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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Desenvolvimento de fatores de normalização de impactos ambientais regionais para avaliação do ciclo de vida de produtos no Estado de São Paulo / Development of normalization factors to life cycle assessment in São Paulo state

Silva, André Luiz Ribeiro Tachard da 30 April 2010 (has links)
A normalização é uma importante etapa da Avaliação do Ciclo de Vida, uma vez que fornece uma unidade comum, permitindo a comparação das diferentes categorias de impacto. A referência de normalização mais utilizada considera o impacto das atividades totais da sociedade num certo período de tempo. Estes dados são inexistentes no Brasil para impactos regionais e locais, de forma que este trabalho objetivou iniciar o preenchimento dessa lacuna, com os fatores de normalização para as categorias \"acidificação\" e \"eutrofização\", no estado de São Paulo. Tais fatores foram calculados com base em um inventário das estimativas anuais de aporte ao meio ambiente de substâncias contribuintes para estas categorias, cuja realização possibilitou a análise do estado da arte desses impactos em São Paulo e dos setores responsáveis pela geração das substâncias contribuintes. Conforme esperado, os fatores (ou referências) de normalização encontrados foram diferentes daqueles por hora utilizados no Brasil, baseados em dados europeus. Entre as razões que explicam esta diferença estão a baixa emissão de \'SO IND.X\' devido a matriz energética brasileira, o uso de etanol com combustível e o despejo de esgoto sem tratamento (ou tratamento inadequado). / Normalization is an important step in Life Cycle Assessment as it provides a common unit, allowing the comparison of the different impact categories. The normalization reference most widely used considers the \"background\" impact from the total activities of society in a chosen reference period. These data are inexistent in Brazil for regional and local impacts so that this work aimed to begin filling this lack, first developing normalization factors for the categories \"acidification\" and \"eutrophication\" in the state of Sao Paulo. These factors were calculated from an inventory of the annual load to the environment of substances contributing to these categories; the production of this inventory allowed the analysis of a) the state of the art of these impacts in Sao Paulo and b) the sectors responsible for the generation of contributors. As expected, normalization factors (or references) were different from those currently used in Brazil, based on European data. Among the reasons for this difference are lower \'SO IND.X\' emissions due to the Brazilian energy matrix, the use of ethanol as fuel and disposal of sewage without treatment (or mistreatment).
262

Life cycle assessment comparison between Pepfactant® and chemical surfactant production.

Huang, Huai January 2008 (has links)
Recently designed Pepfactants® are an innovative type of nano-technological products, which could potentially replace conventional surfactants in broad-ranging applications. Currently, Pepfactants® technology is still in an initial design period at the laboratory scale. In order to develop the industrial-scale production of Pepfactants®, the design group has proposed simulated strategies for industrial-scale Pepfactants® manufacture and a desire to improve these strategies with regards to sustainability. This project aimed to assist Pepfactants® designers to understand the environmental footprint of simulated Pepfactant® AM1 manufacturing process, using the methodology of Life Cycle Assessment (LCA) – a comprehensive tool to quantify the environmental impacts from products and processes. To find the environmental shortcomings of the proposed manufacturing process for Pepfactant® AM1, the LCA outcomes were compared with published life cycle information of traditional chemical surfactant Lineal Alkylbenzene Sulphonate (LAS) production. Following LCA methodology, a life cycle inventory was compiled based on the simulated AM1 manufacture, which determined the environmental impact assessment for both AM1 and LAS production. In the LCA boundaries disregarding the usage of both surfactants, the quantitative LCA comparison results indicated that raw material and energy requirements of AM1 manufacture were much higher than LAS production, estimated to be 3,186 t/t AM1 against 31.1t/t LAS and 1,564,000MJ/t AM1 against 69,870MJ/t LAS respectively. Additionally, compared with LAS production, enormous water consumption (2,651 t/t AM1) and CO2 emission (522 t/t AM1) were also shown to be severe environmental problems for AM1 manufacture. Furthermore, the AM1 manufacture presents apparent problems with environmental impacts of nutrification, human toxicity, photochemical oxidant formation and acidification in comparison with LAS production. Other than providing the optimisation point in the view of environmental impacts for Pepfactant® AM1 manufacture, the results of experimental work in this project showed that as the surfactant concentration increases a greater foam height of Pepfactant® AM1 was achieved than when (from 7mm to 52mm between 15μM and 100μM) compared with LAS (from 8mm to 53mm between 31.3μM and 2,000μM) in the same aeration duration. This result demonstrated the great potential of AM1 to replace LAS based on the LCA functional unit – 1 tonne of products. The experiments results implied that 1 tonne of AM1 is able to have the same foaming ability as approximate 25 tonnes of LAS. Consequently, the environmental impacts from Pepfactant® AM1 manufacture are reduced by 25 times in the extended LCA boundaries linked to the quantitative usage comparison of these two surfactants. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1317664 / Thesis (M.Eng.Sc.) -- University of Adelaide, School of Chemical Engineering, 2008
263

