ix, 68 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / In 1958 Yanktonai Sioux painter Oscar Howe's (1915-1983) submission to the Annual National Indian Painting Competition at the Philbrook Museum of Art was rejected for deviating too far from the established conventions of "traditional Indian painting." Howe's innovative use of style and his subsequent declarations against the premises of his rejection established the artist as a major figure in the development of Native American painting in the twentieth century. The existing literature on Howe is predominantly biographical and lacks contextual or stylistic analysis. In particular, an under-analyzed relationship is prevalent between his mature style and his early works. This thesis aims to address the social, cultural, educational, political, and stylistic influences that prepared the artist to evolve the formal aspects of his painting. This discussion will expand the discourse on Howe by revealing trends of continuity in the artist's transition from his earlier style to an experimental style and showing that neither is without the influence of the other. / Committee in Charge: Leland M. Roth, Chair; Joyce Cheng; Brian Klopotek

Debris torrents (channelized debris flows) are a geomorphological process only relatively recently recognised in southwest British Columbia. They are of interest both because of the tremendous amount of geomorphic work they do, and because of the hazards they pose to engineering works and residential developments. Fourteen torrents on the east side of Howe Sound, near Vancouver, since October 1981, have claimed twelve lives. Debris torrents differ from water floods in that they involve large amounts of coarse organic and inorganic debris. Therefore, a major requirement for torrent occurrence in a given channel is a supply of mobilizable debris. This thesis examines debris supply mechanisms and rates of debris supply in four small watersheds along Howe Sound, near the village of Lions Bay. An inventory of major debris sources has been compiled, and selected typical sites are examined in detail. Study methods include airphoto interpretation, ground surveying and reconnaissance, field instrumentation and site monitoring, dendrochronology, and materials sampling and testing. Debris supply is controlled by natural factors such as the nature and distribution of the bedrock and surficial materials, topographic gradient, vegetation, weather, and surface and groundwater hydrology, and by human activities such as logging and road construction. A wide variety of debris supply mechanisms operate in the study area, including rockfall and rockslide, talus shift, debris slide, soil wedge failure, ravelling, and snow avalanche. In addition to delivering debris to channel systems, some of these processes are capable of triggering debris torrents. Debris redistribution in channels occurs through debris torrents which do not reach the fans, fluvial processes (bedload transport), and snow avalanches. Active debris removal from main supply points, and storage elsewhere in the channel system, can decrease the frequency but increase the magnitude of torrent events in the basin. The wide variety of debris supply, debris redistribution, and torrent triggering mechanisms acting in this relatively small area points to a need for careful study of individual basins if the torrent potential in an area is to be understood. Regionally-based climatological or hydrological models of torrent occurrence should be employed for preliminary hazard assessment only. / Arts, Faculty of / Geography, Department of / Graduate

