We consider the amplitudes of coastally trapped Rossby waves in a high-latitude shear flow on a modified ß-plane, where also the effect of the sphericity of the earth (c5-effect) is taken into account. We present a particular analytical solution and also asymptotic and numerical solutions. We find that the asymptotic WKB solutions are accurate compared to the numerical results. We show that the o-effect is most important for shorter waves and leads to an enhanced selection of trapped Rossby wave modes. / Wir betrachten die Amplituden von küstennah gefangenen Rossby-Wellen in einer Scherströmung hoher Breiten. Die Rechnungen werden auf einer modifizierten ß-Ebene durchgeführt, die auch die Spherizität der Erde berücksichtigt (o-Effekt). Wir zeigen eine spezielle analytische Lösung und auch asymptotische und numerische Lösungen. Die asymptotischen WKB-Lösungen erweisen sich als genau, verglichen mit den numerischen Resultaten. Der o-Effekt wirkt sich a stärksten bei den sehr langen und den kurzen Wellen aus und führt zu einer stärkeren Selektion von Moden gefangener Rossby-Wellen.

In this thesis, I present field, microstructural, and Electron Backscatter Diffraction (EBSD) analyses of rock fabrics from high strain zones in exposures of lower crustal Cretaceous plutons at Breaksea Entrance, Fiordland, New Zealand. The interplay between deformation and metamorphism occurs across multiple scales at the root of a continental arc. I show a series of steps in which retrogressive metamorphism is linked to the accommodation of deformation. I define three main phases of deformation and metamorphism at Breaksea Entrance. The first phase (D1) involved emplacement of dioritic to gabbroic plutons at depths up to 60 km. The second phase (D2) is characterized by deformation and metamorphism at the granulite and eclogite facies that produced high strain zones with linear fabrics, isoclinal folding of igneous layering, and asymmetric pressure shadows around mafic aggregates. New structural analyses from Hāwea Island in Breaksea Entrance reveal the development of doubly plunging folds that define subdomes within larger, kilometer-scale gneiss domes. The development and intensification of S2 foliations within the domes was facilitated by the recrystallization of plagioclase and clinopyroxene at the micro-scale (subgrain rotation and grain boundary migration recrystallization), consistent with metamorphism at the granulite and eclogite facies and climb-accommodated dislocation creep. EBSD data show a strong crystallographic preferred orientation in plagioclase during D2 deformation. The third phase (D3) is characterized by deformation and metamorphism at the upper amphibolite facies that produced sets of discrete, narrow shear zones that wrap and encase lozenges of older fabrics. Structural analyses reveal a truncation and/or transposition relationship between the older S2 and the younger S3 foliations developed during D3. Progressive localization of deformation during cooling, hydration, and retrogression, resulted in the breakdown of garnet and pyroxene to form hornblende, biotite, fine plagioclase and quartz. EBSD data show a strong crystallographic preferred orientation in hornblende. During D3, hornblende and biotite accommodated most of the strain through fluid-assisted diffusion creep. The last two events (D2 and D3) reflect a transition in deformation and metamorphism during exhumation, as well as a focusing of strain and evolving strain localization mechanisms at the root of a continental arc. An examination of structures at multiple scales of observation reveals that fabrics seen in the field are a composite of multiple generations of deformation and metamorphism.

