La experiencia adquirida en las líneas de alta velocidad en explotación comercial ha puesto de relieve la importancia de la rigidez vertical de la vía y en particular la conveniencia de limitar su magnitud para minimizar los esfuerzos transmitidos a la estructura y su consecuente deterioro. Sin embargo, la dispersión de soluciones adoptadas para la superestructura de las líneas de nueva construcción en Europa pone de manifiesto que todavía no existe ningún criterio que establezca cual debe ser la magnitud de diseño de la rigidez vertical de una vía. La presente tesis analiza esta problemática para el caso de vías sobre balasto en el ámbito del diseño de nuevos trazados de alta velocidad. El importante papel de la rigidez vertical en el deterioro de la calidad geométrica de la vía, así como en las resistencias al avance de los vehículos, confirman el interés en lograr un valor de este parámetro que optimice los respectivos costes económicos asociados. En base a los conocimientos disponibles se desarrolla una metodología que permite evaluar dicho impacto económico y a su vez establecer un rango de valores de rigidez vertical óptima en función de la magnitud de los principales parámetros característicos de la línea en estudio (material circulante, condiciones de explotación, coste energético, etc.). Los resultados alcanzados indican que, para una vía de alta velocidad con un importante volumen de tráfico y bajo la perspectiva dual señalada, el valor de rigidez vertical óptimo se sitúa entre 70 kN/mm y 80 kN/mm. Por otra parte, se reflexiona sobre como lograr un diseño estructural de la vía que permita alcanzar el valor óptimo de rigidez vertical en función de las características de la infra-estructura de la línea en estudio. Se evidencia que para una vía típica de alta velocidad, la rigidez de la superestructura ferroviaria debe situarse entorno a 60 kN/mm. A su vez, se analiza la incidencia de las dispersiones de rigidez vertical de la vía a lo largo de un trazado, estableciendo un criterio de máxima variación de ese parámetro entre traviesas consecutivas, que permita prevenir un deterioro acelerado de la vía en zonas puntuales y garantizar la validez del modelo desarrollado. Se comprueba que las máximas variaciones admisibles oscilarían entre 20% y 50% según la rigidez vertical de referencia, criterio muy difícil de cumplir en vías excesivamente rígidas, pero que se cumple siempre si la superestructura ferroviaria corresponde al valor óptimo definido en este estudio. / The experience gained since the beginning of commercial operation on high-speed lines has confirmed the importance of the track vertical stiffness parameter and, specially, the need to limit its value to minimize the track stress level and avoid its excessive deterioration. However, the wide range of solutions adopted for the super-structure on the new European high-speed lines confirms that there is still no design criteria that defines clearly what should be the desired vertical stiffness of the track. The aim of this thesis is to approach this issue from the viewpoint of the design of new high speed ballasted tracks. The significance of the track vertical stiffness on the deterioration of its geometrical quality as well as on the energetic consumption of the rolling stock confirms the interest of reaching a value for this parameter that optimise the costs related to both factors. Therefore, this thesis develops a methodology that allows to define a range of this optimum value, based on the most relevant parameters of a given line (rolling stock characteristics, energy cost, running speed, etc.). It is shown that for a high-speed line with a significant traffic volume, the optimum track vertical stiffness threshold, from the mentioned dual perspective, would be situated 70 and 80 kN/mm. In another hand, the study focus on how to reach this optimum value depending on the infra-structure characteristics of the line. It is seen that for a typical high-speed line, the optimum stiffness of the super-structure is about 60 kN/mm. Additionally, an analysis of the influence of track stiffness dispersion along a route is carried out. Based on the results obtained, the establishment of a criteria that limits the maximum variation of this parameter between consecutive sleepers is proposed, as to avoid an accelerated track deterioration on some punctual locations and to guarantee the validity of the developed model. It is shown that the maximum admissible variations would be situated between 20% to 50% depending on the reference stiffness value, a level very difficult to achieve on track with an excessive stiffness, but that is always accomplished if the track super-structure is close to the defined optimum value.

