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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.
11

Assessment of the Emission Trading Policy: A case study for the Acid Rain Program in the United States

Wang, Qian January 2004 (has links)
Various environmental standards have been established for the sake of public health and ecosystem diversity since environmental awareness was awakened in the late 1960s. However, the results were often unsatisfactory. Either environmental goals achieved were far from desired, or regional development was hampered due to some unpractical high environmental standards. The failure of these environmental standards resulted in innovations of environmental policy instruments to find practical environmental goals and methods approaching them scientifically. Another class of environmental policy instruments, so called economic incentive policies, is established based on environmental economics theory. A neo-classical economics framework is founded for setting appropriate environmental goals and assessing efficiency of environmental policies in reaching these goals. This thesis summarizes rationales and factors affecting the performance for environmental policy instruments under the neo-classical economic framework. Since the acid rain program, the first large-scale implementation of the emissions trading policy, has achieved great success in reducing SO₂ emissions from the electricity generators in the United States, the emission trading policy attracted many interests in this kind of environmental policy instrument. Many countries, such as China, plan to adopt the emissions trading policy to address various environmental problems. Hence, factors leading to the success of this program should be identified. Potential risks and problems must be addressed as well lest the emissions trading policy causes some problem during implementation. Feasibility of implementing an emissions trading policy will be discussed based on these results. Three kinds of geographic analyses, change detection, network analysis, and hot spots identification, are conducted in this thesis to study the effectiveness and efficiency of the acid rain program. It is found that the acid rain program is successful in improving the sustainability of the economic development in the United States. But the effectiveness is not as great as the high emissions cutting rate achieved in this program. In addition, the acid rain program lowers the compliance costs of achieving the environmental goal since the radius of the high quality coal service area doubles. Lastly, hot spots are found around the Ohio River valley and Los Angeles. Suggestions on integrating geographic factors into the economic framework are presented in order to eliminate the risk of causing severe environmental problems. Finally, the feasibility of migrating the emissions trading policy to China is discussed. Further work can be conducted in this direction to realize sustainable development quicker with lower costs.
12

WILDLIFE ROAD MORTALITY ON THE 1000 ISLANDS PARKWAY IN SOUTH EASTERN ONTARIO: PEAK TIMES, HOT SPOTS, AND MITIGATION USING DRAINAGE CULVERTS

Garrah, Evelyn 31 May 2012 (has links)
Road mortality threatens the long-term viability of some wildlife populations, particularly herpetofauna. Wildlife road mortalities were recorded during regular bicycle-based surveys of the 1000 Islands Parkway in south eastern Ontario during 2010 and 2011. These data were grouped with similar data collected in 2008 and 2009 to determine when and where animals were killed along the Parkway to better inform mitigation options. Temporal and spatial clustering was significant for five taxonomic groups: snakes were found dead on the road primarily in September, turtles in June, frogs in July, and birds and mammals in June and July. The majority of turtles found on the Parkway were adult females, which may have implications for long-term population demographics and persistence. Regression tree analysis indicates day-of-year as the most important variable in explaining wildlife road mortality for all taxonomic groups, with higher road mortalities coinciding with higher minimum daily temperature. Precipitation and traffic accounted for little variation in snake road mortality, and had no effect on turtle, frog, bird or mammal road kills. Spatial clustering was found for all taxonomic groups with overlapping areas of significant clustering between years identified as hot spots. In addition, the potential for drainage culverts to reduce wildlife road mortality was tested with two experimental treatments in 2010: (1) blocked culverts to prevent wildlife use, and (2) drift fence installation adjacent to culverts to encourage wildlife use. Wildlife road mortalities at these locations as well as control culverts were compared with 2008 wildlife road mortalities when there were no culvert treatments. The number of road kills in the area of treatments was too low to measure changes for all taxa but frogs, which showed no significant changes in road kills for any culvert treatment. The results of the study are used to evaluate a list of potential options for mitigating wildlife road mortality along the Parkway, and a list of implementable actions is identified. / Thesis (Master, Environmental Studies) -- Queen's University, 2012-05-31 16:33:51.623
13

Moving hotspots evidence from paleomagnetism and modelling /

Antretter, Maria. Unknown Date (has links)
University, Diss., 2001--München.
14

Magmatic and volcanological evolution of the Desertas rift zone (Madeira Archipelago, NE Atlantic)

Schwarz, Stefanie. Unknown Date (has links) (PDF)
University, Diss., 2004--Bremen.
15

En kartläggning av anmälningar angående narkotikabrott i Sundsvall : En djupgående analys för åren 2006, 2010 och 2015

