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Current treatment of wastewater can effectively remove the contaminants; however, the effluent is still not widely reused because of some undesired substances like pathogens and trace organic chemicals. To promote water reuse, membrane-based technologies have emerged as a robust and more efficient alternative to current treatment practice. Among these membrane processes, forward osmosis (FO) utilizes an osmotic pressure gradient across a semi-permeable membrane to reclaim high-quality water. Still, several key challenges remain to be addressed towards broader FO application, including energy-intensive draw regeneration to yield product water and salinity buildup in the feed solution. To bypass energy-intensive draw regeneration, commercial solid fertilizers was utilized as a regeneration-free draw solute (DS), harvesting fresh water towards direct agricultural irrigation. However, using nutrient-rich fertilizers as DS resulted in an elevated reverse solute flux (RSF). This RSF, known as the cross-membrane diffusion of DS to the feed solution, led to deteriorated solute buildup on the feed side, reduced osmotic driving force, increased fouling propensity, and higher operation cost. To effectively mitigate solute buildup while achieving energy-efficient water reclamation, a parallel electrodialysis (ED) device was integrated to FO for DS recovery in the feed solution. The salinity in the feed solution was consistently controlled below 1 mS cm-1 via the hybrid FO-ED system. Considering solute buildup is merely a consequence of RSF, direct control of RSF was further investigated via operational strategy (i.e., an electrolysis-assisted FO) and membrane modification (i.e., surface coating of zwitterion-functionalized carbon nanotubes). Significantly reduced RSF (> 50% reduction) was obtained in both approaches with minor energy/material investment. With two major bottlenecks being properly addressed for energy-efficient water reclamation, FO was further integrated with a microbial electrolysis cell (MEC) to achieve integrated nutrient-energy-water recovery from high-strength wastewater (i.e., the digestor centrate). The abovementioned research projects are among the earliest efforts to address multiple key challenges of FO during practical application, serving as a cornerstone to facilitate the transformation of current water/wastewater treatment plant to resource recovery hub in order to ensure global food-energy-water security. / Doctor of Philosophy / Exploring alternative water supply, for instance via reusing wastewater, will be essential to deal with the global water crisis. Current wastewater treatment can effectively remove the contaminants; however, the treated wastewater is still not widely reused due to the possible presence of residual contaminants. In recent years, membrane-based technologies have emerged as a promising treatment process to produce clean water. Among all available membrane technologies, forward osmosis (FO) takes advantage of the osmotic pressure difference across a special membrane to extract fresh water from a low-salinity FEED solution (for example, wastewater) to a high-salinity DRAW solution. The reclaimed fresh water can be reused for other applications. Still, the FO process is facing several critical challenges for broader applications. The first challenge is that additional energy is required to separate clean water from the diluted DRAW solution, leading to notably increased energy consumption for the FO process. To bypass this energy-intensive separation, commercial solid fertilizers was utilized as a separation-free DRAW solution for FO process. Once the clean water is extracted to the DRAW solution (fertilizer), the diluted fertilizer solution together with the fresh water can be directly used for agricultural irrigation. The second challenge is that, when fertilizer is applied as the DRAW solution, nutrient rich fertilizers can penetrate the FO membrane and escape to the FEED solution (wastewater). This phenomenon is known as the reverse solute flux (RSF). RSF can result in many adverse effects, such as wastewater contamination and increased operational cost. To prevent this, we used an additional device named electrodialysis to effectively recapture the “escaped” fertilizers in the FEED solution. Besides this indirect approach to recover escaped fertilizers, we also investigated direct approaches to control RSF, including operational strategy and membrane modification. With two major challenges being properly addressed for energy-efficient water reclamation, FO was further combined with a microbial electrolysis cell (MEC) to achieve multiple resource recovery from wastewater, including water, nutrient, and energy components. The above mentioned research projects are among the earliest efforts to address multiple key challenges of FO during water and resource recovery from wastewater to ensure global food-energy-water security.

