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945 Uppsatser om Stability calculations - Sida 28 av 63
Validering av glidande statorfötter på Hissmofors G6 och G7
Jämtkraft AB has recently modernized its hydropower station at Hissmofors by replacing four older worn out units with two new units. The generators uses a concept with sliding stator feet to deal with the thermal movements that occur in the stator during operation when the unit is operating intermittently. At other sites, this method revealed shortcomings in the reliability. This has made Jämtkraft AB feel uncertainty about its function and therefore want to investigate it during an early stage. The generators have a built-in monitoring system for the sliding stator feet and by using data from there the function of the sliding stator feet has been investigated. The study focused on how the different stator feet move relative to each other and how the eccentricity and deviation from roundness changed during operation. The results show that there are several indications that the function of the sliding stator feet is not satisfactory.
Biogasanvändning vid Käppalaförbundets Reningsverk: ? en värdering av miljöeffekter
This thesis calculates and compares the values of improved environmental quality due to future possible investment alternatives in biogas production facilities at Käppalaförbundets Reningsverk (Käppala Sewage Treatment Works) in an attempt to determine which alternative yields the highest such value. Käppala faces three investment alternatives for the usage of biogas. The alternatives are production of vehicle fuel, district heating and thirdly, heat and power production. Estimates of the value of environmental change are calculated for each of the three investment alternatives, and these estimates are then compared. The environmental change in question is the change in discharge levels of carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and particle matter.
MIKROVÄRMEKRAFTVERK för hemmabruk
My questions at issue for this report has it´s beginning in the growing problems of thenegative effects of burning fossile fuels and the rapidly growing energyprices.1. Is it possible to design a micro scale powerplant?2. Is it economically interesting for a potential customer to by such a product?The aim with this report is therefor, with the help of design work and calculations, to answerthese questions and to create a platform for building a fully functional micro scale powerplant.The material used in the report is mostly product catalogs from various industries but alsostudy course littrature about steam engines.The result of the report is that it is fully possible to design a fully functional micro scalepower plant.
Näringsämnesretention i fyra nyanlagda våtmarker i Falkenbergs Kommun
This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.
Miljö- och hälsoskyddskontorets tillsynsarbete - ur verksamhetsövarens perspektiv
Nanofiltration is a proper way of preparation of drinking water. The process has a lot in common with reverse osmosis where a semipermeable membrane is used to separate a pure water flow from the remaining water. A pilot plant was used to ensure that nanofiltration is a suitable technology for a specific waterworks station in Glemmingebro, Ystad. The purpose was also to find out if a pH-adjustment is needed for feed water in a possible full scale plant. In this case nanofiltration is used mainly to remove sulphate and calcium since the raw water contains concentrations of these substances which exceed the limits for potable water. It is important to receive a high recovery (RC), otherwise the deliviery of water won?t be high enough.
Försäkringsbolags kostnader för reparation av fuktskadade badrum
The purpose of this report is to compile and examine the cost of renovation of moisture-damaged bathrooms, to derive a target price. The target price can then be used by insurance companies to estimate the ultimate cost of future bathroom renovations. The method is based on the compilation and comparison of the cost of repairs of previous water damage in bathrooms. The calculations compiled based on repair estimates for different insurance losses from one of the leading insurance companies in Sweden. The result shows the average price per square meter of floor area for different sizes of bathrooms. The average price is the basis for the estimate of future renovation costs of bathrooms. The results further show that the bathroom finishes, area and the distance between the entrepreneur and the location of the renovation have great impact on the final repairing cost.
Avblås för torkning av kabel
This report is written on the assignment by Nexans IKO Sweden AB in Grimsås which is a cable manufacturing company. Nexans IKO Sweden AB was in need of help to examine possibilities for saving energy by saving compressed air, in first place by using the compressed air more efficient. The task was to determine the present situation, making the airwipe stations more efficient by reducing the consumption of the compressed air and in turn save money. Even the aspects of the working environment were discussed as the noise levels from the pneumatic systems and engines are usually high. A schedule over the airflow in the factory and the inventory over current airwipessituation was made.
Passivhus vid polcirkeln : Fungerar det?
This report is the product of the course AF101X, a bachelors degree in Samhällsbyggnad atKTH. The task of the course is to design a small house at a given location and also implement adeepening study. The house in this report is located in Kiruna in the north of Sweden, where theclimate is much colder than in the rest of the country.The deepening study of this report is to evaluates how realistic passive housing north of thePolar Circle is based on those facts. The house will to some extent be designed to fit the passivehousing standard.
