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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.
1

Damage Reduction Strategies for a Falling Humanoid Robot

Amico, Peter joseph 29 August 2017 (has links)
Instability of humanoid robots is a common problem, especially given external disturbances or difficult terrain. Even with the robustness of most whole body controllers, instability is inevitable given the right conditions. When these unstable events occur they can result in costly damage to the robot potentially causing a cease of normal functionality. Therefore, it is important to study and develop methods to control a humanoid robot during a fall to reduce the chance of critical damage. This thesis proposes joint angular velocity strategies to reduce the impact velocity resulting from a lateral, backward, or forward fall. These strategies were used on two and three link reduced order models to simulate a fall from standing height of a humanoid robot. The results of these simulations were then used on a full degree of freedom robot, Viginia Tech's humanoid robot ESCHER, to validate the efficacy of these strategies. By using angular velocity strategies for the knee and waist joint, the reduced order models resulted in a decrease in impact velocity of the center of mass by 58%, 87%, and 74% for a lateral, backward, and forward fall respectively in comparison to a rigid fall using the same initial conditions. Best case angular velocity strategies were then developed for various initial conditions for each falling direction. Finally, these parameters were implemented on the full degree of freedom robot which showed results similar to those of the reduced order models. / Master of Science / Instability of humanoid robots is a common problem, especially given external disturbances or difficult terrain. Even with the robustness of most whole body controllers, instability is inevitable given the right conditions. When these unstable events occur they can result in costly damage to the robot potentially causing a cease of normal functionality. Therefore, it is important to study and develop methods to control a humanoid robot during a fall to reduce the chance of critical damage. This thesis proposes strategies that rotate the joints at a constant rate to reduce damage resulting from a lateral, backward, or forward fall. These strategies were used on two and three link simplistic models to simulate a fall from standing height of a humanoid robot. The results of these simulations were then used on a full robot, Viginia Tech’s humanoid robot ESCHER, to validate the efficacy of these strategies. By constant joint rotation strategies for the knee and waist joint, the simplistic models resulted in a decrease in impact velocity of the center of mass by 58%, 87%, and 74% for a lateral, backward, and forward fall respectively in comparison to a rigid fall using the same initial conditions. Best case joint rotation strategies were then developed for various initial conditions for each falling direction. Finally, these parameters were implemented on the full robot which showed results similar to those of the reduced order models.
2

An integrated sustainability framework for environmental impact reduction in the gold mining industry/ Hendrik Gideon Brand

Brand, Hendrik Gideon January 2014 (has links)
The gold mining industry pollutes both water and air resources in numerous ways. Of these, air pollution from greenhouse gasses inducing climate change poses the highest threat to human existence, with water scarcity as a result of pollution presenting the third highest risk (Mathews, 2007; Akorede et al., 2012; Jones et al., 1988). Water pollution, indirect air pollution and direct air pollution should be mitigated for sustainable gold mining. Environmental impact reduction is achieved by the implementation of effective Environmental Management Systems (EMSs). These systems aim to achieve ISO 14001-compliance by setting targets and implementing a systematic approach to achieving these targets. However, ISO 14001-compliant systems do not ensure environmental impact reduction and give the mine no competitive edge (Hilson & Nayee, 2002). EMSs available are too generic for implementation on gold mines. Reporting on Key Performance Indicators (KPIs) on gold mines should also be improved as it is unclear exactly what values should be reported on. This is due to a general lack of an environmental reporting standard (Jones, 2010). Manpower and expertise to identify and implement projects is limited and the mines need assistance with the implementation of projects to effect resource pollution. Priority for the mines is an emphasis on production and safety rather than environmental impact reduction, so implementing projects to reduce pollution is often neglected. A novel sustainability framework is developed in this study. In this framework a database of electricity- and environmental impact reduction projects is created that can be implemented in the gold mining industry. Projects are automatically identified by monitoring key operational indicators. By involving a third party in the form of an Energy Services Company (ESCO), project funding for these sustainability projects can be attained. This novel approach to environmental impact reduction creates a situation where ESCOs implement these EMSs at a reduced cost to the mines. This reduces the cost of lowering the mine’s environmental impact, while aiding the ESCO in identifying sustainability projects. KPIs from various studies are consolidated to determine exactly what values should be reported on. These values are incorporated into a successful EMS. This allows the availability of all the necessary data for reporting to the Department of Energy (DoE) and the South African National Energy Development Institute (SANEDI) on electricity-savings. Projects are prioritised based on an integrated electricity- and environmental impact reduction payback approach. This approach allows funding options to be assessed for each project individually, based on both electricity- and environmental impact reduction advantages. This allowed the best funding option for each individual project to be determined. Automatic identification of these projects reduces the required manpower and resources to implement sustainability projects. Projects proposed by this study showed a combined energy efficiency reduction of 11.8 MW and achieved a load shift of 15.6 MW. In addition to electricity reduction, these projects also reduced the water usage by 1135 Ml per annum and the carbon dioxide equivalent production by 214 205 ton per annum. The proposed projects were effective at increasing the sustainability of gold mining. It also streamlined the implementation of these projects on gold mines. By applying this framework, sustainability improvements can now be achieved on gold mines worldwide. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
3

