Orientadores: Martin Tygel, Eduardo Filpo Ferreira da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-25T22:08:42Z (GMT). No. of bitstreams: 1 Cardoso_ClaudioGuerra_M.pdf: 5757657 bytes, checksum: 5b4ea3b5608c625fce78a747dffdf8e0 (MD5) Previous issue date: 1999 / Resumo: Atualmente, cerca de 90% das reservas brasileiras de óleo localizam-se nas porções submersas das bacias sedimentares costeiras. Nessas bacias, a sísmica de reflexão é uma das principais ferramentas de que dispõe o profissional de exploração e de desenvolvimento de campos de petróleo. Como a interpretação dos dados sísmicos considera somente as reflexões primárias, é necessário que estes estejam livres de ruídos, particularmente, da reflexão múltipla do fundo do mar, que é o ruído mais danoso em dados marítimos. A presente dissertação descreve um método novo de eliminação de múltipla do fundo do mar de 1ª ordem em configuração de afastamento fonte - receptor comum, por empilhamento Kirchhoff, mostrando exemplos numéricos de aplicação do mesmo em dados sintéticos. Num desses exemplos, no qual concorrem a múltipla e uma reflexão primária - que poderia advir de um refletor de interesse - após a eliminação da múltipla, as diferenças nas amplitudes da primária, quando comparadas com as amplitudes sem a interferência da múltipla, não ultrapassam 5%. Dessa forma, o método, por preservar as amplitudes das primárias após a eliminação da múltipla, se configura como muito adequado à geofísica de reservatórios / Abstract: At present, about 90% of Brazilian oil reserves are located in offshore sedimentary basins. In these basins, reflection seismic is one of the most important tools in exploration and field development. As seismic data interpretation only deals with primary reflections, is important to have noise-free, amplitude preserved primaries. The most harmful noise in marine data is the first-order, sea-bottom multiple reflection. This dissertation describes a new method for first order, sea-bottom, multiple elimination by means of a Kirchhoff - type stacking, in common offset configuration, showing its application to synthetic seismic data. In one of the examples, in which the multiple and a primary reflection interfere, the differences between amplitudes of primary reflection after application of the method and primary computed with no such interference are smaller than 5%. Due to the primaries amplitude-preserving property, this method provides a very reliable image to reservoir geophysics, such as amplitude versus offset analysis (AVO) and seismic attribute determination / Mestrado / Mestre em Engenharia de Petróleo

Geophysical investigation of the subsurface through seismic refraction and reflection methods provides an efficient and non-invasive means towards addressing geologic problems across multiple scales. Both seismic techniques, in an active-source exploration setting, involve inducing acoustic waves into the subsurface and measuring their propagation velocities and amplitudes. These measurements have physically-based relationships with the properties of the underlying strata, thus allowing changes in the seismic measurements to be interpreted with respect to changes in the subsurface geology. Two applications of the seismic method are presented in this dissertation: (1) shallow seismic refraction acquisition and processing applied to the near-surface investigations of soil and regolith, which constitute the Critical Zone (CZ), beneath the upland hillslopes of the Valles Caldera, New Mexico; (2) interpretation of 2-D and 3-D marine seismic reflection data that image the upper 10-km of the crust beneath the Southern Guinea Plateau, offshore Guinea, West Africa. In both cases, the seismic data provide necessary constraints for the generation of accurate subsurface models that permit further geophysical modeling. The near-surface results, presented in Appendix A, provided a rich dataset of weathered thicknesses across hillslopes that supported an investigation of potential relationships between CZ geologic architecture and topographic attributes. Quantified relationships suggest that calibrated predictions based on the topography can provide first-order estimates of regolith thickness across upland landscapes. These results add to the ongoing CZ-science endeavor to understand proposed links between subsurface weathering processes and their surface expressions. In Appendix B, interpretations of high-resolution 3-D seismic data have illuminated deformational structures associated with Mesozoic rifting of the Southern Guinea Plateau. The interpretations were expanded onto regional 2-D seismic profiles, permitting a regional synthesis of the southern margin’s structural evolution. Additional tectonic subsidence and forward-gravity modeling highlight the influence of Jurassic rifting on the Southern Guinea Plateau prior to Early-Cretaceous rifting and separation, as well as crustal thickness estimates from the continental shelf out towards oceanic crust. Lastly, the Guinea-Demerara conjugate plateaus, and their associated deformations, were restored to 100 Ma, revealing an apparent upper-crustal asymmetry between the two margins. Appendix C presents two seismic-exploration methodologies based on 3-D seismic reflection data: (1) the calculation and interpretation of two co-rendered volumetric seismic attributes – most-positive curvature and semblance; (2) numerically modeling the tectonic subsidence of an entire 3-D seismic survey. Both techniques are used to address the inherent difficulty in interpreting the extent to which Jurassic rifting affected the Southern Guinea Plateau. Furthermore, the numerical model of subsidence provides a new exploration technique towards qualitatively and quantitatively assisting in the assessment of potential hydrocarbon-bearing basins.