En Cataluña se presentan episodios de contaminación por ozono troposférico, especialmente en verano. El complejo comportamiento del ozono, su interacción con la atmósfera y sus efectos sobre la calidad del aire, pueden ser analizados con un Modelo de Transporte Químico (MTQ). Los inventarios de emisiones proporcionan la distribución espacial y temporal de los precursores de ozono (NOx, COV) y de otros contaminantes que requiere un MTQ. EMICAT2000 es un modelo de alta resolución espacial (1 km2) y temporal (1 hora) desarrollado en un entorno SIG, para la obtención de inventarios de emisiones de Cataluña durante el año 2000. Incluye a los principales contaminantes primarios (NOx, COV, CO, SO2 y PST) y gases de efecto invernadero (CO2, CH4 y N2O). EMICAT2000 integra las emisiones diarias, mensuales y anual; permitiendo su uso tanto con fines de política ambiental o modelización fotoquímica.Incluye las emisiones de la vegetación, tráfico vehicular, industrias y las producidas por el consumo de combustibles fósiles y disolventes en los sectores doméstico y comercial. El modelo de emisiones de COV provenientes de la vegetación (isopreno, monoterpenos, otros COV) utiliza el algoritmo de Guenther et al. (1993), adaptado para considerar el particular comportamiento emisor de ciertas especies mediterráneas. Incorpora factores de emisión, definidos mediante la selección exhaustiva de factores de emisión de las especies vegetales más importantes. El modelo de tráfico incluye las emisiones en caliente, en frío y evaporativas; mediante una red digital de las autopistas y de las más importantes carreteras y vías urbanas (con intensidades medias de tráfico mayores a 3000 vehículos). EMICAT2000 utiliza como base el método y los factores de emisión del modelo EMEP/CORINAIR-COPERTIII, e incorpora perfiles de tráfico mensuales, diarios y horarios; diferenciando el parque automotor circulante para días laborables y festivos.Las emisiones industriales incluyen registros reales de emisión de chimeneas conectadas a la Xarxa de control d'emissions (XEAC) del Departament de Medi Ambient; así como las emisiones estimadas de las centrales eléctricas, cementeras, refinerías, plantas de olefinas, industrias del sector químico e incineradoras, principalmente.Estas fuentes definen la configuración espacial y temporal de las emisiones. La potencial agregación de otras fuentes aportará información a nivel de detalle.En el período anual las emisiones estimadas en Cataluña son: 107 kt a-1 de NOx, 137 kt a-1 de NMCOV, 267 kt a-1 de CO, 65 kt a-1 de SO2, 24 kt a-1 de PST y 32 175 kt a-1 de CO2 equivalente. Las principales fuentes de NOx son el tráfico (58%) y la industria (38%). Las principales fuentes de NMCOV son el tráfico (36%), la vegetación (34%), industrias (17%) y uso de disolventes (13%). La especiación de las emisiones corresponde a las categorías del mecanismo Carbon Bond 4, que EMICAT2000 organiza con diferente resolución espacial (1, 2, 4 y 8 km2) de acuerdo al interfaz netCDF para su uso en un MTQ de tercera generación (Models-3/CMAQ). En un día laborable de agosto, el 80 % de las emisiones de NMCOV corresponde a la categoría PAR (enlace parafínico), que es poco reactiva, en tanto que las emisiones de la categoría ISOP (isopreno), representa solamente el 1 %, siendo la más reactiva.El análisis de incertidumbre comprende criterios de tipo interno y externo. Las emisiones más importantes incluyen una evaluación cualitativa de la incertidumbre.EMICAT2000 fue probado exitosamente en el diagnóstico de varios eventos de contaminación fotoquímica. Es la base potencial el análisis del efecto fin de semana, o el pronóstico de la calidad del aire de Cataluña, bajo diferentes escenarios. Es una herramienta que en materia de emisiones proporciona total libertad, flexibilidad y control, pudiendo ser fácilmente explotado en otras regiones de similares características. / Photochemical pollution episodes by ozone take place in Catalonia, mainly during the summertime. The complex ozone behaviour, its interactions with the atmosphere and the effects on air quality could be understood by modelling, using a Chemical Transport Model (CTM). Emission inventories provide the information of the spatial and temporal emissions distribution of the ozone precursors and other pollutants required by this kind of approach.EMICAT2000 is an emission model with high spatial (cells of 1 km2) and temporal (1 hour) resolutions, which was developed into a GIS environment to estimate the emissions from Catalonia during the year 2000. It includes the most important primary air pollutants (NOx, NMVOCs, CO, SO2 and TSP) and greenhouse gases (CO2, CH4 and N2O). EMICAT2000 integrates daily, monthly and yearly emissions, providing information both for environmental policy and photochemical modelling.This model includes the emissions from vegetation, on-road traffic, industries and emissions by fossil fuel consumption and domestic-commercial solvent use. The NMVOCs emission model from vegetation (isoprene, monoterpenes and other NMVOCs) uses the algorithm by Guenther et al. (1993), suited and adapted for describing the particular emitter behaviour of some Mediterranean species. Emission factors by land-use categories were defined, as result of an exhaustive selection of emission factors of the most important vegetal species. A vast database of hourly records of superficial temperature and solar radiation was incorporated.The on-road traffic emission model includes the hot exhaust, cold exhaust and evaporative emissions, using a digital map of the all the highways and the most important roads and streets (daily average traffic > 3000). EMICAT2000 uses the method and emission factors of the European model EMEP/CORINAIR - COPERTIII as basis, and includes monthly, daily and hourly traffic profiles; differencing the vehicle park composition between weekdays and weekends.Industrial emissions include real records of chimneys connected to the emission control net of the Environmental Agency of Catalonia, and the estimated emissions from power stations, cement factories, refineries, olefins plants, chemical industries and incinerators. The sources included define the spatial and temporal configuration of emissions. The potential aggregation of other sources will contribute mainly in details.In the yearly period total emissions from Catalonia were estimated in 107 kt yr-1 of NOx, 137 kt yr-1 of NMVOCs, 267 kt yr-1 of CO, 65 kt yr-1 of SO2, 24 kt yr-1 of TSP and 32,175 kt yr-1 of equivalent CO2. Main NOx sources are on-road traffic (58%) and industries (38%). Most important NMVOCs sources are on-road traffic (36%), vegetation (34%), industries (17%) and use of solvents (13%). Speciation of hourly emissions was established according to the categories of Carbon Bond 4 chemical mechanism. EMICAT2000 generates data files with different spatial resolutions (1, 2, 4 and 8 km2) using the netCDF protocol for the Models-3/CMAQ. According to the categories of the Carbon Bond 4 mechanism, during an August weekday 80% of the NMVOCs emissions belongs to the PAR (paraffins bond) category, which is low reactive; whereas emissions of ISOP (isoprene) category reaches only 1%, being this lumped-species the most reactive.Uncertainty analysis includes both internal (error propagation) and external (comparison with other estimations, photochemical modelling) criteria for model's evaluation. The most important sources include a qualitative assessment of uncertainty.EMICAT2000 was successfully tested diagnosing some photochemical events. It could be the basis for research activities related with the Weekend Effect or the forecasting of air quality in Catalonia under different scenarios. This tool provides total control, freedom and flexibility on the emission topic. Successful results are currently being obtained using the emission inventories provided by EMICAT2000. In addition, it could be easily applied and exploited for other regions with similar characteristics.

