I denna rapport utreds olika metoder för att kunna reglera vattennivån i vattenkraftverket Avesta Lillfors i Dalarna. Två kraftverk ligger endast 900 m uppströms och detta gör att svarstiderna blir korta och regleringen blir lätt nervös. Att använda sig av vattennivåreglering i ett kraftverk för-enklar dess styrning då anpassning till inflödet sker automatiskt.En flödestabell har tagits fram genom mätningar i turbinen, med hjälp av Winter-Kennedy-metoden. Denna tabell används för att kunna fram-koppla regulatorn och därmed dämpa stora variationer i inflödet. Dessu-tom har en modell av älven skapats och testats med en återkopplad PID-regulator.

I ett samhälle som strävar efter en mer hållbar utveckling måste vi minska vår förbrukning av energi i hela samhället. Fastighetssektorn står för en stor del av den totala energiförbrukningen i Sverige och när vi avser att bygga mer energisnåla byggnader är lufttätheten en viktig fråga att ta hänsyn till. Även om energiförbrukningen är det vanligaste argumentet för att uppföra byggnader med god lufttäthet finns det många fler goda skäl. I en byggnad med god lufttäthet minskar risken för fuktskador, termiska komforten ökar, luftkvaliteten förbättras och byggnadens ljudisolering blir bättre. I det här examensarbetet har en fallstudie genomförts där ett antal olika detaljer har testats för att se vilken påverkan de har för byggnadens lufttäthet.

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).

This essay will focus on video and computer game violence. We hope to uncover, with the help of semiotics, according to Barthes design, if this kind of violence can have a negative effect on youth and adolescents. How intense is the violence and how graphic is it?. PEGI is the European measurement for game age limits.

The Swedish FSC standard (Forest Stewardship Council) is a level standard used to certify forestry. All the major Swedish forest companies are using the FSC standard, and approximately 50% of the Swedish forests are FSC certified today. In the essay six items within the chapter on environmental issues and biodiversity are examined: the proportion of protected forest, the proportion of annually burnt clear-cut stands, the number of trees with large diameter, the amount of dead wood, the proportion of deciduous trees within a stand and the proportion of deciduous-dominated stands. The FSC standard states a level for all items, and the purpose of the essay is to analyse whether these levels are supported by research within the field of conservation biology. The validity of the levels of the six items is them discussed to evaluate whether changes are required to the next revision of the FSC standard.

This report is about helping Q-Med AB in Uppsala to start its implementation of uncertainty of measurements analyses in their manufacturing department. Prior to this, the company relied solely on personal experience or did not take this uncertainty into consideration at all during different kind of measurements, which means that some of the processes that the company previously believed were within specified acceptance limits, will actually fail when considering these sources of uncertainties.Q-Med AB needed some sort of instruction to help the company, in a systematic way, to investigate different types of disorders that are affecting all kinds of measurements. This instruction includes a short summary about measurements and uncertainty of measurements in general and a detailed procedure about how these uncertainties are going to be handled in their daily work.The goal was to be able to use this instruction to systematically locate, eliminate (when possible) and analyze all kinds of disorders when measuring. Q-Med is using a lot of different types of instruments when measuring different types of quantities, including temperature, mass, pressure and density. This instruction will hereafter be used for every instrument, regardless of quantity and type of instrument.The instruction is tested through 4 different kinds of measurements, for mass, temperature and humidity.

A method for measuring the total impulse from a multi hole diesel injector, introduced inprevious thesis work, ?Development of a method and a device for measuring the momentumrate of fuel sprays?, by Mikael Lindström, has been further developed and tested. The conceptis to simultaneously deflect all sprays from a multi hole diesel injector by using a bell shapeddeflector. The fuel sprays are deflected straight down from their initial umbrella angle, andthe resulting deflection force is measured in a thin strained section of the load cell. The strainis given by three strain gauges, with quarter-bridge circuitry for each gauge.

Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).

The 22q11.2 deletion syndrome is a common genetic disorder that affects for example the heart, palate, immune system and hearing and therefore affects a child?s development. The purpose of this study was to investigate the proportion of children (0-18 years) with 22q11.2 deletion syndrome who have a hearing loss. A retrospective study of 103 children diagnosed with 22q11.2 deletion syndrome was conducted by medical records. Of the 103 children, 51 were boys and 52 were girls.

Fire is an important ecological factor, but its consumption of coarse woody debris, CWD, has hardly received any attention. In this study, I investigate the consumption in relation to the time of initial flame exposure and propensity for continued combustion of standing CWD of pine (Pinus sylvestris). Two types of CWD were studied. Firstly, wood that had been dead for one to ten years. Secondly, wood that had been dead for several decades. In the burning experiments, logs of approx.

During the transportation of logging residues (LR) the material´s low density is a problem that results in low use of pay-load capacity. Comminution or compression of LR are possible methods to increase pay-loads. In the present thesis studied a bundling machine which was mounted on a truck chassis, and the subsequent transport and crushing. The truck bundler created bundles that were larger and longer than other bundling equipment on the market. The objectives were to determine the total time consumption and its allocation over work element and machinery, to measure dry matter (DM) content of green and brown LR-bundles.

The wastewater treatment plant at GE Healthcare's facility in Uppsala deployed a three step vacuum evaporator in 2007. The purpose of this was to pre-treat wastewater containing amines. The purpose of this thesis was to optimize thisprocess by reducing the amount of concentrate without releasing more nitrogen tothe environment and to examine if density could be used as a measurement of whenthe process should be ended.To create a foundation for optimization six test cycles were conducted with samples taken from all three steps. Both concentrate and condensate were tested as well as the incoming solution. Furthermore, the thesis has been expanded with a benchmarking part examining two different evaporators.

Today?s system to measure the volume in a tank consists of a vertically placed sensor. When a vehicle is tilted the level of the fluid might change and if the volume is calculated based only on the information from the sensor it could result in a incorrect value.This thesis exams a new method to calculate the volume in tanks by using sensor fusion to crosscheck the i formation from the level sensors when the vehicle is tilted. The information is then used to see if it is possible to identify the grade of tilt by the change of fluid level. If the grade of tilt can be measured then the volume can be calculated in a more accurate way.

The purpose with this bachelor thesis is to identify risks and insufficiencies concerning the production at WilloMaskin AB. The project is limited to only 4 machines, where theories as ?OEE? (overall equipment efficacy) should be illuminated and analyzed. The theory of ?Single Minute Exchange of Die? is also presented.The method used in this project is mostly based on qualitative studies but also quantitative studies are presented.