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Painéis OSB de madeira Pinus sp. e adição de partículas de polipropileno biorientado (BOPP) / OSB of Pinus sp. wood and addiction of particles of bioriented polypropylene (BOPP)Macedo, Laurenn Borges de 19 February 2014 (has links)
O setor da construção civil é um dos que mais consomem recursos naturais e utilizam energia de forma intensiva, gerando consideráveis impactos ambientais juntamente com grande quantidade de resíduos. A utilização de produtos alternativos como painéis de madeira surge como uma possibilidade de redução de tais impactos. O Oriented Strand Board, desenvolvido para substituir o painel compensado, tem conquistado cada vez mais espaço na construção apesar de sua menor estabilidade dimensional perante o seu antecessor. A adição de resíduos, como o plástico, na matriz constituinte destes painéis representa alternativa de reaproveitamento destes descartes e economia de madeira no processo produtivo destes compósitos, além de proporcionar melhoria nas propriedades físicas dos mesmos. O objetivo deste trabalho foi confirmar a viabilidade técnica da produção de painéis OSB de madeira de Pinus sp. com adição de proporções de 20 e 30% de partículas de polipropileno biorientado em sua matriz constituinte e resina poliuretana à base de óleo de mamona. A avaliação de desempenho foi feita por intermédio das propriedades físicas e mecânicas dos painéis, determinadas atendendo as recomendações da EN 300 (1999). Os painéis foram classificados como OSB 4, de acordo com as propriedades físicas avaliadas, e OSB 1, considerando os módulos de elasticidade e ruptura obtidos em ensaios de flexão estática. A adesão interna, para os painéis produzidos com os parâmetros de processo adotados, não alcançou os valores exigidos pela citada norma. De todas as propriedades avaliadas, apenas inchamento em espessura e absorção de água foram influenciadas pela porcentagem de BOPP. Assim, considera-se comprovada a viabilidade técnica da produção dos painéis OSB deste trabalho, para aplicação na construção civil. / Building construction is one of the sectors that most consuming natural resources and use energy intensively, generating considerable environmental impacts coupled with large amount of waste. Employing alternative product like wood panels comes as a possibility to reduce these impacts. Oriented Strand Board, developed to substitute the plywood panel, has gained more space in the construction spite of its lower dimensional stability against its predecessor. The addition of plastic waste in constitutive matrix of these panels represents an alternative to reuse this kind of waste and wood economy in the productive process of these composites, besides improving their physical properties. The aim of this study was to evaluate the technical feasibility of producing OSB of Pinus sp. wood with the addition of various proportions of particles of bioriented polypropylene in its constitutive matrix and polyurethane resin based on castor oil with evaluation of physical and mechanical properties of these panels. In accordance with EN 300 (1999), the OSB panels have been classified as 4 in accordance with the physical properties assessed and as OSB 1 for the elasticity modules and rupture. Property of internal bond not presented the minimum values required by the same standard. Of all properties evaluated, only thickness swelling and water absorption were influenced by the percentage of BOPP. However, it is considered completely evidenced the technical viability of production of the OSB of this work, and its potential employability in civil construction sector.
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Fullriggaren - spektakulärt undantag eller framtid? : konsekvenser av en omvärldsanalys / Fullriggaren - spectacular exeption or the future? : consequences of an environmental scanningSvensson, Mikael, Sjöström, Kristina January 2012 (has links)
Syfte: Åsikterna om Fullriggaren går isär. Gavlegårdarna har, som allmännyttigt bostadsföretag, kritiserats av allmänheten för att bostäderna anses vara för exklusiva. Syftet med studien är att närmare undersöka den omvärldsanalys som legat till grund för det strategiska beslutet att bygga Fullriggaren. Vi vill även skapa oss en uppfattning om hur allmännyttan håller på att förändras och vilken roll den spelat historiskt.Metod: Studien bygger på en kvalitativ metod, med två djupintervjuer som varit av semi-strukturerad karaktär. Vi har även gjort en litteraturstudie av allmännyttans historia. I analysen har sedan empirin tolkats och analyserats mot vår referensram.Resultat & slutsats: Vi har kommit fram till att allmännyttan fortsättningsvis kommer anpassa sig till utvecklingen mot ett mer kvalitativt boende. Vi har även kommit fram till att den omvärldsanalys som legat till grund för Fullriggaren i stort sett är samma omvärldsanalys som den för Gävle Strand. / Aim: Opinions on Fullriggaren differ. Gavlegårdarna, as a public housing company have been criticized by the public because the housing is considered too exclusive. The purpose of this study is to further investigate the environmental scanning that formed the basis for the strategic decision to build Fullriggaren. We also wanted to create an understanding of how public housing is changing and what role it has played historically.Method: The study is based on a qualitative approach, with two in-depth interviews that were of semi structured nature. We have also done a literature study of the public housing history. In the analysis, empirical data have been interpreted and analyzed and compared to our frame of reference.Result & Conclusions: We have found that public housing will continue to adapt to the development towards a more quality accommodation. We have also concluded that the environmental scanning that formed the basis for Fullriggaren in its whole is the same environmental scanning as that of Gävle Strand.
