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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.
251

Application of Techno-Ecological Synergies in Life Cycle Assessment (TES-LCA) to soybean-based biodiesel

Zhao, Ruonan 29 August 2019 (has links)
No description available.
252

Toward Sustainable Metal-Organic Frameworks for Post-Combustion Carbon Capture – Identifying Improvement Opportunities by Molecular Simulation and Life Cycle

Hu, Jingying 20 June 2019 (has links)
No description available.
253

Integrated sustainability assessment and design of processes, supply chains, ecosystems and economy using life cycle modeling methods

Ghosh, Tapajyoti 25 October 2019 (has links)
No description available.
254

The influence of the prefabricated rate on the environmental performance of buildings in a life cycle perspective / Påverkan av prefabriceringsgraden på byggnaders miljöprestanda i ett livscykelperpektiv

Wang, Shaozhe January 2020 (has links)
As the construction sector has caused significant environmental impacts, Sweden has made efforts to develop prefabricated buildings by increasing their prefabricated rates. In a life cycle perspective, this thesis examines how the overall environmental impacts during the construction processes are influenced when the prefabricated rate increases. By modelling in SimaPro version 9, this thesis conducts a life cycle assessment (LCA) of a concrete framed reference building with a prefabricated rate of 26% located in Stockholm Royal Seaport. Nine scenarios with increasing prefabricated rates varying from 6% to 96% are compared in the thesis. The results show that when the prefabricated rate increases, the total water consumption of the building is optimized, while the overall energy consumption and GHG emissions have increased. For other environmental impacts, the thesis finds the terrestrial ecotoxicity is the most affected impact category when the prefabricated rate rises. The thesis indicates that water consumption of the building is mainly influenced by material extraction and processing stage, and the transport is the dominating factor to energy consumption, GHG emissions and terrestrial ecotoxicity as the prefabricated rate rises. The sensitivity analysis in the thesis also reveals that the energy consumption and GHG emissions of the prefabricated building are sensitive to transport scheme, such as transport distance and vehicle types. / För att optimera miljöproblem som orsakas av byggsektorn gör Sverige ansträngningar för att främja prefabricerade byggnader och stödjer också ökad andel prefabricerade komponenter i byggnader. Med fokus på byggverksamheten undersöker denna studie hur en ökad andel prefabricering kan påverka miljöpåverkan från byggsektorn. Denna studie genomför en Life Cycle Assessment (LCA) på en referensbyggnad med en prefabriceringsgrad på 26% i Stockholm Royal Seaport, och studerar nio scenarier med en prefabricerad andel från 6% till 96%. Resultaten indikerar att den totala vattenförbrukningen förbättras, men den totala energiförbrukningen och växthusgasutsläppen försämras när andelen prefabricering ökar. Av de undersökta effekterna har den markbundna ekotoxiciteten den högsta ökningen vid ökad prefabriceringsgrad. Rapporten visar att materialutvinning och -bearbetning är den dominerande påverkande faktorn som orsakar vattenförbrukning när prefabriceringsgraden ökar. Förändringarna i energiförbrukning, växthusgasutsläpp och markekotoxicitet påverkas främst av transporter. Energiförbrukningen och växthusgasutsläppen från den prefabricerade byggnaden är känsliga för transportavstånd och fordonstyper.
255

Implementing simplified LCA software in heavy-duty vehicle design : An evaluation study of LCA data quality for supporting sustainable design decisions / Implementering av förenklad LCA-programvara i design av tunga fordon : En utvärderingsstudie av LCA-datakvalitet för att stödja hållbara designbeslut