Att kommunicera produkters miljöprestanda : - Syften, behov och möjligheter i svenska möbelföretagskommunikation av produkters miljöprestanda / Communication of environmental performance in products : - Objectives, needs and possibilities in Swedishfurniture producers. communication of environmental performance in products

Helgstrand, Anton January 2009 (has links)
<p>Den här studien har ett tudelat syfte där huvuddelen utreder vilka behov och syften två svenska möbelföretag har i att kommunicera produkters miljöprestanda idag. Delsyftet i studien var att se om de studerade företagen har användning för miljödeklarationer för sina syften och behov i produktkommunikationen. För att samla in empiri användes kvalitativa intervjuer. Utifrån en kategorisering av resultatet kunde materialet diskuteras tillsammans med utvalda kommunikativa begrepp samt rådande forskning som behandlar miljödeklarationen och relaterade ämnens koppling till kommunikation.</p><p>Av diskussionen framgick att företagen kommunicerar produkter främst utefter krav som ställs från kunden. Syftena med produktkommunikationen är att sändarna i kommunikationsprocessen förmedlar budskapet om bra produkter som framställs ur ett helhetsperspektiv på miljöarbetet. Idag kommuniceras produkterna främst genom den allmänna marknadsföringen såsom hemsida och försäljare, men även reaktivt via miljödeklarationer. Om möbelföretagen definierar målgrupperna och kundernas kompetens i kommunikationsprocessen kan framtida användning av miljödeklarationen bli effektiv.</p><p>Studien visar slutligen att miljödeklarationen, som kommunikationsverktyg för produkters miljöprestanda, skulle kunna fungera kompletterande till möbelföretagens rådande marknadsföring och således infria de krav som ställs.</p>
264

Assessing the Social Performance of Products: Developing a Set of Indicators for Vattenfall AB Connected to the International EPD® system

Welling, Sebastian January 2013 (has links)
A set of indicators has been developed by the author of this work to assess the social performance of Vattenfall’s products (electricity &amp; heat). This set of indicators has been adapted to the requirements of the International EPD® system. The aim has been to create a set of indicators that can be applied to all processes within the lifecycle. The indicators are supposed to make a best possible statement of the social performance of a companies’ product, including the most relevant issues and topics within the pillar of social science and social sustainability. The method used for the development of the indicators is the Delphi method. The Delphi process includes several rounds of reviewing. A group of experts usually carries out the reviewing. In this study five rounds of reviewing has been conducted with the help of nine experts. The first round has been an extensive literature review. The 390 indicators found in the literature have been classified according to the system and the instruction of S-LCA, which are described in the Guidelines for Social Life Cycle Assessment of Products. The fifth round of reviewing has been the last one and consensus on the list of indicators could be reached. The outcome of the development process has been a set of 30 indicators. Not all subcategories proposed in UNEP/SETAC’s Guidelines for Social Life Cycle Assessment of Products have been covered. The indicators have been distinguished into two categories: core and additional. Some important social issues could not be expressed in the form of an indicator. They have been added in the final outcome of the paper, the ‘socioprofile’, as additional information. The measurement and impact assessment of qualitative indicators have been a major challenge of this study. Data availability can be seen as another critical field of the study and the application of the indicators. Other studies that have been conducted focused on a lower amount of indicators. The study has shown the possibility to quantify and measure social impacts to a certain degree. The proposed indicators are aiming at a globally focused assessment of social sustainability. The inclusion of experts and the group discussions with those experts have shown the importance of these indicators. The next step in the development of social sustainability indicators is the implementation of these indicators in a practical application and the study of the outcome. To be applicable within the International EPD® system, the Product Category Rules also have to be updated to allow for a Sustainable Product Declaration.
265