Renin is the initiator and rate-limiting factor of the renin-angiotensin system, a major mechanism of blood pressure regulation. The synthesis and secretion of this active circulatory enzyme is confined exclusively to the dense core granules of kidney juxtaglomerular (JG) cells where its precursor prorenin is packaged, cleaved to the active form and stored for release on a regulated pathway. Given its importance, surprisingly little is known about this process, in part due to the difficulty in culturing primary JG cells in vitro and the lack of reliable cell lines. The initial aim of the current work was to investigate renin-containing granule dynamics in live JG cells. To achieve this, I attempted to derive novel cell lines from triple transgenic mouse models comprising immortalised granulated or non-granulated JG cells. Due to the nature of JG cells in culture, the use of these cell lines to investigate granulation was not feasible; therefore the culture of primary JG cell culture was modified and enhanced to visualise granule dynamics in live, primary JG cells for the first time. By isolating cells using a Percoll gradient and plating them on fibronectin-coated dishes, rapid and full adhesion of JG cells was achieved, as well as prolonged expression of renin from 3 days to up to 8 days post-isolation. Using this protocol to isolate JG cells from RenGFP renin reporter mice and identifying granules using the acidotropic fluorophore Lysotracker, granule dynamics were investigated in primary JG cells. High resolution, rapid image acquisition was performed using widefield and total internal reflection microscopy, showing that dense core granules respond dynamically to the β-adrenergic agonist isoproterenol, a known renin secretory stimulus. Two different pools of granules of varying granule diameters and dynamic parameters were identified optically, suggesting that separate granule pools were being identified. Mice null for the Ren-1d gene lack renin storage granules in their JG cells, however granulation was restored in Ren1d-null mice carrying a transgene encompassing the human renin (hRen) locus. Therefore in order to investigate the relationship between renin expression and the amount of granulation in JG cells, mice expressing human renin were used. To dissect the granulation phenotype in detail, 2D electron micrographs were taken of JG cells, which were immunogold stained to confirm renin content, and reconstructed in 3D. Female hRen mice showed a significantly higher volume of granulation and an increased granule number compared to males, a finding consistent with the sexually dimorphic expression of the transgene, supporting the hypothesis that granulation in JG cells is dependent on the level of renin expression. The macula densa (MD) is a critical sensor of flow and salt content in the blood; through extensive tubulo-vascular crosstalk known as tubuloglomerular feedback (TGF), it releases key signalling factors stimulating and inhibiting renin synthesis and secretion from JG cells. Ren-1d-/- mice showed a hypercellular and columnar MD plaque, which was not restored by the introduction of the hRen transgene, indicating that TGF may be impaired in these mice. Using an isolated, perfused juxtaglomerular apparatus model it was shown that high salt- and increased flow-induced TGF functioned effectively in Ren1d-/- and huRen+/-Ren1d-/- mice, although animals on a Ren1d-/- background showed decreased sensitivity of glomerular tuft contraction and abnormal calcium signalling within macula densa cells. In conclusion, an appropriate in vitro model was developed for investigating granule dynamics in JG cells, using which granule motion was visualised and quantified for the first time in these cells. Although JG cell granulation is required for normal MD morphology, it was shown to not affect JGA function.