This paper describes the concept of traditional education. Educators define traditional education as a way of life, spirituality, an act of love, wholistic, language, and culture. In economics, children learn by observing a skill like setting a snare and then actually snaring something, like a rabbit. This paper includes a history of the Lubicon Lake First Nation, history of the first Indian Mission and Northland School Division. It concludes with the idea that now is the time to develop a unique Lubicon Lake First Nation approach to education. This idea means that the First Nation school has the chance to develop their own system in conjunction with mainstream curriculum, but would include appropriate cultural concepts such as language, native spirituality and history.

Reclaimed oil sands landscapes are perceived to be low in plant diversity compared with naturally occurring plant communities. Approximately 66 Carex species inhabit the oil sand region. This thesis is unique and represents the first large scale study of Carex establishment on reclaimed oil sands landscapes. Research compared diversity and habitat variables between natural ecosystems and reclaimed landscapes, and examined the colonization mechanism for Carex establishment on reclaimed landscapes (i.e., ingress from adjacent natural ecosystems or emergence from the soil seed bank). Low positive associations between the presence of Carex in natural and reclaimed landscapes, and the presence of species on reclaimed landscapes not accounted for in either the forest or edge plots, suggests Carex established from the soil seed bank and less so from natural ingress. Carex share the same seed dispersal mechanisms as many plants, so the implications may apply to a broader range of plant species.

This study explored the extent to which using online communication tools helped NAIT (the Northern Alberta Institute of Technology) denturist students on third-year practica maintain laboratory and clinical standards of treatment. The inquiry was framed by the Community of Inquiry (CoI) framework, and was conducted from a collaborative constructivist approach with quantitative data used to enhance and support a mainly qualitative design. Results showed that all elements of a CoI were present in the online environment and that participants voluntarily used WebCT communications tools for academic and social interaction. Standards of treatment on practical projects completed by the study group were no different than those of cohorts that did not use communications tools. Modifications to instructional practices made comparison of standards achieved on patient cases unfeasible. Study results informed immediate changes made to the online practicum site, and suggestions for long-term pedagogical changes to denturist practica were made.

In this thesis mercury concentrations in biota of the upper South Saskatchewan River Basin are assessed in three non-industrialized systems. Mercury levels in large sport fish (northern pike, walleye, lake trout) frequently exceeded the consumption limit of 0.5ppm. Goldeye and mooneye of the Oldman River and lake whitefish of Waterton Lakes were below 0.5ppm total mercury. Agricultural and urban effluents constituted no sources of significant mercury loadings to the Oldman River. A doubling of mercury biomagnification factors between longnose dace and their food suggests bioenergetic heterogeneity of these fish along the river gradient. Basin-specific mercury levels were detected for the upper and middle basins in Waterton Lakes, and are associated with food web characteristics, and fish bioenergetics. High mercury levels in a new reservoir were in part attributed to increased loadings from flooded soils, as is commonly observed, but also to bioenergetic constraints and growth inefficiency as a result of non-piscivory of this population. / xiii, 130 leaves : ill. ; 29 cm. --