Yes / In this study, air, steam and CO2-enhanced gasification of rice straw was simulated using Aspen PlusTM simulator and compared in terms of their energy, exergy and environmental impacts. It was found that the addition of CO2 had less impact on syngas yield compared with gasification temperature. At lower CO2/Biomass ratios (below 0.25), gasification system efficiency (GSE) for both conventional and CO2-enhanced gasification was below 22.1%, and CO2-enhanced gasification showed a lower GSE than conventional gasification. However at higher CO2/Biomass ratios, CO2-enhanced gasification demonstrated higher GSE than conventional gasification. For CO2-enhanced gasification, GSE continued to increase to 58.8% when CO2/Biomass was raised to 0.87. In addition, it was found that syngas exergy increases with CO2 addition, which was mainly due to the increase in physical exergy. Chemical exergy was 2.05 to 4.85 times higher than physical exergy. The maximum exergy efficiency occurred within the temperature range of 800 oC to 900 oC because syngas exergy peaked in this range. For CO2-enhanced gasification, exergy efficiency was found to be more sensitive to temperature than CO2/Biomass ratios. In addition, the preliminary environmental analysis showed that CO2-enhanced gasification resulted in significant environmental benefits compared with stream gasification. However improved assessment methodologies are still needed to better evaluate the advantages of CO2 utilization.

The main objective of this thesis was to determine how far a biomass quantity, equal to the potential produced within the Swedish borders, could cover the present energy needs inSwedenwith respect to economic and ecological circumstances. Three scenarios were studied where the available biomass was converted to heat, electricity and vehicle fuel. Three different amounts of biomass supply were studied for each scenario: 1) potential biomass amounts derived from forestry, non-forest land, forest industry and community; 2) the same amounts as in Case 1, plus the potential biomass amounts derived from agriculture; 3) the same amounts as in Case 1, plus 50% of the potential pulpwood quantity. For evaluating the economic and ecological circumstances of using biomass in the Swedish energy system, the scenarios were complemented with energy, cost and emergy analysis. The scenarios indicated that it may be possible to produce 170.2 PJ (47.3 TWh) per year of electricity from the biomass amounts in Case 2. From the same amount of biomass, the maximum annual production of hydrogen was 241.5 PJ (67.1 TWh) per year or 197.2 PJ (54.8 TWh) per year of methanol. The energy analysis showed that the ratio of energy output to energy input for large-scale applications ranged from 1.9 at electric power generation by gasification of straw to 40 at district heating generation by combustion of recovered wood. The cost of electricity at gasification ranged from 7.95 to 22.58 €/GJ. The cost of vehicle work generated by using hydrogen produced from forestry biomass in novel fuel cells was economically competitive compared to today’s propulsion systems. However, the cost of vehicle work generated by using methanol produced from forestry biomass in combustion engines was rather higher compared to use of petrol in petrol engines. The emergy analysis indicated that the only biomass assortment studied with a larger emergy flow from the local environment, in relation to the emergy flow invested from society after conversion, was fuel wood from non-forest land. However, even use of this biomass assortment for production of heat, electricity or vehicle fuels had smaller yields of emergy output in relation to emergy invested from society compared to alternative conversion processes; thus, the net contribution of emergy generated to the economy was smaller compared to these alternative conversion processes. / <p>QC 20120217</p>

A questão energética, associada às mudanças climáticas e à dependência dos recursos naturais é um dos principais desafios do século XXI. A necessidade de produzir alimentos, para atender a crescente demanda da população, requer o aumento da utilização de máquinas e equipamentos, demandando maior quantidade de energia e causando emissões dos gases de efeito estufa. Fontes de materiais e de energia são consumidas ao longo do ciclo de vida do produto, portanto é importante reduzir a demanda dessas fontes e aperfeiçoar o uso de recursos pelo reuso, reciclagem e materiais renováveis, além da preservação do ambiente. No sistema de produção agrícola, as máquinas agrícolas são consideradas fundamentais