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104 Uppsatser om Leakage inductance - Sida 2 av 7

Övergödning i Laholmsbukten  En studie av Laholmsbuktens övergödningssituation

This essay discusses the Laholm?s bay and its eutrofication problems. The question of issue is: Have the efforts to limit the eutrofication in the Laholm?s bay been effective? What is the local actor?s opinion whether the measures have been effective or not? What efforts have been made to prevent the leakage of nutrients from fields and forestland? The Laholm's bay is located in the south part of the Swedish west coast. The problem was noticed in the 1960´s by local fishermen that experienced a lack of catch.

Identifiering av fosfatfosfors käll- och flödesfördelning i ett litet jordbruksområde

Eutrophication of lakes and streams are nowadays a well known environmental problem and implies an enrichment of the nutrients phosphorus (P) and nitrogen (N). Phosphorus is considered to be the most important component for the growth of aquatic plants and leads in too large quantities to an intensification of growth. Phosphate (PO4) is the fraction of phosphorus that can easiest be taken up by plants and thus have the greatest impact on eutrophication. Increased plant growth in lakes and unfavorable conditions for aquatic animals are two examples of negative consequences. A significant portion of the increased nutrient supply to nearby water can be derived to phosphate leaching from agricultural areas, where private sewers and agriculture is two main sources.

Demonstrationsprojektets roll i framväxten av ny teknik: Fallstudier av två vindkraftprojekt

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Modell av en synkronmaskin för PSCAD/EMTDC med magnetisk mättning i d-led och elektriskt gränssnitt för fältmatare

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Årlig gödsling med NPK bäst för gröda, miljö och ekonomi

Yesterdays common fertilizing strategy was to apply phosphor (P) and potassium (K) in thefall a few times in the crop rotation. In the spring only nitrogen (N) was applied. Recent trialsand studies has shown that this strategy, N+P/PK, is ineffective compared with the systemwhere NPK is spread every year in the spring. The strategy with annual NPK-fertilizer in thespring has proven to be better for the crop, the environment and the farmers economy.In the NPK-system the crop responds with higher yields and better quality, especially in thespring cereals. This is mainly because of an interaction between the different nutrients in thefertilizer.

Konstruktion och utvärdering av diplexer

The report descripbs how a diplexer for a hybrid analog/digital filterbank has been constructed and tested. A diplexer divides the frequency band into two different bands that do not who doesn't overlapp each other. The sampling rate for the two ADC:s is 80 Msps, and therefore it is advantage to have zero at 80 MHz. The reason for this is that a proposed class of hybrid filterbanks with very good quality requires a zero at or close the sampling frequency to work well. The diplexer was made in three versions.

Produktionsvåtmarker mot övergödning

In ambition to produce more and better harvests, artificial fertilizers are used to produce a better growth of crops in the agriculture landscape. This contributes to leakage of nutrients. Our forests also exhibit a leakage of nutrients. Air pollution contributes to more nutrients. High precipitation with high water flows as a consequence seems currently to occur more frequently in the county of Halland.

Lufttäta byggnader

The viscosity of air buildings is a hot topic within the construction performers, which the industry feel they have too little knowledge about. This study is mainly aimed against air density in apartment buildings and airflow measurement. The study consists of a theoretical reference, educational visit, interviews and a survey conducted among construction workers at Magistratshagen in Linkoping.Earlier requirement in terms of air leakage through the climate screen was removed and today there are only energy requirement for a dwelling in Boverkets Building Regulations. The difference between a passive and a typical air tight construction is that the passive house have a maximum requirement of 0.3 l /s m2 of air leakage through the building climate screen. The requirement imposed on passive houses is to minimize the supply of power and energy for heating the building.Air tight constructions have heavy demands on the performance and accuracy of everyone involved with the project. The client must specify their requirements and also be prepared to pay for any additional costs. The architect and building planners have to design the building with regard to air tightness. Finally, the construction workers are required to do a careful work in order to get all the connections in the building air tight.The study suggests that an air tight building is a closed system where no forced ventilation exists. There are no reasons not to build too tight as long as there is a functioning ventilation. In this study the authors ask themselves how an air tight building changes over time. No theoretical information has been found on these changes, but the respondents assume that air density decreases with time. The deterioration is mainly assumed to be caused by construction materials changes over time. The study shows that construction workers knowledge of air tight construction is mixed, which they themselves admit in the survey..