This study combines structural field data with microstructural observations in an analysis of a mid-crustal shear zone related to the emplacement of the Misty pluton during a high-flux magmatic event in Northern Fiordland, New Zealand. These high-flux magmatic events transport massive amounts of heat and material as they develop along accretionary continental margins, and represent a primary source of continental crust. Fiordland, New Zealand possesses, perhaps, the most extensive middle and lower crustal exposure of these systems on earth. Therefore, this study area provides a significant opportunity to understand processes of continental crust formation in the mid-crust and how these events relate to the broader construction of continents. Herein, I document the four-stage geologic history of the Cozette Burn field area. Pre-existing structures along the Gondwana accretionary margin hosted a regional flare-up magmatic event that produced the Misty pluton and several other large plutons of the West Fiordland Orthogneiss (WFO). This study primarily focuses on the mid-crustal emplacement of the Misty pluton during oblique convergence along the accretionary margin, forming the upper-amphibolite facies Misty Shear Zone (MSZ). The exposures of the MSZ within the Cozette Burn preserve rare structural relationships between host rock and the intrusive Misty pluton. Together, these structures developed during end-stage contractional tectonics that constructed a long-lived (~270+ Ma) composite batholith. Heterogeneous ductile shearing defines the MSZ, with microstructural evidence indicating an interplay of high-temperature crystal plastic deformation along with partial melting of host rock and melt channeling. This resulted in focused, melt-assisted shearing under regional transpressive deformation. These accommodative processes provided an efficient mechanism for moving heat, fluids and magma sourced from the lower crust/mantle boundary into the mid-crust during 15-25 km of crustal thickening related to arc flare-up magmatism. This flare up magmatism and MSZ formation occurred during the final stages of crustal thickening along Gondwana continental margin. High-strain, mylonitic- ultramylonitic shear zones developed in a later phase of deformation, cutting MSZ fabrics near contacts between the Misty pluton and host rock. These more localized shear zones can be attributed to either accommodation of localized melt-pressure buildup or the shift to extensional tectonics. Brittle faulting cut these structures with oblique-thrust in the Tertiary. These mid-crustal structures carry economic relevance: thickened-crust events along accretionary continental margins produce deep-crustal sourced, metal-bearing magmas that are transferred into mid-crust prior to their hydrothermal emplacement as ore deposits in the upper crust. The lasting influence of these processes warrants consideration when assessing continental crust architecture at all scales.

Enamel decalcification caused by poor oral hygiene is a significant problem in orthodontics. Bioactive glass-containing resins have been shown to release Ca2+ ions into surrounding solution. The purpose of this study was to determine the shear bond strength of four different compositions of orthodontic resin prepared with bioactive glass (N=20). Premolars were bonded using one of four BAG-BOND compositions. Brackets were debonded and ARI scores were given. The mean shear bond strength was 7.23 ± 2.47 MPa (62 BAG-BOND), 8.25 ± 2.87 MPa (65 BAG-BOND), 8.78 ± 3.08 MPa (81BAG-BOND) and 5.80 ± 2.27 MPa (85 BAG-BOND). 65 and 81 BAG-BOND were significantly higher than 85 BAG-BOND. The 62 BAG-BOND group was not statistically significantly different from any other group. All groups exhibited a cohesive bond failure and were not statistically significant from each other. Three compositions of the novel orthodontic adhesive exhibited adequate bond strength for clinical applications.

Fumed silica filler has long been used to structurally reinforce silicone elastomers. Unfortunately, the combination of as little as a few weight percent of untreated fumed silica nanoparticles [uFSN] with a siloxane polymer, such as PDMS, forms a difficult to process waxy solid admixture that even long periods of high shear mixing will not thin. In the course of the current work it was noted that after a period of storage certain solid admixtures would become viscous liquids when subjected to additional high shear mixing. It was further found that the required aging period could be decreased if the admixture storage temperature were increased. The only known interaction of PDMS and uFSN at moderate conditions is the adsorption of polymer on filler, and this interaction is also known to occur more quickly at higher temperature. This study examines the relationship between polymer adsorption and admixture liquefaction. Further, the mechanical properties of cured elastomers containing liquefied admixtures are examined to assess the degree of reinforcement that these materials afford.

Determining the factors affecting drizzle formation in marine boundary layer (MBL) clouds remains a challenge for both observation and modeling communities. To investigate the roles of vertical wind shear and buoyancy (static instability) in drizzle formation, ground-based observations from the Atmospheric Radiation Measurement Program at the Azores are analyzed for two types of conditions. The type I clouds should last for at least 5h and more than 90% time must be nondrizzling and then followed by at least 2h of drizzling periods, while the type II clouds are characterized by mesoscale convection cellular structures with drizzle occur every 2 to 4h. By analyzing the boundary layer wind profiles (direction and speed), it was found that either directional or speed shear is required to promote drizzle production in the type I clouds. Observations and a recent model study both suggest that vertical wind shear helps the production of turbulent kinetic energy (TKE), stimulates turbulence within cloud layer, and enhances drizzle formation near the cloud top. The type II clouds do not require strong wind shear to produce drizzle. The small values of lower tropospheric stability (LTS) and negative Richardson number (R-i) in the type II cases suggest that boundary layer instability plays an important role in TKE production and cloud-drizzle processes. By analyzing the relationships between LTS and wind shear for all cases and all time periods, a stronger connection was found between LTS and wind directional shear than that between LTS and wind speed shear.