The Kribi-Campo sub-basin is the northernmost of a series of Aptian basins along the coast of West Africa. These extensional basins developed as a result of the northward progressive rifting of South America from West Africa, initiated c. 130 Ma ago. Post-rift sediments of the Kribi-Campo sub -basin contain several regional unconformities and changes in basin-fill architecture that record regional tectonic events. The tectono-stratigraphic evolution and plumbing system has been investigated using a high-quality 3D seismic reflection dataset acquired to image the deep-water Cretaceous-to-Present-day post-rift sediments. The study area is located c. 40 km offshore Cameroon in 600 to 2000 m present-day water depth, with full 3D seismic coverage of 1500 km2, extending down to 6.5 seconds Two-Way Travel time. In the late Cretaceous the basin developed as a result of tectonism related to movement of the Kribi Fracture Zone (KFZ), which reactivated in the late Albian and early Senonian. This led to inversion of the early syn-rift section overlying the KFZ to the southeast. Two main fault-sets - N30 and N120 - developed in the center and south of the basin. These normal faults propagated from the syn-rift sequences: the N120 faults die out in the early post-rift sequence (Albian time) whilst N30 faults tend to be associated with the development of a number of fault-related folds in the late Cretaceous post-rift sequence, and have a significant control on later deposition. The basin is filled by Upper Cretaceous to Recent sediments that onlap the margin. Seismic facies analysis and correlation to analogue sections suggest the fill is predominantly fine-grained sediments. The interval also contains discrete large scale channels and fans whose location and geometry were controlled by the KFZ and fault-related folds. These are interpreted to contain coarser clastics. Subsequently, during the Cenozoic, the basin experienced several tectonic events caused by reactivation of the KFZ. During the Cenozoic, deposition was characterized by Mass Transport Complexes (MTCs), polygonal faulting, channels, fans and fan-lobes, and aggradational gullies. The main sediment feeder systems were, at various times, from the east, southeast and northeast. The plumbing system shows the effects of an interplay of stratigraphic and structural elements that control fluid flow in the subsurface. Evidence for effective fluid migration includes the occurrence of widespread gas-hydrate-related Bottom Simulating Reflections (BSRs) 104 - 250 m below the seabed (covering an area of c. 350 km2, in water depths of 940 m - 1750 m), pipes and pockmarks. Focused fluid flow pathways have been mapped and observed to root from two fan-lobe systems in the Mid-Miocene and Pliocene stratigraphic intervals. They terminate near, or on, the modern seafloor. It is interpreted that overpressure occurred following hydrocarbon generation, either sourced from biogenic degradation of shallow organic rich mudstone, or from effective migration from a thermally mature source rock at depth. This latter supports the possibility also of hydrocarbon charged reservoirs at depth. Theoretical thermal and pressure conditions for gas hydrate stability provide an opportunity to estimate the shallow geothermal gradient. Variations in the BSR indicate an active plumbing system and local thermal gradient anomalies are detected within gullies and along vertically stacked channels or pipes. The shallow subsurface thermal gradient is calculated to be 0.052 oC m-1. With future drilling planned in the basin, this study also documents potential drilling hazards in the form of shallow gas and possible remobilised sands linked with interconnected and steeply dipping sand bodies.

University of Macau / Faculty of Science and Technology / Department of Civil and Environmental Engineering

No description available.

Boat-towed high-frequency, short source and receiver spacing, reflection seismic data, 16 profiles and in total 3884 m long, were acquired in 2008 for the planning of the Stockholm Bypass multilane (3 lanes in each direction in two different tubes) underground motorway tunnel designed to ease the ever increasing car traffic on the city and neighbouring regions. The planned bypass will be about 21 km long of which 18 km will be in the form of bedrock tunnel. The planned tunnel will intersect three water passages at where the tunnel will be at around 40-50 m depth. In this study, the seismic data along two of three water passages have been processed and interpreted. Due to the relatively shallow water depth (< 10 m), the main challenge for the reflection data processing was the interferences of strong multiples from lake sediments and bedrock. After a number of tests, it was found that conventional processing methods could not attenuate multiples effectively. Therefore, an optimized workflow based on predictive deconvolution de-multiple method was developed. The new workflow proved to be effective at suppressing multiple reflections, while primary reflections as well as diffraction signals could be well preserved. After carefully attenuating the multiples in the pre-stack and post-stack domains, processing continued with time-to-depth conversion for data interpretations. To reduce uncertainty with time-to-depth conversion errors, bathymetry data available from the study area were used to match the water-sediment interface that also generated a clear reflection in the data. Bedrock surface shows strong undulations, which is typical for the Scandinavian geology from steep valleys to sometimes sub-horizontal at some parts of the water passages. Nevertheless, a dominant bedrock valley-type direction can be recognized striking in the same direction as the water passages. The planned tunnel at the nearest point is estimated to locate approximately 19 m below bedrock surface, which is important factor for the excavation planning of the tunnel and its reinforcements. The steep valley-shaped bedrock may also imply a zone of weakness, fault and/or fracture zone, where the water passages were formed and the reflection seismic data clearly depict this shape under the overlying saucer-shaped unconsolidated sediments.

