A transient, one-dimensional, model of the membrane of a proton exchange membrane fuel cell is presented. The role of the membrane is to transport protons from the anode to cathode of the fuel cell while preventing the transport of other reactants. The membrane is modeled assuming mono-phase, multi-species flow. For water transport, the principle driving forces modeled are a convective force, an osmotic force (i.e. diffusion), and an electric force. The first of these results from a pressure gradient, the second from a concentration gradient, and the third from the migration of protons from anode to cathode and their effect (drag) on the dipole water molecules. Equations are developed for the conservation of protons and water, the conservation of thermal energy, and the variation of proton potential within the membrane. The model is solved using a fully implicit finite difference approach. Results showing the effects of current density, pressure gradients, water and heat fluxes, and fuel cell start-up on water concentration, temperature, and proton potential across the membrane are presented. / Master of Science

Diploma work is focused on computational comparison of con-rod of spark ignition four-cylinder engine with volume 1289 cubic centimeters and con-rod of spark ignition three-cylinder engine with volume 1198 cubic centimeters. 3-D models of inspected con-rods were based on real shape. Force loads effects were established after kinematic and dynamic analysis. Stress analysis was made for these force loads effects in selected cases with help of Finite element method. Two con-rods were compared by using of these results.

Two-dimensional (2-D) micro-autoradiography is typically used to identify the location of a radio-labeled ligand bound to a cellular target in tissue sections. Data, such as a histological image, combined with the autoradiographic data provide a spatial relationship of the radiolabel to cellular structures. However, the disadvantage of 2-D imaging is that it only provides a local distribution of the radiolabel within a tissue slice, and not a volumetric regional distribution in the structure of interest. The development of 3-D autoradiographic/histological visualizations would provide important information not otherwise apparent, such as the ability to visualize the distribution of the labeled agents in subcutaneous tissue. We plan to obtain digital micro-autoradiographic images and fuse them to their corresponding histological images using commercially available software. We plan to create a series of 2-D fused images. This series of 2-D fused images will then form a basis for creating 3-D visualization of autoradiographic/histological images using another commercially available software. These type of fused 3-D images, which we will refer to as micro-autoradiographic fusion tomography (MAFT), are not currently available. We will illustrate the use of MAFT with the distribution of vascular endothelial growth factor (VEGF) in subcutaneous tissue. [14C]-VEGF will be injected into rat subcutaneous tissue. VEGF has been found to stimulate angiogenesis, or the growth of new blood vessels, which could prove beneficial by aiding the function of an implantable blood glucose sensor. The diffusion coefficient for VEGF in subcutaneous tissue has not yet been characterized. MAFT would be an ideal technique to use for this type of study. My thesis will address the following specific aims: 1) To label the nicotine receptors in adult and adolescent rat brains, and to obtain digital micro-autoradiographic images and histological images; 2) To fuse a 2-D digital micro-autoradiographic image with a 2-D histological image; 3) To create a 3-D image from a series of 2-D fusion images; and 4) To assess the increased information value obtained using MAFT.

The UK Health & Safety Executive are responsible for advising on ways to ensure the safety of employees within the workplace. One of the main areas of concern is the potential problem of unwanted fire, and it has been identified that within the area of large-scale storage in warehouses, there is an uncertainty posed by large quantities of thermoplastic. Some forms of thermoplastic exhibit melt-flow behaviour when heated, and a large vertical array exposed to a fire may melt and ignite forming a pool fire in addition to a wall fire. This project is largely experimental, and aimed at quantifying the effect of a growing pool fire fuelled by a melting wall on overall fire growth rate. The pool fire has been found to increase melting and burning rates, producing a much faster growing fire. It has also been found that - 80% of flowing and burning material will enter a potential pool fire, with only 20 - 25% of total mass loss actually burning from the original array. During the project 400+ small-scale tests and several medium-scale experiments have been undertaken at both Edinburgh University and the HSE's Fire & Explosion Laboratory, Buxton. The experiments have confirmed the main parameters governing pool fire development are molecular weight degradation rate and mechanism, which control flow viscosity. There have also been investigations into other influences, the most significant of which was found to be flooring substrate. These parameters then form the basis of a simple 1-D model. A semi-infinite heat transfer approximation is used to determine temperature profile through a thermoplastic exposed to its own flame flux, with extrapolated temperature dependant material properties. The derived profile is then inserted into a gravity driven flow model, to produce estimates of flow rate and quantity for plastics undergoing either random or end chain scission thermal degradation processes. The model identifies property data which are required to permit its use as a hazard assessment tool.