An integrated sustainability framework for environmental impact reduction in the gold mining industry/ Hendrik Gideon Brand

Brand, Hendrik Gideon January 2014 (has links)
The gold mining industry pollutes both water and air resources in numerous ways. Of these, air pollution from greenhouse gasses inducing climate change poses the highest threat to human existence, with water scarcity as a result of pollution presenting the third highest risk (Mathews, 2007; Akorede et al., 2012; Jones et al., 1988). Water pollution, indirect air pollution and direct air pollution should be mitigated for sustainable gold mining. Environmental impact reduction is achieved by the implementation of effective Environmental Management Systems (EMSs). These systems aim to achieve ISO 14001-compliance by setting targets and implementing a systematic approach to achieving these targets. However, ISO 14001-compliant systems do not ensure environmental impact reduction and give the mine no competitive edge (Hilson & Nayee, 2002). EMSs available are too generic for implementation on gold mines. Reporting on Key Performance Indicators (KPIs) on gold mines should also be improved as it is unclear exactly what values should be reported on. This is due to a general lack of an environmental reporting standard (Jones, 2010). Manpower and expertise to identify and implement projects is limited and the mines need assistance with the implementation of projects to effect resource pollution. Priority for the mines is an emphasis on production and safety rather than environmental impact reduction, so implementing projects to reduce pollution is often neglected. A novel sustainability framework is developed in this study. In this framework a database of electricity- and environmental impact reduction projects is created that can be implemented in the gold mining industry. Projects are automatically identified by monitoring key operational indicators. By involving a third party in the form of an Energy Services Company (ESCO), project funding for these sustainability projects can be attained. This novel approach to environmental impact reduction creates a situation where ESCOs implement these EMSs at a reduced cost to the mines. This reduces the cost of lowering the mine’s environmental impact, while aiding the ESCO in identifying sustainability projects. KPIs from various studies are consolidated to determine exactly what values should be reported on. These values are incorporated into a successful EMS. This allows the availability of all the necessary data for reporting to the Department of Energy (DoE) and the South African National Energy Development Institute (SANEDI) on electricity-savings. Projects are prioritised based on an integrated electricity- and environmental impact reduction payback approach. This approach allows funding options to be assessed for each project individually, based on both electricity- and environmental impact reduction advantages. This allowed the best funding option for each individual project to be determined. Automatic identification of these projects reduces the required manpower and resources to implement sustainability projects. Projects proposed by this study showed a combined energy efficiency reduction of 11.8 MW and achieved a load shift of 15.6 MW. In addition to electricity reduction, these projects also reduced the water usage by 1135 Ml per annum and the carbon dioxide equivalent production by 214 205 ton per annum. The proposed projects were effective at increasing the sustainability of gold mining. It also streamlined the implementation of these projects on gold mines. By applying this framework, sustainability improvements can now be achieved on gold mines worldwide. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
4

How to integrate life cycle thinking in the working process at Volvo Group Real Estate to improve the environmental performances of new dealerships / Hur man integrerar livscykeltänkande i arbetsprocessen på Volvo Group Real Estate för att förbättra miljöprestanda hos nya återförsäljare