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Cumulative effects assessment and sustainable development under the National Environmental Policy ActSenner, Robert Glenn 31 January 2011 (has links)
This dissertation presents a clear and systematic method for conducting cumulative effects assessments in the United States in a manner consistent with the 1997 guidelines of the President's Council on Environmental Quality and the 1999 guidance of the U.S. Environmental Protection Agency's Office of Federal Activities. This method has been developed in a collaborative process with federal and State of Alaska regulatory agency scrutiny during the renewal of the federal and state right-of-way leases for the Trans Alaska Pipeline System in 2004 and in the June 2004 Alaska Groundfish Fisheries Final Programmatic Supplemental Environmental Impact Statement prepared for the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Region. The dissertation describes the process through which the cumulative effects assessment method presented here was developed and presents this approach as a predictive tool with the potential to improve the implementation of sustainable development in the United States. In this context, the dissertation presents an overview of sustainability theory, distinguishing and reviewing representative examples from two major sectors of the sustainable development literature, called here the intergenerational equity strand and the human development strand. It identifies weaknesses in three key areas of the intergenerational equity strand -- lack of theorectical cohesion, insufficient tools for implementation, and an imbalance between normative goals and practical feasibility -- and argues that the human development strand, with its empirical emphasis on metrics and institutional frameworks, offers a model that can serve as a basis for unifying the two strands by providing a theoretical core, implementation tools, and practicable goals. Finally, the dissertation argues that sustainable development is implemented most effectively when it is enabled by institutions that facilitate public involvement, particularly participation by the broadest feasible representation of the affected stakeholders, and that such institutional mobilization can provide a stable and enduring basis to foster the intergenerational equity that is the central, distinguishing feature of sustainability. / text
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Development and use of a discrete element model for simulating the bulk strand flow in a rotary drum blenderDick, Graeme 11 1900 (has links)
In 2006 resin accounted for approximately 17% of the direct manufacturing costs for oriented strand board (OSB). Because of their increased dependency on pMDI-resins, this percentage is likely greater for oriented strand lumber (OSL) and laminated strand lumber (LSL). The cost of PF- and pMDI-resins is expected to face upward pressure as the cost of their primary constituents, natural gas and crude oil, continue to reach new highs. Therefore, there is strong economic incentive to optimize the use of resin in the production of these three products. This can be accomplished by addressing two key issues: reducing resin wastage and optimizing resin distribution on the strands. Both issues will be overcome by focusing on the blending process, where resin is applied to the strands.
This work focused on development and use of a discrete element model (DEM) for simulating strand flow in a rotary drum blender using the EDEM software package. EDEM required the input of three material and three interaction properties. Development of the model involved creating the simulated environment (i.e. physical dimensions) and assigning appropriate material and interaction properties given this environment and the assumptions that were made. This was accomplished in two steps, completing baseline bench-top experiments and a literature review to determine appropriate parameters and initial value ranges for these properties, and then fine-tuning these values based on a validation process.
Using the validated model, an exploratory study was conducted to determine the effect of four blender design and operating parameters (flight height, number of flights, blender rotational speed, and blender fill level) on bulk strand flow. The results were analyzed with regards to overall trends and by focusing on two perspectives, end users and blender manufacturers. It was found that there was a strong relationship between these key parameters and bulk strand flow. These results suggest that operating parameters of a blender, namely rotational speed and tilt angle, should be linked directly to the blender feed rate to ensure an optimal blending environment is maintained. In addition, manufacturers of blenders must take into consideration the range in final operating conditions when designing and positioning flights.
