribution patterns of syngenetic ore bodies in layered rocks correspond in area, symmetry, and metal variation with the rock facies structures. Distribution patterns of epigenetic ore bodies either correspond to antecedent and contemporary tectonic structures or deviate systematically under their influence.
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On Stress Distribution in Layered Rock Masses

Izvestiya, Physics of the Solid Earth, 2018
Spatial distribution of principal stresses in a layered elastic medium is considered in the paper. Transformations of the principal stresses across an interface between the layers are analyzed. A method for reconstructing the spatial stress distributions in layered medium from several spot measurements is proposed. The introduced approach is capable of
N. V. Dubinya, A. N. Galybin
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Patterns to ores in layered rocks

Economic Geology, 1961
Takes exception to a recently published interpretation of the Basal Reef in the Orange Free State gold field (South Africa) as a stream deposit, pointing out that these and adjacent beds of the upper Witwatersrand sequence are all of blanket type and exhibit features characteristic of the basal conglomerates of a transgressing sea.
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Tension Tests on Layered Rocks

Geological Society of America Bulletin, 1969
Tension tests were performed on four layered rocks: a shale, a gneiss, and two sandstones. Cores 2.125 by 4.25 inches were prepared, with the layers dipping at 0°, 15°, 30°, 45°, 60°, 75°, and 90° to the short cylinder axis. All tests were carried to failure, and strain was measured by gauges mounted on the cores. Rupture strength in tension is highly
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Differentiated layering in metamorphic rocks

Earth-Science Reviews, 1990
Abstract Metamorphic or differentiated layering is best developed in low prograde metamorphic rocks such as slates and metaturbidites and is most easily recognised where it cuts a demonstrably earlier layering such as bedding. It commonly occurs as an axial plane foliation and typically comprises layers rich in phyllosilicates and opaque minerals ...
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Compositional convection and layering in a rock melt

Nature, 1987
When a crystal grows (or dissolves) in a solution it becomes surrounded by a thin boundary zone of liquid that is relatively depleted (or enriched) in crystal components. The compositional difference and, hence, the horizontal density gradient that exist in this zone, may cause it to convect away from the crystal1. This process of natural convection is
C. H. Donaldson, D. L. Hamilton
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Mechanisms of dike propagation in layered rocks and in massive, porous sedimentary rocks

Journal of Geophysical Research: Solid Earth, 1991
The mechanisms of dike propagation are analyzed through detailed examination of small structures associated with the dike intrusion. Exposures in the Ramon area, Israel, offer an opportunity to evaluate theoretical models of tensile fracture propagation and to better understand the factors governing the dike geometry.
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Airflow through crushed-rock layers

2011 Second International Conference on Mechanic Automation and Control Engineering, 2011
Pressure drops through packed concrete spheres and crushed rocks were investigated by wind tunnel experiments. The diameters of concrete spheres were 0.041 m and 0.052 m, respectively. The mean particle size of the crushed rocks was 0.096 m. The experimental results show that the Ergun equation with revised coefficient values can be used to predict ...
null Yuanming Lai, null Jingbo Li, null Qingze Li   +2 more
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