Studies were carried out to determine the circulation of water in the northern basin of Howe Sound, a small fjord on the mainland coast of British Columbia, and to determine the extent of the influence of the winds, the tide and river runoff on the circulation. In one experiment, surface-layer drogues were tracked by radar for four periods each of approximately three days duration. Data sere recorded photographically, then digitized for computer processing. Cubic spline interpolation was used to produce positions, velocities and accelerations at one minute intervals along every drogue track. The interpolated data were averaged in a suitable manner to produce pseudo-Eulerian estimates of velocity. Near the head of the fjord, both wind and tide appeared to cause temporal fluctuations in the surface current of magnitude similar to the expected mean flow due to the river. The river was the cause of spatial inhomogeneity in the flow, but did not appear to be a significant source of temporal variations. Farther down the inlet, wind forcing was the dominant cause of temporal variations in the surface-layer flow of about five times the magnitude of the expected mean river-driven flow. At no distance along the fjord was the velocity observed to be laterally uniform. Lateral gradients of long-channel velocity were strong at the inlet head and decreased away from it, indicating that the fresh water from the river was slowly mixing across the inlet. Another experiment using drogues at three depths in the upper 6 m of the water indicated that the velocity structure was not uniform, either laterally or with depth. Analysis was done on data from six current meters moored in the northern basin of Howe Sound. The mean currents from these meters showed a surface-layer outflow and a return inflow in the waters just below. A mean down-inlet current was seen at 150 m, 80 m below sill depth. Spectra of the currents showed dominant peaks at diurnal and semi-diurnal periods. The wind was coherent with the currents at 3m for periods longer than 10 hours. Below this depth, no consistent relationship was seen. In the diurnal band, the currents were strongest at the surface, indicative of forcing from the surface by the wind. In the semi-diurnal band, the currents were strongest at 10m depth. Both bands also showed a phase variation with depth indicative of a baroclinic structure. These results were compared with some models for surface-layer behaviour. The first model assumed that the wind momentum input was distributed uniformly throughout the surface layer and that the layer was not frictionally coupled to the deeper waters. Drag coefficients calculated from the wind stress and drogue acceleration gave values of 1 to 2x10-3, similar to values measured in other ways. This model was only valid for the first few hours after the onset of the wind. Another model, developed by Farmer (1972), analysed the behaviour of the surface layer of a semi-infinite canal under the influence of a steady wind stress. It predicted correctly the length of time of wind dominance of the flow, the magnitude of the velocity change and the magnitude of the acceleration of the water. A baroclinic tidal model in a two-layer fjord, adapted from Rattray (1960), correctly predicted the phase of the surface-layer currents near the head of a fjord with respect to the height of the tide. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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Submitted by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-03-04T17:14:07Z No. of bitstreams: 2 Dissertaçao DOUGLAS DE LIMA.pdf: 10575310 bytes, checksum: 038758641d3f5c3754bab96c873b9c9e (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-04T17:14:07Z (GMT). No. of bitstreams: 2 Dissertaçao DOUGLAS DE LIMA.pdf: 10575310 bytes, checksum: 038758641d3f5c3754bab96c873b9c9e (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013-01-17 / FACEPE / O bambu constitui um material que tem atraído a atenção do meio científico há décadas e muitas aplicações do uso desta gramínea ao longo dos últimos séculos têm sido relatadas na literatura. Entre tais aplicações, destacam-se a fabricação de laminados colados de bambu que, dentro do contexto deste estudo, podem ser aplicados na construção civil. Deste modo, esse trabalho teve como objetivo o estudo de laminados colados de bambu da espécie Dendrocalamus giganteus aplicados na fabricação de treliças planas tipo Howe e de vigas de seção transversal retangular. Realizou-se inicialmente uma extensa revisão bibliográfica sobre o tema e foram avaliados dois tipos de adesivos: um à base de resorcinolformaldeído (CASCOPHEN) e outro à base de poliacetato de vinila (CASCOREZ). Foram realizados ensaios de caracterização físico-mecânica do BLC (bambu laminado colado). Posteriormente, foram ensaiadas 4 (quatro) treliças de BLC com vão livre de 2,5 m e altura de 0,4 m. Para o projeto destas, fez-se a análise prévia de suas ligações utilizando-se três variáveis de estudo: o ângulo de montagem das ligações; o tipo de adesivo e o número de ripas de bambu utilizadas. As treliças foram ensaiadas por meio de aplicação de carga nos três nós superiores e instrumentadas utilizando-se medidores de deslocamentos (LVDT) e extensômetros elétricos (strain gage). Em seguida, foram ensaiadas 15 (quinze) vigas de BLC (bambu laminado colado) com 75,0 cm de vão, 2,88 cm de base e 4,99 cm de altura, por meio de ensaio de Stuttgart. Os resultados destas vigas foram confrontados com vigas de referências fabricadas com madeiras de reflorestamento (Pinho do Paraná e Eucalyptus grandis). As treliças confeccionadas à base de resorcinol-formaldeído apresentaram-se, em média, 42% mais resistentes do que as à base de PVA. Além disso, as vigas confeccionadas à base de resorcinol-formaldeído apresentaram-se, em média, 160% mais resistentes do que as à base de poliacetato de vinila. Por fim, verificou-se que esse novo material (BLC) apresenta características físico-mecânicas comparáveis as madeiras nobres dicotiledôneas e as estruturas estudadas (treliças e vigas) apresentaram desempenho estrutural excelente.

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La présente thèse s'inscrit dans le cadre de travaux sur la représentation de Weil. Elle consiste en trois parties. Aux chapitres 2 et 3, on généralise la correspondance de Howe aux groupes de similitudes sur un corps local non archimédien de caractéristique résiduelle impaire. Aux chapitres 4 et 5, on répond dans beaucoup de cas à une question, soulevée par V. Drinfeld, sur la représentation de Weil de GSp8(F) de restreinte à un groupe GL2(A), où A est une algègre étale sur un corps local ou fini F. D'autre part, au chapitre 5, on montre que sur un corps fini, les représentations de Weil sont compatibles au changement de base au sens de Shintani-lift. / This present thesis is working on the Weil representation. It consists of three parts. In chapter 2 and chapter 3, we generalize the Howe correspondance for the similitudes groupes over the non archimedien field with odd residual characteristic. In chapter 4 and chapter 5, we answer one question, raised by V. Drinfeld, about the restriction of the Weil representation of the group GSp8(F) to GL2(A) where A is an étale algebra over a non archimedien field or a finite field F. On the other hand, in the chapter 5, we prove that in finite field case, the Weil representations are invariant under the operator of base change in the sens of Shintani-lifting.