Raju, Parvathy Suresh January 2020 (has links)
Dealerships are the main interface for customer interaction when it comes to a multinational manufacturing company like Volvo Group. A lot of studies in the field of environmental impact is done on different kind of buildings like office buildings, residential buildings, public buildings etc by performing Life Cycle Analysis (LCA), Life Cycle Cost analysis (LCC) etc. However, the number of studies done on an industrial building are very less when compared to other types of buildings. Industrial buildings are equally important in the construction industry since they play a good share in environmental impacts caused by buildings. The main objective of the thesis is to analyse the working process at VGRE and suggest ways to incorporate life cycle thinking in their working process to improve the environmental performance of new dealerships. Interviews were conducted with VGRE employees; literature reviews were done and analysis of internal documents from VGRE were studied and analysed as a part of the thesis. The views and opinions of the VGRE employees in the area of environment impact reduction, life cycle assessment and certification scheme/system were obtained and the steps involved in the development of a dealership as well as the different type of contract were also studied from the internal documents provided from VGRE. Cost was one of the main barrier/challenges in all the cases. Lack of interest in getting a dealership certified was also mentioned during the interviews. Energy saving measures like the solar panels were considered as additional cost for a building. Their preference in referring to previous Life Cycle studies of similar buildings rather than doing a Life cycle study on each building was also observed. / I syfte att identifiera hur man integrerar livscykeltänkande i arbetsprocessen hos Volvo Group Real Estate (VGRE) för att förbättra miljöprestanda för nya återförsäljare är detta examensarbete i princip en analys av arbetsprocessen hos Volvo som gjordes genom att göra intervjuer med Volvos anställda både i Göteborg, Sverige och Finland. Litteraturöversikter om livscykelanalys (LCA) samt certifieringssystem var också en del av metodiken. Slutligen analyserades och studerades några interna dokument från Volvo. LCA på Volvo, hinder och utmaningar som möter under arbetsprocessen, intern dokumentation, skillnaderna mellan en återförsäljare och andra byggnader, kostnadsfaktorer / affärssaker är de viktigaste slutsatserna som diskuteras i resultatsektionen.
5

O prolongamento da vida útil do vestuário de moda como alternativa para a redução de seu impacto socioambiental / The lifetime extension of fashion clothing as an alternative for reducing its social and environmental impact

Lima, Verena Ferreira Tidei de 28 June 2013 (has links)
Atualmente, o excesso de produção, consumo e descarte de vestuário de moda - e o ritmo acelerado e contínuo como isso acontece - resulta em um impacto socioambiental de proporções consideráveis. Neste contexto, o presente trabalho buscou discutir possíveis requisitos projetuais para o design de vestuário de moda orientados à redução de seu impacto socioambiental, com ênfase no prolongamento da vida útil do vestuário de moda e consequentemente na alteração da dinâmica do ciclo de vida desses produtos. Para tanto, foi necessário compreender e estudar a relação entre o design e a sustentabilidade, identificar os impactos socioambientais do vestuário de moda, elencar os aspectos projetáveis do vestuário de moda que influenciam o consumidor em relação ao produto, e assimilar a opinião do consumidor a respeito da relação entre o vestuário de moda e a sustentabilidade. A partir de uma revisão de literatura e de uma pesquisa exploratória, foi possível inferir que o prolongamento da vida útil do vestuário de moda, ao alterar a dinâmica do ciclo de vida desses produtos, desacelerar o ritmo de sua produção, seu consumo e seu descarte, configurando-se como uma alternativa para a redução de seu impacto socioambiental. / Currently, the excess of production, consumption and disposal of fashion clothing - and the accelerated and continuous rhythm as it happens - results in a social and environmental impact of considerable proportions. This work aimed to discuss possible projectual requirements for the fashion clothing design geared to reducing its social and environmental impact, with emphasis on the lifetime extension of fashion clothing and consequently on change of life cycle dynamics of these products. In order to reach this aim, it was necessary to understand and to study the relation between design and sustainability, to identify the social and environmental impacts of fashion clothing, to list the projectable aspects of fashion clothing that influence the consumer respecting the product, and to assimilate the consumer opinion about fashion clothing and sustainability. From a literature review and an exploratory research, it was possible to infer that the lifetime extension of fashion clothing, in changing the lifecycle dynamics of these products, decelerates the rhythm of its production, its consumption and its disposal, setting up as an alternative for reducing its social and environmental impact.
6

O prolongamento da vida útil do vestuário de moda como alternativa para a redução de seu impacto socioambiental / The lifetime extension of fashion clothing as an alternative for reducing its social and environmental impact