The complex human process of sport coaching is a dynamic and evolving practice that develops over a long period of time. Coaches learn from a number of different situations and their past experiences influence what they choose to pay attention to and learn from (Werthner & Trudel, 2009). This dissertation explores the lifelong learning process through a collective case study involving four coaches for athletes with a physical disability. The theoretical framework that guides this study is Jarvis’ (2006, 2007, 2009) comprehensive view on human learning, including his concept of lifelong learning, and key concepts such as biography, experience and disjuncture, and types of learning. Jarvis' psychosocial perspective on human learning is a useful lens for a closer examination of how coaches develop over a lifetime and how they change and continue the process of becoming through new experiences, which they gain, more often than not, within a social context. The work of Moon (1999, 2004) and her metaphor of a network view of learning is a complementary framework for examining learning through reflective practice. Moon's generic view of learning (1999) illustrates how a network of knowledge, feelings and emotions make up one’s "cognitive structure" and suggests that this structure plays an important role in the learning process as it guides what we choose to pay attention to and what we choose to learn. A thematic analysis (Braun & Clarke, 2006) was used to extract themes and examples from three in-depth interviews with each coach, observation of the coach in their coaching contexts, as well as interviews with key collaborators in their coaching practice. The transcripts were member checked to increase trustworthiness. Three articles comprise the results section and the main points in this dissertation are as follows: (a) a case study of one exemplary parasport coach and how he learned through a wide variety of life experiences, such as pragmatic problem solving, education, and building relationships; (b) the four coaches who engaged in social learning through meaningful interactions with a variety of key collaborators who contributed to their learning and coaching practice; and (c) the four coaches who used reflection to learn and to build their coaching practices within the unique context of the parasport world. These findings contribute to the emerging body of literature on coaches for athletes with disabilities by adding to our understanding of how coaches’ life experiences and biographies determine what kinds of learning opportunities they each found meaningful; the importance of the social context in learning to coach athletes with disabilities; and the role and importance of reflection in understanding the interconnections of learning from life experiences, particularly in the unique and developing parasport setting. The study will also aid coach educators in understanding the role and importance of past learning experiences and the social context in coach learning.

The capability to map anthropogenic aerosol quantities and properties over land can provide significant insights for climate and environmental studies on global and regional scales. One of the primary challenges in aerosol information monitoring is separating two signals measured by downward-viewing airborne or spaceborne instruments: the light scattered from the aerosols and light reflected from the Earth's surface. In order to study the aerosols independently, the surface signal needs to be subtracted out from the measurements. Some observational modalities, such as multispectral and multiangle, do not provide enough information to uniquely define the Earth's directional reflectance properties for this task due to the high magnitude and inhomogeneity of albedo for land surface types. Polarization, however, can provide additional information to define surface reflection. To improve upon current measurement capabilities of aerosols over urban areas, Jet Propulsion Laboratory developed the Multiangle SpectroPolarimetric Imager (MSPI) that can accurately measure the Degree of Linear Polarization to 0.5%. In particular, data acquired by the ground-based prototype, GroundMSPI, is used for directional reflectance studies of outdoor surfaces in this dissertation. This work expands upon an existing model, the microfacet model, to characterize the polarized bidirectional reflectance distribution function (pBRDF) of surfaces and validate an assumption, the Spectral Invariance Hypothesis, on the surface pBRDF that is used in aerosol retrieval algorithms. The microfacet model is commonly used to represent the pBRDF of Earth's surface types, such as ocean and land. It represents a roughened surface comprised of randomly oriented facets that specularly reflect incoming light into the upward hemisphere. The analytic form of the pBRDF for this model assumes only a single reflection of light from the microfaceted surface. If the incoming illumination is unpolarized, as it is with natural light from the Sun, the reflected light is linearly polarized perpendicular to the plane that contains the illumination and view directions, the scattering plane. However, previous work has shown that manmade objects, such as asphalt and brick, show a polarization signature that differs from the single reflection microfacet model. Using the polarization ray-tracing (PRT) program POLARIS-M, a numerical calculation for the pBRDF is made for a roughened surface to account for multiple reflections that light can experience between microfacets. Results from this numerical PRT method shows rays that experience two or more reflections with the microfacet surface can be polarized at an orientation that differs from the analytical single reflection microfacet model. This PRT method is compared against GroundMSPI data of manmade surfaces. An assumption made regarding the pBRDF for this microfacet model is verified with GroundMSPI data of urban areas. This is known as the Spectral Invariance Hypothesis and asserts that the magnitude and shape of the polarized bidirectional reflectance factor (pBRF) is the same for all wavelengths. This simplifies the microfacet model by assuming some surface parameters such as the index of refraction are spectrally neutral. GroundMSPI acquires the pBRF for five prominent region types, asphalt, brick, cement, dirt, and grass, for day-long measurements on clear sky conditions. Over the course of each day, changing solar position in the sky provides a large range of scattering angles for this study. The pBRF is measured for the three polarimetric wavelengths of GroundMSPI, 470, 660, and 865nm, and the best fit slope of the spectral correlation is reported. This investigation shows agreement to the Spectral Invariance Hypothesis within 10% for all region types excluding grass. Grass measurements show a large mean deviation of 31.1%. This motivated an angle of linear polarization (AoLP) analysis of cotton crops to isolate single reflection cases, or specular reflections, from multiple scattering cases of light in vegetation. Results from this AoLP method show that specular reflections off the top surface of leaves follow the Spectral Invariance Hypothesis.

