Esta dissertação tem por objetivo a implementação de um código para simular problemas hidrodinâmicos, bem como a possibilidade de controlar as elevações de onda resultantes numa determinada região por meio de uma vazão ótima controlada dentro do sistema estudado. O algoritmo implementado é baseado nas equações de águas rasas, as quais são aplicáveis em situações onde a altura d’água é de ordem muito menor do que as dimensões do sistema, que é discretizado espacial e temporalmente pelo Método dos Elementos Finitos e pelo método CBS (Characteristic Based-Split), respectivamente. O método de controle consiste na busca de uma curva de vazão de controle ótima que minimize a função objetivo, a qual compara os valores de altura d’água que se deseja encontrar em uma região especificada com os calculados pela simulação numérica. Para isso, utiliza-se um algoritmo evolutivo SCE-UA (Shuffled Complex Evolution – University of Arizona), que busca otimizar parâmetros de geração das curvas de vazão de controle, podendo estas serem modeladas por NURBS (Non- Uniform Rational B-Splines), que são capazes de encontrar a solução ótima, ou modeladas com curvas de forma triangular (linear) ou parabólica (quadrática) que apresentam uma solução aproximada de fácil implementação. Por fim, várias aplicações são realizadas, tanto para a simples simulação, quanto para o controle de problemas hidrodinâmicos, a fim de validar os algoritmos desenvolvidos e os resultados obtidos mostraram que os objetivos foram alcançados, encontrando uma forma eficiente de se fazer o controle de enchentes. / Implementation of a computational code for the numerical simulation of hydrodynamic problems as well as the ability to control the resulting wave elevations in a specific area, using an optimal flow controlled within the studied system are the aims of this work. The implemented algorithm is based on the shallow waters equations, which are applicable in situations where the water height is much smaller than the system dimensions, and are spatial and temporally discretized by the Finite Element Method and the CBS method (Caractheristic Based-Split), respectively. The control method consists in finding an optimal control flow curve that minimizes the objective function, which compares the objective value of water elevations in a specified region with those calculated by numerical simulation. An evolutionary algorithm called SCE-UA (Shuffled Complex Evolution - University of Arizona), which looks for optimize parameters of control flow curves generation, is used. These curves may be modeled by NURBS (Non-Uniform Rational B-Splines) which are able to find the optimal solution, or by curves of triangular (linear) or parabolic quadratic forms, which are an approximate solution easy to implement. Finally, several applications are performed for both simulation and control of hydrodynamic problems in order to validate the developed algorithms, and the results showed that the aims of this work were reached, finding an efficient way to control floods.

