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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"Backfilling"”.
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An economic evaluation of backfilling in Virginia's coal mines
Backfilling is a technique used to place material in the voids created by underground mining. This technique has been used extensively abroad to reduce surface subsidence, fire hazards, and temperatures in underground workings. It can also help to eliminate environmental problems caused by coal …
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The Effects of Backfilling on Ground Control and Recovery in Thin-Seam Coal Mining
… in order to exploit thin-seam reserves. Backfilling is one alternative that may find applicability in thin-seam coal mining. The ability of backfill to provide additional ground support may enhance coal recovery by allowing for the design of undersized pillars. Backfill has been used …
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Investigation of the critical specific gravity for cables and pipelines during various backfilling and installation processes
… and the uplift of pipelines/cables due to backfilling in granular materials at different speeds.<br/><br/>The effect of embedment depth and trench width on the soil resistance to the flotation of pipelines/cables were studied. Two types of test, free flotation and pull-out tests were used …
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Geotechnical characterization of coal refuse for use as a backfill material
… to a much lesser extent in U.S. coal mines, is backfilling. In addition to the possible benefits of subsidence mitigation, backfilling has the potential to increase coal recovery, enhance ventilation control, and to minimize mine fires. Backfilling can also be used as a means of mine refuse …
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Scheduling algorithms to improve utilization in toroidal-interconnected systems
… we present simulation results for migration and backfilling techniques on BlueGene/L. These techniques are explored individually and jointly to determine their impact on the system. We develop an efficient Projection Of Partitions (POP) algorithm for determining the size of the largest free …
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Understanding the Structure and Properties of Self-Assembled Monolayers for Interfacial Patterning
… printing a pattern onto the substrate and then backfilling the remaining gold substrate by solution adsorption. Backfilling with the same alkanethiol used to create the pattern generates a homogeneous monolayer; however, it is found that the contact printed/backfilled monolayer has an impedance …
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Feasibility of an Integrated Thin Seam Coal Mining and Waste Disposal System
… the feasibility of an integrated mining and backfilling system applicable to thin seams. Two conceptual mining systems, namely Auger mining and Self Advancing Miner, have been proposed for this purpose. Both these systems are designed to remotely mine coal from the seams. Several attempts …
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BEHAVIOUR OF GRAVITY CAISSON ON SANDBED
… sequences included infilling of caisson, backfilling of caisson and live load imposition on the caisson. The centrifuge studies showed that the caisson would generally settle uniformly during the infilling stage. During thebackfilling and live loading stages, it would settle further with …
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Investigation of the Failure Mechanisms of Intact and Deteriorated Culverts
… the behaviour of these structures during backfilling and live loading. The horizontal ellipse culvert was tested at two different burial depths (0.9 m and 0.45 m) using tandem axle loading. The results suggest that the ellipse behaves similar to a circular culvert during backfilling, …
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Configuration of the Pleistocene Surface Beneath Cat Island, Mississippi and Implications for Barrier Island Formation and Evolution
… and abundant local sediment supply provided by a backfilling fluvial channel is presented here.
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A vibration-based bridge scour monitoring technique
… a repair process involving controlled scour backfilling, i.e., “scour in reverse”. The effect of this scour backfilling was captured by measuring changes in two of these parameters, mode shape and spectral density, derived from the ambient vibrations. The mode shapes, in particular, showed …
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Koste-aspekte by terugvulmynbou
… is pumped to the section underground where the backfilling is taking place. The complexity of the method created many costing problems for the mining industry. Vaal Reefs Mining and Exploration Co. (Pty) Ltd approached me to identify the problem areas in backfill mining and to make the necessary …
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Evaluation of Marine Corps Manpower computer simulation model
… showed biasness toward retaining Marines over backfilling vacancies through accessions.
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Método dos elementos finitos aplicado ao problema de escavação
… on the struts 8. construction of galeries, 9. backfilling. Three applications of the program are presented: a) parametric study of the influence of the temperature on strut loads; b) determination of settlements of buildings during the excavation of a diaphragm wall trench adjacent to these …
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Coal mine waters in South Africa: Their Geochemistry,quality and classification. Volume one and two
… in hydropower and as a transport medium for backfilling. In addition, potable water is required for drinking purposes. Large volumes of water are affected by chemical contaminants in the coal mines (Azzie, 1999). These contaminants vary significantly depending on the coal seam mined, the …
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Terahertz quantum cascade lasers
… and provides protection from thermal backfilling due to the large energy separation between the lower radiative state and the injector. Both properties are important in allowing higher temperature operation at longer wavelengths. Lasers using a surface plasmon based waveguide grown on …
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Highly tunable room temperature quantum cascade lasers
… efficient electron injection and reduce thermal backfilling at high temperatures. This allowed wavelength emission at ~3.3µm in pulsed mode at room temperature. A system was developed which could drive the laser by delivering an electrical pulse as brief as 5ns and with frequencies into the MHz …
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Chemical treatment of corroding steel reinforcement after removal of chloride contaminated concrete
… chemically treated through solution pondings and backfilling with treated mortar. Seventeen treatments and combination of treatments were evaluated including corrosion inhibitors, polymer sealers, and a possible chloride ion scavenging mineral. The treatment effects were monitored using half-cell …
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Complex retreat behavior in experimental barrier island response to base level rise
… way across the island. This begins a process of backfilling the overwash fan, eventually creating a new ridge. These simple experiments support previous theoretical suggestions that periodic overwash is a key part of a barrier island’s behavior during a transgression, and that this can lead to …
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Orienting structure to serve medical functions
… that produced a minimal and uniform noise. A backfilling approach in which additional polymer was extruded into an existing 3D printed background layer was developed to create multiple levels of image contrast. A print with nine infill angles and a rectilinear infill pattern was found to have …
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