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Showing 1 to 20 of 49 for “"stress changes"”.
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Workload Transitions and Stress: Changes Over Time
… transitions may affect the operators' state of stress and coping behaviors but previous research has not conclusively demonstrated the nature of those. The first goal of the current work was to investigate the discrepant findings of the previous literature. Two experiments were conducted where …
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Stress changes in reinforced concrete members due to creep
… and materials. Within the allowable working stress range of concrete, creep strain can be considered proportional to the induced stress. Assuming known stress - creep strain - time relations, a series of equations have been derived analytically to calculate the stress changes in both the …
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Modelling the impact of total stress changes on groundwater flow
… FEMWATER code to investigate the impact of total stress changes on groundwater flow in the vicinity of a salt tailings pile. Total stress and pore-pressure data observed at the Lanigan and Rocanville potash-mine sites were used to assist the development of a generic FEMWATER model. The original …
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Stress Changes in Railroad Car Wheels Due to Axially Symmetric Thermal Loads
… wheels to determine the behavior of initially stress free wheels subjected to axially symmetric thermal loadings. Residual stress levels after final cooling of the wheels is determined by a sectioning technique. Results from the tests are compared to predictions from two elastic-plastic …
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Improvement of aftershock models based on Coulomb stress changes and rate-and-state dependent friction
… has proven the most useful tool to forecast changes in seismicity rates in the short and medium term (hours to months), and efforts are currently being made to extend the scope of such models to operational earthquake forecasting. The overarching goal of the research presented in this thesis …
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Defining Stress Changes Ahead of a Tunnel Face and Design of a Data Acquisition System
… is a non-invasive technique to map the stress changes induced by mining ahead of the active face. Seismic tomography maps the velocity distributions of elastic waves traveling through a rock mass. The velocity distributions mapped in the tomograms can relate to anomalies in the rock such …
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Investigation of a method for monitoring stress changes in the burst prone seams of southwestern Virginia
… The design and construction of a borehole stressmeter is discussed. Laboratory testing. which yielded promising results of the stressmeter (inclusion) is presented along with preliminary field test results. Laboratory testing involved comparison with the results of a two-dimensional finite …
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Investigations of Crack Growth in Railroad Car Wheels Caused by Thermally Induced Residual Stress Changes and Cyclic Mechanical Loading
Made available in DSpace on 2014-12-14T14:42:16Z (GMT). No. of bitstreams: 1 7913513.pdf: 3373295 bytes, checksum: 7fc27308ba81e7cf636b7928b98d9e7e (MD5) Previous issue date: 1978
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Understanding Time-Variant Stress-Strain in Turkey: A Numerical Modeling Approach
… events and tectonic influences affect the stress regime of the NAFZ and how these stress changes affect the probability of future rupture along any unbroken segments of the fault zone using a two dimensional finite element modeling program. In this study, stress changes due to an earthquake …
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Using wave attenuation techniques for monitoring of stress levels
Stress can have a significant effect on the stability of pillars. To get an accurate picture of pillar stability, information is needed not only on the initial stress magnitude and distribution but also on all subsequent stress changes. Sonic methods have the potential to be among the fastest, most …
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Stress paths and collapsing soils
… and last step should be the investigation of changes in external or local conditions on these parameters. The importance of this step is brought to the fore when considering collapsing soils and heaving clays. The next stage of the design would be to consider the stress changes at either an …
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INFERRED RHEOLOGY AND UPPER MANTLE CONDITIONS OF WESTERN NEVADA AND SOUTHERN CALIFORNIA-NORTHWEST MEXICO
… unloading) events that have induced differential stress changes within the crust and mantle, which in turn, create surface deformation. The viscoelastic relaxation is constrained using geodetic methods, such as GPS, InSAR, or measurements of shoreline rebound. We can use these observed surface …
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Seismic Wave Velocity Variations in Deep Hard Rock Underground Mines by Passive Seismic Tomography
… be both safe and efficiently productive. Induced stress in deep mines has a significant role in the stability of the underground mines and hence the safety of the mining workplace because the behavior of the rock mass associated with mining-induced seismicity is poorly-understood. Passive seismic …
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Improving statistical seismicity models
… earthquake triggering process, including static stress interactions and dynamic stress transfer. Significant differences of these mechanisms are particularly expected in the spatial distribution of aftershocks. However, testing the different hypotheses is challenging because it requires the …
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Evolução das tensões residuais e sua relação com a “misorientação” microestrutural de um aço astm dh36 após soldagem
The residual stress is an important parameter to be studied in order to guarantee reliability and resistance of the structures and to avoid their future failures. A particular phenomenon about residual welding stress changes over time has recently been observed with the residual stress evaluation …
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Investigating volcano tectonic interactions in the Natron Rift of the East African Rift System
… activity in close proximity. We examine the stress transferred from these events to the Natron Fault, which is the major border fault in the area, with analytical modeling using the USGS program Coulomb 3.4. We processed Global Positioning System (GPS) data that recorded slip on the major …
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Crustal stress variability across spatial scales - examples from Canada, Northern Switzerland and a South African gold mine
The quantitative descriptions of the state of stress in the Earth’s crust, and spatial-temporal stress changes are of great importance in terms of scientific questions as well as applied geotechnical issues. Human activities in the underground (boreholes, tunnels, caverns, reservoir management, …
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Structure and mechanics of the subducted Gorda plate: constrained by afterslip simulations and scattered seismic waves
… that would be expected as a result of the stress changes from offshore strike-slip earthquakes. Chapter 3 develops array analysis methods to identify P-to-S and S-to-P seismic converted phases that convert at the subducted Gorda plate interface from local earthquakes and uses them to …
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Structure and mechanics of the subducted Gorda Plate : constrained by afterslip simulations and scattered seismic waves
… that would be expected as a result of the stress changes from offshore strike-slip earthquakes. Chapter 3 develops array analysis methods to identify P-to-S and S-to-P seismic converted phases that convert at the subducted Gorda plate interface from local earthquakes and uses them to …
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Sustainable Machining of Aerospace Alloys for Improved Product and Process Sustainability: Evaluation of Dry, Near-dry (MQL) and Cryogenic Machining Processes
… This aspect has to be considered when planning changes in the manufacturing process which also affect the product. It is crucial to contemporarily evaluate the sustainability of the process and the product. This problem become more severe when manufacturing of aerospace components that need to …
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