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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.
121

Klimatpåverkan av stommaterial på Regnbågens förskola i Årjäng : Med fokus på koldioxidutsläpp vid val av KL-trästomme alternativt stålstomme med utfackningsväggar av trä och bjälklag av betong. / Climate impact of frame materials at Regnbågens Preschool in Årjäng : Focusing on carbon dioxide emissions depending on selection of CLT frame or a steel frame with timberstructure compartment walls and concrete floors.

Klemetz, Jacob, Eklund, Joseph January 2020 (has links)
Idag förbrukas jordens resurser i högre takt än vad jorden klarar av att bearbeta. Byggbranschen tillhör en av de sektorer som har högst klimatpåverkan, främst i form av koldioxidutsläpp. Därför pågår ett kontinuerligt arbete med att ta fram byggnadsmaterial som skall minska belastningen på miljön.  I byggbranschen kan man se en trend att korslimmat trä (KL-trä) blir allt mer efterfrågat som stommaterial. Det sägs ge upphov till mindre miljöpåverkan samt ge ett bättre inneklimat än vad andra stommaterial gör.   Denna studie visar en teoretisk jämförelse av klimatpåverkan samt av inomhusmiljön mellan en KL-trästomme och en kombinerad stål- och betongstomme. Båda stomalternativen har projekterats av ByggDialog tillsammans med deras samarbetspartners. Referensbyggnaden är Regnbågens förskola i Årjängs kommun. Syftet med denna studie är att uppmärksamma, skapa en medvetenhet samt ge verktyg till ByggDialogs kunder för att göra ett klimatsmart stomval, vilket i sin tur också kan bidra till att de svenska hållbarhets målen uppnås till 2030. Klimatpåverkan beräknades under produktskedet vilket innebär råvaruförsörjning, transport och tillverkning för ingående material (modul A1-A3) med hjälp av ett Global Warming Potential-värde (GWP-värde). Vilket är ett värde på hur stor klimatpåverkan ett material ger upphov till i form av utsläpp av koldioxidekvivalenter. För att undersöka hur stomval påverkar inomhusmiljön gjordes en litteraturstudie.   Resultatet visade att KL-trä som stommaterial gav upphov till cirka hälften så stor miljöpåverkan vad gäller koldioxidutsläpp men var cirka 12% dyrare att uppföra jämfört med en kombinerad stål- och betongstomme. Vid beräkning av koldioxidutsläpp per SEK visade det sig att en stomme av KL-trä hade cirka 67% lägre koldioxidutsläpp per SEK än vad en kombinerad stål- och betongstomme hade.  Litteraturstudien visade att KL-trä som stommaterial gav en jämnare luftfuktighet men sämre värmelagringsförmåga och ljudabsorption i form av steg- och stomljud jämfört med en kombinerad stål- och betongstomme. Forskning visade att synligt trä till exempel KL-trä, ger en upplevelse av trygghet, avkoppling och allmänt välbehag för människor som vistas i byggnaden. / Today, the Earth's resources are used at a higher rate than the Earth can manage. The construction industry is one of the sectors that have the greatest negative climate impact, mainly related to high carbon dioxide emissions. This industry continuously strives to develop building- and construction materials resulting in an as low  environmental footprint as possible. Recent trends, in the construction industry, shows an increase in the use of cross-limbed timber (CLT) for frame material. The claim is lower environmental footprint at the same time as it gives a better indoor climate compared to other frame materials.  This study will be a theoretical comparison of the climate impact as well as the indoor environment between a CLT frame and a combined steel and concrete frame. Both frame alternatives have been designed by the construction company ByggDialog together with their partners. The reference building for this study is Regnbågens Preschool in Årjäng Municipality. The purpose of this study is to raise and create awareness and also provide tools for ByggDialog and their customers enabling a climate-smart frame selection. This will most likely also  contribute to achieving the Swedish sustainability goals by 2030. By using data from the Global Warming Potential (GWP) for the input materials, the climate impact was calculated. Each construction frame type data was analyzed during the product phase which include raw material supply, transport and manufacturing (module A1-A3) in the form of emissions of carbon dioxide equivalents. A literature study was also conducted to analyze how a frame of CLT affects indoor environment.  The result showed that by using a CLT frame material versus a combined steel and concrete-frame the environmental reduction was about 50% and about 12% increase in cost. When calculating the carbon dioxide emissions per SEK, it was found that the CLT frame construction had about 67% lower carbon dioxide emissions per SEK compared to a combined steel and concrete frame. The literature study showed that a frame material of CLT provides a more evenly distributed humidity, poorer heat storage capacity and less sound absorption capacity in the form of step- and frame sound compared to a combined steel and concrete frame construction. Further research in this field indicates that by having visible wood, for example a CLT frame provides an experience of safety, relaxation and general well-being for people in the building.
122