Resurseffektivare energi- och växthusföretag genom industriell symbios / More resource-efficient energy and greenhouse companies through industrial symbiosis

Andersson, Stina January 2010 (has links)
Syftet med examensarbetet är att utreda vilken potential det finns för en samverkan mellan Tekniska Verken och växthus. Målet är att genom industriell symbios skapa en resurseffektiv systemlösning där Tekniska Verkens produktionsanläggningars miljöprestanda förbättras samtidigt som växthusets klimatpåverkan minskas. Tekniska Verken har överskottsvärme i sina produktionsanläggningar. Under 2007 hade Gärstad- och Kraftvärmeverket 54 GWh överskottsvärme. Största delen av överskottsvärmen fanns på sommaren, då värmebehovet i fjärrvärmesystemet var som lägst. Effekten som kyldes bort under sommaren uppgick till 25 MW. Om ett par år kommer Svensk Biogas anläggning i Linköping ha överskottsvärme på 26 GWh per år. Effekten kommer då vara 4 MW på vintern och 2 MW på sommaren. Koldioxidmängden från biogasanläggningen uppgår till 16 000 ton per år vilket ger ett flöde på 1,8 ton i timmen. Biogasanläggningen i Linköping producerar 45 000 ton biogödsel per år. Grönsaker som tomat, gurka, örter och sallat odlas i växthus och trivs bäst vid temperaturer på 15-26 ˚C. Under dagen bör temperaturen vara något högre än nattetid. För att öka tillväxten hos plantorna kan koldioxid tillföras. Vid stark ljusinstrålning och varmt klimat kan koldioxidhalten höjas från 375 ppm till 1 200 ppm. Värmeenergibehovet för en tomatodling ligger mellan 350 till 550 kWh per kvadratmeter och år. Maxeffekten för uppvärmningssystemet varierar mellan 200 och 300 W per kvadratmeter beroende på växthusets placering och isoleringsmaterial. Koldioxidtillförseln är 7-20 gram per kvadratmeter växthus. Överskottsvärmen från Tekniska Verkens produktionsanläggningar räcker till att försörja ett traditionellt växthus på 2 hektar. Växthuset har lägst värmebehov på sommaren vilket gör att endast en liten del av värmen från Gärstad- och Kraftvärmeverket kan tas tillvara. Mängden överskottsvärme från biogasanläggningen är som störst under vintern och något lägre under sommaren, vilket gör den väl lämpad för en matchning med växthus. Mängden koldioxid räcker för att tillgodose en växthusareal på 9 hektar. Eventuellt kan det bli möjligt att använda biogödsel som växtnäring i växthus. Dock bör vidare studier utföras innan detta kan fastställas. Tekniska Verken utreder hur ett samarbete med företaget Plantagon skulle kunna se ut. Plantagon har tillsammans med Sweco tagit fram ett innovativt odlingskoncept där växter odlas på höjden i ett sfärformat växthus. För att verifiera Swecos uppgifter om energi- och effektbehov samt få en uppfattning om vilka parametrar som påverkar växthusklimatet har beräkningar utförts. De faktorer som tagits hänsyn till i beräkningarna är värmeledning, konvektion, solstrålning, ventilation, avfuktning och vattenanvändning. För att se hur effektbehovet varierar över året har beräkningarna upprepats för varje månad. Överskottsvärmen från Tekniska Verken räcker gott och väl för att täcka Plantagons växthus värmebehov. För att uppskatta hur mycket Tekniska Verkens resurser skulle kunna reducera en växthusodlings klimatpåverkan har sex olika scenarier ställts upp. Med hjälp av en befintlig livscykelanalys för svensk tomatodling har koldioxidekvivalenterna per kilogram producerade tomater för de olika scenarierna beräknats och jämförts. Två av scenarierna är kopplade till Tekniska Verken. Det ena scenariot är en traditionell växthusodling och den andra är Plantagons växthus. En traditionell växthusodling som förses med Tekniska Verkens resurser samt producerar närproducerade grönsaker visade sig få en väsentligt mycket lägre klimatpåverkan än en genomsnittlig växthusodling. Produktion av 78 kilogram tomater i det växthuset motsvarar samma klimatpåverkan som 1 kilogram tomater från en genomsnittlig svensk växthusodling.  Plantagons växthus kan på samma sätt producera 7 kilogram tomater för samma klimatpåverkan som 1 kilogram tomater från en genomsnittlig växthusodling. Genom att använda överskottsvärme, koldioxid och biogödsel från Tekniska Verken till att driva växthus kan en systemlösning med låg miljöpåverkan skapas. Resurser som tidigare inte utnyttjats kan få ett användningsområde, vilket ökar miljöprestandan för produktionsanläggningarna. Grönsakerna som produceras får en låg miljöpåverkan vilket gör att de exempelvis kan klimatcertifieras samt säljas som närproducerade i Linköpingstrakten. Genom att undvika långa och kostsamma transporter samt kunna sälja grönsaker till ett högre pris ökar förtjänsten för odlingsföretaget. / The purpose of this master thesis is