para produção de biomassa. A análise de energia em máquinas agrícolas tem sido feita, porém com dados de indicadores da década de 1960. Estudos de energia incorporada e emissões em máquinas agrícolas devem ser feitos, devido à importância do sistema de produção de bioenergia na economia, além da otimização do consumo em operações necessárias à obtenção do produto. Esse estudo propôs determinar o inventário de materiais, energia incorporada e emissões dos gases de efeito estufa em máquinas agrícolas. Foram avaliadas oito máquinas: colhedora de café, pulverizador autopropelido, semeadora-adubadora, colhedora de grãos, trator 55 kW, trator 90 kW, trator 172 kW e trator 246 kW, em seus ciclos de vida útil. Tais sidos adotados segundo três fontes distintas. Os dados foram coletados em uma montadora multinacional, em suas unidades localizadas nos municípios de Piracicaba e Sorocaba, Estado de São Paulo e no município de Curitiba, Estado do Paraná, Brasil. Para cada máquina foi contabilizado o consumo dos insumos diretos utilizados na fase de montagem, e também o consumo dos insumos utilizados na fase de manutenção. Os dados de consumo dos insumos foram processados apresentando os fluxos de materiais utilizados, os quais foram multiplicados pelo seu índice de energia incorporada e fator de emissões, resultando na energia incorporada e nas emissões dos gases de efeito estufa, requeridos pelo sistema de produção. Os resultados apresentaram que a energia incorporada e emissões foram maiores no ciclo de vida indicado pelo fabricante, para colhedora de café, pulverizador, semeadora-adubadora, colhedora de grãos, e no ciclo de vida indicado pelo (BRASIL, 2010), para os tratores 55 kW, 90 kW, 172 kW e 246 kW, respectivamente. Para avaliação ambiental em tratores, equações foram fornecidas para demanda de energia e emissões pela massa (energia = -0,0057 massa + 129,2669), (emissões = -0,0003 massa + 5,9845) e pela potência motor (energia = -14,7672 potência motor + 6.507,9639), (emissões = -0,6861 potência motor + 299,1242). / The energy subject, associated with global climate changes and the environment dependency is one of the main challenges of 21st century. The need to produce food, to meet the growing demand of the population, requires increased use of machinery and equipment, demanding more energy and raising greenhouse gases emissions. Materials and energy sources are consumed during the product life cycle, so it is important to reduce the demand for these sources and optimizing the use of resources by reuse, recycling and renewable materials, plus environment preservation. At agricultural production system, agricultural machinery are considered fundamental for biomass production. The energy analysis in agricultural machinery has been done, but with indicator data from late 1960s. Embodied energy and emissions studies in agricultural machinery should be done, because of bioenergy production system importance in economy, beyond consumption optimization in operations necessary to obtain the product. This study aimed to determine the inventory for materials, embodied energy and greenhouse gases emissions in agricultural machinery. Eight machines were evaluated, so called: coffee harvester, self-propelled sprayer, seeder-fertilizer, combine harvester, tractor 55 kW, tractor 90 kW, tractor 172 kW and tractor 246 kW, on their life cycle. Such were taken from three different sources. The data were collected in a multinational manufacturer, in its units located at Piracicaba and Sorocaba regions, State of São Paulo and Curitiba region, State of Paraná, Brazil. For every harvester, the consumption of the direct input used in the assembly phase, was accounted, and also the consumption of the input used in the maintenance phase. The consumption data of the inputs were processed presenting the materials flows used, which they were multiplied by their embodied energy indices and emissions factor, resulting in the embodied energy and greenhouse gases emissions required by the production system. The results presented higher embodied energy and emissions on life cycle mentioned per manufacturer, for coffee harvester, sprayer, seeder-fertilizer, combine harvester, and on life cycle mentioned per (BRASIL, 2010), for tractors 55 kW, 90 kW, 172 kW and 246 kW, respectively. For environmental assessment on tractors, equations were provided to energy demand and emissions per mass (energy = -0.0057 mass + 129.2669), (emissions = -0.0003 mass + 5.9845) and per engine power (energy = -14.7672 engine power + 6,507.9639), (emissions = -0.6861 engine power + 299.1242).