The Potential of Reducing Carbon Footprint Through Improved Sorting / Potentialen att minska klimatavtrycket genomen en ökad källsortering

Olsson, Fredrika January 2020 (has links)
Almost five million tonnes of household waste was generated in Sweden in 2018, half of which was residual waste sent for incineration with energy recovery. For materials that can not be recycled or biologically treated, incineration with energy recovery is considered a preferred management option. The issue is that the fraction for residual waste contains considerable amounts of wrongly sorted materials, such as food waste and plastic packaging, which can be recycled or biologically treated, thus causing a smaller environmental impact. To quantify the composition and waste quantities of the wrongly sorted materials a waste composition analysis of the residual waste from four community bins in Västmanland county was conducted. The analysis revealed that about two-thirds of the waste was wrongly sorted and only one-third was actual residual waste. Life cycle analysis was subsequently used to calculate the carbon footprint of the wrongly sorted food waste and plastic packaging waste as well as the carbon footprint from optimal sorting and treatment of the materials. The investigation concluded that for food waste, anaerobic digestion caused a smaller climate impact than incineration with energy recovery and for plastic packaging, recycling generated a smaller climate impact than incineration with energy recovery. The size of the carbon footprint for the different management methods was in line with the priority order given in the waste hierarchy, stated in Swedish legislation.  However, the size of the potential climate savings partly depended on the choices made in the life cycle analysis where the most sensitive parameters were related to external production of heat, polymer resin and vehicle fuel. If the potential climate savings is extrapolated for VafabMiljö's entire collecting area, the total climate savings per year would be 8 263 tonnes of carbon dioxide equivalents per year for food waste and 2 070 tonnes of carbon dioxide equivalents per year for plastic packaging waste. This would be equivalent to driving 1 250 laps around the Earth with a car every year or flying 14 900 times Sweden–Thailand back and forth every year. / Nästan fem miljoner ton hushållsavfall genererades i Sverige under 2018, varav ungefär hälften skickades till energiåtervinning. För avfall som inte kan materialåtervinnas eller behandlas biologiskt anses energiåtervinning vara den bästa metoden för avfallshantering. Problemet är att stora mängder återvinningsbart material såsom matavfall och plastförpackningar felaktigt hamnar i restavfallet när det istället hade kunnat återvinnas och på så sätt medfört en mindre miljöpåverkan. För att kvantifiera samansättning och avfallsmängder av det felaktigt sorterade materialet, gjordes en plockanalys på restavfallet från fyra miljöbodar i Västmanland. Analysen visade att ungefär två tredjedelar av materialet var felaktigt sorterat och endast en tredjedel utgjordes av övrigt restavfall. Livscykelanalys användes därefter för att beräkna klimatavtrycket för det felaktigt sorterade matavfallet och för plastförpackningarna som återfanns i restavfallet såväl som klimatavtrycket för optimal sortering och hantering av materialen. Ordningen i avfallshierarkin visade sig stämma väl överens med klimatavtrycket från de olika behandlingsmetoderna i det undersökta området. För matavfall innebar rötning en lägre klimatpåverkan än energiåtervinning och för plastförpackningar medförde materialåtervinning en lägre klimatpåverkan än energiåtervinning. Storleken på besparingarna av växthusgaser berodde dock till viss del på val av inparametrar och de faktorer som främst påverkade var alternativ produktion av värme, plastråvara och drivmedel. Om resultaten extrapoleras över hela VafabMiljös upphämtningsområde så skulle de totala klimatbesparingarna för matavfall vara 8 263 ton koldioxidekvivalenter per år och för plastförpackningar 2 070 ton koldioxidekvivalenter per år. Dessa besparingar är jämförbara med bilkörning motsvarande 1 250 varv runt jorden varje år eller 14 900 tur- och returresor med flyg Sverige–Thailand varje år.
123