Chih-Chin Teng, Chih-Chin Teng January 2020 (has links)
Simplified life cycle assessment (LCA) method quickly delivers an estimation of the product’s life- cycle impacts without intense data requirements, which are taken as a practical tool in the early stage of product development (PD) to support sustainable decisions. However, obstacles are to integrate the LCA tool efficiently and effectively into the designers’ daily workflows. To give a comprehensive overview of the potential challenges in integrating simplified LCA software to vehicle PD processes, the research conducts accessibility, intrinsic, contextual and representational data quality evaluation of the two vehicle-LCA software, Granta Selector and the Modular-LCA Kit, by the means of interviews, case studies and usability testing. From the four data quality evaluation, the results demonstrate (1) the importance of the company’s collaboration with the software developers to ensure the software’s accessibility; (2) the data accuracy constraints of the software due to the generic database and over-simplified methods; (3) the vehicle designer engineers reactions in the two software’s data fulfilments in conducting the complicated vehicle LCA models; and (4) the LCA results’ effectiveness in supporting sustainable design decisions. Overall, the two simplified LCA software’s reliability is sufficient merely in the very beginning stage of PD while the user satisfaction and effectiveness of the simplified LCA data are positive for the design engineers with a basic level of sustainability knowledge. Still, there is a need of systematic strategies in integrating the software into PD processes. A three-pillar strategy that covers the approaches of company administrative policy, software management, and promotion, and LCA and vehicle data life-cycle management could tackle the data gaps and limitations of the software and company. Based on this strategy, the research proposes an example roadmap for Scania. / Genom en förenklad livscykelanalys(LCA), kan man tidigt i produktutvecklingen få en indikation över ett fordons miljöpåverkan. Analysen kan agera som ett verktyg för att ge stöd till mer hållbara beslut i produktutvecklingen. En svårighet ligger dock i att integrera LCA i designers dagliga arbetsflöde på ett effektivt sätt. För att skapa en översikt av Scanias utvecklare och designers LCA- datakrav för hållbar fordonsutveckling genomfördes en datakvalitetsutvärdering (“accessibility, intrinsic, contextual, and representational”) av två LCA-programvaror, Granta Selector och Modular-LCA-kit. Från detta kunde en strategi och handlingsplan tas fram för implementering av LCA-programvara inom fordonsutveckling. Resultaten indikerar att programvarornas tillförlitlighet endast är tillräckliga i ett tidigt skede i produktutvecklingen. Dessutom varierar användarnas tillfredsställelse och effektiviteten av programvarans förenklade data utifrån designerns kunskapsnivå inom hållbarhet. För att ha en framgångsrik integrering av LCA-programvaran i fordonskonstruktionen, utvecklades en strategi med tre pelare. Dessa täcker Scanias företagspolicy och mjukvaruhantering samt hanteringen av livscykel inventariet och BOM-data, för att hantera brister i dataseten men även begränsningar hos programvaran och företaget. Baserat på denna strategi presenteras en möjlig handlingsplan för Scania.
256

LCA: A Tool to Study Feasibility and Environmental Impacts of Substituting Asphalt Binders

Adesokan, Qudus, 0000-0003-2503-3688 January 2021 (has links)
Finding innovative technologies for building our roads has always been of paramount importance. From moving to warm mix asphalt to decrease our indulgence in high energy consumption to substituting fly ash for asphalt binders to reduce dependence on pure asphalt binders from petroleum, engineers have painstakingly tried to develop new ways to improve the ways that flexible pavements are made. The major problem facing the next generation of civil engineers is sustainable practices on the field. Over the years, significant progress has been made in this regard on the impacts of building pavements on the environment. Characterizing these improvements tends to be difficult, and that is where Life Cycle Assessment (LCA) comes in. LCA is a technique used to analyze and quantify the environmental impacts of a product, system, or process. LCA shows where the significant impacts occur and how improvements can be made while recommending better practices. Even with its many advantages, its use is very constrained, especially in the United States, as it is still a very novel approach in design coupled with limited datasets and protocol for its operation. With modern technologies of substitute materials for binders like bio-oil from food waste, reclaimed asphalt pavement (RAP), and fly ash, there is a need to understand their environmental impacts. Furthermore, in this regard is where LCA can help using three significant areas: selection of materials, normalization, and characterization. Characterization refers to the identification and quantification of the relationships between the life cycle results and the environmental impacts. This research explores the environmental impacts of substituting other materials for asphalt binders using LCA. With variations in modifying levels of substitutes, results show promising levels in emissions of harmful gasses to both the air and water. This study explores ways used in normalizing this process as well as setting up a pathway for other asphalt binder substitutes. / Civil Engineering
257