Det särskilda sektorsansvaret är en ordning inom miljöpolitiken som innebär att varje sektor har ansvar för att hantera de miljöproblem som orsakas inom sektorn. På grund av detta ansvar finns ett behov av att kartlägga miljöproblem från sektorer, att identifiera de viktigaste problemen och att hitta strategier för att minska miljöpåverkan. Jordbrukssektorn och energisektorn är två sektorer som orsakar stor miljöpåverkan, vilket gör dem intressanta som fallstudier. För att undersöka miljöpåverkan och möjligheten att minska denna i de båda sektorerna används ett systemanalytiskt perspektiv. Ett sådant angreppssätt ger möjlighet att analysera frågorna på ett mer genomgripande sätt, så att problemen inte endast förflyttas och istället skapar problem på andra håll i världen eller för framtida generationer, eller att ett problem reduceras medan ett annat istället ökar. Med ett systemperspektiv kan även indirekta effekter inkluderas när strategier för minskad miljöpåverkan i sektorn analyseras. De indirekta effekterna omfattar påverkan som sker uppströms och nedströms produktionskedjan, liksom påverkan från konsumenter. En metod för att bedöma miljöpåverkan från en sektor har utarbetats och testats på jordbruks- och energisektorn (Artikel I och II). Metoden är en hybridmetod baserad på miljöexpanderad input-output analys (IOA) och livscykelanalys (LCA). IOA-data från Miljöräkenskaperna används som utgångspunkt för inventeringen. Dessa data ger information om både direkt och indirekt miljöpåverkan från sektorn. För att fånga även sådana miljöaspekter som inte omfattas av miljöräkenskaperna används sedan de svenska miljökvalitetsmålen som en checklista, och information om den miljöpåverkan som inte finns med i IOA hämtas från litteraturen. För vidare hantering av den insamlade informationen om utsläpp och resursanvändning används karaktäriserings- och värderingsmetoder från LCA-metodologin. Därigenom kan s.k. hotspots, dvs de viktigaste problemen, identifieras. Baserat på denna hybridmetod blev resultatet att i jordbrukssektorn är de viktigaste frågorna biologisk mångfald, växthuseffekt, övergödning, användning av icke-förnybara resurser och troligen även toxicitet genom användningen av bekämpningsmedel. I energisektorn är de viktigaste problemen luftkvalitet, växthuseffekt, användning av icke-förnybara resurser och toxicitet. En analys av policies inom sektorerna (Artikel III) visar att både jordbruks- och energisektorn fokuserar delvis på de problem som identifierats som hotspots i sektorsanalyserna, men att vissa av de viktiga problemen inte ägnas så stor uppmärksamhet. I jordbrukssektorn är fokus huvudsakligen riktat mot biologisk mångfald och toxicitet, medan energisektorn framför allt fokuserar på växthuseffekt och användning av icke-förnybara resurser. En andra IOA-LCA hybridmetod, Energy Analysis Programme, har använts för att studera hushållens direkta och indirekta energianvändning (Artikel IV och V). Genom en kombination av IOA och processdata kan energiintensiteten (dvs. energi per monetär enhet, MJ/SEK) beräknas av ett stort antal varor och tjänster. När dessa beräkningar kombineras med information om hur ett hushåll spenderar sin inkomst kan hushållens totala energianvändning beräknas. Beräkningarna ger också information om hur inkomsten kan spenderas på mer energisnåla sätt. En ytterligare studie gjordes för att visa på betydelsen av minskat livsmedelssvinn som strategi för minskad miljöpåverkan inom livsmedelssektorn (Artikel VI). Resultaten från studierna med konsumentperspektiv kan användas för att identifiera strategier för hur konsumenterna kan bidra till minskad miljöpåverkan i de båda fallsektorerna. För jordbrukssektorns del kan konsumenterna bidra till minskad miljöpåverkan framför allt genom en minskad konsumtion av animalier. När det gäller energisektorn är minskad energianvändning en viktig strategi, liksom att fortsatt sträva efter att ersätta fossila bränslen och uran med förnybara bränslen. / National sector responsibility legislation places specific obligations on Swedish sector authorities to handle environmental issues within their sector. Because of this responsibility, there is a need to map environmental impacts from sectors and to identify key problems and strategies to reduce impacts in each sector. Agriculture and energy are two sectors causing severe environmental impacts, and these are therefore interesting as case studies. Employing a systems perspective when exploring impacts and options for their reduction ensures that problems are not simply shifted in time or space or between problems, but are considered in a holistic manner. Using this