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433 Uppsatser om Particle-emissions - Sida 10 av 29

Effektiva lösningsmetoder för Schrödingerekvationen : En jämförelse

In this paper the rate of convergence, speed of execution and symplectic properties of the time-integrators Leap-Frog (LF2), fourth order Runge-Kutta(RK4) and Crank-Nicholson (CN2) have been studied. This was done by solving the one-dimensional model for a particle in a box (Dirichlet-conditions). The results show that RK4 is the fastest in achieving higher tolerances, while CN2 is the fastest in achieving lower tolerances. Fourth order corrections of LF (LF4)and CN (CN4) were also studied, though these showed no improvements overLF2 and CN2. All methods were shown to exhibit symplectic behavior..

Utveckling av en Multi-Zonsmodell för NOx Bildning i Diesel Motorer

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

Metod för beslutsstöd vid formulering och uppföljning av en kommuns klimatmål : Fallstudie Uppsalakommun

The purpose of this study is to create a method that can be used to produce decision supportdata for the climate goals of a municipality. The method should be able to demonstrate the potential for reducing energy use and greenhouse gas emissions for measures aimed at the stationary energy system in the municipality. It will be used to make long term projections of energy use and greenhouse gas emissions in order to be able to demonstrate the ability to reach climate goals. The aim was also to test the method's applicability by using the municipality of Uppsala and the Uppsala climate protocol project in a case study. Uppsala climate protocol is a project consisting of participants from business, government and organizations that voluntarily want to commit to reducing their carbon footprint by reducing their energy use and thus work to achieve the municipality's overall climate goal.

OneCore

The Swedish building and property management sector are responsible for about 30 % of the total energy use. In order to take environmental consideration, different environmental assessment tools and standards are used. Miljo?byggnad, Svanen, FEBY12 and PHI are some of these. There has been increased interest to certify buildings and therefore it is of interest to evaluate the assessment of the energy field to see if relevant energy aspects are assessed.

Utveckling av Analysverktyg för GEMS PET Systems : En användningscentrerad utvecklingsmetod

The company GEMS PET Systems produces cyclotrons which is a type of particle accelerator. The cyclotrons create log files that are analyzed by the company?s employees for different purposes like troubleshooting or installation. The purpose of the project is to with a usage-centered design method create a paper prototype of a tool that will help the employees to analyze the log files in a more efficient way than earlier.The result shows how the usage-centered design method was used to create the paper prototype and how the user interface was created according to human-computer interaction (HCI)..

Textile Electronics -Screentryckta konduktiva ledningsbanor pa? textila material

Studien underso?ker mo?jligheten att anva?nda ledande partiklar besta?ende av silver- belagda kopparflingor, fo?r att tillverka konduktiva ledningsbanor pa? textilsubstrat. Syftet med denna studie har varit att tillverka de banorna med hja?lp av screentryck- teknik. Sammansa?ttningen av bela?ggningsformuleringen har en stor inverkan pa? den be- lagda textilen och de ledande egenskaperna.

Samhällsekonomisk analys av ett djupförvar för använt kärnbränsle i Forsmark :

This thesis investigates the socio- and environmental economic effects of a deep repository for spent nuclear fuel in Forsmark in the municipality of Östhammar. I seek to show the general picture but focus on the effects on employment, environment and income. Cost-benefit analysis is used to investigate the differences in utility between a scenario with and a scenario without a deep repository in Forsmark. Most of the possible effects can not be valued and many can not even be quantified with the data available today. Therefore this thesis has a bit of a ?preliminary study character? and seeks to show what we know today and what needs to be further investigated when available data allow it. The costs that could be valued are noise from the traffic during the period of building and emissions of carbon dioxide and nitrogen oxides from the transportation of rock masses during the building period.

Individualiseringens dilemma : Hur uppnås ett fungerande samspel mellan individualisering och gemensam undervisning i matematik?

Abstract.The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that.

En kognitiv semantisk analys av partikelverbet gå upp: : Conceptual Metaphor Theory (CMT) kontra Principled Polysemy Approach to Meaning Analysis (PPAMA)

This essay examines the differences and similarities, weaknesses and strengths of the two Cognitive Semantic theories Conceptual Metaphor Theory and Principled Polysemy Approach to Meaning Analysis. To illustrate the two theories, the Swedish verb-particle construction "gå upp" is examined and analyzed accordingly. The results showed differences in the number of polysemous meaning found. The methodological evaluation showed that the differences in the underlying ideas concerning meaning-construction behind these two theories make them incompatible..

Påverkande faktorer vid valet mellan vanlig el och grön el - en studie av hushåll i Göteborgsområdet

To be able to hinder the global warming the emissions of greenhouse gases, carbon dioxide foremost, must decrease. By switching to green electricity, it is possible to reduce the emissions from electricity producing sources.In 1999, Swedenergy conducted a study about whether or not Swedish households would consider buying green electricity. According to the study, about 75 percent were willing to buy green electricity. 40 percent of these were prepared to pay a premium for green electricity. However, according to the results from the study, only one percent actually bought green electricity, and since 1999, this proportion has merely increased slightly.

Rederiers hantering av nya miljökrav : En studie om Birka Cruises, Tallink Silja och Viking Lines arbete med ekonomisk och miljömässig hållbar utveckling

The purpose of this study is to examine how Viking Line, Tallink Silja and Birka Cruises work with economic and environmental sustainability, and also to see how they work with new environmental legislations. In 2015 a new environmental legislation will be introduced, by the name Sulphur directive. The Sulphur directive entails a reduction in Sulphur dioxide emissions from ships where the emissions cannot exceed 0,1 percent. There are three alternatives to achieve the new environmental legislation, the use of Marine Gas Oil, LNG or scrubbers. All three alternatives will lead to increasing costs for the shipping industry.

Är saltglaseringsindustrin en källa till tidig organokloridförekomst?

Abstract.The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that.

Ärtrev som substrat för biogasproduktion : En litteraturstudie och rötning i labbskala

Until 2020, 49% of Sweden's use of energy must derive from renewable sources. Greenhouse gases must as well decline with 40% compared to 1990 as a part of Sweden's 16 environmental objectives. Biogas is part of the effort to achieve these objectives, but as the demand for biogas increases, more substrates are needed to meet the demand. The purpose is to investigate the conditions for pea residue as substrate by performing lab-scale mesophilic digestion with different fractions and notch lengths and then to summarize pea residue as a substrate for biogas production. During anaerobic digestion, 1000 ml bottles were used as reactors for digestion.

Axellagring till Klasserare

GE Healthcare wants to investigate whether additive manufacturing would be an alternative method in their workshops in the Umea? plant. Additive manufacturing is called 3D printing in everyday language and manufactures details by building them up layer by layer in an automated machine. The purpose of this work is therefore to investigate how mature additive manufacturing methods are and how they could be used at GE.The work has been divided into three parts. The first section investigates how additive manufacturing would work in the production workshop at GE.

Skogsbränslets fraktionsfördelning

This study has analyzed particel size distribution and needle content in chipped logging residuals (branches and tops) delivered to the district heating plant Ryaverket in city of Borås, Sweden. Two fuel assortments has been analyzed: Chipped logging residuals from pure softwood and from mixed fuel (connifers and broadleaves). The samples has been sieved at Linneaus University laboratory.The study of particle sizes indicates that only 53,2 % of delivered fuel is within the fuels specification (7? 45 mm). The needle content is in this study 12,4 % (dry mass) which is higher than expected..

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