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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

Structural analysis of the perdido fold belt: timing, evolution, and structural style

Waller, Troy Dale, II 17 September 2007 (has links)
The Perdido fold belt is the compressional toe of the complex system of detached structures in the western Gulf of Mexico. Located in the Alaminos Canyon protraction area in ultra deep-water, this extensive fold belt has the potential to accommodate large amounts of hydrocarbons. These folds detach upon Jurassic-age Louann salt, and are northeast-southwest trending and symmetrical to asymmetrical. The lower units in these folds are comprised of mostly carbonates and limy carbonate mud, whereas the upper portion consist of fine grained and muddy siliciclastics which are typical of turbidite and other typical deep water deposits. 2-D, prestacked, depth-migrated seismic data (TGS Phase 45) was interpreted in conjunction with Hess Corporation to determine the geometry and timing of the folds outboard of the allochthonous Sigsbee salt nappe. The interpretation of the seismic data consisted of evaluating the folds by mapping age-dated reflections and kink-band boundaries (fold axial surfaces), along with creating isochores and dip maps. Through the development of new geometric model building of excess areas, which identifies material being added to the cores of the anticlines, along with the extensive seismic interpretation, the Perdido fold belt is identified to have originated in the west as early as the early Paleocene, with some continual fold growth to near present day. The folds in the Perdido fold belt continue to form eastward into the basin, up to the basinward limit of the autochthonous Louann salt. Also, it has been determined that the geometries and structural styles of the folds are partially dependent on the type of sediment or rock type in place. The lower portions consisting of the carbonates give shallower dipping fold axial surfaces, whereas the upper portions (siliciclastics) provide more steeply dipping fold axial surfaces.
2

Estimates of stratal shortening in South Wales and South-West Ireland

Hanna, Samir S. January 1983 (has links)
No description available.
3

Electrospun Elastomeric Vocal Fold Constructs for the Application of Vocal Fold Tissue Engineering

Hughes, Lindsay 28 September 2013 (has links)
Voice disorders affect up to 9% of the population, and can be caused by vocal fold scarring. They can reduce the ability of a person to participate in the workplace and can also cause depression in individuals. Vocal fold scarring changes the organization and composition of the lamina propria, and affects the biomechanical properties of the tissue. These changes cause an inability of the lamina propria to produce a normal mucosal wave during speech, resulting in hoarseness or complete voice loss. Currently there is a clinical need for treatment options for vocal fold scarring. This work focuses on developing a novel, elastomeric electrospun biomaterial to be used as a model system to evaluate the response of immortalized human vocal fold fibroblast cells (HVFF) to scaffold architecture and to the presence of an elastin polypeptide. The scaffold was developed by electrospinning Tecoflex™. Electrospun scaffolds were successfully made with aligned and unaligned fibers, and they were characterized using scanning electron microscopy (SEM) and uniaxial tensile testing. The aligned scaffolds had initial elastic moduli of ~14 MPa and ~0.3 MPa in the preferred and cross-preferred direction respectively. The unaligned scaffolds had initial elastic moduli of ~5 MPa and ~0.6 MPa in the preferred and cross-preferred direction respectively. An elastin-like polypeptide (ELP) developed in the Woodhouse lab, ELP4, was successfully adsorbed onto the scaffolds to investigate the effect of ELP’s on the HVFF cells. HVFF cells were seeded onto the scaffolds and their viability, proliferation, morphology, and gene expression were characterized. Over the culture period the cells remained viable, and showed signs of proliferation. The scaffold topography had a significant impact on the orientation of the cells, with very aligned cultures on the aligned scaffold, and randomly oriented cells on the unaligned scaffold. The scaffold alignment and the ELP4 coating impacted the extracellular matrix gene expression. The ELP4 coating, and the aligned scaffolds promoted elastin synthesis when tested on day 7, and may also reduce collagen-3 expression on day 3. These results signify that aligned electrospun scaffolds, as well as an ELP4 coating, may be promising to use in future biodegradable vocal fold constructs. / Thesis (Master, Chemical Engineering) -- Queen's University, 2013-09-26 09:49:22.891
4