Sustainable Public Procurement : Development and analysis of tools for construction works

Verzat, Benoit January 2008 (has links)
Embedded in the economic competition, public procurement has amajor role to play in being a driving force for the promotion of a globallypositive competition that prides the best sustainable products and services,rather than only the more economically efficient ones. Responsible for ahuge part of the human pressure on natural resources, and having a largeshare in the public funding, the built environment sector provides animportant venue for the use of sustainable public procurement as a tool toenhance the sustainability of societies.Selecting the best sustainable offer is a challenging task requiringenvironmental and social assessments that can only be based on complexlife cycle thinking analysis. Through the development of the “ExhaustiveSustainable public procurement clauses Manual”, this paper analyses publicprocurement issues and their potential solutions, with a focus on theenvironmental performance in buildings procurement.
124

Environmental Systems Analysis of Waste Management : Prospects of Hydrogen Production from Waste for use in FCVs

Assefa, Getachew January 2000 (has links)
ORWARE, an evolving systems analysis based computer model is used to assess the performance of different waste management options from a life cycle perspective. The present version of the model consists of different submodels for transport, treatment, and disposal of different types of liquid and solid wastes and recycling of materials. Flows between submodels are described by a vector of several substances of different relevance to the system. The model calculates emissions to water and air, amount of residues returned to arable land and energy flows using the tools of life cycle analysis (LCA) and substance flow analysis (SFA). In going in the direction of stringent environmental standards and policies, there is a need for maximizing energy recovery from waste for both environmental and economic benefits. Sweden has already experience of recovering energy from waste for district heating. Recovering energy not only of high value but also of higher quality from waste would be of interest. Hydrogen is one carrier of such energy. The possibility of using hydrogen from waste as a fuel in the transport sector would contribute in heading for creating a clean environment. In this thesis a new submodel for steam reforming of biogas recovered from an anaerobic digester is developed and used with other submodels within the ORWARE framework. Four scenarios representing alternative ways of energy recovery from the organic waste in Stockholm have been simulated to compare the associated energy turnover and different environmental impacts. Digestion of the organic waste and using the biogas to fuel cars is compared against steam reforming of biogas to hydrogen or thermal gasification of the waste and processing the product gases to hydrogen. In the latter two cases hydrogen produced is used in fuel cell cars. Avoided impacts of using the biogas and hydrogen are analyzed using the fourth scenario where the waste is incinerated to generate heat and electricity. Functional equivalence between scenarios is achieved by external supply of heat, electricity and petrol. While recognizing the uncertainties during modelling and simulation, it is possible to conclude that the results indicate that there is advantage of reduced environmental impact and high energy turnover in introducing the technologies of producing hydrogen from waste into the waste management system. Further and thorough investigation is recommended to come up with a sound and firm conclusion. Key words: Systems analysis, Life cycle analysis, Substance flow analysis, Waste management, Environmental impact, Steam reforming, Thermal gasification, Fuel cell vehicles, Hydrogen <img src="http://www.webforum.com/form/kthima/images/spacer.gif" /> / www.ima.kth.se
125

EKODESIGN I INDUSTRIN : En lägesanalys av producenters problem, drivkrafter och framtida utmaningar inom ekodesign / ECO DESIGN IN PRODUCT INDUSTRY : An analysis, based on producers problems, driving forces and future challenges in eco design