Na cidade de São Paulo, é freqüente a ocorrência de escorregamentos, causando a destruição de moradias e muitos danos econômicos com vítimas fatais e aumentando, a cada ano, o número de áreas de risco. O objetivo geral desta pesquisa é analisar o grau de risco e a suscetibilidade a escorregamentos translacionais rasos na bacia do rio Limoeiro, localizada na cabeceira da bacia do rio Aricanduva, uma das principais da cidade de São Paulo. Especificamente, objetiva-se, identificar e analisar as principais intervenções antropogênicas (classes de uso do solo) no período 1973-2007, identificar em escala de zoneamento e caracterizar espacialmente as áreas de risco, caracterizar e analisar o papel dos parâmetros topográficos e avaliar a concordância entre o mapa de risco e o de suscetibilidade. No mapeamento de risco, foi elaborada uma ficha de campo para avaliar o grau de risco em quatro escalas: R1 (baixo risco), R2 (médio), R3 (alto) a R4 (muito alto). A análise evolutiva do uso do solo foi realizada pela interpretação de fotografias aéreas. A partir de um Modelo Digital do Terreno foram gerados os mapas de ângulo, aspecto, curvatura e área de contribuição e calculada a Freqüência de Distribuição (FD), que foram correlacionados com o mapa de risco, gerando-se dois índices: Concentração de Risco (CR) e Potencial de Risco (PR). Na análise da suscetibilidade a escorregamentos foi utilizado o modelo matemático SHALSTAB (Shallow Landsliding Stability) e calculados os índices de FD, de CR e de PR. A última etapa consistiu numa análise conjunta entre os mapas de risco e de suscetibilidade, na qual foi verificada a concordância ou discordância em cada setor de risco. A análise evolutiva do uso do solo, mostrou uma redução de 36% de cobertura vegetal e o aumento de 23% de áreas urbanas no período 1973-2007. Foram mapeados 16 setores de risco contendo aproximadamente 1872 moradias, sendo 6 setores com grau muito alto de risco (R4). Topograficamente, as áreas mais suscetíveis foram aquelas com ângulos superiores a 16,8°, orientadas para SW, com formas côncavas e com os maiores valores de área de contribuição. O mapa de suscetibilidade apresentou 41% de áreas Estáveis e 20% de áreas Incondicionalmente Instáveis que, embora em menor proporção, apresentaram uma CR de 40% com PR de 12%. Concluiu-se que houve concordância entre as áreas previstas como instáveis pelo modelo com as áreas de risco mapeadas, acreditando-se que a combinação destes métodos possa ser aplicada na avaliação final do risco a escorregamentos em áreas urbanas, podendo subsidiar a gestão pública na definição de áreas instáveis para a ocupação. / In the city of São Paulo, landslides occur frequently, causing the destruction of houses and economic damage with fatalities and the number of areas threatened by landslides has been increasing each year. The general objective of this research is to analyze the probability of risk and susceptibility to shallow landslides in the Limoeiro River basin, which is located at the head of the Aricanduva River basin, one of the main in the city of São Paulo. Specifically, the objective is to identify and analyze major anthropogenic interventions (land use classes) in 1973 to 2007 period, identify scale zoning and characterize spatially the risk areas, characterize and analyze the role of topographic parameters and assess the correlation between the risk areas and susceptibility maps. To map risk areas, we created a cadastral survey form to evaluate landslide risk in the field into four levels: R1 (low risk), R2 (average risk), R3 (high risk), and R4 (very high risk). To land use evolutionary analyses, was made the aerial photographs interpretation. From a Digital Elevation Model were generated slope angle, aspect, curvature and contributing area maps and calculated the Frequency Distribution (FD), that subsequently, these maps were correlated with the risk map, generating two indexes: Risk Concentration (RC) and Risk Potential (RP). To analyze susceptibility to landslides, we used the SHALSTAB (Shallow Landsliding Stability) mathematical model and calculated the FD, RC and RP. The last step was a joint analysis of the risk areas and of the susceptibility maps, which was verified the agreement or disagreement on each risk sector. From the land use evolutionary analysis, there was a 36% reduction of plant cover and increase of 23% in urban areas in the period 1973-2007. We mapped 16 risk sectors containing approximately 1872 at-risk homes, with 6 sectors with very high risk degree (R4). Topographically, the most susceptible areas those located at slope angles above 16,8°, oriented southwest quadrant, with concave forms with the largest contributing area. In the susceptibility map, 41% of the area was classified as stable and 20% as unconditionally unstable. Although the latter category accounted a smaller proportion of the total area, it contained a RC of 40% with a RP of 12%. We found that the locations of areas predicted to be unstable coincided with the risk areas mapped and this combination of methods can be applied to evaluate the landslides risk in urban areas and can assist public managers in defining areas that are unstable for occupation.

In this study, the development and testing of a finite-difference model for wind-induced flow in shallow lakes, and, in particular, a new technique for improving the land--water boundary representation, are documented. The model solves nonlinear, as well as linear, versions of the two-dimensional depth-integrated shallow water equations. Finite-difference methods on rectangular grids are widely used in numerical models of environmental flows. In these models, land--water boundaries are usually approximated by a series of perpendicular line segments, which enable the impermeability condition to be easily implemented. A disadvantage of this approach is that the actual boundary is often poorly approximated, particularly in regions which have complicated coastlines, and, as a result, currents in these regions cannot be accurately predicted. A technique for improving the land--water boundary representation in finite-difference models is introduced. This technique permits the model boundary to contain diagonal line segments, in addition to the vertical and horizontal line segments used in traditional models. The new technique is based on a simple concept and can easily be included in existing finite-difference models. In order to test the new method, the linearised shallow water equations are solved numerically for oscillatory wind-driven flow in lakes with simple geometry. Predictions obtained using the new approach are compared with predictions from the traditional stepped boundary and known analytic solutions. A significant improvement in the accuracy of results is noticed when the new approach is used, particularly in currents close to shore. The increased accuracy obtained using the improved boundary representation can lead to a significant computational saving, when compared with running the rectangular grid model with smaller grid spacings. A second-order analytic solution to the nonlinear shallow water equations is developed for oscillatory wind-driven flow in a rectangular lake. Comparisons between this solution and numerical results, obtained using the traditional stepped boundary and the improved boundary, verify the finite-difference formulae used in these models, including the approximations used for the cross-advective terms close to shore. Once more, currents are predicted with greater accuracy when the new technique for representing the land--water boundary is implemented. The lake circulation model is applied to the Lower Murray Lakes, South Australia, and predicted water levels at Tauwitchere Barrage are shown to agree very well with observations. The model is then used to examine the effectiveness of two schemes that have been proposed to increase wind-induced circulation, and therefore potentially decrease salinity, in Lake Albert, demonstrating the model's use as an efficient and effective tool for analysing flow behaviour in lakes. / Thesis (Ph.D.)--Mathematical Sciences (Applied Mathematics), 2005.

