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5089 Uppsatser om Water level regulation - Sida 63 av 340
Inställning av automatikermed spänningsreglerande verkani det sydsvenska 400-130 kV nätet
The voltage level in the power grid varies due to variations in load and production. Normally these variations are manageable, but they may be excessively large during a disturbance. If the voltage is too high it may damage the equipment in the grid and too low voltages may cause problems like voltage instability. The magnitude of the voltage variation depends on the short circuit power capacity of the point of interest.This problem may become lore prominent due to automatic voltage regulation that acts on shunt reactors and shunt capacitors. When the shunt reactor is connected or disconnected to the grid it may cause such large changes in the voltage that the shunt reactor starts hunting.
Metaller i dagvatten - Effekter i recipient : En analys av koppar, kdamium och zink i dagvatten från en parkering i Halmstad, Sverige
When stormwater occurs near human activity the water gets polluted. The purity and composition vary widely depending on the types of activities in the area, the type of surface the water comes in contact with, precipitation and many more parameters. It has long been known that stormwater quality can affect both human health and the environment as stormwater is a major contributor to pollution of receiving waters.A human activity that has an impact on the environment in several different ways is traffic and stormwater is no exception. Airborne gases that react with precipitation, oil leaks and fuel systems that drops down on the ground, metals from brake linings and rubber particles from tire wear are some of the aspects you have to take into account when categorizing the relationship between traffic and polluted stormwater.In this project, stormwater samples from a parking lot in Halmstad, Sweden were collected and analyzed with an atomic spectrophotometer. The presence and relationship between copper, cadmium and zinc with different rainfall parameters have been studied.
Känslighets- och osäkerhetsanalys av parametrar och indata i dagvatten- och recipientmodellen StormTac
Three methods of sensitivity and unceartainty analysis have been applied to the operative stormwater- and recipient model StormTac. The study area is the watershed of lake Flaten in the municipality Salem. StormTac?s submodels for stormwater, pollutant transport and the recipient are cosidired. In the sensitivity assessment, the model parametres and inputs were varied one at a time by a constant percentage according to the ?one at a time? (OAAT) method and the response of the outputs were calculated.
Läsförmågan hos barn med mild och måttlig hörselnedsättning : Hur ser sambandet med underliggande kognitiva förmågor ut?
While reading in deaf children has been the object of a number of studies, the reading abilitiesof children with mild and moderate hearing impairment and their relation to cognitiveprocessing have not received very much attention. Predictive factors of reading ability inhearing children are well known, with phonological and working memory abilities beingnecessary prerequisites for reading development. Existing studies suggest, however, thatcertain hearing-impaired children achieve a reading level comparable to that of hearingchildren in spite of impaired phonological abilities. In the present study, reading abilities anda range of cognitive processing abilities were measured in a group of hearing-impairedchildren and compared with hearing controls in equivalent school grades. Comparisons weremade at group and school-grade level, and the cognitive profile of hearing-impaired childrenat level with controls (those being within one standard deviation) was discussed.
Kodens påverkan på börskurser : En event study på publiceringen av bolagsstyrningsrapporter enligt Svensk kod för bolagsstyrning
Recent accounting scandals, often led by managers trying to improve results and thereby their own bonuses, have severely damaged the publics view of management. In the aftermath of scandals such as Enron, Parmalat and Skandia, demand has increased for Corporate Governance codes and similar regulation. The Swedish code for Corporate Governance came into effect on July 1, 2005. The code requires all Swedish companies listed on the Swedish Stock Exchange (OMX A- and O-list), with a turnover exceeding 3 billion SEK, to disclose a report regarding Corporate Governance, attached to the annual report.The purpose of this paper is to examine whether the new disclosure required by the Swedish Corporate Governance code will have a measurable effect on stock prices. The authors have applied event study methodology examining daily returns around the announcement of the Corporate Governance reports.
Vertikal förtätning : En del av ett hållbart stadsbyggande?
This is an essay concerning the density of the city. An increasing amount of today?s cities have a shortage of space available for the erection of new buildings and settlements, especially in areas close to the city-centre. New buildings and settlements are therefore often found in the outskirts of the city, resulting in long distances between work and living for many people. These long distances are a waste of limited resources and are inconsistent with the vision of the sustainable city.The challenge for the future is to insert new buildings and settlements in the existing city-structure and in this way reduce the distances between different city-functions.The density of the city can be increased in two different ways; by inserting new buildings between existing ones or by extension existing buildings, for example by an additional floor.
Inverkan av torrsubstanshalt och temperatur på kompostens syrabildning :
Composting is a process in which organic matter is mineralized by microorganisms. In January 2005 landfilling of organic waste was prohibited in Sweden. With this prohibition composting has become an important alternative to handle the produced organic wastes. One problem with continuous small-scale composting is the production of organic acids that will inhibit a further composting process. The aim of these theses was to study what effects temperature and dry matter content had on the production of organics acids, and what effect the organic acids had on the mineralisation of the substrate as well as the stability during storage of the product.