Bergsten, Karolina, Langborg, Ida January 2012 (has links)
SammanfattningProdukter produceras idag i stor utsträckning för att tillfredsställa konsumenters behov varpåmiljöbelastningen eskalerar i takt med efterfrågan och produktionen som sker därefter. Lösningenpå problemet kan sammanfattas i ekodesign där miljöoptimering av produktutvecklingen skerutifrån ett helhetsperspektiv; råvaruutvinning, produktion, användning, återvinning, slutligtomhändertagande samt transporter.Teknik-konsultföretaget ÅF uppmärksammade detta problem hos svenska producenter ochstartade 2008 en intern sektion, EcoDesign center, som erbjöd sina kunder ekodesignrelateradetjänster. Utmaningarna och problemen hos kunderna har med tiden förändrats och för att centretska kunna erbjuda sina kunder relevanta tjänster, undersöks i detta arbete svenska producentersrelation till ekodesign idag.Syftet med arbetet har varit att kartlägga producenternas problem och utmaningar inommiljöanpassad produktutveckling och samtidigt utvärdera ÅF EcoDesign centers förutsättningaratt tillgodose sina kunder. Att utifrån denna kunskap komma med förbättringsförslag ochrekommendationer på hur centrets ekodesigntjänster kan optimeras har varit målet med arbetet.Resultatet visar att ekodesignarbetet inte är tillräckligt utbrett vilket främst beror på bristfälligefterfrågan av ekodesignade produkter. Kundefterfrågan är direkt kopplat till ekonomiskaincitament, företag drivs i vinstsyfte och utan en efterfrågan kommer ekodesignarbete inteimplementeras. Producenterna har inte insett eller förstått den ekonomiska potentialen medmiljöeffektiv produktutveckling och tror det är dyrt och tidsödande. En orsak till detta kan varabristen på enkla ekodesignverktyg, då de flesta existerande verktyg kräver experter.Kunskapsbristen är ett faktum, vilket producenterna själva ser som ett av de största hindren förimplementering av ekodesign i produktutvecklingsprocessen.ÅF:s EcoDesign center bör satsa på en inledande ekodesigntjänst som kartlägger vad för typ avekodesigntjänst deras kunder behöver hjälp med. Denna tjänst ska fungera som en inkörsport tillövriga ekodesignområden som EcoDesign center rekommenderas att satsa på i framtiden; PRS(Product Regulatory Support), strategi, eco screening, utbildning, tjänstedesign ochmarknadsföring. / Products are currently produced to satisfy customer needs to a large extent whereupon theenvironmental impact escalates due to the demand and production. A solution to the problemcan be summarized in the term eco design where the environmental optimization of a producthas a holistic perspective, including everything from raw material extraction, production, uses,recycling, disposal and transport.ÅF, a technology consulting firm, drew attention to this problem and started EcoDesign centerin 2008, an in-house section where they offered their customers eco design related services. Thechallenges and problems in their customers needs have changed over time and understandinghow the center should provide their customers with relevant service is investigated in this thesis.The aim of the thesis has been to identify producers’ problems and challenges with greenproduction and at the same time evaluate EcoDesign center's prerequisites to satisfy theircustomers’ needs. Based on this knowledge, the aim has been to come up with suggestions andrecommendations on how the center can optimize their eco design related services.The result shows that the eco design work is not sufficiently widespread, mainly due to a poordemand for eco designed products. Customer demand is directly linked to economic incentives,companies run for profit and without a demand an eco design work will not be implemented.Producers have not realized the economic potential of eco effective products and think it isexpensive and time consuming. One reason can be the lack of simple eco design tools, sinceexisting tools require expertise. The lack of knowledge is a fact, which the producers consider tobe one of the biggest obstacles to implement eco design in the product developing process.EcoDesign center should invest in an initial eco design service that identifies in which types ofeco design areas their customer needs help. This service will act as a gateway to other eco designservices offered at the center. In the future, EcoDesign center is recommended to focus on thefollowing, eco design related work; PRS (Product Regulatory Support), strategy, eco screening,education, service design and marketing.
126