A temática da produção de alimentos destaca-se entre as discussões do desenvolvimento sustentável, principalmente por constituir uma das atividades fundamentais para a existência humana, a qual tem sido responsável por inúmeros impactos socioambientais, tais como a destruição das florestas e da biodiversidade genética, a erosão dos solos e a contaminação dos recursos naturais e dos alimentos, bem como o êxodo rural e a concentração de terras. Nesse contexto, a Agroecologia apresenta-se sob um enfoque teórico e metodológico que, agregando diversas disciplinas científicas, se propõe a estudar a atividade agrária sob uma perspectiva ecológica. Sua unidade de análise, portanto, é o agroecossistema, que, a partir de um enfoque sistêmico proporciona as bases científicas para a implantação de agriculturas mais sustentáveis. Assim, percebe-se que a Agroecologia, ao incorporar múltiplas dimensões, promove discussões relacionadas à do desenvolvimento sustentável. Dada a importância de áreas naturais preservadas para a manutenção da biodiversidade e de serviços ecossistêmicos na discussão tanto da Agroecologia como do desenvolvimento sustentável, o objetivo dessa pesquisa foi analisar as diferentes propriedades agroecológicas na área de influência de unidades de conservação do Litoral Norte do estado do Rio Grande do Sul e que fazem parte do Organismo Participativo de Avaliação da Conformidade – OPAC Litoral Norte, a partir do Modelo 3-D de Sustentabilidade de Mauerhofer (2008). Esse modelo foi escolhido porque, além de englobar as três dimensões, ambiental, social e econômica, elas são apresentadas em outro nível de discussão, em um cone, representando uma hierarquia, onde as paredes do cone representam a capacidade de suporte do ambiente, enquanto a base representa o capital ambiental. Interior a esse cone, há outro, em que as paredes representam a capacidade de suporte social e a base o capital social. Da mesma forma, interior a esse segundo cone, há o cone da capacidade econômica e do capital econômico. Os cones estão assim dispostos devido a uma relação de dependência, pois a dimensão social só existe porque há a dimensão ambiental, e a econômica só existe porque há a dimensão social. Portanto, a partir de uma abordagem qualitativa, por meio de entrevistas em profundidade com auxilio de roteiros semiestruturados, a pesquisa foi realizada em seis propriedades agroecológicas do Litoral Norte do Rio Grande do Sul. Uma proposta de operacionalização do modelo 3-D de sustentabilidade de Mauerhofer (2008) foi elaborada, em que os dados coletados resultaram em modelos de triângulo 3-D de sustentabilidade para cada um dos agrossistemas analisados. Um modelo 3- D de sustentabilidade para cada um dos extremos (propriedade sustentável e insustentável) foi também elaborado. Assim, pode-se constatar que os modelos das propriedades rurais analisadas encontram-se bem mais próximos ao modelo da propriedade sustentável, sendo as questões econômicas as que apresentam relações de menor eficiência. Essas propriedades possuem, portanto, inúmeros aspectos que podem contribuir com a efetividade das unidades de conservação. Entre esses aspectos destacam-se a preservação da mata nativa e implantação de sistemas agroflorestais, os quais podem atuar como corredores ecológicos e o envolvimento dos agricultores com os gestores das unidades de conservação, que contribuem para o apoio da população local. / Food production consists in an important topic among the discussions of sustainable development, mainly because of its fundamental role to human existence. However, numerous social and environmental impacts have been generated due to the dominant style of food production, such as the forests destruction and genetic biodiversity lost, soil erosion and contamination of natural resources and food, as well as the rural exodus and the land ownership concentration. In this context, Agroecology is issued as a theoretical and methodological approach that proposes to study the agrarian activity from an ecological perspective, taking into consideration several scientific disciplines for its analysis. The Agroecology unit of analysis is therefore the agroecosystem, which, from a systemic approach, provides the scientific basis for the implementation of more sustainable agriculture. Thus, Agroecology is able to promote discussions related with sustainable development, by incorporating multiple dimensions into its analysis. Given the importance of preserved natural areas for the maintenance of biodiversity and ecosystem services in both discussions, Agroecology and sustainable development, this study aimed to analyze the different agroecological agrosystems located in the influence zone of conservation unities from the North Coast of Rio Grande do Sul which belong to the Participatory Organization for Conformity Assessment (OPAC North Coast) – Organismo Participativo de Avaliação da Conformidade Litoral Norte – from the perspective of 3-D Model of Sustainability of Mauerhofer (2008). This model was chosen because it includes the three sustainable dimensions, environmental, social and economic, which are analyzed through a cone. The cone represents a hierarchy, and its walls mean the carrying capacity of the environment, while the base represents the environmental capital. Inside this cone, there is a second cone, whose walls represent the social carrying capacity and the base represents the social capital. Likewise, inside this second cone, there is a third cone with the economic capacity and economic capital. The cones are arranged through a dependency relationship, since the social dimension only exists because there is the environmental dimension, and economic exists only because there is a social dimension. In order to achieve this purpose, this research had a qualitative approach and it was carried out through in-depth interviews with semi-structured guide in six agroecological farms. An operational proposal of the 3-D sustainability model of Mauerhofer (2008) was elaborated. From that the collected data resulted in models of 3-D sustainability triangle for each agroecosystems. A 3-D sustainability model for each extreme category (sustainable and unsustainable farms) was also elaborated. Thus, the results illustrate that the farms models produced in this research are closer to the sustainable farm model. They also show that economic issues have the lowest efficiency ratios. These farms, however, have many aspects which can contribute to effectiveness of protected areas. Among these aspects, the forest fragments preservation and agroforestry systems implementation can act as ecological corridors and the involvement of these farmers with the protected areas managers can contribute to local population support.