IMO:s barlastkonventions konsekvenser för sjöfarten inom Östersjön
Arbetet behandlade vilka konsekvenser inom driften (ekonomiska kostnader och teknologi) som rederier kommer att drabbas av när IMO:s barlastkonvention träder i kraft då barlastvattnet måste renas innan inträde i Östersjön. Arbetets syfte var att få fram vilka konsekvenser det blir för rederier när IMO:s barlastkonvention träder i kraft. Resultatet skulle jämföra skillnaden mellan lag och rekommendation då Helsingforskonventionens rekommendationer baseras på IMO:s barlastkonventions krav. En kvalitativ metod valdes för att komma fram till resultatet, i form av en öppen intervjustudie, där fyra olika företag har intervjuats. Syftet med intervjuerna var att se ifall de följde Helsingforskonventionens rekommendationer och vilka konsekvenser det skulle innebära och skulle komma att krävas då Barlastkonventionen träder i kraft.
Lycka: en studie av ekonomins inverkan på lyckan
The purpose of this study was to examine and illustrate how people look at themselves and their happiness in relation to their economic situation. This study was based on interviews with eight adults divided in two groups, four were big-income earners and four were unemployed/sick-listed. I identified factors that affected the feeling of happiness such as family, friends and economy. During the process four themes were identified, happiness, work, economic strain and the importence of money versus happiness. The analysis was based on the concept of aspiration levels and an economic perspective.The conclusion of the analysis was a surprise to me, showing that economic strain could be detected in both groups but by different means.
Undersökning av vissa beläggningars påverkan på antenners effektivitet i tågmiljö
For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.
En studie om kommunerna Malmö, Lund och Landskronas mångfaldsarbete "Det du inte vet - kan du faktiskt ha ont av"
This paper investigates the level of consciousness regarding to the diversity work in the municipalities of Malmö, Lund and Landskrona. The study focuses on persons in a middle management position connected to various spheres of activities in each municipality. A survey concerning each municipality's diversity plan, diversity work, recruiting process, education and knowledge was used to investigate the participants' consciousness. The survey poses similar questions regarding equality between the sexes to compare the results from each field. The paper presents an overview of the development of Sweden's labour market and society, and gives an account for the differences between immigrants and natives positions in the labour market.
Den svenska arbetarrörelsens utmaningar och visioner - En undersökning av synen på kollektivet i LO- Tidningen 1991-2005
In this essay I have studied the Swedish Working Class whose part of LO.Ideological texts in LO- Magazines is used to quote texts by collective orindividual terms. Method and theory material show high level of solidarity andequality while theory shows higher level of individualism and autonomy. Myresearch is closer to Boréus than Blocks. Politics taking under the 1980: s apowerful right turns holding a steady course through my material.The question in the essay is: What vision on the collective shows in theLO- Magazine in a time during individualization? Answer to this question is thatthe collective unofficially through LO: s: staff on central level tries to showstrength and unity with terms like solidarity and equality between the sexes.
Resonans
This report describes how the system may be exposed to oscillations and how this can lead to resonance. Resonance is a phenomenon that occurs when a system is affected by external periodic oscillations with frequencies close to the system's natural frequencies. Structures subjected to resonance can risk great damage and destruction, why resonance is something that is important to take into account when designing structures. Alternative ways to counteract resonance is to supply damping in the system. Damping means that the resonance decreases instead of letting the amplitude increase.The report discusses some examples on constructions that have experienced the effect of resonance.
VISION SJÖSTAD : Flytande Bostäder
Floating housing is a concept gaining ground in Sweden. The dwellings are different in many ways from traditional homes, not only regarding flotation, but also several other technologies. The purpose of this thesis is to emphasize the qualities that exist in living on water. The ambition was to present a proposal for a floating residential area located in Jönköping, containing homes of varying sizes, and to present their technologies. In order to find inspiration and solutions studies have been made on existing floating homes in Stockholm and Kalmar, focusing on their technical and functional solutions.
Karakterisering och klassificering av gotländska ytvatten enligt ramdirektivet för vatten
In this study the practical work with the EU Water Framework starts on the island of Gotland. 33 lakes and 32 streams have been characterized and classified regarding to their ecological status. The aim with the characterisation is to create a uniform discription of all waterbodies and a comparable estimation for the future. The aim with the classification is both to study the waterbodies ecological status and to gain knowledge of where the resources should be concentrated so that the ecological status in all waterbodies will be good in 2015.The characterisation has been done according to the EU Water Framework Directive, and the factors that have been applied are the mean depth and area of the lake. The length and size on the catchment area are the factors that have been used on streams.