Klimatpåverkan : Jämförelse mellan sandwichelement i stål och betong

Englund, Oskar, Olsson, Per January 2021 (has links)
Vid byggnationer av hallbyggnader är konstruktioner av stål eller betong vanliga. Klimatpåverkan som härleds till respektive byggnadssystem är undersökta i detalj, material kontra material eller byggnadsdel mot byggnadsdel. Vår undersökning ger ett resultat av klimatpåverkan för byggnadssystemen i sin helhet med byggnader som uppfyller samma krav. Denna studie utmynnar i en jämförelse av antalet CO2-ekvivalenter respektive vad byggnadssystemen bidrar med per m2. Genom att studera en befintlig betongbyggnad och dimensionera en stålbyggnad utefter samma förutsättningar. Dimensionering innefattar: pelare, upplagsplåt, fotplåt, vindkryss och brandgips för pelare, stommen bekläds med stålelement från Paroc. Utifrån dessa mängder beräknas klimatpåverkan med hjälp av EPD:er som sammanställts och beräknats i Excel. Detta arbetssätt säkerställer en relevant och rättvis jämförelse. Vår studie visar att ett självbärande betongelement bidrar med 83,80 kg CO2-ekv/m2 och stålsystemet bidrar med 60,59 CO2-ekv/m2. De skeden i livscykeln som bidrar med störst skillnad mellan systemen är: Produktskede (A1-A3) och byggproduktionsskede (A4-A5). / In the construction of hall buildings, steel or concrete constructions are common. The climate impact that is derived from the respective building system is examined in detail, material versus material or building part against building part. This study provides a result of the climate impact for the building systems as a whole, with buildings that meet the same requirements. This study results in a comparison of the amount of CO2-ekv each building systems contribute per m2. By studying an existing concrete building and dimensioning a steel building according to the same conditions. Dimensioning includes: pillars, support plate, foot plate, wind cross and fire plaster for pillars, the frame is clad with steel elements from Paroc. Based on these quantities, the climate impact is calculated with the help of EPDs, compiled and calculated in Excel. This approach ensures a relevant and fair comparison. Our study shows that a self-supporting concrete element contributes 83.80 kg CO2-ekv/m2 and the steel system contributes 60.59 CO2-ekv/m2. The stages in the life cycle that contribute the greatest difference between the systems are: Product stage (A1-A3) and construction stage (A4-A5). / <p>Betyg 2021-06-04</p>
127

Livscykelanalys av interiöra golvmaterial / Life cycle analysis of interior floor material

Svärd-Husu, Jennie, Ljungman, Martin January 2020 (has links)
I Sverige används många olika interiöra golvmaterial i offentliga byggnader. Studien har undersökt fyra interiöra golvmaterial, keramik, enomer, massivt furu och linoleum. Dessa material är vanligt förekommande i svenska offentliga miljöer och de jämfördes ur ett livscykelperspektiv. Studien undersökte materialens olika livsskeden, från produktion till slutskede och omfattade materialens totala GHG-utsläpp för en referensbyggnad med en livslängd på 75 år, belägen i Växjö.Denna fallstudie visar att en byggnads klimatpåverkan går att minimera vid val av interiört golvmaterial. Keramik är att rekommendera i fuktkänsliga utrymmen då klimatpåverkan är 38 % minder och linoleum rekommenderas i allmänna utrymmen då klimatpåverkan är 20 % mindre. Det finns ytterligare möjlighet att minimera klimatpåverkan genom att använda trägolv i utrymmen med mindre folk i rörelse. / In Sweden, lots of different interior flooring materials are used in public buildings. This study examines four interior flooring materials, ceramics, mineral based, solid pine floor and linoleum flooring. These materials appear regularly in public buildings in Sweden and are compared to each other in a life cycle assessment perspective. The study examines the materials different life stages from production to its end of life and included the materials GHG-emissions for a reference building with a lifespan of 75 years in Växjö, Sweden.This case study shows that a buildings climate impact can be minimized through choices for interior flooring materials. Ceramics are to recommend in areas sensitive to moisture, do to 38 % less climate effect and linoleum are to recommend more public areas do to 20 % less climate effect. Further possibilities to minimize climate impact is through use of massive pine flooring in areas with low traffic.
128

Coproduction of Biomass Crops and Anaerobic Digestion: Effects on the Life Cycle Emissions of Bioenergy and Bioproducts

Rodjom, Abbey Michaella 03 June 2021 (has links)
No description available.
129

Grundisolering för flerbostadshus : Jämförelse av cellglas och cellplast avseende energieffektivisering, ekonomiska aspekter och miljöpåverkan