A temática da produção de alimentos destaca-se entre as discussões do desenvolvimento sustentável, principalmente por constituir uma das atividades fundamentais para a existência humana, a qual tem sido responsável por inúmeros impactos socioambientais, tais como a destruição das florestas e da biodiversidade genética, a erosão dos solos e a contaminação dos recursos naturais e dos alimentos, bem como o êxodo rural e a concentração de terras. Nesse contexto, a Agroecologia apresenta-se sob um enfoque teórico e metodológico que, agregando diversas disciplinas científicas, se propõe a estudar a atividade agrária sob uma perspectiva ecológica. Sua unidade de análise, portanto, é o agroecossistema, que, a partir de um enfoque sistêmico proporciona as bases científicas para a implantação de agriculturas mais sustentáveis. Assim, percebe-se que a Agroecologia, ao incorporar múltiplas dimensões, promove discussões relacionadas à do desenvolvimento sustentável. Dada a importância de áreas naturais preservadas para a manutenção da biodiversidade e de serviços ecossistêmicos na discussão tanto da Agroecologia como do desenvolvimento sustentável, o objetivo dessa pesquisa foi analisar as diferentes propriedades agroecológicas na área de influência de unidades de conservação do Litoral Norte do estado do Rio Grande do Sul e que fazem parte do Organismo Participativo de Avaliação da Conformidade – OPAC Litoral Norte, a partir do Modelo 3-D de Sustentabilidade de Mauerhofer (2008). Esse modelo foi escolhido porque, além de englobar as três dimensões, ambiental, social e econômica, elas são apresentadas em outro nível de discussão, em um cone, representando uma hierarquia, onde as paredes do cone representam a capacidade de suporte do ambiente, enquanto a base representa o capital ambiental. Interior a esse cone, há outro, em que as paredes representam a capacidade de suporte social e a base o capital social. Da mesma forma, interior a esse segundo cone, há o cone da capacidade econômica e do capital econômico. Os cones estão assim dispostos devido a uma relação de dependência, pois a dimensão social só existe porque há a dimensão ambiental, e a econômica só existe porque há a dimensão social. Portanto, a partir de uma abordagem qualitativa, por meio de entrevistas em profundidade com auxilio de roteiros semiestruturados, a pesquisa foi realizada em seis propriedades agroecológicas do Litoral Norte do Rio Grande do Sul. Uma proposta de operacionalização do modelo 3-D de sustentabilidade de Mauerhofer (2008) foi elaborada, em que os dados coletados resultaram em modelos de triângulo 3-D de sustentabilidade para cada um dos agrossistemas analisados. Um modelo 3- D de sustentabilidade para cada um dos extremos (propriedade sustentável e insustentável) foi também elaborado. Assim, pode-se constatar que os modelos das propriedades rurais analisadas encontram-se bem mais próximos ao modelo da propriedade sustentável, sendo as questões econômicas as que apresentam relações de menor eficiência. Essas propriedades possuem, portanto, inúmeros aspectos que podem contribuir com a efetividade das unidades de conservação. Entre esses aspectos destacam-se a preservação da mata nativa e implantação de sistemas agroflorestais, os quais podem atuar como corredores ecológicos e o envolvimento dos agricultores com os gestores das unidades de conservação, que contribuem para o apoio da população local. / Food production consists in an important topic among the discussions of sustainable development, mainly because of its fundamental role to human existence. However, numerous social and environmental impacts have been generated due to the dominant style of food production, such as the forests destruction and genetic biodiversity lost, soil erosion and contamination of natural resources and food, as well as the rural exodus and the land ownership concentration. In this context, Agroecology is issued as a theoretical and methodological approach that proposes to study the agrarian activity from an ecological perspective, taking into consideration several scientific disciplines for its analysis. The Agroecology unit of analysis is therefore the agroecosystem, which, from a systemic approach, provides the scientific basis for the implementation of more sustainable agriculture. Thus, Agroecology is able to promote discussions related with sustainable development, by incorporating multiple dimensions into its analysis. Given the importance of preserved natural areas for the maintenance of biodiversity and ecosystem services in both discussions, Agroecology and sustainable development, this study aimed to analyze the different agroecological agrosystems located in the influence zone of conservation unities from the North Coast of Rio Grande do Sul which belong to the Participatory Organization for Conformity Assessment (OPAC North Coast) – Organismo Participativo de Avaliação da Conformidade Litoral Norte – from the perspective of 3-D Model of Sustainability of Mauerhofer (2008). This model was chosen because it includes the three sustainable dimensions, environmental, social and economic, which are analyzed through a cone. The cone represents a hierarchy, and its walls mean the carrying capacity of the environment, while the base represents the environmental capital. Inside this cone, there is a second cone, whose walls represent the social carrying capacity and the base represents the social capital. Likewise, inside this second cone, there is a third cone with the economic capacity and economic capital. The cones are arranged through a dependency relationship, since the social dimension only exists because there is the environmental dimension, and economic exists only because there is a social dimension. In order to achieve this purpose, this research had a qualitative approach and it was carried out through in-depth interviews with semi-structured guide in six agroecological farms. An operational proposal of the 3-D sustainability model of Mauerhofer (2008) was elaborated. From that the collected data resulted in models of 3-D sustainability triangle for each agroecosystems. A 3-D sustainability model for each extreme category (sustainable and unsustainable farms) was also elaborated. Thus, the results illustrate that the farms models produced in this research are closer to the sustainable farm model. They also show that economic issues have the lowest efficiency ratios. These farms, however, have many aspects which can contribute to effectiveness of protected areas. Among these aspects, the forest fragments preservation and agroforestry systems implementation can act as ecological corridors and the involvement of these farmers with the protected areas managers can contribute to local population support.