Djupströbädd -bra för miljö och djur?

Deep litter is a system for animals kept in separate stalls, loafing and bedding in wind shelters. The litter can consist of different bedding, like straw and peat. The system is allowed to build over and to ensure optimal proportions it is necessary to add new straw regularly and to have good conditions. Important conditions are aerobic state, humidity, amount of organic substance and acceptable temperatures in the litter. The micro organisms are depending on temperature for their living conditions and to get the bottom layer in the litter to start burning.

Exponeringsrisker i samband med inhalationsbehandling av häst :

Bronchiolitis is a common performance decreasing disease in horses (Bracher et al, 1991¸Dixon et al, 1995) Its medical treatment includes inhalation therapy with corticosteroids and b2-adrenoceptorer stimulators. Use of both these medicines is prohibited for sport horses and athletes. Because the facemasks used for inhalation therapy are not airtight, there is a risk for leakage of these medicines. We wanted to see if cross exposure of nearby horses can result during normal recommended treatment of a horse, and assess if this could result in doping positive urine sample from the person treating the horse and from horses in the same airspace. We did a pilot study with four healthy horses. The experiment was divided into four parts.

Modellering och simulering av det evaporativa bränslesystemet i en personbil

This thesis work has been performed at the department of diagnosis and dependability at Volvo Car Company, Torslanda. The background of this project is based on interest in ascertaining how different factors possibly can affect a diagnosis method, which has been developed to find leaks in the fuel tank and evaporation system. According to the OBD II requirements leaks with an orifice diameter larger or equal to 0,5 mm, must be detected. The idea of the diagnosis method is to create an over pressure in the system with an air-pump. The current through the pump is measured and correlates to the power consumed by the pump.

Modellerade och uppmätta kväveflöden i energiskog som bevattnas med avloppsvatten

The aim of this essay was to study the nitrogen flow in two willowplantations, at different locations in the south of Sweden, that wereirrigated with sewage. The study was also performed to compare thedifferences in nitrogen flows between two years, 1998 and 1999. The studywas made in three parts. First, the denitrification activity was measuredusing the acetylen inhibition method. Second the nitrogen flow, as well asthe water- and heat flows, were modeled through the SOIL-SOILN-modelThird; the nitrogen flow was calculated to compare with the results fromthe model.The results from the measurements were then compared with the resultsfrom the SOILN-simulations to detect differences in the denitrificationrate.

Är Lerbodaälven verkligen en problemälv? : undersökning av fosforhalter

Lerbodaälven is a river in the municipality of Kil which, due to high phosphorus content is not meeting the requirements for good ecological status according to the Water Framework Directive. The purpose of this report is to investigate the causes for the high content of phosphorus that has been measured in Lerbodaälven between 1995-2010. Four questions will be answered in this report. 1. Does the sewage treatment work affect the phosphorus level in Lerbodaälven? The result from the time series analysis shows that the sewage treatment works have a small impact on the phosphorus level in Lerbodaälven.

Outnyttjade resurser inom park- och naturvård

As a small and land scarce country, effective waste management is ofoutmost importance in Singapore. In this study the production of biogasthrough anaerobic digestion from the organic fraction of municipal solidwaste (OFMSW) was compared to incineration of the waste. At the momentalmost all of the OFMSW in Singapore is incinerated. Three differentscenarios were compared to the reference scenario (incineration): one with alarge scale biogas plant that can treat half of all OFMSW in Singapore, onewith a medium scale biogas plant about 15 times smaller than the large oneand one with a small scale biogas plant that can treat waste from e.g. ashopping center or a food center.By using life cycle assessment (LCA) the different scenarios were comparedin terms of global warming potential (GWP), acidification, eutrophication,energy use and land use.

Energiinventering av Soldathemmet

This examination paper is an energy-inventory of Soldathemmet at the regement in Halmstad, in colaboration with Fortifikationsverket in Halmstad. The building is first an foremost for the soldiers, where they can go for a cup of coffee or watch TV. There is also a museum and a drivers school in the building. Calculations have been done with two computerprograms; VIP+ and ISOVER Energy. The results were well matched with the statistics that were provided by Fortifikationsverket.

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