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623 Uppsatser om Fuel cell - Sida 7 av 42
VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor
Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.
Åkerinäringens inställning till biodiesel : en marknadsundersökning
In Sweden, there an increasing need for transport and this leads directly to fuel demand of the transport sector is expected to increase. Both politicians and industry believes that renewable fuels are a realistic and significant method to reduce the transport sector's environmental impact. This study aims to document the Swedish haulage contractor?s attitude to biodiesel. Also to document the strengths and weaknesses of biodiesel, based on opinions from the ultimate consumers.
Stokastiska processer f?r modellering av cellpopulationer: Simulerad cell?ldrande och f?ryngring p? populationsniv?
I den h?r rapporten till?mpas tv? f?rgreningsprocesser, en diskret tid Galton-Watson och en
kontinuerlig tid Markov f?rgreningsprocess, i syfte att studera hur en population av ?ldrande
celler utvecklas beroende p? populationens celldelningsf?rm?ga och delningshastighet, d?r
?ldrandet ?r direkt kopplat till ackumulering av defekta proteiner. Vi kollar ?ven p? effekten
hos cellens ?ldrande baserat p? hur k?nsliga de ?r f?r defekta proteiner. Populationens delningsf?rm?ga
har en avg?rande effekt p? hur v?l populationen v?xer och bibeh?ller ett l?gre
antal defekta proteiner hos cellerna, med dessa f?ruts?ttningar ses ytterligare effekt baserat p?
delnigshastigheten hos cellerna.
Analysis of CD4+ and CD8+ T-lymphocytes : A comparison between EPICS XL and Celldyn Sapphire
Flowcytometric technology has been widely used for measurement of the absolute numbers of T-lymphocytes subsets in Human Immunodeficiency virus (HIV), defining the disease state, monitoring antiviral treatment, and identifying any risk for opportunistic infections. A manual preparing of the samples is required. More recently an automated and enclosed blood cell counting, Celldyn Sapphire has been introduced. In this study the performance of the Flow cytometer EPICS XL as a reference method for analysis of CD3+, CD4+ and CD8 T-lymphocytes was evaluated with blood from 40 individual?s samples.
Pelletskvalitet : Test av olika råvarumixer i pelletstillverkningen vid Rindi Västerdala AB:s bioenergikombinat i Vansbro
Fuel pellets are a refined bio fuel mostly consisting of residues from sawmills and wood industry. At Rindi Västerdala AB's combined bio energy plant in Vansbro fuel pellets are produced, while the waste heat from the process is used for district heating. The pellets are produced from sawdust, wood shavings and dry wood chips that is dried, milled and pressed into small cylindrical rods. The advantage of refining the wood material in this manner is that the energy value is greater per unit volume and unit weight, thereby the cost of transportation per energy unit is reduced. Also, less storage space is needed.Pellet manufacturing is a complex process since many parameters affects the final results.
Hör träbränslena hemma i växthusen? :
With the elevated oil prices of today it is necessary to look for other heating alternatives. If the oil price continues to develop in the same way it has done the last years it will soon be impossible for many producing garden companies to survive.
The purpose of this diploma work is to compare three different fuel options in order to find the most economic one considering the conditions of Katrinebergs Handelsträdgård AB.
In relation to oil it is profitable to change to any of the three alternatives: wood chips, wood pellets and grain. The most profitable option is to change to wood chips. This alternative has a payoff time less than three years and after that the annual saving compared to the oil is relatively high. The annual cost is 65 % of the cost of the oil alternative.
Energioptimering : Resteffektkylning av mellanlager för använt kärnbränsle (CLAB) Oskarshamn
This thesis is done in cooperation with SWECO Energuide in Växjö. They have been assigned by SKB in Oskarshamn to renew their electrical power supply and the ancillary processing systems in their Central provisional storage of spent nuclear fuel, CLAB. Today in the CLAB facility, the spent fuel is cooled down with water pumps, driven by asynchronous induction motors, where the water is regulated by mechanical valves to the desired flow. After the upgrade, the engines will be powered by AC drives that can control the pumps by changing the rotational speed and thus change the water's cooling effect on the nuclear fuel. In this study, I investigated the interference AC drives causes the feeding network and how to go about averting them.