perspective, indirect effects such as changes upstream or downstream of the production chain, as well as among consumers, can be considered when seeking strategies to reduce environmental impacts in a sector. A method to investigate environmental impacts from a sector was developed and tested in the cases of agriculture and energy (Papers I and II). The method was based on environmentally extended Input-Output Analysis (IOA) and Life Cycle Assessment (LCA). IOA-data from Swedish Environmental Accounts were used as the starting point for the inventory. Such data provide information on direct and indirect impacts from the sector. To capture those aspects not included in the Environmental Accounts, the Swedish Environmental Quality Objectives were subsequently used as a checklist, and information on the missing aspects was obtained from literature. For further processing of the data, characterisation and weighting methods from LCA methodology were used to identify hotspots, i.e. the most important problems. The results showed that biodiversity, greenhouse effect, eutrophication, use of non-renewable resources and toxicity were potential hotspots in the agriculture sector. In the energy sector, the hotspots were air quality, greenhouse effect, use of non-renewable resources and toxicity. Analysis of sector policies (Paper III) showed that both sectors are focusing on some of the hotspots identified, but other important problems are not receiving sufficient attention. In the agriculture sector, the focus is principally on biodiversity and toxicity, while the energy sector mainly focuses on issues of climate change and non-renewable resources. A second hybrid IOA-LCA method (Energy Analysis Programme, EAP) was employed to study direct and indirect use of energy carriers in households (Papers IV and V). Through a combination of IOA and process data, the energy intensity (energy per monetary unit, e.g. MJ/SEK) of a large number of goods and services was calculated. When combined with information on household expenditure, these data provided information on total household use of fuels and electricity and provided insights into spending patterns that could result in lower energy intensity. A final study investigated the significance of reducing food losses as a strategy to reduce environmental impacts from the food sector (Paper VI). The results from the studies with a consumer perspective were used to identify how consumers can contribute to reducing environmental impacts in the two sectors investigated. For agriculture, consumers can help reduce impacts through reduced consumption of animal products, while for energy, reduced energy use in households is important, as is further substitution of fossil fuels. / QC 20110124

<p>Det särskilda sektorsansvaret är en ordning inom miljöpolitiken som innebär att varje sektor har ansvar för att hantera de miljöproblem som orsakas inom sektorn. På grund av detta ansvar finns ett behov av att kartlägga miljöproblem från sektorer, att identifiera de viktigaste problemen och att hitta strategier för att minska miljöpåverkan. Jordbrukssektorn och energisektorn är två sektorer som orsakar stor miljöpåverkan, vilket gör dem intressanta som fallstudier.</p><p>För att undersöka miljöpåverkan och möjligheten att minska denna i de båda sektorerna används ett systemanalytiskt perspektiv. Ett sådant angreppssätt ger möjlighet att analysera frågorna på ett mer genomgripande sätt, så att problemen inte endast förflyttas och istället skapar problem på andra håll i världen eller för framtida generationer, eller att ett problem reduceras medan ett annat istället ökar. Med ett systemperspektiv kan även indirekta effekter inkluderas när strategier för minskad miljöpåverkan i sektorn analyseras. De indirekta effekterna omfattar påverkan som sker uppströms och nedströms produktionskedjan, liksom påverkan från konsumenter.</p><p>En metod för att bedöma miljöpåverkan från en sektor har utarbetats och testats på jordbruks- och energisektorn (Artikel I och II). Metoden är en hybridmetod baserad på miljöexpanderad input-output analys (IOA) och livscykelanalys (LCA). IOA-data från Miljöräkenskaperna används som utgångspunkt för inventeringen. Dessa data ger information om både direkt och indirekt miljöpåverkan från sektorn. För att fånga även sådana miljöaspekter som inte omfattas av miljöräkenskaperna används sedan de svenska miljökvalitetsmålen som en checklista, och information om den miljöpåverkan som inte finns med i IOA hämtas från litteraturen. För vidare hantering av den insamlade informationen om utsläpp och resursanvändning används karaktäriserings- och värderingsmetoder från LCA-metodologin. Därigenom kan s.k. hotspots, dvs de viktigaste problemen, identifieras.