to assess the potential from a joint venture between Tekniska Verken and greenhouses. The goal is to, through industrial symbiosis, create a resource-efficient solution in which Tekniska Verken’s facilities can improve their environmental performance while the greenhouse’s climate impact is reduced. Tekniska Verken has excess heat in their facilities. In 2007 Gärstad- and Kraftvärmeverket had 54 GWh excess heat. The largest quantity of excess heat occur during the summer when the demand for heat in the district heating system is the lowest. The excess heat during the summer reached a high level as 25MW. In a few years, Swedish Biogas’s plant in Linköping will have an excess heat of about 26 GWh per year. The effect will then be 4 MW during the winter and 2 MW during the summer. The amount of carbon dioxide released from the biogas plant is 16 000 tons a year resulting in a flow of 1.8 tons per hour. The biogas plant in Linköping produces 45 000 tons of bio-fertilizer a year. Vegetables like tomatoes, cucumbers, herbs and lettuces are grown in greenhouses thrives best at temperatures of 15-26 ˚ C. During the day, the temperature should be slightly higher than during the night. In order to enhance growth of the plants, carbon dioxide can be added. In strong light and warm climates, carbon dioxide concentration can be increased from 375 ppm to 1200 ppm. The energy demand for tomato cultivation is somewhere between 350-550 kWh per square meter and year. The power requirement varies between 200 and 300 W per square meter depending on plant location and the house insulation. The carbon dioxide supply is 7-20 grams per square meter greenhouse. The excess heat from Tekniska Verken’s facilities is enough to support a traditional greenhouse with the size of two hectares. The greenhouse has its lowest heat demand in the summer, which has the effect that only a small portion of excess heat from Gärstad- and Kraftvärmeverket can be used. The amount of excess heat from the biogas plant is highest in the winter and slightly lower in the summer, making it well suited for a match with the greenhouse. The amount of carbon dioxide is enough to meet the demand of a greenhouse with an area of 9 hectares. It could potentially be possible to use bio-manure as fertilizer in the greenhouse. However, further studies should be conducted before this can be assured. Tekniska Verken is investigating how a joint venture with the company Plantagon could be set up. Plantagon together with Sweco has developed an innovative cultivation concept in which plants are grown in levels in a sphere-shaped greenhouse. To verify the data on energy and power needs given by Sweco, and to get an idea of the parameters that affect greenhouse climate, calculations have been performed. The factors taken into account in the calculations are the heat conduction, convection, solar radiation, ventilation, dehumidification and the use of water. To see how the power requirements vary throughout the year, the calculations have been repeated for every month. The excess heat from Tekniska Verken is more than enough to cover the greenhouse’s heat demand. In order to estimate how much Tekniska Verken could reduce a greenhouse cultivation’s climate impact, six different scenarios is set. Using an existing life cycle analysis of Swedish tomato cultivation the carbon dioxide emission per kilogram of tomatoes for the different scenarios were calculated and compared. Two of the scenarios are linked to Tekniska Verken. One scenario is traditional greenhouse cultivation and the other is Plantagon greenhouse. A traditional greenhouse cultivation which is provided with resources from Tekniska Verken and is locally producing vegetables has a smaller carbon footprint than average greenhouse cultivation. The production of 78 kg of tomatoes in that greenhouse corresponds to the same carbon footprint as 1 kilogram tomatoes from average greenhouse cultivation. Plantagon greenhouse can similarly produce 7 kilograms of tomatoes in the same climate impact as 1 kilogram of tomatoes from average greenhouse cultivation. By using excess heat, carbon dioxide and bio-manure from Tekniska Verken to power the greenhouse, a system solution with low environmental impact is created. Previously not used resources will have a sector of application, which increases the environmental performance of the production facilities. The produced vegetables will get a lower environmental impact and could, for example be climate certified and sold as locally produced in the Linköping area. By avoiding long and expensive transports and to be able to sell vegetables at a higher price increases the profits for cultivation company.
266