En jämförande studie av fem lastbilsmonterade flishuggar
The study was carried out as a time study of five wood chippers placed on trucks,so?called huggbilar. They are trucks with built?in wood chipper, chip bowl and crane pulling a chip trailer. The system is used for chipping wood fuel, transporting, and delivering the chips to heating plants.
Ekonomi vid uttag av långa toppar som skogsbränsle i slutavverkning :
The market for biofuels from the forests have had a positive development and the job initiators for this master´s thesis wanted to examine the profitability of a method for harvesting forest fuel, which was unfamiliar to them. The method was the ?long tree tops-method?, here called the LT-method.
The LT-method is characterised by the fact that timber is harvested as the only roundwood assortment while the rest of the stem, which in other cases would become pulpwood, is harvested as forest fuel together with the logging residues. The method is based on the assumption that advantages in handling of the forest fuel assortment such as increased load weights for forest hauling and truck transportation, should compensate for the lower price for pulpwood when sold as forest fuel.
The aim of the study was to compare the profitability of the LT-method with the GROT-method (harvest of timber, pulpwood and logging residues) and conventional logging without any harvest of forest fuel, and aslo to try to identify factors affecting the profitability of the different methods.
Integration av simuleringsmodeller för bränslesystemet i JAS 39 Gripen
In this final thesis two simulation models have been integrated. The simulation models are models of JAS 39 Gripen?s fuel system, software and hardware. The time consuming and costly work to develop software has made the department of fuel system to build two models in Xmath/Systembuild. The software model also simplifies the comprehension of how the software in the control computer of the fuel system works.
Optimization of Lentivirus Production for Cancer Therapy
Vectors based on lentivirus backbones have revolutionized our ability to transfer genesinto many cell types. Lentiviral vectors integrate into the chromatin of target cells and do not transfer any viral genes causing vector replication. Both of these features arecommonly used in gene therapy and have been used clinically in individuals sufferingfrom cancer, infections and genetic diseases. It has been discovered that T-cells can be genetically modified to be used as effective weapons against cancer: therefore virus mustbe produced to deliver the gene of interest into the T-cells. In this project, lentiviralvectors have been produced to transfer the gene coding for a chimeric antigen receptor(CAR) which is directed to CD19 on B-cells.
Vätedriven förbränningsmotor : Klarläggande av framtida hållbarhet
Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.
Transporter på väg - En studie över Sveriges lastbilscentralers metoder för att möta ökande drivmedelspriser
Background and problem: In the last few years the threat against the environment and especially the emissions of carbon dioxide has become increasingly debated. The government have set up a goal to lower the emissions of carbon dioxide with 40 percent until 2020 compared to the level in 1990. The emissions in the transportation sector have, in contrast to the total emissions, increased since 1990 and will continue to increase unless powerful control measures are implemented. The lorry centres have to use strategies to answer to these external threats which lead us to the two questions of this thesis: - What methods do the lorry centres use actively and which do they consider as the most important methods for fuel saving? - Are there any differences which methods small, medium and large centres considers as important? Purpose: The main purpose of this thesis is to examine which methods lorry centres use actively and which they consider as important for fuel saving.
Small scale dairy farming in Zambia
Milk yield levels in dairy cows are influenced by many factors such as nutrition, breed, health status, management and environment. This study was conducted among small scale farmers in Zambia, where the climate can be dry for up to six months per year and cause a lack of green pasture for livestock and on-farm produced feed. The purpose of this study was to identify management factors that can influence milk yield at small scale dairy farms in Zambia, and present advice that could improve productivity, without the need of expensive investments. The study included semi-structured questionnaires presented to the farmers (n=29) including questions about cattle management and milk production. Testing of somatic cell count (SCC) with DCC (DeLaval Cell Counter) from herd milk samples (n=56) and observation of housing and animal body condition on-farm was also made.
Paketering av digital musik: Intervjuer med nyckelpersoner inom digital musik i Sverige
This exploratory thesis uses qualitative research to investigate how digital music is beeing packaged. The main study consists of 11 deep interviews with key representatives of the digital music industry in Sweden. These are (record companies) EMI, SonyBMG, Universal, Warner, (DSP) InProdicon, (mobile operators) 3, TeliaSonera and (cell phone producer) SonyEricsson. Packaging is a concept of marketing that has specific implications depending on which good or service that is being packaged. Packaging occurs at different levels in the production chain.