Rapp, Maja, Ödbro, Erica January 2017 (has links)
Introduktion: Forskning har visat att brott inte är jämt fördelat på kartan, på vissa platser är brottskoncenrationen högre än på andra. Dessa platser kallas för hot spots. Hot spots för narkotikabrott kan enligt tidigare forskning vara belägna vid ett gathörn, över flera kvarter eller till stora delar av en stad. Syftet i den aktuella studien var att kartlägga och analysera anmälningar angående narkotikabrott i Sundsvall mellan åren 2006 och 2015. Metod: Den aktuella studien var retrospektiv där en kvantitativ design tillämpades. Materialet som nyttjades var anmälningar gällande narkotikabrott tagna från polisens anmälningsregister RAR. Studiens resultat har visualiserats med hjälp av diagram, tabeller, samt densitetskartor vilka framtagits i SPSS respektive ArcGIS online. Resultat: Anmälningsfrekvensen har minskat från år 2006 jämfört med år 2015 i Sundsvall. Fem olika hot spots identifierades, varav en var bestående över tid i och med att den förekom under åren 2006, 2010 och 2015. Mellan klockan 12.00 och 17.59 gjordes 44% av alla anmälningar angående narkotikabrott de tre studerade åren. Slutsats: Vissa platser/områden samt tidpunkter visades vara mer utsatta för narkotikabrott än andra i Sundsvalls centrum. Till följd av hur polisen prioriterar sina insatser och hur människor rör sig, koncentrerar sig anmälningar angående narkotikabrott till utmärkande hot spots. / <p>2017-06-01</p>
16

High performance and network fault tolerant MPI with multi-pathing over infiniBand

Vishnu, Abhinav 11 December 2007 (has links)
No description available.
17

Um modelo para previsão de vida à fadiga de juntas soldadas submetidas a carregamentos combinados. / A fatigue life prediction model of welded joints under combined cyclic loading.

Goes, Keurrie Cipriano 09 April 2010 (has links)
O presente trabalho teve como objetivo desenvolver uma metodologia prática e confiável para previsão de vida à fadiga de juntas soldadas a cordão pelo processo MIG/MAG, quando estas estão submetidas a carregamentos cíclicos combinados. A máxima tensão linear no pé da solda, região típica de início de trinca, conhecida como hot spot foi utilizada para prever a vida através do método de Fadiga de Alto Ciclo S x N (Tensão x Vida), largamente empregado em códigos de projeto de estruturas soldadas. O Método dos Elementos Finitos foi utilizado para determinação das tensões estruturais resultantes do carregamento e das descontinuidades geométricas presentes nos cordões de solda. A análise de fadiga foi efetuada em ambiente virtual, através de um software (programa) de fadiga capaz de importar as tensões atuantes na região da solda para cada carregamento, combinando-as e obtendo assim a vida à fadiga decorrente da somatória dos diferentes tipos de carregamento ao qual a junta foi submetida. As propriedades monotônicas e cíclicas dos materiais da junta foram obtidas da literatura e de um extenso banco de dados disponível no software de fadiga. Estas propriedades foram ajustadas com base em ensaios de laboratório nas juntas investigadas. A medição ou modelagem das tensões residuais inerentes ao processo de soldagem não fazem parte do escopo deste trabalho. Contudo, os efeitos térmicos e metalúrgicos resultantes do processo de soldagem, como distorções, tensões residuais, variações microestruturais e propriedades mecânicas foram considerados de forma indireta, através da correção das curvas de fadiga nos corpos de prova investigados. Corpos de prova do tipo tubo-placa foram submetidos a carregamentos cíclicos combinados (flexão e torção) de amplitude constante. O resultado da análise virtual de durabilidade foi, portanto, calibrado com base nestes experimentos e curvas disponíveis em códigos de projeto de fadiga como BS7608 e Eurocode 3. A aplicabilidade deste método numérico-experimental e suas contribuições para a garantia da Integridade Estrutural do projeto de juntas soldadas são apresentadas. Seus desafios e melhorias são por fim discutidos. / The main purpose of this work is to develop a practical and robust methodology to evaluate the fatigue life in seam weld joints fabricated with GMAW process when subjected to combine cyclic loading. The maximum linear stress at the typical crack initiation region, better known as hot spot stress, was used to calculate the fatigue life through high cycle fatigue method S x N (Stress x Life), widely used in design codes for the life assessment of welded structures. The Finite Element Method (FEM) was used to obtain the structural stresses distribution due the external loading and geometric discontinuities very common in seam weld joints. The fatigue analysis was conducted in virtual environment. The FEM stress results from each loading were imported to fatigue code FE-Fatigue and combined to perform the fatigue life prediction. The monotonic and cyclic properties of the joint materials were obtained in the literature and from the fatigue software database. These properties were adjusted based on laboratory fatigue tests in the investigated welded joints configurations. The measurement or modeling of the residual stresses resulted from the welded process is not part of this work. However, the thermal and metallurgical effects, like distortions and residual stresses, were considered indirectly through fatigue curves corrections in the samples investigated. A tube-plate specimen was submitted to combine cyclic loading (bending and torsion) with constant amplitude. The virtual durability analysis result was calibrated based on these laboratory tests and design codes such as BS7608 and Eurocode 3. The feasibility and application of the proposed numerical-experimental methodology and contributions for the welded joints structural integrity design are presented. The challenges and improvements are finally discussed.
18