The research in this dissertation was undertaken because of a need for a more accurate, reliable and relatively simple method for determining the combined loading (i.e., axial, flexure and shear) along rock bolts. This combined load determination and understanding also resulted in a relatively simple and reliable new rock bolt design methodology. The new design method was based on a clearer understanding of the actual loading along a grouted rock bolt. To accomplish these research goals, double shear tests were conducted in the lab with reinforced concrete specimens, and field trials were conducted in room and pillar coal mines, with the aim to measure in-situ rock shear. Strain measurements were obtained using rock bolts instrumented with optical fibers that possessed high spatial resolution (≈ 1.25 – 2.5 mm). Corroboration with a past database of rock bolt measurements in shale aided in the deduction of the final support design method. The scientific contributions from this research include the conceptualization of a ground reaction curve that considers time effects such as rock relaxation, long term weakening effects, and lateral rock movement. A new explanation as to why rock bolts creep in practice (i.e., dislocation creep) is described based upon field measurements, which also indicated that the process of in-situ rock shear involves slow episodic movements. Specifically, there are localized compression (i.e., rock pinch) and tensile zones (i.e., dilatation) prior to the occurrence of plastic relief (i.e., rock slip). Finally, the design method is developed using simple factors (i.e., strain and shape factors) and loading conditions (e.g., installed load, rock slip) that occurred throughout the rock bolt’s design life. This approach results in a methodology that considers effects on reinforcement with time and combined loadings. The method is then extended by producing survival and hazard functions for rock bolts to ultimately reduce risk associated with design.

Orientador: Sandro D, Mancini / Banca: Sandra Andrea Cruz / Banca: Rogerio Scatena Biscaro / Resumo: O processo de fabricação das pás de turbinas eólicas envolve a colagem de estruturas fabricadas em plásticos reforçados com fibra de vidro. Neste trabalho foram analisadas os três principais tipos de adesivos estruturais utilizados pelos fabricante de pás (epóxi, poliuretano e metil-metacrilato), com o objetivo de desenvolver critérios que auxiliem na seleção de adesivos e de tratamentos superficiais aplicados às estrutuaras a serem coladas. A caracterização dos adesivos envolveu dois tipos de ensaios mecânicos: o cisalhamento de juntas de sobreposição simples e a clivagem de juntas adesivas. Dois tipos de tratamento das superfícies dos aderentes foram utilizados: camada de sacrifício removível (peel-ply) e abrasão. Também foi realizada a análise dos modos de falha das juntas ensaiadas como auxílio de compatibilidade entre adesivo e substrato. Os resultados mostram que o tratamento via peel-ply foi o mais eficiente para as juntas coladas com epóxi e testadas em cisalhamento, ao apresentar um aumento de 28% na resistência em relação às superfícies sem tratamento. Imagens de microscopia eletrônica de varredura sugerem que esse tratamento gerou uma área maior de contato em relação à superfície não tratada e que causou menos danos à superfície do aderente do que o método abrasivo. Os grupos colados com adesivo metil metacrilato, independentemente do tipo de tratamento, obtiveram os maiores valores nos ensaios de clivagem, cerca de 170% superiores aos demais grupos. Para estruturas de pás corretamente projetadas para evitar cargas de peeling em suas juntas adesivas, este trabalho mostra que a melhor opção são aderentes tratados com peel-ply e colados com epóxi. Contudo, um plano de testes deve ser elaborado sempre que houver a necessidade do emprego de um novo adesivo ou método de preparação superficial / Abstract: The manufacturing process of wind turbine blades involves the bonding of structures made of glass reinforced plastic. This work analyzes the theree main types of structural adhesives used by blades manufactures (epoxy, polyurethane and methyl methacrylate), with the goal of developing criteria to assist in the selection of adhesives and surface treatments applied to the structures to be bonded. The characterization of the adhesives involved two types of mechanical tests: single lap shear joints and cleavage of adhesive joints. Two types of surface treatment of the adherents were used: removable sacrifical layer (peel-ply) and abrasion. The joint failure mode analysis was also carried out as an aid to the study of compatibility between adhesive and substrate. The results show that treatment via peel-ply was the most efficient for epoxy bonded substrates tested in shear, by presenting a 28% increase in strengh compared to untreated surfaces. Images of scanning electron microscopy suggest that this treatment led to a larger area of contact relative to untreated surfaces and caused less damage to the substrate's surface than the abrasive method. The groups bonded with methyl methacrylate regardless the type of treatment, had the highest values in the cleavage test, approximately 170% higher than other groups. For propertly designed blades, that avoid peeling loads in their adhesive joints, this work shows that the best option are substrate treated with peel-ply and bonded with epoxy. However, a test plan should be prepared whenever there is the necessity of using a new adhesive or method of surface preparation / Mestre