Informal Electronic Waste Recycling in Pakistan

Umair, Shakila January 2015 (has links)
The aim of this thesis was to study governance aspects of informal electronic waste recycling and to provide better knowledge of the business in terms of structure, stakeholders, governance aspects and social impacts. The thesis consists of a cover essay and two papers appended at the end of the thesis. The cover essay summarizes the papers and puts them in context. The objective of Paper I is to study the business of informal electronic waste recycling in Pakistan and highlight its governance issues. Paper II assesses the social impacts of this business using UNEP-SETAC Guidelines. The thesis examines these specific questions: Q1) What is the current situation of informal e-waste recycling in Pakistan? Q2) Who are the important stakeholders and what are their roles in this business? Q3) What are the governance issues enabling this informal business? Q4) What are the social impacts for individuals and society arising from this business? Paper I presents the international and local e-waste flows, business structure, the stakeholders involved and the existing governance issues of the business. It shows weak enforcement of legislation, the complexities emerging with numerous stakeholders, the profitability of informal recycling, little concern for the health damaging exposure for workers from poorest and most vulnerable people in society, and the lack of awareness of the hazards involved results in several governance issues. The paper also highlights how this business lacks characteristics of good governance, which makes it a challenge to control this business. Paper II assesses the social impacts of informal e-waste recycling in Pakistan using UNEP/SETAC guidelines for conducting a Social Lifecycle Analysis (SLCA). It showed that this business has positive impacts relating to societal issues and individual/family economics, and in the economic development of Pakistan but otherwise most impacts were negative. The findings of Paper II fill an important data gap and can be integrated with data on other stages of ICT product lifecycle to produce a full SLCA of such products. / Syftet med denna avhandling var att studera styrningsaspekter informella återvinning elektroniskt avfall och för att ge bättre kunskap om verksamheten i fråga om struktur, intressenter, styrningsaspekter och sociala konsekvenser. Avhandlingen består av en täck uppsats och två tidningar bifogade i slutet av uppsatsen. Locket uppsats samman tidningarna och sätter dem i sitt sammanhang. Syftet med papper I är att studera verksamheten i informella återvinning elektroniskt avfall i Pakistan och belysa dess styrningsfrågor. Papper II bedömer de sociala konsekvenserna av denna verksamhet med hjälp av UNEP-SETAC riktlinjer. Avhandlingen undersöker dessa specifika frågor: Q1) Vad är den nuvarande situationen för informella återvinnings e-avfall i Pakistan? Q2) Vilka är de viktigaste intressenterna och vilka är deras roller i den här branschen? Q3) Vilka styrningsfrågor som möjliggör denna informella företag? Q4) Vilka är de sociala konsekvenserna för enskilda och samhället som följer av detta företag? Papper I presenterar internationella och lokala e-avfallsflöden, företagsstruktur, de inblandade aktörerna och de befintliga styrningsfrågor i verksamheten. Det visar en svag tillämpning av lagstiftningen, komplexiteten växande med många intressenter, lönsamheten för informella återvinning, lite oro för hälsan skadliga exponering för arbetstagare från de fattigaste och mest utsatta människorna i samhället, och bristen på medvetenhet om de risker inblandade resultaten i flera styrningsfrågor. Papperet belyser också hur denna verksamhet saknar egenskaper för god förvaltning, vilket gör det till en utmaning att styra denna verksamhet. Papper II bedömer de sociala konsekvenserna av informella återvinnings e-avfall i Pakistan använder UNEP / SETAC riktlinjer för att genomföra en social livscykelanalys (SLCA). Det visade sig att denna verksamhet har positiva effekter avseende samhällsfrågor och individ / familj ekonomi, och i den ekonomiska utvecklingen i Pakistan men annars de flesta effekterna var negativa. Resultaten av pappers II fyller ett viktigt tomrum uppgifter och kan integreras med uppgifter om andra stadier av IKT produktlivscykeln för att producera en full SLCA av sådana produkter. / <p>QC 20150525</p>
258

Feasibility of Whole-plant Corn Logistics for Biobased Industries

Khanal, Asmita 10 August 2022 (has links)
No description available.
259

Assessing the environmental impacts of a tool rental service from Husqvarna using Life Cycle Assessment  Confirmation that the opposition is completed / Miljöpåverkansutredning av en verktygshyrningstjänst från Husqvarna med hjälp av livscykelanalys