A temática da produção de alimentos destaca-se entre as discussões do desenvolvimento sustentável, principalmente por constituir uma das atividades fundamentais para a existência humana, a qual tem sido responsável por inúmeros impactos socioambientais, tais como a destruição das florestas e da biodiversidade genética, a erosão dos solos e a contaminação dos recursos naturais e dos alimentos, bem como o êxodo rural e a concentração de terras. Nesse contexto, a Agroecologia apresenta-se sob um enfoque teórico e metodológico que, agregando diversas disciplinas científicas, se propõe a estudar a atividade agrária sob uma perspectiva ecológica. Sua unidade de análise, portanto, é o agroecossistema, que, a partir de um enfoque sistêmico proporciona as bases científicas para a implantação de agriculturas mais sustentáveis. Assim, percebe-se que a Agroecologia, ao incorporar múltiplas dimensões, promove discussões relacionadas à do desenvolvimento sustentável. Dada a importância de áreas naturais preservadas para a manutenção da biodiversidade e de serviços ecossistêmicos na discussão tanto da Agroecologia como do desenvolvimento sustentável, o objetivo dessa pesquisa foi analisar as diferentes propriedades agroecológicas na área de influência de unidades de conservação do Litoral Norte do estado do Rio Grande do Sul e que fazem parte do Organismo Participativo de Avaliação da Conformidade – OPAC Litoral Norte, a partir do Modelo 3-D de Sustentabilidade de Mauerhofer (2008). Esse modelo foi escolhido porque, além de englobar as três dimensões, ambiental, social e econômica, elas são apresentadas em outro nível de discussão, em um cone, representando uma hierarquia, onde as paredes do cone representam a capacidade de suporte do ambiente, enquanto a base representa o capital ambiental. Interior a esse cone, há outro, em que as paredes representam a capacidade de suporte social e a base o capital social. Da mesma forma, interior a esse segundo cone, há o cone da capacidade econômica e do capital econômico. Os cones estão assim dispostos devido a uma relação de dependência, pois a dimensão social só existe porque há a dimensão ambiental, e a econômica só existe porque há a dimensão social. Portanto, a partir de uma abordagem qualitativa, por meio de entrevistas em profundidade com auxilio de roteiros semiestruturados, a pesquisa foi realizada em seis propriedades agroecológicas do Litoral Norte do Rio Grande do Sul. Uma proposta de operacionalização do modelo 3-D de sustentabilidade de Mauerhofer (2008) foi elaborada, em que os dados coletados resultaram em modelos de triângulo 3-D de sustentabilidade para cada um dos agrossistemas analisados. Um modelo 3- D de sustentabilidade para cada um dos extremos (propriedade sustentável e insustentável) foi também elaborado. Assim, pode-se constatar que os modelos das propriedades rurais analisadas encontram-se bem mais próximos ao modelo da propriedade sustentável, sendo as questões econômicas as que apresentam relações de menor eficiência. Essas propriedades possuem, portanto, inúmeros aspectos que podem contribuir com a efetividade das unidades de conservação. Entre esses aspectos destacam-se a preservação da mata nativa e implantação de sistemas agroflorestais, os quais podem atuar como corredores ecológicos e o envolvimento dos agricultores com os gestores das unidades de conservação, que contribuem para o apoio da população local. / Food production consists in an important topic among the discussions of sustainable development, mainly because of its fundamental role to human existence. However, numerous social and environmental impacts have been generated due to the dominant style of food production, such as the forests destruction and genetic biodiversity lost, soil erosion and contamination of natural resources and food, as well as the rural exodus and the land ownership concentration. In this context, Agroecology is issued as a theoretical and methodological approach that proposes to study the agrarian activity from an ecological perspective, taking into consideration several scientific disciplines for its analysis. The Agroecology unit of analysis is therefore the agroecosystem, which, from a systemic approach, provides