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<p>Methane is an important green house gas as it is responsible for 15-20 % of the green house effect. Marine environments in general and shallow near-coastal waters specifically may be important contributors of methane emissions but are as of today poorly studied.  In this study we measured total fluxes of methane from shallow near-coastal waters at two sites along the east coast of Sweden. The sea-to-air emissions of methane where captured using floating chambers. This gave measured fluxes as compared to earlier studies of the Baltic Sea where calculated fluxes are often used. Measured fluxes have the merit of not having to rely on several highly varying and complex variables e.g. mean wind speed and piston velocity that vary and give an uncertainty to the results.  The fluxes ranged from -2.14 to 0.37 mg CH4 m-2 d-1 with a mean of 0.05 mg CH4 m-2 d-1. The results show a correlation, however not strong, between depth and methane. No difference in flux between the study sites could be seen. We look forward to further studies using floating chambers on shallow near-coastal waters with longer sampling periods to catch seasonal variations.</p>

<p>Uppsatsen tar upp Arne Naess djupekologi. Den undersöker djupekologins struktur och vilka krav som ställs på en teori för att den skall vara en djupekologi. Uppsatsen tar även upp skillnader mellan djupekologi och grundekologi på en praktisk nivå. Uppsatsen behandlar Warwick Fox kritik rörande djupet i djupekologin och Arne Naess svar på den kritiken. Författaren till uppsatsen finner att Fox kritik inte är helt träffande och att Naess svar på kritiken är för svag.</p> / <p>This paper discusses Arne Naess’ theory of deep ecology. It investigates the structure of deep ecology and what conditions a theory has to fulfil to be a deep ecology. The paper demonstrates differences between deep ecology and shallow ecology on a practical level. The paper presents a criticism put forward by Warwick Fox which focuses on the deepness of deep ecology, and an answer from Arne Naess on this criticism. The author of this paper finds Fox’ criticism not quite convincing, and that Naess’ answer is too weak.</p>

Methane is an important green house gas as it is responsible for 15-20 % of the green house effect. Marine environments in general and shallow near-coastal waters specifically may be important contributors of methane emissions but are as of today poorly studied.  In this study we measured total fluxes of methane from shallow near-coastal waters at two sites along the east coast of Sweden. The sea-to-air emissions of methane where captured using floating chambers. This gave measured fluxes as compared to earlier studies of the Baltic Sea where calculated fluxes are often used. Measured fluxes have the merit of not having to rely on several highly varying and complex variables e.g. mean wind speed and piston velocity that vary and give an uncertainty to the results.  The fluxes ranged from -2.14 to 0.37 mg CH4 m-2 d-1 with a mean of 0.05 mg CH4 m-2 d-1. The results show a correlation, however not strong, between depth and methane. No difference in flux between the study sites could be seen. We look forward to further studies using floating chambers on shallow near-coastal waters with longer sampling periods to catch seasonal variations.

A new shallow junction formation process, based on selective silicon etching followed by selective growth of in situ B-doped SiGe, is presented. The approach is advantageous compared to conventional ion implantation followed by thermal activation, because perfectly abrupt, low resistivity junctions of arbitrary depth can be obtained. In B-doped SiGe layers, the active doping concentration can exceed the solid solubility in silicon because of strain compensation. In addition, the compressive strain induced in the Si channel can improve drivability through increased hole mobility. The process is integrated by performing the selective etching and the selective SiGe growth in the same reactor. The main advantage of this is that the delicate gate oxide is preserved. The silicon etching process (based on HCl) is shown to be highly selective over SiO2 and anisotropic, exhibiting the densely packed (100), (311) and (111) surfaces. It was found that the process temperature should be confined between 800 ºC, where etch pits occur, and 1000 ºC, where the masking oxide is attacked. B-doped SiGe layers with a resistivity of 5×10-4 Ωcm were obtained. Well-behaved pMOS transistors are presented, yet with low layer quality. Therefore integration issues related to the epitaxial growth, such as selectivity, loading effect, pile-up and defect generation, were investigated. Surface damage originating from reactive-ion etching of the sidewall spacer and nitride residues from LOCOS formation were found to degrade the quality of the SiGe layer. Various remedies are discussed. Nevertheless, high-quality selective epitaxial growth could not be achieved with a doping concentration in the 1021 cm-3 range. The maximum doping level resulting in a high-quality layer, with the loading effect taken into account, was 6×1020 cm-3. After this careful process optimization, a high-quality layer was obtained in the recessed areas. Finally, Ni mono-germanosilicide was investigated as a material for contact formation to the epitaxial SiGe layers in the recessed source and drain areas. The formation temperature is 550 ºC and it is stable up to 700 ºC. The observation of a recessed step and lateral growth of the silicide led to a detailed treatment of the contact resistivity of the NiSi0.8Ge0.2/Si0.8Ge0.2 interface using 2-D as well as 3-D modeling. Different values were obtained for square shaped and rounded contacts, 5.0x10-8 Ωcm2 and 1.4x10-7 Ωcm2, respectively. / QC 20101028