</p><p>Baserat på denna hybridmetod blev resultatet att i jordbrukssektorn är de viktigaste frågorna biologisk mångfald, växthuseffekt, övergödning, användning av icke-förnybara resurser och troligen även toxicitet genom användningen av bekämpningsmedel. I energisektorn är de viktigaste problemen luftkvalitet, växthuseffekt, användning av icke-förnybara resurser och toxicitet.</p><p>En analys av policies inom sektorerna (Artikel III) visar att både jordbruks- och energisektorn fokuserar delvis på de problem som identifierats som hotspots i sektorsanalyserna, men att vissa av de viktiga problemen inte ägnas så stor uppmärksamhet. I jordbrukssektorn är fokus huvudsakligen riktat mot biologisk mångfald och toxicitet, medan energisektorn framför allt fokuserar på växthuseffekt och användning av icke-förnybara resurser.</p><p>En andra IOA-LCA hybridmetod, Energy Analysis Programme, har använts för att studera hushållens direkta och indirekta energianvändning (Artikel IV och V). Genom en kombination av IOA och processdata kan energiintensiteten (dvs. energi per monetär enhet, MJ/SEK) beräknas av ett stort antal varor och tjänster. När dessa beräkningar kombineras med information om hur ett hushåll spenderar sin inkomst kan hushållens totala energianvändning beräknas. Beräkningarna ger också information om hur inkomsten kan spenderas på mer energisnåla sätt. En ytterligare studie gjordes för att visa på betydelsen av minskat livsmedelssvinn som strategi för minskad miljöpåverkan inom livsmedelssektorn (Artikel VI). Resultaten från studierna med konsumentperspektiv kan användas för att identifiera strategier för hur konsumenterna kan bidra till minskad miljöpåverkan i de båda fallsektorerna. För jordbrukssektorns del kan konsumenterna bidra till minskad miljöpåverkan framför allt genom en minskad konsumtion av animalier. När det gäller energisektorn är minskad energianvändning en viktig strategi, liksom att fortsatt sträva efter att ersätta fossila bränslen och uran med förnybara bränslen.</p> / <p>National sector responsibility legislation places specific obligations on Swedish sector authorities to handle environmental issues within their sector. Because of this responsibility, there is a need to map environmental impacts from sectors and to identify key problems and strategies to reduce impacts in each sector. Agriculture and energy are two sectors causing severe environmental impacts, and these are therefore interesting as case studies.</p><p>Employing a systems perspective when exploring impacts and options for their reduction ensures that problems are not simply shifted in time or space or between problems, but are considered in a holistic manner. Using this perspective, indirect effects such as changes upstream or downstream of the production chain, as well as among consumers, can be considered when seeking strategies to reduce environmental impacts in a sector.</p><p>A method to investigate environmental impacts from a sector was developed and tested in the cases of agriculture and energy (Papers I and II). The method was based on environmentally extended Input-Output Analysis (IOA) and Life Cycle Assessment (LCA). IOA-data from Swedish Environmental Accounts were used as the starting point for the inventory. Such data provide information on direct and indirect impacts from the sector. To capture those aspects not included in the Environmental Accounts, the Swedish Environmental Quality Objectives were subsequently used as a checklist, and information on the missing aspects was obtained from literature. For further processing of the data, characterisation and weighting methods from LCA methodology were used to identify hotspots, i.e. the most important problems.</p><p>The results showed that biodiversity, greenhouse effect, eutrophication, use of non-renewable resources and toxicity were potential hotspots in the agriculture sector. In the energy sector, the hotspots were air quality, greenhouse effect, use of non-renewable resources and toxicity.</p><p>Analysis of sector policies (Paper III) showed that both sectors are focusing on some of the hotspots identified, but other important problems are not receiving sufficient attention. In the agriculture sector, the focus is principally on biodiversity and toxicity, while the energy sector mainly focuses on issues of climate change and non-renewable resources.