Verena Ferreira Tidei de Lima 28 June 2013 (has links)
Atualmente, o excesso de produção, consumo e descarte de vestuário de moda - e o ritmo acelerado e contínuo como isso acontece - resulta em um impacto socioambiental de proporções consideráveis. Neste contexto, o presente trabalho buscou discutir possíveis requisitos projetuais para o design de vestuário de moda orientados à redução de seu impacto socioambiental, com ênfase no prolongamento da vida útil do vestuário de moda e consequentemente na alteração da dinâmica do ciclo de vida desses produtos. Para tanto, foi necessário compreender e estudar a relação entre o design e a sustentabilidade, identificar os impactos socioambientais do vestuário de moda, elencar os aspectos projetáveis do vestuário de moda que influenciam o consumidor em relação ao produto, e assimilar a opinião do consumidor a respeito da relação entre o vestuário de moda e a sustentabilidade. A partir de uma revisão de literatura e de uma pesquisa exploratória, foi possível inferir que o prolongamento da vida útil do vestuário de moda, ao alterar a dinâmica do ciclo de vida desses produtos, desacelerar o ritmo de sua produção, seu consumo e seu descarte, configurando-se como uma alternativa para a redução de seu impacto socioambiental. / Currently, the excess of production, consumption and disposal of fashion clothing - and the accelerated and continuous rhythm as it happens - results in a social and environmental impact of considerable proportions. This work aimed to discuss possible projectual requirements for the fashion clothing design geared to reducing its social and environmental impact, with emphasis on the lifetime extension of fashion clothing and consequently on change of life cycle dynamics of these products. In order to reach this aim, it was necessary to understand and to study the relation between design and sustainability, to identify the social and environmental impacts of fashion clothing, to list the projectable aspects of fashion clothing that influence the consumer respecting the product, and to assimilate the consumer opinion about fashion clothing and sustainability. From a literature review and an exploratory research, it was possible to infer that the lifetime extension of fashion clothing, in changing the lifecycle dynamics of these products, decelerates the rhythm of its production, its consumption and its disposal, setting up as an alternative for reducing its social and environmental impact.
7

Klimatpåverkan av klimatförbättrad betong : En fallstudie om exponeringsklass-, hållfasthetsklass och CO2 utsläpp / Climate impact of climate improved concrete : A casestudy on exposure class, strength, and CO2 emission

Sabado Manansala, Daniel, Hamnäs, Ponthus January 2022 (has links)
Påverkan på klimatet är idag ett av de största fokusområdena för byggbranschen. Forskning kring klimatförbättrade material och tillverkningsmetoder utvecklas i takt med att klimatkraven ökar. Betongtillverkning och -användning är en del av byggbranschen som måste förändras för att kunna vara hållbar i framtiden. Syftet med studien är att bidra med kunskap kring orsaker till överdimensionering och fel exponeringsklasser gällande betongkonstruktioner, samt vilken av de undersökta överdimensioneringar som ger störst CO2 utsläpp. För att visa detta så utförs en fallstudie av kvarteret Kaptenen i Lomma, och klimatberäkningar för att uppskatta betongkonstruktionernas CO2 utsläpp samt för att finna förbättringsområden i fallstudiens betongkonstruktioner. Studien genomförs i samarbete med Anders Rönneblad från Cementa, Betongindustri och Abetong, som bidrar med data för fallstudien samt kunskaper inom ämnesområdet. Utifrån fallstudien visar det sig att det inte finns resurser att skräddarsy varenda konstruktionsdetalj, vilket leder till att konstruktionselement blir dimensionerade enhetligt. Undersökningen av fallstudien påvisar även att den huvudsakliga anledningen till överdimensionering är förenkling av byggprocessen. Om man i fallstudien använt kantavstyvning och voter hade det medfört en minskning av volymen med 28 procent hos betongplattan. Vidare om projektets original betong ersatt i garage och källare till ThomagarageGrön kunde exponeringsklassen sänkas från XD3 till XC4. I så fall sänks CO2 utsläppen för källarbetongen med 22 procent och med 53 procent för garagebetongen. Genom beräkningar av klimatpåverkan hos Kv. Kaptenen i Lomma så visar det sig att ändringen från original betong till klimatförbättrad betong tillsammans med användandet av kantavstyvningar och voter, ger en minskning av koldioxidutsläppen med 47 procent. För att minska koldioxidutsläppen ytterligare, så har fallstudien undersökts med framtida betongtyper. Med framtida betongtyper menas ytterligare klimatförbättrad betong, vilket uppnås genom arbete med alternativa bindemedel som förväntas vara tillgängliga på marknaden i framtiden. Genom användandet av dessa betongtyper samt kantavstyvningar och voter uppnås en minskning av koldioxidutsläppen med 57 procent. / Finding different alternative methods/materials to minimize the climate impact of concrete is one of the many objectives that the concrete industry must achieve to meet the demanding building regulations. Therefore, new types of concrete such as “climate-enhanced concrete” are being developed currently and different complementary measure to minimize the climate impact of concrete are being explored. The aim of the thesis is to study how over dimensioning and using wrong exposure class can be avoided for concrete structures and to determine how over dimensioning can impact climate. To ascertain the answer, a case study is carried out on an ongoing construction project “Kvarteret” by JM AB, located in Lomma, Sweden. The information and guidance which is used to draw different conclusions are provided by Anders Rönneblad from Cementa AB. In summary the solutions this study has examined wouldn’t be achievable without an early collaboration between the supplier and project team. Methods that the study reviewed are for example minimizing the amount of concrete and exploring the use of different strength class on a shallow foundation, using a different alternative such as Thomagarage Grön, using different strength class on the concrete filling for the prefabricated concrete double-wall element and using different climate enhanced concrete in the concrete elements. Another aspect that wasexamined is by using climate enhanced concrete from Betongindustri BIO 40. By applying the solutions that were discussed in the study, a total of 57% climate impact reduction for the concrete structures be attained.
8