Life Cycle Exergy Analysis of Wind Energy Systems : Assessing and improving life cycle analysis methodology

Davidsson, Simon January 2011 (has links)
Wind power capacity is currently growing fast around the world. At the same time different forms of life cycle analysis are becoming common for measuring the environmental impact of wind energy systems. This thesis identifies several problems with current methods for assessing the environmental impact of wind energy and suggests improvements that will make these assessments more robust. The use of the exergy concept combined with life cycle analysis has been proposed by several researchers over the years. One method that has been described theoretically is life cycle exergy analysis (LCEA). In this thesis, the method of LCEA is evaluated and further developed from earlier theoretical definitions. Both benefits and drawbacks with using exergy based life cycle analysis are found. For some applications the use of exergy can solve many of the issues with current life cycle analysis methods, while other problems still remain. The method of life cycle exergy analysis is used to evaluate the sustainability of an existing wind turbine. The wind turbine assessed appears to be sustainable in the way that it gives back many times more exergy than it uses during the life cycle.
267

A new comprehensive map of LCAs for decision makers in China : case study in FAST project

Shi, Rong, Yue, Jianting January 2011 (has links)
The starting point for this thesis project is the increasing intense demands of using Life Cycle Assessment (LCA) to improve the environmental performance of projects, i.e. theFive-hundred-meter Aperture Spherical radio Telescope project(FAST project) inChina. As a prevailing systematic and strategic assessment tool, LCA is used to evaluate and assess all environmental impacts of products, services and industrial processes from cradle to grave. It is also well recognized and practiced to achieve the goal of sustainability.   Following the increasing trend of sustainable development, the idea of conducting LCA technique is gaining more support from the governments, local authorities and institutes inChina. Still, recent researches have only focused on the technical issues of this tool as such, rather than the context it is involved in. To give a broader perspective instead, this thesis focuses on how to make the rankings and quantitative eco-files generated from LCAs be understood more effectively and easily by the decision makers. An effective and comprehensive map of life cycle assessment building on the results of life cycle assessment is presented.This map in this thesis is named as CLCA. Through ranking and mapping the complicated and recondite environmental performance information from the LCAs, a holistic and systematic view can be provided to the decision makers. Thus, to some extent, this CLCA approach can lend support to strategic decisions making and sustainable development.   For this purpose, literature on LCA and literature from relevant disciplines are reviewed. The empirical analysis of FAST project sheds light on that it is necessary to develop a new method that can contribute to convertingcomplicated and reconditedata into a comprehensive and visualized one. Therefore, a survey paper based on the literature review and empirical analysis is designed, distributed and collected. Some influential and necessary essentials of the LCA reports for the decision makers are picked out and summarized in accordance with the results of survey papers. This thesis concludes by presenting a new map of LCA reports and suggestions for further research.
268

Indirect Land-Use Change from BiofuelProduction : Uncertainties and Policymaking from an EUPerspective

Offergeld, Taniya January 2012 (has links)
No description available.