</p><p>A second hybrid IOA-LCA method (Energy Analysis Programme, EAP) was employed to study direct and indirect use of energy carriers in households (Papers IV and V). Through a combination of IOA and process data, the energy intensity (energy per monetary unit, e.g. MJ/SEK) of a large number of goods and services was calculated. When combined with information on household expenditure, these data provided information on total household use of fuels and electricity and provided insights into spending patterns that could result in lower energy intensity. A final study investigated the significance of reducing food losses as a strategy to reduce environmental impacts from the food sector (Paper VI). The results from the studies with a consumer perspective were used to identify how consumers can contribute to reducing environmental impacts in the two sectors investigated. For agriculture, consumers can help reduce impacts through reduced consumption of animal products, while for energy, reduced energy use in households is important, as is further substitution of fossil fuels.</p>

Statistical Energy Analysis (SEA) is one of the methods in literature to estimate high frequency vibrations. The inputs required for the SEA power balance equations are damping and coupling loss factors, input powers to the subsystems. In this study, the coupling loss factors are derived for two and three plates joined with a stiffener system. Simple formulas given in the literature for coupling loss factors of basic junctions are not used and the factors are calculated from the expressions derived in this study. The stiffener is modelled as line mass, Euler beam, and open section channel having double and triple coupling. Plate is modelled as Kirchoff plate. In the classical SEA approach the joint beam is modelled as another subsystem. In this study, the beam is not a separate subsystem but is used as the characteristics of the joint and to calculate the coupling loss factor between coupled plates. Sensitivity of coupling loss factors to system parameters is studied for different beam approaches. The derived coupling loss factors and input powers are used to calculate the subsystem energies by SEA. The last plate is joined to the first one to simulate the fuselage structure. A plate representing floor structure and acoustic volume are also added. The different modelling types are assessed by applying pressure wave excitation. It is shown that deriving the parameters as given in this study increases the efficiency of the SEA method.

Made available in DSpace on 2014-12-17T14:08:35Z (GMT). No. of bitstreams: 1 SandroRAFpdf.pdf: 3399052 bytes, checksum: df66802bf0108d40809857894310d319 (MD5) Previous issue date: 2009-07-31 / The thermoelectric energy conversion can be performed directly on generators without moving parts, using the principle of SEEBECK effect, obtained in junctions of drivers' thermocouples and most recently in semiconductor junctions type p-n which have increased efficiency of conversion. When termogenerators are exposed to the temperature difference (thermal gradient) eletromotriz a force is generated inducing the appearance of an electric current in the circuit. Thus, it is possible to convert the heat of combustion of a gas through a burner in power, being a thermoelectric generator. The development of infrared burners, using porous ceramic plate, is possible to improve the efficiency of heating, and reduce harmful emissions such as CO, CO2, NOx, etc.. In recent years the meliorate of thermoelectric modules semiconductor (TEG's) has stimulated the development of devices generating and recovery of thermal irreversibility of thermal machines and processes, improving energy efficiency and exergy these systems, especially processes that enable the cogeneration of energy. This work is based on the construction and evaluation of a prototype in a pilot scale, for energy generation to specific applications. The unit uses a fuel gas (LPG) as a primary energy source. The prototype consists of a porous plate burner infrared, an adapter to the module generator, a set of semiconductor modules purchased from Hi-Z Inc. and a heat exchanger to be used as cold source. The prototype was mounted on a test bench, using a system of acquisition of temperature, a system of application of load and instrumentation to assess its functioning and performance. The prototype had an efficiency of chemical conversion of 0.31% for electrical and heat recovery for cogeneration of about 33.2%, resulting in an overall efficiency of 33.51%. The efficiency of energy exergy next shows that the use of primary energy to useful fuel was satisfactory, although the proposed mechanism has also has a low performance due to underuse of the area heated by the small number of modules, as well as a thermal gradient below