Cassava as an additive in biomass fuel pellet production :
In this study, the effects of using fine milled cassava stems as an additive in biofuel pellet production was compared to the effects of refined starch addition. The bulk biomass fuel raw material, to which the additive was added, was a blend of spruce and pine sawdust. An experimental design in the factors cassava/starch content, moisture content and material temperature was used. Measured responses were pellet bulk density, pellet durability, amount of fines, pelletizer motor current, pellet temperature, die temperature and CV for pelletizer motor current (a measure of process stability). Each response was modeled by multiple linear regression (MLR).
Icke-linjära modelleringsteknikerav förspänd betongkonstruktion : Reaktorinneslutningen på Forsmark 3
A new material model, for the FE-program ADINA, has been verified against twoexperiments. One unreinforced concrete beam and one reinforced concrete beam.The model, DF-concrete, has the possibility to estimate true concrete. However theresults indicate that in order to be sure that the estimations are true, there ought tobe data from the true concrete to verify against.Two FE-models have simulated the behavior of a ring-shaped part of the nuclearcontainment vessel. The results from the first, frictionless, model agree with similarsimulations and hand calculations for high pressures in the containment vessel. Thesimulations of the nuclear containment vessel show cracking in the concrete after10-11 bars of over pressurization.
Lokalisering av vågkraftanläggningar : Metodutveckling med GIS och fallstudie Bohuskusten
In this thesis work a Geographical Information System (GIS) based methodology to identify locations suitable for the installation of wave energy converters has been developed. Parameters of importance have been identified and a GIS-database has been set up, containing data about the marine environment. In a case study of the Swedish west coast the methodology has been applied, resulting in a number of maps showing possible areas. The results show that large areas are suitable for installation of wave energy converters, from a technical and economical point of view. When consideration is taken to other interests in the area, such as navigation, fishing and environmental protection, the size of the suitable area diminishes considerably.
Hjälpen till ett drogfritt liv! : En kvalitativ studie om återfall och återfallsprevention.
AbstractTitel: Hjälpen till ett drogfritt liv- En kvalitativ studie om återfall och återfallsprevention.Writers: Jonna Håkansson och Louise Hag.Keywords: Abuse, addiction, relapse, relapse prevention. Abuse is a major problem and leads to negative consequences for the individual, such as illness, criminality and death. It?s also a big problem in the society, because the most common crimes are drug-related and the consequences lead to high economic costs. In order to overcome an addiction, treatment is often required.
Optimering av prestanda och utnyttjande av flertrådsteknik
The purpose of this thesis was to help the company Medius AB with optimization of selected parts in an existing system to minimize the execution time by implementing multithreading. The idea was to manipulate the code so that calculations could be executed at the same time. The main work in this thesis consisted of three optimizations. The first one was to reconstruct a big ?for-loop? so it would execute every loop's work in an own thread. The second optimization also was a reconstruct of a ?for-loop? so it could execute the work in different threads. The third and last optimization consisted of reconstructing a stored procedure on the database, so different parts of it each could be executed in an own thread to create data at the same time. To implement the optimizations Visual Basic .NET and its support for multithreading and connection-pools was used. The result of the optimizations meant that one of the modules could be executed more efficiently and it was 12 % faster. The other modules execution time was more efficient by 25 % faster. The meanings and requirements for this thesis are fulfilled by now letting the system make use of its resources in a better way..
Uppvärmning av mjölkgård med ved, flis eller havre :
The background for my thesis is the fact that with rising electricity and oil prices it becomes interesting to calculate on alternative heating systems. I have chosen to calculate upon my parents? farm, which today heats the dwelling house with wood. This is very time-consuming work, time which could be spent on other work.
The main objective for this study is to compare three different heating systems to decide how they differ considering effort and cost.
The result from the calculations was that grain-heating system demanded the least amount of work, but the total cost was a little higher compared to chips heating. Chips heating required half as much work as today?s wood heating and had a little lower total costs compared with the corn heating.
Which system to choose largely depends on how the own work is valued.
Transporter för hållbar utveckling : En optimering av utsläppsberäkningarna inom Coop
Man?s impact on the environment is something that increasingly becomes topical in today?s society. Because of this, several companies have started to take interest in the effects they?re responsible for, not least considering their image. Emissions of carbon dioxide generated from goods traffic are accountable for a large part of the total emissions of greenhouse gases in the world.