Akhras, Samir, Arab, Mustafa, Yasin, Ahmed January 2023 (has links)
Purpose: This project compares two foundation insulation materials: cellular plastic and cellular glass. Currently, cellular plastic is the most used material for foundation insulation. While cellular glass is not widely utilized. Its disadvantage lies in its higher cost, which makes contractors prefer the cheaper alternative, cellular plastic. Cellular glass exhibits exceptional properties, including its notable attributes of high load-bearing capacity and superior moisture resistance. The aim of this study is to demonstrate how material savings can be achieved by using cellular glass instead of cellular plastic in the load-bearing parts of the foundation. In addition to cost savings, the study also includes the analysis of carbon dioxide emissions during the production of these materials and specific heat losses through the material. Method: To facilitate understanding of the study, two different buildings were visualized: a two-story building and a seven-story building. The choice of different building sizes aimed to investigate how different loads on foundation insulation affect insulation material costs, carbon dioxide emissions, and the heating requirements of the buildings. Revit and AutoCAD were used for modelling and visualization. Flixo and manual calculations were employed for energy calculations, while manual calculations were used for structural calculations. One Click LCA Software was used to determine the carbon dioxide emissions for the different foundation insulation scenarios. Results: The study suggests that for buildings with lighter loads, cellular plastic is a cost-effective choice, while a hybrid insulation approach combining cellular glass and cellular plastic is the best option considering environmental factors. However, for buildings with higher loads, cellular glass outperforms cellular plastic both in terms of economics and the environment. Nonetheless, a combination of cellular glass and cellular plastic remains the most favourable choice among the three scenarios, as energy losses are approximately the same due to the similar thermal conductivity values of these materials. Conclusion: Hybrid insulation proves to be the most advantageous option in terms of both the environment and economics for both types of buildings studied: the two-story residential building and the seven-story residential building. By using cellular glass F for the load-bearing structures and cellular plastic EPS S60 for the ground slab, effective insulation is achieved. The use of cellular glass F results in material savings, such as cellular plastic XPS 700, which has half the load-bearing capacity of cellular glass F. Additionally, reducing the use of extra concrete for load-bearing foundation constructions decreases the load on the foundation insulation material.
130

Characterizing quantity and physical dimensions of consumer electronic devices: A pilot study of Indiana households

Juliette Fernada Bermudez Camelo (12797204) 01 August 2023 (has links)
<p>To accurately estimate the potential recovery of metals from electronic devices, various tools such as mass flow analysis, dynamic models, and forecasting models have been employed. However, the reliability of the model-generated outputs hinges on the accuracy of the input data. To ensure accurate data collection, it is imperative to examine and compare different methodologies. Although surveys have conventionally been used in information and telecommunications technologies to gather consumer information, their validity is seldom contrasted with alternative methods due to the lack thereof. In response, a new mixed methodology has been developed to obtain primary consumer data through tangible information, offering new avenues for data acquisition. The methodology involves quantitative and qualitative approaches taking direct physical measurements (dimensions, weight, and quantity) of devices and including a ten question semi-structured interview to discussed consumer devices use, stock and transfer patterns, composition changes of the electronic devices, and disposal behavior. As a result, it was found new methodology measured 79% of the devices directly at laboratories and 21% of the remaining devices were self-reported by the participant. The devices on consumer stage frequently have the same type and number of components as fabric and a positive difference of about 17.99 g compared with the mass reported by fabricants or literature. The sequential steps undertaken by participants in the new methodology to acquire consumer-stage data offer distinct advantages over surveys, particularly in capturing a more comprehensive inventory of devices in storage.</p><p>Additional results indicate that the proposed methodology can provide valuable insights into the stock of electronic devices. Nevertheless, further research is required to understand the implications of surveys versus direct measurements in accurately representing mass flows during the user stage. Additionally, the relevance of external power supply or charging systems on storage will be explored as part of the supplementary findings. By improving the accuracy of metal recovery estimation and exploring more effective data collection methods, we can optimize closed-loop projects and contribute to sustainable resource management.</p>

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