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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Along-strike changes in the active tectonic configuration of the northwestern Himalaya: insights from landscape morphology, erosion rates, and river profiles

Mearce, Trevor 20 December 2017 (has links)
Geodetic models suggest that much of the convergence across the Himalaya (~20 mm yr-1) is taken up on the Main Himalayan Thrust, the main decollement beneath the Himalayan orogenic wedge. In Central Nepal and the majority of Northwest India, several geomorphic, geophysical and seismological datasets indicate that this decollement has a mid-crustal ramp that continues uninterrupted for hundreds of kilometers along strike from Nepal in the east to Uttarakhand in the west. In this study, I use spatial analyses of elevation, relief, channel steepness indices, and basin-wide erosion rates from cosmogenic 10-Be concentrations to outline a potential large-scale change in the active fault configuration between the Main Himalayan Thrust and Main Boundary Thrust near longitude 77°E in the Northwestern Indian Himalaya. The physiography in the areas to the east of 77ºE appears similar to that observed along much of the Himalaya where topographic relief, erosion rates, and river channel steepness (ksn <200) remain relatively low in the areas to the south of a line known as the Physiographic Transition-2. North of the Physiographic Transition-2, these metrics increase sharply within a 30-km zone due to higher rock uplift rates above a mid-crustal ramp on the decollement or an unidentified out-of-sequence thrust fault that soles to the decollement. Either of these models are perceivable with a duplex growing by underplating of the Indian plate into the Himalayan orogenic wedge contributing to higher rock uplift rates north of the Physiographic Transition-2. To the west of 77ºE, however, the landscape morphology indicates the Main Boundary Thrust makes a northward bend coinciding with the along-strike termination of the Physiographic Transition-2 and an arc-perpendicular Bouguer gravity anomaly reflecting a trough on the Indian plate near longitude 77°E. These data suggest that the Main Boundary Thrust merges along strike with the ramp or with an emergent fault soling into the Main Himalayan Thrust at this location, potentially marking a significant change in tectonic configuration along the Himalayan arc. / Graduate
2

Measurements versus Predictions for a Hybrid (Hydrostatic plus Hydrodynamic Thrust Bearing for a Range of Orifice Diameters

Esser, Paul R. 2010 May 1900 (has links)
A fixed geometry hybrid thrust bearing is investigated with three different supply orifice diameters. The test rig uses a face-to-face thrust bearing design, with the test bearing acting as the rotor loading mechanism. A hydraulic shaker applies the static axial load, which is reacted by a second thrust bearing. The rotor is supported radially by two water-lubricated fluid film journal bearings and is attached to a 30,600 rpm motor via a high speed coupling with very low axial stiffness. Thrust bearings with three different orifice diameters (1.63, 1.80, and 1.93 mm) are tested for a range of supply pressures, fluid film thicknesses, and rotational speeds. The water-lubricated test bearings have eight pockets, with feed orifices located centrally in each pocket. Experimental results are comparted to predictions found using bulk flow model HYDROTHRUST. Analysis of the data reveals generally good agreements between predictions and measurements. Thrust-bearing inlet supply and inner radius flow rates all decreased with decreasing orifice diameters and bearing axial clearances. In most cases, the bearings with larger orifice diameters exhibit higher recess pressure ratios, operating clearances, and flow rates. The largest orifice diameter configuration does not display higher recess pressure ratios or operating clearances at high speeds for some supply pressures, but it does continue to require additional lubricant flow rate compared to the smaller orifice bearings. In these cases, the results are not reflected in predictions, which otherwise correlate very well with experimental measurements. Estimations of static loading axial stiffness are obtained using experimental results. An optimum hybrid thrust bearing orifice diameter will depend on the conditions of individual applications. Larger orifices generally provide larger operating clearances and higher stiffnesses, but also require higher flow rates. For most applications, a compromise of bearing performance parameters will be desired. The test results and comparisons presented will aid in sizing orifice diameters for future hybrid thrust bearing designs.
3