Heiska, Mirjami January 2019 (has links)
To decouple ever-increasing production and the related environmental impacts, collaborative use of products and product-service-systems including rental services can help to intensify the use of products during their designed lifetimes. While these approaches present potential to decrease environmental impacts compared to traditional linear product sales, they need to be assessed with a holistic scope to avoid counterintuitive trade-offs. This study evaluates the potential environment impacts of Husqvarna’s tool rental service with a hypothetical case example from Stockholm, Sweden. The objectives are to analyse the potential environmental impacts of the rental service, to identify hotspots for improvement and to compare the potential impacts of the rental system to a sales alternative. The annual service of one electric chainsaw is analysed using Life Cycle Assessment (LCA) methodology with different user scenarios. The potential impacts are analysed for global warming potential, fossil and mineral resource scarcity, marine ecotoxicity and human carcinogenic and non-carcinogenic toxicity. The analysis for the rental system shows that user transport back-and-forth to the rental service is a key contributor to all the environmental impacts analysed, if done by private cars. The comparative results to sales business model indicate that while the rental service can help to reduce the potential impacts in mineral resource scarcity and toxicities due to the lower number of products needed, the user transport may outweigh the potential improvements in global warming potential and fossil resource scarcity, depending on the distances and modes of transport. Different scenarios illustrate that the results are however sensitive to the assumptions made. Based on the results, it can be recommended to optimally place the service close to the users and to take efforts to reduce user transports around the service, to reach the environmental potential of the service. The sensitivity analyses also indicate the importance for accounting detailed data for LCAs for product-service-systems and covering the service holistically in system boundaries. Further studies on user behaviour are suggested to reach more robust analyses on consumer services, to cover also potential rebound effects. / Gemensam konsumtion av produkter kan minska dess miljöpåverkan, sett över produktens livstid, genom intensifiering av produktanvändning och minskad nyproduktion. Även om detta koncept har potential att minska miljöpåverkan, jämfört med traditionell linjär produktförsäljning, måste det granskas på ett systematiskt sätt. Denna studie utvärderar den potentiella miljöpåverkan av ett verktygshyrningssystem av Husqvarna med ett hypotetiskt exempel från Stockholm, Sverige. Målen är att analysera den potentiella miljöpåverkan av hyrestjänsten, identifiera förbättringspunkter och jämföra de potentiella effekterna av hyressystemet med ett försäljningsalternativ. Miljöpåverkan av en motorsåg under ett år är analyserad genom livscykelanalysmetod med olika scenarier. Analysen för hyressystemet visar att den högsta miljöpåverkan kommer från transporten av användare fram och tillbaka till hyresdepån, om transporten är gjord med personbilar. Resultaten indikerar att hyrestjänsten kan bidra till att minska potentiella effekter av mineralresursbrist och toxicitet, jämfört med försäljningsmodellen, på grund av det lägre antal producerade produkter. Hyrestjänsten kan dock riskera att öka växthuseffekten och påverkan på fossilresursbrist, beroende på transportens längd och transportsätt. Olika scenarier illustrerar att resultaten är känsliga för andantagen. Resultaten visar att det kan rekommenderas att placera tjänsten optimalt nära användarna och att försöka minska användartransporten runt tjänsten för att nå tjänstens optimala miljöpotential. Känslighetsanalyserna indikerar också att detaljerade data och omfattande systemgränser är viktiga med LCA studier om produktrelaterade tjänster. Ytterligare studier om användarbeteende föreslås för att nå mer robusta analyser av konsumenttjänster, för att utvärdera även potentiella rekyl-effekter.
260

Life Cycle Assessment and comparison of the climate impact of structural members and floor systems constructed in concrete, steel and timber

Rask, Fredrik January 2019 (has links)
In this report the climate impact is determined for some basic structural elements made in steel,&gt;mber and concrete. The aim is to compare the climate impact of these three building materials byquan&gt;fying the emissions related to the produc&gt;on and construc&gt;on of some typical structures.The comparison comprise two parts, were one is the comparison of members in bending,compression and tension and the other part is the comparison of a couple of floor structures.The emissions are determined through a Life Cycle Assessment, LCA. The members are comparedwith respect to their load bearing resistance and the floor structures is compared per square meter.The mo&gt;va&gt;on for this inves&gt;ga&gt;on is that the construc&gt;on industry is a large contributor to the totalamount of greenhouse gas emissions and in order to reduce these emissions new solu&gt;ons andprac&gt;ses must be adopted. A more thoughVul choice of the materials used in structures has thepoten&gt;al of reducing the emissions.The method of determining the climate impact is based on first determining the material quan&gt;&gt;esfor all the inves&gt;gated structures and then calcula&gt;ng the amount of carbon dioxide equivalentsrelated to the produc&gt;on of these materials with the help of a Life Cycle Assessment.The material quan&gt;&gt;es of the structural members is determined based on the load. The dimensionsof the cross sec&gt;on is determined with respect to the required load resistance. The materialquan&gt;&gt;es of the floor structures is based on some exis&gt;ng solu&gt;ons from manufacturers.The study show that the &gt;mber based design solu&gt;ons almost always has a smaller climate impactand that the differences can be considerable. Members made in steel oZen result in very largeamount of greenhouse gas emissions but the sca[er in the results indicate that the origin of the steelhas great importance. Primary steel has a much larger impact as opposed to recycled steel.The comparison of the floor designs show that beyond the material choice itself, also the materialefficiency is important. The hollow core slab made in concrete is a very material efficient design andmay in some cases be on par with &gt;mber based designs.The massive &gt;mber floors made of Cross Laminated Timber, CLT, has a fairly large climate impactbecause of the sheer volume of material and may be on the same level as the floor made in concretefor some scenarios. There is however a wide range in the result based on whether the material istransported a long distance and depending on the choice of insula&gt;on material. If these choices isop&gt;mised, the emissions of the CLT floor is instead on a much lower level, closer to that of the otherlightweight floors inves&gt;gated.The process of evalua&gt;ng and comparing the material choices and structural designs form a lifecycleperspec&gt;ve can be u&gt;lised during the design in order to reduce the emissions. With a be[erknowledge of the climate impact of the design, be[er choices can be made in order to reduce theemissions.

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