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Showing 1 to 20 of 20 for “"Rock material"”.
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Development and evaluation of an instrumentation system for high acceleration centrifuge testing of an artificial rock material
… acceleration centrifuge testing of an artificial rock material.</p> <p>A stress analysis of the centrifuge rotor was performed to ensure its safe operation. The centrifuge was found to be safe for operation to a maximum of 1000 rpm for a payload of 15 pounds (6.82 kg).</p> <p>The instrumentation …
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The Role of Horizontal Stress in the Formation of Valley Stress Relief Features in Flat-Lying Sedimentary Rocks
… linear elastic models without the inclusion of material plasticity. Stress conditions include gravitational loading as well as a regional horizontal stress. The results of this analysis were compared to previous studies. Next, a layered geologic sequence including plastic slip along bedding is …
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Analytical and Numerical Modelling of Thermal Conductive Heating in Fractured Rock
… Modelling was conducted in a fractured bedrock environment containing a system of parallel, equally-spaced horizontal fractures. A semi-analytical solution to the two-dimensional heat conduction equation was developed and used to study temperature distributions between two thermal wells. A …
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Ancient stonewall fish traps on the south coast of South Africa : documentation, current use, ecological effects and management implications
… sheltered environments, constructed from in situ rock material built into walls with either angular or curved shapes. These walls may occur singularly or in complexes of up to 25 traps. Vywers are prone to decimation by wave action and storm damage and so require maintenance to retain their …
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Fracture Toughness Based Models for the Prediction of Power Consumption, Product Size, and Capacity of Jaw Crushers
… of individuals, the characterization of rock material using inadequate and unrepresentative tests, and the desire to limit secondary breakage, resulting in the conservative selection and operation of jaw crushers. A method for predicting the power consumption, product size, and volumetric …
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Seasonal and interannual variability in the hydrology and geochemistry of an outlet glacier of the Greenland Ice Sheet
… Greenland underlain by metamorphic silicate rocks. Data collected from a continuous 222Rn monitor in the proglacial river were used as a component of a mass balance model. I demonstrated that Jdis, the 222Rn fraction derived from the distributed system, was >90% of the 222Rn flux on average, …
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Nonlinear site amplification functions for Central and Eastern North America
… to modify ground motions from a reference bedrock condition to a surface condition based on the geologic features of the site of interest. Site amplification has been extensively studied and evaluated empirically for seismic regions such as the Western United States where there are abundant …
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Seasonal and interannual variability in the hydrology and geochemistry of an outlet glacier of the Greenland Ice Sheet
… Greenland underlain by metamorphic silicate rocks. Data collected from a continuous 222Rn monitor in the proglacial river were used as a component of a mass balance model. I demonstrated that Jdis, the 222Rn fraction derived from the distributed system, was >90% of the 222Rn flux on average, …
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Geoarchaeological Assessment of Horseshoe Cave (24RB1094, Rosebud County, Montana
… this sandstone cave site reveals the cave host rocks to be sandstones of the Tongue River Member of the Early Tertiary Fort Union Formation. Results of the geoarchaeological inquiry demonstrate that a difference in the calcite cementation between the two host sandstone units is the leading …
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Geoarchaeological Assessment of Horseshoe Cave (24RB1094, Rosebud County, Montana
… this sandstone cave site reveals the cave host rocks to be sandstones of the Tongue River Member of the Early Tertiary Fort Union Formation. Results of the geoarchaeological inquiry demonstrate that a difference in the calcite cementation between the two host sandstone units is the leading …
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A new method of meshing in discontinuous deformation analysis (DDA)
… by Shi [1988] specifically for modelling blocky rock masses. The DDA method is based on the assumption that deformation and failure of such rock masses is primarily due to differential movements of rock blocks, rather than strain and fracture of intact rock material. Strains and stresses are …
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Microtextures of Cyanobacterial Mats in Siliciclastic Sedimentary Environments (Modern & Ancient): Applications to the Search for Life on Mars
… order to compare fossil and modem MISS, I used rock material from the 2.9 Ga old Archean Pongola and Witwatersrand Supergroups, South Africa, that record former tidal and shelf settings. I also investigated modern examples on Fishermans Island, located on the coast of Virginia at the mouth of …
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An Examination of Site Response in Columbia, South Carolina: Sensitivity of Site Response to "Rock" Input Motion and the Utility of Vs(30)
… overlying high velocity Paleozoic crystalline rock. An equivalent-linear algorithm is used to estimate site response for vertically incident shear waves in a horizontally layered Earth model. Non-linear mechanical behavior of the soils is analyzed using previously published strain-dependent …
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Formation and alteration of magnetite nanoparticles
… is an iron oxide, which is ubiquitous in rocks and is usually deposited as small nanoparticulate matter among other rock material. It differs from most other iron oxides because it contains divalent and trivalent iron. Consequently, it has a special crystal structure and unique magnetic …
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Hydraulic Fracturing Behavior of Opalinus Shale: A Framework, Experimentation & Insights
… bedding planes. Opalinus Shale was used as the material of study, which visually had two distinct, alternating layers: a tough light layer and a soft dark layer. The following framework was set to investigate the complex rock material and hydraulic fracture process. First, the mineralogy and …
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Volcanic and sedimentary processes in phreatomagmatic volcanoes
… which contain subsided subaerially-deposited material, allow a model for activity of this type to be constructed. The Saefell tuff-ring SW Iceland is a surtseyantype structure whose crater remained open to the sea during most of its activity, allowing easy access of water to the magma. …
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Soil-Landscape Modelling in an Andean Mountain Forest Region in Southern Ecuador
… within the investigation area are parent material and landslides. Strong evidence was found that topsoil horizons did not form from the bedrock underlying the soil profile. Parent material changes within short distance and often within one soil profile. Landslides have a strong influence …
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Προσδιορισμός μηχανικών παραμέτρων του βραχώδους υλικού και εφαρμογή αυτών στην εκτίμηση της αντοχής και παραμορφωσιμότητας της βραχομάζας
Αντικείμενο της παρούσας διατριβής αποτελεί η διερεύνηση των μηχανικών παραμέτρων του βραχώδους υλικού και η εφαρμογή αυτών στην εκτίμηση της αντοχής και παραμορφωσιμότητας της βραχομάζας. Προς την κατεύθυνση αυτή, έγινε οριοθέτηση της μηχανικής συμπεριφοράς του βραχώδους υλικού, διατύπωση …
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Borehole Breakouts in Transversely Isotropic Posidonia Shale
… shale is one of the most productive source rocks for conventional reservoirs in Europe and has the greatest potential for unconventional oil and gas in Europe (Littke et al., 2011). In this work, Posidonia shale specimens from the North (PN) and South (PS) German basins were selected and …
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Geochemistry of artificial groundwater recharge into the Kopoasfontein breccia pipe near Calvinia, Karoo
… pipe, a roughly cylindrical body of fractured rock, 12 km east of the town. Subsurface water storage would then mjnjmjse evaporative losses, so that the injected water could be recovered when emergency water supplies are needed. Underground storage space for an estimated 70 000 m3 of water is …