A presente dissertação enfoca as características de resistência ao cisalhamento e os mecanismos básicos que governam o fenômeno de atrito em rochas fraturadas. Especial atenção é dedicada à identificação de fatores geométricos e geotécnicos importantes e a sua relação com o comportamento e esforços resistentes de rochas fraturadas. A caracterização de fraturas por meio de parâmetros geomecânicos adequados permitirá incluí-los nos modelos de cálculo e simular mais realisticamente o comportamento geomecânico do maciço rochoso fraturado. / This thesis focuses on the shear strenght and mechanisms that change the shear characteristics of jointed rocks. Special attention was devoted to the identification of geometric and geotechnical factors and its relationship with the behavior and strenght of jointed rocks. The characterization of the fractures by apropriated geomechanical parameters Will permite to include them in the models and to simulate more realistically the behavior of fractured rock mass.

O comportamento de solos reforçados depende amplamente da interação entre o solo e o reforço, baseado nas solicitações que o conjunto experimentará ao longo da sua vida útil. Tal interação é comumente caracterizada através de ensaios normatizados como o de arrancamento, que buscam simular as solicitações a que o conjunto estará sujeito. Porém, algumas estruturas reforçadas experimentam ações cíclicas de cargas móveis consideráveis, que dificilmente tem seu comportamento representado nestes ensaios comuns. Diante disso, esta pesquisa buscou aperfeiçoar o equipamento de ensaios cíclicos da Escola de Engenharia de São Carlos EESC-USP, a fim de realizar ensaios cíclicos em diferentes tipos de solos (uma areia, um silte argiloso e uma brita graduada simples), reforçados com uma geogrelha de poliéster comumente utilizada para reforço de base de pavimentos. Após esta etapa se iniciaram os ensaios de arrancamento nos solos, fornecendo parâmetros para a realização dos ensaios cíclicos. No arrancamento a areia apresentou ganho de resistência com o aumento da tensão confinante, e os maiores deslocamentos, já o silte e a brita não sofreram influência deste aumento. O comportamento cíclico causou desconfinamento da areia e degradação do reforço na brita, apresentando o comportamento mais estável no silte. Durante os ensaios o reforço apresentou grandes deformações conforme solicitado, o que contribuiu para os valores de módulos de resiliência abaixo dos descritos na literatura, que utiliza corpos de prova curtos e diferentes níveis de tensões. Nos ensaios cíclicos a areia variou seu módulo relativamente pouco com as variações de tensão confinante e cisalhante, o silte foi mais sensível à variação da cisalhante e a brita variou igualmente com as duas. / The behavior of reinforced soils depends largely on the interaction between soil and reinforcement, based on requests that the group will experience throughout its service life. Such interaction is commonly characterized by standardized tests such as the pullout, which seek to simulate the stresses to which the group is subject. However, some reinforced structures experience cyclic loads by considerable moving loads, that their behavior is hardly represented in these common tests. Thus, this research sought to improve the equipment of cyclic tests of the School of Engineering of São Carlos EESC-USP, in order to perform cyclic tests on different types of soil (one sand, clayey silt and a simple graded gravel), reinforced with one polyester geogrid commonly used for reinforcing pavements base. After this step began the pullout tests on soils, providing parameters for the realization of the cyclic tests. In the pullout tests, the sand had resistance gain with confining tension increasing and greater displacements, already silt and gravel not affected by this increase. The cyclical behavior caused deconfinement of sand, and the gravel causes degradation of reinforcement, with the more stable behavior on silt. During the test, the reinforce presented large deformations as requested, which contributed to the values of resilience modules below in the literature, which uses specimens shorter and different tension levels. In the cyclic tests the sand modulus varied relatively little with confining pressure and shear variations, the silt was more sensitive to the variation of shear and gravel also varied with both.