You Are What You’re Wearing : An Analysis of Strategies Promoting for an Environmentally Sustainable Fashion Industry / Du Är Vad Du Har På Dig : En Analys av Strategier som Främjar för en Miljömässigt Hållbar Modeindustri

Lindgren, Kristina January 2022 (has links)
The fashion industry's progress towards sustainability is often a complex journey and changes within the industry, both ongoing changes and those required to achieve sustainability, cannot be singled out as something only of material considerations or bound to a specific stage within a lifecycle. This paper examines how a selection of environmentally inclined sustainability strategies within the fashion industry, contributes to or counteracts the industry's progress towards environmental sustainability. Including the overall work towards a sustainable development. The aim is also to understand how to lead the fashion industry toward an environmentally sustainable development and understand how sufficient they are in their current work. Strategies that aim to improve the environmental sustainability within the fashion industry are plenty, which can cover large and significant parts of the industry. Many depart from innovative approaches and aim to bring significant change and contribution to the fashion industry's work toward sustainable development. As concluded within this study, one strategy is not enough to solve the entire sustainability conundrum, since each strategy has proven to contribute with significant environmental impact reduction potentials, however the resulting environmental impacts' counteractions are equally significant. Thus, the most considerable potential for environmental sustainability can be gained when combining various strategies and implementing them during certain stages - because where one strategy is lacking, another can contribute, complement and/or reinforce. / Modebranschens framsteg mot hållbarhet är oftast en komplex resa. Förändringar inom branschen, både pågående förändringar och de som krävs för att uppnå hållbarhet, kan inte pekas ut som något enbart materiellt eller bundet till ett specifikt skede i en livscykel. Denna studie undersöker hur ett urval av miljöanpassade hållbarhetsstrategier inom modebranschen bidrar till eller motverkar branschens framsteg mot miljömässig hållbarhet. Syftet med studien är att delvis förstå hur man leder modebranschen mot en miljömässigt hållbar utveckling samt förstå hur tillräckliga de är i sitt nuvarande arbete.  Det finns ett antal strategier som syftar till att förbättra den miljömässiga hållbarheten inom modebranschen och kan täcka stora samt betydande delar av branschen. Många vilka utgår från innovativa tillvägagångssätt som strävar efter att åstadkomma betydande förändringar och bidrag till modebranschens arbete mot hållbar utveckling. Slutsatsen i denna studie är det inte är tillräckligt med en strategi för att lösa hela hållbarhetsproblemet, eftersom varje strategi inom denna studie har visat sig bidra med betydande potential för att minska miljöpåverkan, men även resulterat till lika betydande motverkningar. Den största potentialen för miljömässig hållbarhet är när man kombinerar olika strategier och implementerar dem under vissa skeden.

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