INTERACTIONS BETWEEN STRUCTURES IN THE APPALACHIAN AND OUACHITA FORELAND BENEATH THE GULF COASTAL PLAIN

Surles, Donald Matthew 01 January 2007 (has links)
In Alabama, the Paleozoic Appalachian thrust belt plunges southwest beneath the Mesozoic-Cenozoic Gulf Coastal Plain. In Arkansas, the Paleozoic Ouachita thrust belt plunges southeast beneath the Coastal Plain. The strikes of the exposed thrust belts suggest an intersection beneath the Coastal Plain. Well data and seismic reflection profiles confirm the strike and intersection of the thrust belts, and provide information to determine the structure and general stratigraphy of each thrust belt. In east-central Mississippi, the Appalachian thrust belt curves from the regional northeast trace to westward at the intersection with the southeastern terminus of the Ouachita thrust belt, to northwest where Ouachita thrust sheets are in the Appalachian footwall, and farther west, to a west-southwest orientation. At the intersection, the frontal Appalachian fault truncates the Appalachian thrust sheets. The Appalachian thrust sheets are detached in Lower Cambrian strata and contain a distinctive Cambrian-Ordovician passive-margin carbonate succession. The Ouachita thrust sheets are detached above the carbonate succession and contain a thick Carboniferous clastic succession. The Appalachian thrust sheets east of the intersection rest on an autochthonous footwall with a thin Lower Cambrian sedimentary cover above Precambrian crystalline basement. To the west, the Appalachian thrust sheets rest on an allochthonous footwall of thick Ouachita thrust sheets. The top of Precambrian crystalline basement rocks dips southwestward beneath the Ouachita thrust belt; large-magnitude down-to-southwest basement faults enhance the deepening. Appalachian thrust sheets on the northeast are detached above relatively shallow basement, but to the west, are detached above thick Ouachita thrust sheets, which overlie deeper basement. The structure of the basement reflects the Iapetan rifted margin, where the northwest-striking Alabama-Oklahoma transform bounds the southwest side of the Alabama promontory. The trends of basement structures and subsidence toward the Ouachita thrust belt parallel the Alabama-Oklahoma transform. Shallower basement and synrift basement grabens underlie the northeast-striking Appalachian thrust belt. The curves in strike and along-strike change in footwall structure of the Appalachian thrust belt reflect controls by basement structure and by the structure of the Ouachita thrust belt.
4

An investigation of new concepts in two-dimensional curved thrust augmentors

El-Banna, R. A. M. January 1986 (has links)
No description available.
5

Structural geometry, tectonic history and deformation mechanisms in the Moine thrust zone near Ullapool N.W. Scotland

Winter, D. A. January 1984 (has links)
No description available.
6

Thrust vectoring experiments with gas injection

Sekhon, Kalwant Singh, 1938- January 1964 (has links)
No description available.
7

Test-Theory Correlation Study for an Ultra High Temperature Thrust Magnetic Bearing

Desireddy, Vijesh R. 14 January 2010 (has links)
Magnetic bearings have been researched by the National Aeronautics and Space Administration (NASA) for a very long time to be used in wide applications. This research was to assemble and test an axial thrust electromagnetic bearing, which can handle 1000 lb-f of axial thrust load, when rotating at high speed, in a high temperature environment of 1000 0F. This high temperature magnetic bearing system would be used in high performance, high speed and high temperature applications like space vehicles, jet engines and deep sea equipment. An experimental procedure was developed to measure actual load capacity of the designed bearing in the test rig. All the results obtained from the experiment were compiled and analyzed to determine the relation between bearing force, applied current and temperature. The thesis incorporates the assembly, testing of the electromagnetic bearing at various speeds and temperatures and compare predicted to measured force vs. speed, current, gap and temperature. The results showed that the high temperature thrust magnetic bearing is capable of handling 1000 lb-f at 10000F and 5500 rpm.
8

Orthodontic and biological considerations of deglutition, oro-linguo-facial muscle function, and tongue thrust : diagnosis

Kift, Russell J January 1985 (has links)
Master of Dental Surgery / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au
9

Orthodontic and biological considerations of deglutition, oro-linguo-facial muscle function, and tongue thrust : diagnosis

Kift, Russell J January 1985 (has links)
Master of Dental Surgery / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au
10

Surficial mapping and kinematic modeling of the St. Clair thrust fault, Monroe County, West Virginia

Sturms, Jason M. January 2008 (has links)
Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains vii, 84 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 75-78).

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