The thesis describes the application of the relaxation labelling algorithm to NLP disambiguation. Language is modelled through context constraint inspired on Constraint Grammars. The constraints enable the use of a real value statind "compatibility". The technique is applied to POS tagging, Shallow Parsing and Word Sense Disambigation. Experiments and results are reported. The proposed approach enables the use of multi-feature constraint models, the simultaneous resolution of several NL disambiguation tasks, and the collaboration of linguistic and statistical models. / La tesi descriu l'aplicació de l'algorisme d'etiquetat per relaxacio (relaxation labelling) a la desambiguació del llenguatge natural. La llengua es modela mitjançant restriccions de context inspirades en les Constraint Grammars. Les restriccions permeten l'ús d'un valor real que n'expressa la "compatibilitat". La tècnica s'aplica a la desambiguació morfosintàctica (POS tagging), a l'anàlisi sintàctica superficial (Shallow Parsing) i a la desambiguació semàntica (Word Sense Disambigation), i se'n presenten experiments i resultats. L'enfoc proposat permet la utilització de models de restriccions amb trets múltiples, la resolució simultània de diverses tasques de desambiguació del llenguatge natural, i la col·laboració de models linguístics i estadístics.

Linking diagenesis to depositional facies and sequence stratigraphy enables better prediction of spatial and temporal distribution of diagenetic alterations, and thus of evolution of reservoir quality in sandstones. This thesis demonstrates that employing this approach is possible because depositional facies and sequence stratigraphy can provide useful information on parameters controlling the near-surface diagenesis, such as changes in: (i) pore-water chemistry, (ii) residence time of sediments under certain geochemical conditions, (iii) detrital composition and proportion of extra- and intra-basinal grains, and (iv) types and amounts of organic matter. Evidence from four case studies enabled the development of conceptual models for distribution of diagenetic alterations and of their impact on evolution of reservoir quality in sandstones deposited in paralic, shallow marine and fluvio-lacustrine environments. Diagenetic alterations that have been constrained within the context of depositional facies and sequence stratigraphy include: (i) carbonate cement (microcrystalline and equant calcite spars dolomite over poikilotopic calcite), pyrite and glaucony are most abundant in progradational braid-delta fan sequences, particularly along the topsets (i.e. maxiumum flooding surface, MFS) and along parasequences boundaries in the deltaic facies of the early highstand systems tract HST, (ii) cementation by coarse spar calcite, dolomite, and the formation of moldic porosity by the dissolution of framework carbonate grains are most abundant in the aggradational fan deltas sequences, (iii) eogenetic kaolinitization of framework silicates is largely restricted to the fluvial and paralic HST sandstones, whereas telogenetic kaolinite may occur in the transgressive systems tract TST sandstones too, (iv) formation of goethite ooids in the TST sediments, (v) formation of glaucony, siderite spherules, and extensive grain-coatings, grain-replacing and ooidal berthierine, more in the TST than in the HST sediments, particularly below the transgressive surface TS and MFS, (vi) cementation by calcite with (δ18OV-PDB = -11.5‰ to -5.4‰) and Fe-dolomite/ankerite (δ18OV-PDB = -10.8‰ to -9.6‰) occurs in both TST and HST sandstones, (vii) syntaxial quartz overgrowths are most extensive in the HST sandstones owing to the presence of incomplete grain-coating berthierine/chlorite, (viii) greater amounts of micro-porosity in the TST sandstones than in the HST sandstones are related to the greater amounts of berthierine/chlorite in the former sandstones, and (ix) chlorite rims around quartz grains retarded the precipitation of quartz overgrowths, and hence prevented a greater loss of primary intergranular porosity in fluvio-lacustrine sandstones. Therefore, constraining the distribution of diagenetic alterations in the contexts of depositional facies and sequence stratigraphic context is a powerful approach to be used in hydrocarbon exploration.