269

Characterization of material behavior during the manufacturing process of a co-extruded solid oxide fuel cell

Eisele, Prescott L. (Prescott Lawrence) 08 April 2004 (has links)
Recent developments in powder metal oxide processing have enabled co-extrusion of a honeycomb structure with alternating layers of metal and ceramic. Such a structure is envisioned for use as a Solid Oxide Fuel Cell (SOFC) if defects can be minimized during the manufacturing process. The two dissimilar materials tend to shrink at different rates during hydrogen reduction and sintering, inducing internal stresses that lead to structural defects such as cracks, or high residual stresses. The objective of this thesis is to characterize the shrinkage and relaxation mechanisms inherent in both the metal and ceramic so that internal stresses developed during manufacturing can be estimated and ultimately minimized. Constitutive models are adapted from the literature to simulate the sintering and viscoelastic behaviors of the ceramic. Likewise, existing models in the literature are used to characterize the viscoplastic relaxation of the porous powder metal phase and its sintering behavior. Empirical models are developed for the reduction behavior of the metal oxides, based on a series of experiments conducted that measure water vapor (hygrometry) and dimensional change (dilatometry) during reduction and sintering. Similarly, the necessary parameters for the sintering model and viscoplastic model were determined through a series of experiments. The constructed system of constitutive equations appears to have the essential elements for modeling dimensional change, porosity/strength and development of internal (residual) stresses in co-extruded SOFC structures.
270

The fabrication of thin-walled steel alloys through the gas carburization of reduced metal oxide extrusions

Cerully, Laura B. 26 April 2010 (has links)
Investigations of the production of thin-walled steel alloys through the reduction and subsequent gas carburization of structures made from metal oxide powders were performed. Batch compositions, as well as the heat treatment parameters necessary for the formation of structures were determined through the use of thermogravimetric analysis, dilatometric measurements, and microstructural investigation. Parameters for the high temperature carburization of thin-walled 4140 structures were determined. The research has shown that the amount of carbon in the walls of the structures can be controlled and uniform carbon contents across the cross-sections can be achieved in less than 30 minutes. Heat treatments for carburized samples were performed and subsequent microhardness testing resulted in values similar to conventionally produced 4140 steel. Studies on the decarburization behavior of similar alloys under various conditions were also performed in order to aid in the prediction of the microstructural behavior of samples during carburization and subsequent heat treatment. Low temperature gas carburization of structures with 316 steel composition has also been performed. Hardness variations present through the cross-section of the part after carburization suggest some transfer of carbon, though contents are not as high as anticipated. Suggestions for future work in this area are presented. The results of these investigations yield a novel method for the production of steel parts from metal oxide powders. The speed and low cost of the process, coupled with the proven ability of the process to yield parts with similar microstructural and mechanical characteristics as conventionally made alloys, allows for the techniques presented in this study to be used for the development of alloys which could not be previously done economically.

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