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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.
11

Structural geology and tectonics /

McClay, K. R. January 2000 (has links) (PDF)
Thesis (D.Sc.)--University of Adelaide, Dept. of Geology and Geophysics, 2000. / Includes bibliographical references.
12

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).
13

The tectonic evolution of Epirus, northwest Greece

Waters, David William January 1994 (has links)
No description available.
14

Aerospike Thrust Vectoring Slot-Type Compound Nozzle

Case, William Scott 01 June 2010 (has links) (PDF)
A study of thrust vectoring techniques of annular aerospike nozzles was conducted. Cold-flow blow-down testing along with solid modeling and rapid prototyping technology were used to investigate the effects of slot size, placement, geometry and orientation. The use of slot-type compound nozzles proved to be a feasible approach to thrust vectoring. Previous methods of thrust vectoring have proved to be difficult to implement in a cost effective manner or have had limited effectiveness or durability.
15

Correlates and consequences of varus knee thrust in osteoarthritis

Wink, Alexandra Elisabeth 12 June 2018 (has links)
Varus knee thrust is an abnormal frontal-plane movement (i.e., an out-bowing) of the knee that occurs during the weight-acceptance phase of gait. Varus thrust is of clinical interest, as it is a potentially-modifiable biomechanical risk factor for knee osteoarthritis (OA) progression and has been associated with knee pain. The overall aim of this dissertation is to identify the structural and symptomatic consequences of varus thrust at the knee and along the lower limb, and the possible anatomical and sensorimotor causes of varus thrust in older adults with or at risk for OA. Varus thrust was assessed in Multicenter Osteoarthritis (MOST) Study participants using high-speed videos of self-paced walking. Varus thrust was observed in 31.3% of 3730 knees. We investigated the longitudinal relation of varus thrust to MRI lesions and found that thrust was associated with increased odds of incident and worsening bone marrow lesions and worsening cartilage loss. We then investigated the longitudinal association of varus thrust with WOMAC knee pain and found that thrust was associated with increased odds of incident and worsening total WOMAC knee pain and worsening pain during weight-bearing and non-weight bearing activities. In an ancillary quantitative gait analysis of a single subject with unilateral varus thrust, we found altered joint moments at the hip, knee, and ankle in the thrust limb compared to the non-thrust limb. We bolstered this pilot data with an investigation of low back and lower extremity pain in the presence of thrust in MOST participants: limbs with thrust had increased odds of incident frequent pain proximal (hip or low back) and distal (ankle and foot) to the knee compared to limbs without thrust. Finally, we investigated the cross-sectional relation of anatomical and sensorimotor impairments at the knee and lower extremity to the prevalence of varus thrust. Thrust was most prevalent in limbs with static varus malalignment and supinated feet during gait, while increasing static knee laxity had a protective effect against thrust. These results fill substantial gaps in the narrative regarding the role of varus thrust in OA development.
16

Field based study of thrust faults in the Appalachian Valley and Ridge Province Newport, Virginia

Overby, Kyle Eugene 24 March 2016 (has links)
This study focuses on a series of thrust sheets exposed in the Appalachian Valley and Ridge Province Blacksburg-Pembroke area in southwest Virginia. Structures in the hanging wall of the Saltville thrust (Saltville thrust sheet) and the footwall of the Saltville thrust (Narrows thrust sheet) are examined. The first part of this study involves the construction of a series of thrust transport-parallel 1:24,000 scale geologic cross sections to constrain the subsurface geometry of fault and fold structures within the Saltville and Narrows thrust sheets. The second part of the study involves an outcrop-scale study of geologic structures exposed along a series road cuts in the footwall of the Saltville thrust and the geometric and relative timing relationships between folding, cleavage formation and thrust faulting. The cross sections show a series of interconnected splay faults branching off of the Saltville thrust and cutting both its hanging wall and footwall. Angle of dip and magnitude of dip-slip displacement on thrust and splay faults progressively decrease from hinterland to foreland within this fault system that is referred to as the Spruce Run Mountain-Newport (SRMN) fault system. Bedding within this fault system essentially forms a structural transition zone between the Saltville and Narrows thrust sheets, defining a km-scale fractured synform-antiform fold structure that has many structural attributes usually associated with fault propagation folding. In the road cut outcrops, early meter-scale faults are folded by later foreland-(NW) vergent folds. Although cleavage defines convergent cleavage fans about these folds, subtle obliquities between folds and cleavage indicate that folding post-dates early layer-parallel shortening and associated foreland-vergent thrusting. / Master of Science
17

Mineral growth and fluid migration in mid-crustal shear zones

Warwick, Alison Julie January 2000 (has links)
No description available.
18

Constrained Low-Thrust Satellite Formation-Flying Using Relative Orbit Elements : Autonomous Guidance and Control for the NetSat Satellite Formation-Flying Mission