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Västermalms Strand : Arbetet för en hållbar stadsutveckling i StockholmSondell, Malin January 2015 (has links)
Sustainable urban development is a concept that has become increasingly important as the urbanization continues and more and more challenges are focused to the cities. The Swedish government and authorities regulates and sets goals for how a sustainable urban development is to be achieved. These laws and goals are vaguely defined, which leads to disputes between the actors about how the term should be interpreted. By examining Västermalms Strand, an urban development project in Stockholm, this study strives to describe how involved actors interpret the concept of sustainable urban development and what the consequences of this are for urban development in Stockholm from an ecological, social and economic perspective. A case study has been carried out where a document study and interviews have been conducted. The interviews were conducted with four key actors from the private and public sector. The study shows that there exists no unified definition of what sustainable urban development is among the interviewees. Possible consequences of this are that the economic aspect can gain higher priority than the ecological and social, this because the economics of a project rarely can be compromised. However, there is a large common desire to develop a good city, which can be seen as a prerequisite for future sustainable urban development in Stockholm.
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Development and use of a discrete element model for simulating the bulk strand flow in a rotary drum blenderDick, Graeme 11 1900 (has links)
In 2006 resin accounted for approximately 17% of the direct manufacturing costs for oriented strand board (OSB). Because of their increased dependency on pMDI-resins, this percentage is likely greater for oriented strand lumber (OSL) and laminated strand lumber (LSL). The cost of PF- and pMDI-resins is expected to face upward pressure as the cost of their primary constituents, natural gas and crude oil, continue to reach new highs. Therefore, there is strong economic incentive to optimize the use of resin in the production of these three products. This can be accomplished by addressing two key issues: reducing resin wastage and optimizing resin distribution on the strands. Both issues will be overcome by focusing on the blending process, where resin is applied to the strands.
This work focused on development and use of a discrete element model (DEM) for simulating strand flow in a rotary drum blender using the EDEM software package. EDEM required the input of three material and three interaction properties. Development of the model involved creating the simulated environment (i.e. physical dimensions) and assigning appropriate material and interaction properties given this environment and the assumptions that were made. This was accomplished in two steps, completing baseline bench-top experiments and a literature review to determine appropriate parameters and initial value ranges for these properties, and then fine-tuning these values based on a validation process.
Using the validated model, an exploratory study was conducted to determine the effect of four blender design and operating parameters (flight height, number of flights, blender rotational speed, and blender fill level) on bulk strand flow. The results were analyzed with regards to overall trends and by focusing on two perspectives, end users and blender manufacturers. It was found that there was a strong relationship between these key parameters and bulk strand flow. These results suggest that operating parameters of a blender, namely rotational speed and tilt angle, should be linked directly to the blender feed rate to ensure an optimal blending environment is maintained. In addition, manufacturers of blenders must take into consideration the range in final operating conditions when designing and positioning flights.
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Painéis OSB de madeira Pinus sp. e adição de partículas de polipropileno biorientado (BOPP) / OSB of Pinus sp. wood and addiction of particles of bioriented polypropylene (BOPP)Laurenn Borges de Macedo 19 February 2014 (has links)
O setor da construção civil é um dos que mais consomem recursos naturais e utilizam energia de forma intensiva, gerando consideráveis impactos ambientais juntamente com grande quantidade de resíduos. A utilização de produtos alternativos como painéis de madeira surge como uma possibilidade de redução de tais impactos. O Oriented Strand Board, desenvolvido para substituir o painel compensado, tem conquistado cada vez mais espaço na construção apesar de sua menor estabilidade dimensional perante o seu antecessor. A adição de resíduos, como o plástico, na matriz constituinte destes painéis representa alternativa de reaproveitamento destes descartes e economia de madeira no processo produtivo destes compósitos, além de proporcionar melhoria nas propriedades físicas dos mesmos. O objetivo deste trabalho foi confirmar a viabilidade técnica da produção de painéis OSB de madeira de Pinus sp. com adição de proporções de 20 e 30% de partículas de polipropileno biorientado em sua matriz constituinte e resina poliuretana à base de óleo de mamona. A avaliação de desempenho foi feita por intermédio das propriedades físicas e mecânicas dos painéis, determinadas atendendo as recomendações da EN 300 (1999). Os painéis foram classificados como OSB 4, de acordo com as propriedades físicas avaliadas, e OSB 1, considerando os módulos de elasticidade e ruptura obtidos em ensaios de flexão estática. A adesão interna, para os painéis produzidos com os parâmetros de processo adotados, não alcançou os valores exigidos pela citada norma. De todas as propriedades avaliadas, apenas inchamento em espessura e absorção de água foram influenciadas pela porcentagem de BOPP. Assim, considera-se comprovada a viabilidade técnica da produção dos painéis OSB deste trabalho, para aplicação na construção civil. / Building construction is one of the sectors that most consuming natural resources and use energy intensively, generating considerable environmental impacts coupled with large amount of waste. Employing alternative product like wood panels comes as a possibility to reduce these impacts. Oriented Strand Board, developed to substitute the plywood panel, has gained more space in the construction spite of its lower dimensional stability against its predecessor. The addition of plastic waste in constitutive matrix of these panels represents an alternative to reuse this kind of waste and wood economy in the productive process of these composites, besides improving their physical properties. The aim of this study was to evaluate the technical feasibility of producing OSB of Pinus sp. wood with the addition of various proportions of particles of bioriented polypropylene in its constitutive matrix and polyurethane resin based on castor oil with evaluation of physical and mechanical properties of these panels. In accordance with EN 300 (1999), the OSB panels have been classified as 4 in accordance with the physical properties assessed and as OSB 1 for the elasticity modules and rupture. Property of internal bond not presented the minimum values required by the same standard. Of all properties evaluated, only thickness swelling and water absorption were influenced by the percentage of BOPP. However, it is considered completely evidenced the technical viability of production of the OSB of this work, and its potential employability in civil construction sector.