Gränslöst. En global utställning på Historiska museet

Lundell, Linnéa January 2011 (has links)
This thesis is a report concerning the practical aspects on exhibition techniques. During an internship at the National History Museum in Stockholm I participated in the work with their new, temporary exhibition Gränslöst - en global utställning på Historiska museet [Boundless - a global voyage of discovery at the National Historical Museum]. I was part of a small project team of museum staff. The purpose of this exhibition was to show how cultures have met and influenced each other throughout history. The National Historical Museum has in its collections and exhibitions several examples of objects that has been imported from or inspired by other cultural areas. The primary goal was to give the visitors a new perspective, to show that these “Swedish” objects have a long history of trading and cultural exchange. Additionally, Gränslöst is an attempt to draw the visitors into the permanent exhibitions; it is not an independent production and shares some characteristics with so- called “Hot spot” exhibitions. My ambition is to describe the planning, implementation and delivery of the exhibition and highlight problems and solutions that arise during that process.
19

Fatigue analysis of welded joints in a forestry machine : Utilizing the notch stress concept

Nyström, Martin, Tomaz, Tainan Pantano January 2015 (has links)
Welding is one of the most applied technics in the world for joining steel. Welds are liable to the phenomenon of fatigue, which is, primarily, the formation of a crack and consequently reduction of strength due to the action of time varying loads. Fatigue is one of the main causes of failure in steel structures. The aim of this thesis is to do static and dynamic analyses of a forestry crane with the purpose of using the analyses to determine the lifetime due to fatigue of welded components. Two methods for fatigue assessment are used in this work, the Hot-Spot Method and the Notch Stress Method. The first boom, which is a key component for the crane, is analyzed in a Finite Element Method (FEM) software. The found principal stress in accordance with the notch stress method in the first boom is ±165 MPa for the analyzed load case, rendering in a stress range of 330 MPa. The fatigue strength class FAT-225 (m=3), leads to an expected number of 633000 cycles, with a probability of survival of 97,7% for this case. / Svetsning är en av de vanligaste teknikerna för sammanfogning av stål. Svetsar är känsliga för utmattning. Utmattningsfenomenet består primärt av en initial dislokation som genom tidsvarierande belastning formar en spricka som växer och därmed reducerar styrkan i konstruktionen. Utmattning är en av de vanligaste orsakerna till skador i stålkonstruktioner. Målet med detta arbete är att genomföra både statiska och dynamiska analyser av en skogsmaskins kran i avseende att bestämma utmattningslivslängden för dess svetsade konstruktioner. Två metoder för utvärdering används i detta arbete, hot-spot-metoden och notch-stress-metoden. Kranens första bom (lyftarmen) som är en huvudkomponent i kranen analyseras med hjälp av ett Finita Element program i enlighet med notch-metoden. Högsta funna spänningsvariationen i första huvudspänningsriktningen var ±165 MPa för ett av de analyserade lastfallen. Utmattningsklass FAT 225 (m=3) ger en uppskattning om utmattningslivslängd på 633000 cykler med en sannolikhet för överlevnad på 97.7% i detta fall.
20

Demografické stárnutí a reprodukce pracovní síly / Demographic ageing and reproduction of the workforce

KOHOUTOVÁ, Martina January 2016 (has links)
The aim of this thesis is to describe the situation of a demographic ageing in the Czech Republic from perspective a reproduction of the workforce and the human capital. Most conclusions regarding a demographic ageing are based on a number of people in each generation. On the other side conclusions based on a human capital data are often ignored and marginalized.The main aim of this thesis is not to discover the unknow, but to describe and analyze demographic ageing in the Czech Republic. This thesis want to show that the demographic ageing is a serious topic that cannot be overlooked.

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