Understanding the behaviour of polymers which are located in the presence of nuclear materials is important in order to predict the lifespan of the materials. Artificial ageing experiments are undertaken at elevated temperatures to infer how the materials may age. This study was concerned with the monitoring of trace gases (H2O, CO2, CO and acetic acid) within a materials ageing vessel which contained ethylene-vinyl acetate (EVA) polymer and uranium in order to deduce the rate of polymer degradation and/or uptake of the gases by uranium. A novel circular multi-reflective (CMR) cell was designed, developed and deployed in situ in order to extend the optical pathlength within the vessel to improve detection limits of the trace gases. One cell was located at the 6 millimetre solid/solid interfacial region between cylindrical coupons of the EVA polymer and uranium, to enable representative sampling in proximity to where the gases were evolved, adsorbed or reacted. The unique planar star-like beam profile of the CMR cell was crucial in enabling detection within this narrow interfacial region. A second CMR cell was incorporated within the vessel headspace, above the two material coupons, to address a specific research problem which aimed to ascertain whether differences in the gaseous composition existed between the two regions, which would indicate poor gas mixing. Two spectroscopic techniques were employed in conjunction with the CMR cells to monitor the trace gases: these comprised broadband absorption spectroscopy (BBAS) and tunable diode laser absorption spectroscopy (TDLAS). Near-infrared (IR) radiation sources, in the form of diode lasers, a superluminescent light emitting diode (SLED) and supercontinuum (SC) source were utilised in BBAS experiments. TDLAS was used for the detection of CO2, CO and H2O, whilst BBAS was used for the detection of acetic acid, and other potential unknown species. The requirement for using near-IR radiation was a consequence of using flexible silica-based optical fibres to remotely monitor the vessel which was located within a temperature controlled chamber. As a result, this was the first demonstration of CMR cells being used in conjunction with near-IR radiation sources. An optical pathlength of 69 cm was achieved within the materials ageing vessel, which led to the following limits of detection at 75 °C, 150 Torr with a 10 second averaging time: H2O = 3 ppm; acetic acid = 157 ppm; CO2 = 596 ppm and CO = 37500 ppm. Manufacturing issues with the cell optics, coupled with monitoring weak ro-vibrational absorption features led to considerably higher limits of detection than expected. The CMR spectroscopic system was used successfully to observe the outgassing trend of partially cured EVA polymer, which was shown to depend on cure time. A key finding of this research, however, was the observation of a difference between the interfacial gaseous composition versus the headspace gas in a system that contained both a source and sink material (i.e. one that evolved, and one that adsorbed gases). This was only made possible by using the CMR spectroscopic system. This observation was also supported by a computational fluid dynamic (CFD) model.