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Development and use of a discrete element model for simulating the bulk strand flow in a rotary drum blenderDick, Graeme 11 1900 (has links)
In 2006 resin accounted for approximately 17% of the direct manufacturing costs for oriented strand board (OSB). Because of their increased dependency on pMDI-resins, this percentage is likely greater for oriented strand lumber (OSL) and laminated strand lumber (LSL). The cost of PF- and pMDI-resins is expected to face upward pressure as the cost of their primary constituents, natural gas and crude oil, continue to reach new highs. Therefore, there is strong economic incentive to optimize the use of resin in the production of these three products. This can be accomplished by addressing two key issues: reducing resin wastage and optimizing resin distribution on the strands. Both issues will be overcome by focusing on the blending process, where resin is applied to the strands.
This work focused on development and use of a discrete element model (DEM) for simulating strand flow in a rotary drum blender using the EDEM software package. EDEM required the input of three material and three interaction properties. Development of the model involved creating the simulated environment (i.e. physical dimensions) and assigning appropriate material and interaction properties given this environment and the assumptions that were made. This was accomplished in two steps, completing baseline bench-top experiments and a literature review to determine appropriate parameters and initial value ranges for these properties, and then fine-tuning these values based on a validation process.
Using the validated model, an exploratory study was conducted to determine the effect of four blender design and operating parameters (flight height, number of flights, blender rotational speed, and blender fill level) on bulk strand flow. The results were analyzed with regards to overall trends and by focusing on two perspectives, end users and blender manufacturers. It was found that there was a strong relationship between these key parameters and bulk strand flow. These results suggest that operating parameters of a blender, namely rotational speed and tilt angle, should be linked directly to the blender feed rate to ensure an optimal blending environment is maintained. In addition, manufacturers of blenders must take into consideration the range in final operating conditions when designing and positioning flights. / Forestry, Faculty of / Graduate
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Continuous Unbonded Post-Tensioned Members: Quantifying Strand Stress IncreaseSix, Philip D. 01 May 2015 (has links)
Unbonded post-tensioning tendons are an efficient and cost effective method of reinforcing concrete floor slabs, slabs-on-grade, parking garages, and bridge structures. However, the behavior of these structures is not well understood. There is concern that due to the lack of a significant amount of reliable research data on specimens reinforced in this manner, the commonly used design methods tend to significantly under-predict the strength. Four large, scaled, floor slab sections were constructed and destructively tested with the intent of more accurately understanding the strength of specimens reinforced with this method. Four test specimens represent a significant percentage of the current body of reliable research in this field. In order to accurately predict the design strength of these members, it is necessary to predict the increase in the reinforcing strand stress when the member is loaded to a flexural failure. This increase in strand stress was measured on each of the four laboratory tests which were performed. This allowed the strength of these concrete members to be more accurately predicted, and it was observed that the current design methods are significantly under-predicting this increase in strand stress as well as the flexural capacity of the members. The behavior of the deflection of the slabs in relation to the applied load was also analyzed, as well as the cracking behaviors. The four test specimens were combined with the available body of research data to complete the largest known database of members reinforced in this manner.
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Scientific research impact and data mining applications in hydrogeologyFang, Yao-chuen 29 September 2004 (has links)
No description available.
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