the ideal informed by the manufacturer, and other factors. The test methodology adopted proved to be suitable for evaluating the prototype / A convers?o termoel?trica da energia pode ser realizada diretamente em geradores sem partes m?veis, que utilizam o princ?pio do efeito SEEBECK, obtido em jun??es de condutores termopares e mais recentemente nas jun??es semicondutoras tipo p-n que apresentam maior efici?ncia de convers?o. Quando os termogeradores s?o expostos a uma diferen?a de temperatura (gradiente t?rmico), uma for?a eletromotriz ? gerada induzindo o surgimento de uma corrente el?trica no circuito. Desta forma, ? poss?vel converter em energia t?rmica a energia t?rmica da combust?o de um g?s atrav?s de um queimador, constituindo-se em um Gerador Termoel?trico. O desenvolvimento de queimadores infravermelhos, utilizando placa cer?mica porosa, tem possibilitado melhorar a efici?ncia dos processos de aquecimento, al?m de reduzir as emiss?es nocivas como CO, NOx, etc. Nos ?ltimos anos, o aperfei?oamento de m?dulos semicondutivos termoel?tricos (TEG?s) tem estimulado o desenvolvimento de dispositivos geradores e de aproveitamento de irreversibilidades t?rmicas de m?quinas t?rmicas e processos, melhorando a efici?ncia energ?tica e exerg?tica desses sistemas, principalmente de processos que permitem a cogera??o de energia. O presente trabalho est? baseado na constru??o e avalia??o de um prot?tipo, em escala piloto, para gera??o de energia visando aplica??es espec?ficas. A unidade utiliza g?s combust?vel (GLP) como fonte prim?ria de energia. O prot?tipo ? composto de um queimador infravermelho de placas porosas, um adaptador para o m?dulo gerador, um conjunto de m?dulos semicondutores adquiridos da Hi-Z Inc. e um trocador de calor para ser utilizado como fonte fria. O prot?tipo foi montado em uma bancada de testes, utilizando um sistema de aquisi??o de temperatura, um sistema de aplica??o de carga e instrumenta??o para avaliar o seu funcionamento e desempenho. O prot?tipo apresentou uma efici?ncia de convers?o qu?mica para el?trica de 0,31% e aproveitamento t?rmico de cogera??o da ordem de 33,2%, resultando numa efici?ncia global de 33,51%. A efici?ncia exerg?tica pr?xima da energ?tica mostra que o aproveitamento ?til da energia prim?ria do combust?vel foi satisfat?rio, embora o dispositivo proposto tenha apresentado, ainda, um baixo desempenho devido a subutiliza??o da ?rea aquecida pelo n?mero reduzido de m?dulos, como tamb?m, um gradiente t?rmico abaixo do ideal informado pelo fabricante, al?m de outros fatores. A metodologia de ensaio adotada mostrou-se adequada para avalia??o do prot?tipo

abstract: Buildings in the United States, account for over 68 percent of electricity consumed, 39 percent of total energy use, and 38 percent of the carbon dioxide emissions. By the year 2035, about 75% of the U.S. building sector will be either new or renovated. The energy efficiency requirements of current building codes would have a significant impact on future energy use, hence, one of the most widely accepted solutions to slowing the growth rate of GHG emissions and then reversing it involves a stringent adoption of building energy codes. A large number of building energy codes exist and a large number of studies which state the energy savings possible through code compliance. However, most codes are difficult to comprehend and require an extensive understanding of the code, the compliance paths, all mandatory and prescriptive requirements as well as the strategy to convert the same to energy model inputs. This paper provides a simplified solution for the entire process by providing an easy to use interface for code compliance and energy simulation through a spreadsheet based tool, the ECCO or the Energy Code COmpliance Tool. This tool provides a platform for a more detailed analysis of building codes as applicable to each and every individual building in each climate zone. It also facilitates quick building energy simulation to determine energy savings achieved through code compliance. This process is highly beneficial not only for code compliance, but also for identifying parameters which can be improved for energy efficiency. Code compliance is simplified through a series of parametric runs which generates the minimally compliant baseline building and 30% beyond code building. This tool is seen as an effective solution for architects and engineers for an initial level analysis as well as for jurisdictions as a front-end diagnostic check for code compliance. &#8195; / Dissertation/Thesis / Rocky Mountain Institute- Model Manager Tool / ECCO Spreadsheet Tool / M.S. Built Environment 2011