The tectonic evolution of Epirus, northwest Greece

Waters, David William January 1994 (has links)
No description available.
5

Pressures and Flows for a Convergent and Divergent Oblique Glottis of 15 Degrees

Whitfield, Jason A. 04 April 2012 (has links)
No description available.
6

Recognition of secondary structure by the molecular chaperonin groEL

Preuss, Monika Kathrin January 1999 (has links)
No description available.
7

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.
8

The Influence of Mechanical Stratigraphy on Thrust-Ramp Nucleation and Propagation of Thrust Faults

Wigginton, Sarah S. 01 December 2018 (has links)
Our current understanding of thrust fault kinematics predicts that thrust faults nucleate on low angle, weak surfaces before they propagate upward and forms a higher angle ramp. While this classic kinematic and geometric model serves well in some settings, it does not fully consider the observations of footwall deformation beneath some thrust faults. We examine an alternative end-member model of thrust fault formation called “ramp-first” fault formation. This model hypothesizes that in mechanically layered rocks, thrust ramps nucleate in the structurally strong units, and that faults can propagate both upward and downward into weaker units forming folds at both fault tips. To explore this model, we integrate traditional structural geology field methods, two dimensional cross section reconstructions, and finite element modeling. Field data and retro-deformable cross sections suggest that thrust faults at the Ketobe Knob, in Utah nucleated in strong layers and propagated upward and downward creating folds in weak layers. These findings support the hypothesis that thrust faults and associated folds at the Ketobe Knob developed in accordance with the ramp-first kinematic model.We can apply this understanding of the mechanics behind thrust fault nucleation and propagation in mechanically layered stratigraphy to a wide range of geological disciplines like structural geology and tectonics, seismology, and petroleum geology. By incorporating our knowledge of lithology into fault models, geologists are more likely to correctly interpret structures with limited data sets.
9

The Allegorical Fold. Evoking physical and psychological presence and absence in the painting of folded fabric.

Fraser, Terrie A., tfra5205@bigpod.net.au January 2008 (has links)
In this project notions of presence and absence will be explored through a study of 'the fold'. I will closely examine a number of paintings that depict folded drapery or cloth and from this examination I will select examples that evoke a response in me to these fundamental states of being, My objective is to produce a body of paintings that explore the structure of the fold and its expression through light, shadow and darkness to develop a range of images that metaphorically represent these phenomena and the possibility of a relational field between the two. This examination will re-present, reinterpret, fragment and transform the selected images using the materials of oil painting and drawing to visualize my response to the changing perceptions of this phenomenon. This investigation is informed by philosophical and psychoanalytical writings that explore the phenomenology of states of presence and absence. In part, these states are suggested by other terminologies, for example, form and space or volume and void. The project draws on the work of writers who have examined and changed perceptions of this phenomenon, particularly where they attribute the structure of absence to contribute to an understanding of subjectivity, question the favouring of presence in Western thought and explore the relationship between the two.
10

Kinematic and Mechanical Reconstruction of Walker Ridge Structures, Deepwater Gulf of Mexico

Majekodunmi, Oluwatosin Eniola 2009 December 1900 (has links)
Recent high-resolution seismic imaging has allowed detailed reconstruction of the relationship between fold development and crestal faulting of the Chinook and Cascade folds in the deepwater Gulf of Mexico. Using 3-D seismic and biostratigraphic data, we have found that (1) short wavelength (~2300m), small amplitude folds (~540m) within the upper Cretaceous and upper Jurassic stratigraphic sequences took place no later than the late Jurassic, (2) large wavelength and amplitude fold growth, starting in the early Cretaceous, was produced by salt withdrawal, and (3) periods of increased sedimentation, fold growth, and fault slip occurred during the middle Miocene and late Miocene. Although the dominant stage of long wavelength, large amplitude fold growth started around early Cretaceous, the development of the Cascade and Chinook structures was continuous, punctuated by episodes of accelerated growth during the middle Miocene at rates of 337 and 235 m/Ma in the Cascade and 203 and 230 m/Ma in the Chinook. A later event of accelerated growth occurred during the late Miocene at rates of 1038 m/Ma in the Cascade and 1189 m/Ma in the Chinook. Accompanying fold growth was sedimentation, which was highest at 1949 m/Ma in the Cascade and 2585 m/Ma in the Chinook. Although limb tilt rates varied through fold growth, the highest rates also occurred during the middle Miocene at 0.330 and 0.196 degree/Ma for the Cascade and Chinook, respectively with the development of crestal faults at maximum slip rates of 88 and 90 m/Ma.

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