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Seismotectonics of the explorer region and of the Blanco Transform Fault ZoneBraunmiller, Jochen 23 October 1998 (has links)
In this thesis, we present the first detailed, long-term seismotectonic studies of oceanic
ridge-transform systems. The proximity of the Juan de Fuca plate to a network of
broadband seismic stations in western North America provides a unique synergy of
interesting tectonic targets, high seismicity, and recording capabilities. Our main tools are
earthquake source parameters, determined by robust waveform modeling techniques, and
precise earthquake locations, determined by joint epicenter relocation. Regional broadband
data are used to invert for the source moment tensors of the frequent, moderate-sized (M ≥
4) earthquakes; this analysis began 1994. We include Harvard centroid moment-tensors
available since 1976 for larger (M ≥ 5) earthquakes.
Two studies comprise the main part of this thesis. In the first, we determine the current
tectonics of Explorer region offshore western Canada. Earthquake slip vector azimuths
along the Pacific-Explorer boundary require an independent Explorer plate. We determine
its rotation pole and provide a tectonic model for the plate's history over the last 2 Ma.
Plate motion changes caused distributed deformation in the plate's southeast corner and
caused a small piece in the southwest corner to transfer to the Pacific plate. Capture of the
plate fragment indicates that preserved fragments not necessary represent entire
microplates.
In the second study, we investigate seismicity and source parameters along the Blanco
Transform Fault Zone (BTFZ). The deformation style-- strike slip and normal faulting--
correlates well with observed changes in BTFZ's morphology. We infer that Blanco Ridge
probably consists of two fault segments, that several parallel faults are active along BTFZ's west part, and that Cascadia Depression possibly is a short spreading center. The slip
distribution along the BTFZ is highly variable, although seismicity could account for the
full plate motion rate along the entire BTFZ.
The final part is a short study where we locate an earthquake in the tectonically active
Mendocino triple junction region offshore northern California using land and offshore data.
The precise location may be useful as a master event for relocating other earthquakes. / Graduation date: 1999
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Seismicity and structure of the Orozco transform fault /Tréhu, Anne Martine. January 1982 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982. / Supervised by Sean C. Solomon. Vita. Includes bibliographical references (leaves 312-321).
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Seismicity and structure of the Orozco transform fault from ocean bottom seismic observation Anne Martine Tréhu.Tréhu, Anne Martine. January 1900 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1982. / Includes bibliographical references (p. 312-321).
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Fault evolution and earthquakes a finite element study /Li, Qingsong, January 2006 (has links)
Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 28, 2007) Vita. Includes bibliographical references.
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Development of a Control and Monitoring Platform Based on Fuzzy Logic for Wind Turbine GearboxesChen, Wei 19 December 2012 (has links)
It is preferable that control and bearing condition monitoring are integrated, as the condition of the system should influence control actions. As wind turbines mainly work in remote areas, it becomes necessary to develop a wireless platform for the control system. A fuzzy system with self-tuning mechanism was developed. The input speed error and speed change were selected to control the shaft speed, while the kurtosis and peak-to-peak values were used as another set of inputs to monitor the bearing conditions. To enhance effectiveness, wait-and-see (WAS) logic was used as the pre-processing step for the raw vibration signal. The system was implemented on the LabVIEW platform. Experiments have shown that the system can effectively adjust motor rotating speed in response to bearing conditions. For future studies, more advanced fault detection methods can be integrated with proper tuning mechanisms to enrich the performance and function of the controller.
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Analysis of electrical signatures in synchronous generators characterized by bearing faultsChoi, Jae-Won 15 May 2009 (has links)
Synchronous generators play a vital role in power systems. One of the major mechanical
faults in synchronous generators is related to bearings. The popular vibration
analysis method has been utilized to detect bearing faults for years. However, bearing
health monitoring based on vibration analysis is expensive. One of the reasons
is because vibration analysis requires costly vibration sensors and the extra costs
associated with its proper installation and maintenance. This limitation prevents
continuous bearing condition monitoring, which gives better performance for rolling
element bearing fault detection, compared to the periodic monitoring method that
is a typical practice for bearing maintenance in industry. Therefore, a cost effective
alternative is necessary. In this study, a sensorless bearing fault detection method
for synchronous generators is proposed based on the analysis of electrical signatures,
and its bearing fault detection capability is demonstrated.
Experiments with staged bearing faults are conducted to validate the effectiveness
of the proposed fault detection method. First, a generator test bed with an in-
situ bearing damage device is designed and built. Next, multiple bearing damage
experiments are carried out in two vastly different operating conditions in order to
obtain statistically significant results. During each experiment, artificially induced
bearing current causes accelerated damage to the front bearing of the generator.
This in-situ bearing damage process entirely eliminates the necessity of disassembly and reassembly of the experimental setup that causes armature spectral distortions.
The electrical fault indicator is computed based on stator voltage signatures
without the knowledge of machine and bearing specific parameters. Experimental
results are compared using the electrical indicator and a vibration indicator that is
calculated based on measured vibration data. The results indicate that the electrical
indicator can be used to analyze health degradation of rolling element bearings in
synchronous generators in most instances. Though the vibration indicator enables
early bearing fault detection, it is found that the electrical fault indicator is also
capable of detecting bearing faults well before catastrophic bearing failure.
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Development of a bridge fault extractor toolBhat, Nandan D. 17 February 2005 (has links)
Bridge fault extractors are tools that analyze chip layouts and produce a realistic list of
bridging faults within that chip. FedEx, previously developed at Texas A&M University,
extracts all two-node intralayer bridges of any given chip layout and optionally extracts
all two-node interlayer bridges. The goal of this thesis was to further develop this tool.
The primary goal was to speed it up so that it can handle large industrial designs in a
reasonable amount of time. A second goal was to develop a graphical user interface
(GUI) for this tool which aids in more effectively visualizing the bridge faults across the
chip. The final aim of this thesis was to perform FedEx output analysis to understand the
nature of the defects, such as variation of critical area (the area where the presence of a
defect can cause a fault) as a function of layer as well as defect size.
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A hydrogeologic and geophysical investigation of a fault as a groundwater flow barrier in Reno, NV /Clark, Matthew, January 2009 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2008. / "Decmber 2008." Includes bibliographical references (leaves 60-62). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2009]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Escarpement de faille synsédimentaire : perturbation des écoulements gravitaires sous-marins et détermination de la cinématique des failles /Pochat, Stéphane. January 2003 (has links)
Thesis (doctoral)--Université de Rennes I, 2003. / Errata sheets inserted. Includes bibliographical references (p. 239-253, 266-270). Also available on the Internet.
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Structural geology and dislocation modeling of the East Coyote anticline, eastern Los Angles basin /Myers, Daniel J. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2002. / Typescript (photocopy). Includes bibliographical references (leaves 42-44). Also available via the World Wide Web.
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