Steindorf, Lukas January 2017 (has links)
This thesis proposes a continuous low-thrust guidance and control strategy for satellite formation-flying. Stabilizing feedback based on mean relative orbit elements and Lyapunov theory is used. A novel feedback gain matrix inspired by the fuel-optimal impulsive solution is designed to achieve near-optimal fuel consumption. A reference governor is developed to autonomously guide the spacecraft through the relative state-space in order to allow for arbitrarily constrained satellite formations. Constraints include desired  thrust levels, time constraints, passive collision avoidance and locally constrained state-space areas. Keplerian dynamics are leveraged to further decrease fuel consumption. Simulations show fuel consumptions of only 4% higher delta-v than the fuel-optimal impulsive solution. The proposed control and guidance strategy is tested in a high-fidelity orbit propagation simulation using MATLAB/Simulink. Numerical simulations include orbit perturbations such as atmospheric drag, high-order geopotential, solar radiation pressure and third-body (Moon and Sun) effects. Test cases include reconfiguration scenarios with imposed wall, thrust and time constraints and a formation maintenance experiment as flown by TanDEM-X, the TanDEM-X Autonomous Formation-Flying (TAFF) experiment.
19

Le piémont nord du Tian Shan : cas d'école d'un front de chaîne immature / The northern piedmont of Tian Shan : a case study of immature range front

Chen, Ke 01 December 2010 (has links)
La chaîne actuelle du Tian Shan (Asie centrale) est considérée comme une conséquence directe de la réactivation d'une ceinture orogénique du Paléozoïque due à la collision Inde-Asie, au Cénozoïque. Un travail détaillé a été réalisé le long du piémont nord de la chaîne en intégrant les observations géologiques de terrain, analyses structurales, profils sismiques, nouvelles mesures des anomalies gravimétriques et des données de forages. Tout d'abord cette étude apporte de nouvelles preuves directes, à différentes échelles, sur l'existence d'un paléo-relief majeur le long du front nord du Tian Shan au cours du Mésozoïque, et plus particulièrement pendant le Jurassique. Deuxièmement, la quantité de raccourcissement calculée à travers cette ceinture de plis et chevauchements nord du Tian Shan est relativement faible et les structures reconnues le long du front de la chaîne présentent une hétérogénéité latérale forte. Ainsi, alors qu’un chevauchement du socle paléozoïque sur les séries sédimentaires mésozoïques et cénozoïques du bassin est remarquablement exposé le long de certaines vallées, d'autres sections montrent que les séries sédimentaires du Trias au Jurassique peuvent être suivies de manière continue, depuis le bassin jusque sur le toit du socle Paléozoïque où ils reposent en discordance relativement haut dans la chaîne. Quatre coupes géologiques ont été construites par l'intégration des données pluridisciplinaires acquises. La restauration de ces coupes montre que les taux de raccourcissement sont inférieurs à 20% et peuvent descendre à un minimum de 6%. Ces observations suggèrent que le piémont nord du Tian Shan est plutôt «jeune» et que la chaîne d’avant pays est encore à un stade primaire de son évolution tectonique. En d'autres termes, le piémont nord du Tian Shan peut être considéré comme un exemple type de front de chaîne immature. / The modern Tian Shan (Central Asia) is considered as a direct consequence of the reactivation of a Paleozoic orogenic belt due to the India – Asia collision, during Cenozoic times. A detailed work has been investigated along the northern piedmont of Tian Shan, integrating the field work, structural analysis, seismic profile data, gravity anomaly measurements and drilled wells. Firstly, this study brings new and direct evidences, at different scales, for the existence of a major paleo-relief along the northern Tian Shan range during Mesozoic, and particularly during Jurassic times. Secondly, the calculated shortening amount in the northern piedmont of Tian Shan is rather small and the structural pattern of its front is heterogeneous along-strike. While, thrusting of the Paleozoic basement on the Mesozoic or Cenozoic sedimentary series of the basin is remarkably exposed along several river valleys, other sections display continuous Triassic to Jurassic sedimentary series from the basin to the range where they unconformably overlie on the Carboniferous basement. Four cross-sections are made by integrating multi-method data, showing that shortening amounts are less than 20% and could be even until to 6%. This suggests that the Tian Shan intracontinental range is rather “young” and still at a primary stage of its tectonic evolution. In other words, its front may be considered as a typical example of an immature range front.
20

Structural geology and tectonics / by Kenneth Ronald McClay.

McClay, K. R. (Kenneth R.) January 2000 (has links)
Includes bibliographical references. / 1 v. (various pagings) : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Consists of 75 published papers on structural geology and tectonics grouped into 5 broad themes -- and ore deposits; analogue modelling; extensional tectonics; thrust tectonics; and, tectonics, all presented in chronological order within the group. / Thesis (D.Sc.)--University of Adelaide, Dept. of Geology and Geophysics, 2000

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