Freshwater and terrestrial ecosystems are connected through biomass exchanges such as the flow of predators, prey, nutrients and detritus between them. Emerging aquatic insects provide an alternate food source to riparian consumers often termed an allochthonous subsidy. Stable isotope analyses of naturally occurring carbon and nitrogen is effective for tracing energetic food sources to consumers. This thesis evaluated whether stable isotope analysis would be effective in the Oldman River Basin, Alberta. Aquatic and riparian primary consumers are distinct in their isotopic signatures and valid for to use in stable isotope analysis. Stable isotope modelling was then used to evaluate the proportional contribution of aquatic insects to riparian spider and beetle diets. Carbon analysis showed an overall aquatic insect contribution of 25 % and 18 % for spiders and beetles, respectively; while nitrogen analysis showed an overall contribution of 36 % and 20 %, respectively. The spatial extent of the aquatic insect contribution upland from the river was shown to decrease from 50 - 55 % at 1 m to 0 % at 30 m for both consumers using carbon, and from 35 - 40 % at 1 m to 0 % at 40 m using nitrogen. Finally, regression modelling of the size of a river and the spatial scale of an aquatic insect dietary contribution showed a significant relationship, indicating larger water bodies support higher production of aquatic insects. A meta-analysis of published literature applied to this model also indicated a significant relationship between the size of the river and the extent of an aquatic insect contribution. / xii, 126 leaves m ; 29 cm

La presente Tesina de Grado tiene como objetivo la investigación y el estudio de las plataformas de memoria compartida GPU y cluster de Multicore para la resolución de problemas con alta demanda computacional. Se presentan soluciones al problema planteado con el fin de comparar rendimiento en sus versiones secuencial, paralela con memoria compartida, paralela con pasaje de mensajes, paralela híbrida y paralela en GPU. Se analiza la bondad de las soluciones en relación al tiempo de ejecución y aceleración, y se introduce el análisis de consumo energético.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this study the possible use of smart structures for noise control in a higher order acoustic duct was considered. The best option for this control was the use of axial splitters in the duct in order to prevent higher order mode propagation. It is possible to perform the active noise control in each splitter section by using a single channel control system. The use of smart structures takes advantage of the splitter plate and uses it as the control source, which substitutes the traditional loudspeakers used in active noise control systems. In order to evaluate the possibility of the noise control using smart structures, an analytical model of a thin plate with piezoelectric actuators was built then the acoustic field generated by this vibrating structure inside of the duct was obtained. However, to obtain the acoustic field inside an splitted duct, a numerical method such as the Component Mode Synthesis has to be used. Using the equation of the acoustic field generated in the duct by the plate, it was possible to obtain the acoustic field inside the splitted duct. After that, the active noise control simulations for harmonic excitations were performed and the influence of the size of the plate excited by the PZT actuators was studied. Finally the active control for random noise was simulated, in which the number of actuators in the plate was changed. In conclusion, it is possible to say that the smart structures can be used in active noise control of ducts with splitters and the advantages and disadvantages of the conveyed technique were presented. / Neste trabalho, foi estudada a proposta da utilização de estruturas inteligentes para o controle de ruído em um duto acústico com propagação de modos de alta ordem. A técnica mais adequada para este controle foi o particionamento do duto a fim de planificar as ondas que se propagam. Nesta região particionada, é possível realizar o controle ativo de ruído utilizando apenas um sensor e um atuador para cada lado da partição. A aplicação das estruturas inteligentes é proposta no sentido de aproveitar a placa particionadora para que, com a sua vibração, atuará como a fonte secundária necessária para o controle. Para a avaliação da possibilidade de controle utilizando esta técnica, primeiramente foi modelado o comportamento de uma placa instrumentada com atuadores piezoelétricos e, em seguida, obtida a modelagem analítica do campo sonoro gerado por uma estrutura vibrante no interior de um duto. Porém, a obtenção do campo acústico em um duto particionado não é facilmente obtido, sendo, então, realizada através da técnica de Síntese Modal de Componentes. Utilizando as equações do duto excitado por uma estrutura vibrante na técnica de síntese modal, foi possível obter campo acústico gerado no interior de um duto particionado. A partir disto, foram realizados simulações de controle ativo de ruído variando o trecho da placa a ser excitado para tons puros e para ruídos de banda estreita. Nesta última situação também foi avaliada a influência da quantidade de atuadores instalados. Concluiu-se deste trabalho que é possível a utilização de estruturas inteligentes no controle ativo de ruído em dutos particionados, sendo apresentadas suas vantagens e desvantagens. / Mestre em Engenharia Mecânica