the scientific basis for the implementation of more sustainable agriculture. Thus, Agroecology is able to promote discussions related with sustainable development, by incorporating multiple dimensions into its analysis. Given the importance of preserved natural areas for the maintenance of biodiversity and ecosystem services in both discussions, Agroecology and sustainable development, this study aimed to analyze the different agroecological agrosystems located in the influence zone of conservation unities from the North Coast of Rio Grande do Sul which belong to the Participatory Organization for Conformity Assessment (OPAC North Coast) – Organismo Participativo de Avaliação da Conformidade Litoral Norte – from the perspective of 3-D Model of Sustainability of Mauerhofer (2008). This model was chosen because it includes the three sustainable dimensions, environmental, social and economic, which are analyzed through a cone. The cone represents a hierarchy, and its walls mean the carrying capacity of the environment, while the base represents the environmental capital. Inside this cone, there is a second cone, whose walls represent the social carrying capacity and the base represents the social capital. Likewise, inside this second cone, there is a third cone with the economic capacity and economic capital. The cones are arranged through a dependency relationship, since the social dimension only exists because there is the environmental dimension, and economic exists only because there is a social dimension. In order to achieve this purpose, this research had a qualitative approach and it was carried out through in-depth interviews with semi-structured guide in six agroecological farms. An operational proposal of the 3-D sustainability model of Mauerhofer (2008) was elaborated. From that the collected data resulted in models of 3-D sustainability triangle for each agroecosystems. A 3-D sustainability model for each extreme category (sustainable and unsustainable farms) was also elaborated. Thus, the results illustrate that the farms models produced in this research are closer to the sustainable farm model. They also show that economic issues have the lowest efficiency ratios. These farms, however, have many aspects which can contribute to effectiveness of protected areas. Among these aspects, the forest fragments preservation and agroforestry systems implementation can act as ecological corridors and the involvement of these farmers with the protected areas managers can contribute to local population support.

No description available.

This study is part of a three year project aimed to assess the effects of industrial water withdrawals on the ice regime of the Athabasca River. A 2-D numerical model was used to provide quantitative data for this effort. Freeze-up monitoring was carried out over two years along 80-km of the river from Fort McMurray to Bitumount. Summer bathymetric and winter ice surveys were conducted along with discharge measurements on a 5-km long detailed study reach that exhibited the full range of ice cover initiation processes. The data collected was used to build a CRISSP2D river ice process model for the simulation of freeze-up processes. An extensive parametric assessment was carried out to evaluate the capabilities of the model. Although it was not possible to simulate bridging, the simulated border ice agreed very well with field observations. Limitations of the model are addressed and future research recommendations are included. / Water Resources Engineering

This master thesis describes the design and optimization of connecting rod motor racing car. At the beginning of the whole work is a 3D-model of rods, from which then the whole work is based. Then it analyzes the current model of stress and on the basis of the results are made structural changes to the solution of rods. Newly adapted connecting rod is again analyzed using FEM and newly obtained results are compared with results of the original model of connecting rods. The conclusion deals with sensitivity analysis of selected parameters of rods and their potential effect on the resulting changes in strength connecting rod .Then is an assessment of all results.