Gap, outflow, or Squamish wind, is the cold low level seaward flow of air through fjords which dissect the coastal mountain barrier of northwestern North America. These flows, occurring mainly during winter, can be strong, threatening safety, economic activity and comfort. Howe Sound gap winds were studied using a combination of observations and several types of models. Observations of winds in Howe Sound showed that gap wind strength varied considerably along the channel, across the channel and vertically. Generally, winds increase down the channel, are strongest along the eastern side, and are below 1000 m depth. Observations were unable to answer all questions about gap winds due to data sparseness, particularly in the vertical direction. Therefore, several modelling approaches were used. The modelling began with a complete 3-dimensional quasi-Boussinesq model (CSURAMS) and ended with the creation and testing of models which are conceptually simpler, and more easily interpreted and manipulated. A gap wind simulation made using RAMS was shown to be mostly successful by statistical evaluation compared to other mesoscale simulations, and by visual inspection of the fields. The RAMS output, which has very high temporal and spatial resolution, provided much additional information about the details of gap flow. In particular, RAMS results suggested a close analogy between gap wind and hydraulic channel flow, with hydraulic features such as supercritical flow and hydraulic jumps apparent. These findings imply gap wind flow could potentially be represented by much simpler models. The simplest possible models containing pressure gradient, advection and friction but not incorporating hydraulic effects, were created, tested, and found lacking. A hydraulic model, which in addition incorporates varying gap wind height and channel geometry, was created and shown to successfully simulate gap winds. Force balance analysis from RAMS and the hydraulic model showed that pressure gradient and advection are the most important forces, followed by friction which becomes an important force in fast supercritical flow. The sensitivity of gap wind speed to various parameters was found from sensitivity tests using the hydraulic model. Results indicated that gap wind speed increases with increasing boundary layer height and speed at the head of channel, and increasing synoptic pressure gradient. Gap wind speed decreases with increasing friction, and increasing boundary layer height at the seaward channel end. Increasing temperature dilterences between the cold gap wind air and the warmer air aloft was found to increase the variability of the flow — higher maximum but lower mean wind speeds.

Gap, outflow, or Squamish wind, is the cold low level seaward flow of air through fjords which dissect the coastal mountain barrier of northwestern North America. These flows, occurring mainly during winter, can be strong, threatening safety, economic activity and comfort. Howe Sound gap winds were studied using a combination of observations and several types of models. Observations of winds in Howe Sound showed that gap wind strength varied considerably along the channel, across the channel and vertically. Generally, winds increase down the channel, are strongest along the eastern side, and are below 1000 m depth. Observations were unable to answer all questions about gap winds due to data sparseness, particularly in the vertical direction. Therefore, several modelling approaches were used. The modelling began with a complete 3-dimensional quasi-Boussinesq model (CSURAMS) and ended with the creation and testing of models which are conceptually simpler, and more easily interpreted and manipulated. A gap wind simulation made using RAMS was shown to be mostly successful by statistical evaluation compared to other mesoscale simulations, and by visual inspection of the fields. The RAMS output, which has very high temporal and spatial resolution, provided much additional information about the details of gap flow. In particular, RAMS results suggested a close analogy between gap wind and hydraulic channel flow, with hydraulic features such as supercritical flow and hydraulic jumps apparent. These findings imply gap wind flow could potentially be represented by much simpler models. The simplest possible models containing pressure gradient, advection and friction but not incorporating hydraulic effects, were created, tested, and found lacking. A hydraulic model, which in addition incorporates varying gap wind height and channel geometry, was created and shown to successfully simulate gap winds. Force balance analysis from RAMS and the hydraulic model showed that pressure gradient and advection are the most important forces, followed by friction which becomes an important force in fast supercritical flow. The sensitivity of gap wind speed to various parameters was found from sensitivity tests using the hydraulic model. Results indicated that gap wind speed increases with increasing boundary layer height and speed at the head of channel, and increasing synoptic pressure gradient. Gap wind speed decreases with increasing friction, and increasing boundary layer height at the seaward channel end. Increasing temperature dilterences between the cold gap wind air and the warmer air aloft was found to increase the variability of the flow — higher maximum but lower mean wind speeds. / Arts, Faculty of / Geography, Department of / Graduate

Temperature microstructure observations obtained in Howe Sound are presented and related to their oceanographic context, In some instances, two free-falling probes have been launched simultaneously with separations of 10 to 20 m at the surface in an attempt to look at the lateral extent of temperature microstructure features. Patches of temperature gradient variance were found where the gradient presented peak values of both signs at smaller scales. These patches were usually observed by one probe only and seem to extend laterally over less than 20 m. In other instances the peak gradient values took mostly the same sign within a given patch. Such patches were usually detected by both probes, indicating that their horizontal extent is significantly larger than 20 m. These types of temperature microstructure are also discussed in terms of mechanisms that could provide an explanation for their existence. In Howe Sound's Inner Basin, the Deep Water occasionally receives large influxes of water from the Strait of Georgia. Otherwise, it stays essentially trapped behind a 75 m deep sill and becomes more homogeneous with time. A model is presented which relates the rate at which temperature becomes homogeneous to temperature gradient variance and the molecular coefficient of heat diffusion. Other parts of the water column are discussed in terms of the Osborn-Cox (1972) model of vertical heat transport. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Unknown