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1194 Uppsatser om Nitrogen flow - Sida 24 av 80
Water balance and nitrate leaching from arable land in a changed climate : a model study
This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.
Tillförsel av använda fosforfilter påverkar inte tillväxten eller fosforupptaget hos korn
The eutrophication of inshore seas, lakes and watercourses is mainly due to leaching of nitrogen and phosphorus (P) from agriculture. Many efforts are made to reduce the lea-kage of phosphorus in Sweden and the Baltic Sea countries. Phosphorus is also a finite resource and the mining of good quality raw material gets more and more difficult. Se-dimentation dams in combination with filters is one relatively new method to separate P from run-off and drainage water from agricultural land. This study was a part of an IVL Swedish Environmental Research Institute?s project which tests the capacity and func-tion for separation of phosphorus in four phosphorus filters.
Uppskattning av Ytkurvatur och CFD-simuleringar i Mänskliga Bukaortor
By applying a segmentation procedure to two different sets of computed tomography scans, two geometrical models of the abdominal aorta, containing one inlet and two outlets have been constructed. One of these depicts a healthy blood vessel while the other displays one afflicted with a Abdominal Aortic Aneurysm. After inputting these geometries into the computational dynamics software FLUENT, six simulations of laminar, stationary flow of a fluid that was assumed to be Newtonian were performed. The mass flow rate across the model outlet boundaries was varied for the different simulations to produce a basis for a parameter analysis study. The segmentation data was also used as input data to a surface description procedure which produced not only the surface itself, but also the first and second directional derivatives in every one of its defining spatial data points.
Försöksmetod för automatisering av kvalitetssäkring av SKB
Within all industries, there is a change in working time required; this also includes the construction sector. However, the way construction sectors are differentiated is by not having been given the opportunity to be practiced or tested. The aim of this thesis that we have done in collaboration with the Concrete Industry was to investigate the possibility of developing an automated method for quality assurance of SKB at the site. The idea is to make the O-funnel to be more utilized and therefore ensuring that the appropriate concrete quality is provided which eventually would lead to a better development in the production process.The project has involved theoretical work and laboratory experiments. The theoretical work gave us a good foundation at the beginning of the project. After gathering the information and material, the laboratory experiments began by SCC in their laboratory in Hammarby. The collected data from the various laboratory tests formed the foundation for trying to relate measurements for consistency of SCC with each other and therefore find out how measurements from O-funnel varies with different concrete mixtures.
Utformning & placering av vädringskanaler i ett passivhus, drivet av naturliga krafter
A passive house in Norra Djurgårdsstaden drawn by Tengbom Arkitekter is going to be built. A shaft for airing is needed for a few apartments in the house.The airing shaft is designed for a few two room apartments in the house, which are not able to achieve satisfactory airing, as their outer walls are facing a single direction. The other apartments on the same floor are corner apartments. These apartments do not have the same difficulty with airing since they have their outer walls in different directions, with different pressures at the facades. The airflow in the airing shaft is supposed to be driven only by natural forces, by the sun. The purpose of natural driven forces is to achieve low energy consumption for the house.In this thesis, a design of the shaft for airing has been developed.Initially an open shaft for all apartments was analyzed.
En grafisk webläsarkomponent med hjälp av WPF i Visual Studio
WPF is a newly introduced graphical system that is a part of Microsoft?s .NET Framework. This report will evaluate WPF and its features. A comparison is made mainly towards the previous version of .NET which is .NET 2.0. The work is partly theoretical and partly implementational.
Kartläggning av föroreningars förekomst och spridning i Gräsötippen enligt MIFO
It is estimated that 22 000 contaminated areas exist in Sweden today. In order to classify the risk of contaminant migration from these areas and to prioritize which of these contaminated areas should first be treated, the Swedish Environmental Protection Agency (EPA) has designed a method, for the investigation of contaminated areas (MIFO). One of these contaminated areas is the landfill Gräsötippen outside Köping. The landfill has been used by both Yara AB and the Köping municipality between the years 1945 and 1975, and both industrial and household waste have been deposited there. The aim of this report is to survey which contaminants that can be found in the soil and water in the landfill Gräsötippen and to evaluate the migration of these contaminants.
Silver och vismut i plaster och färger : Källor till förhöjda halter i slam?
Chemical substances are spread diffusely and uncontrollably as a result of the increased consumption of goods. REVAQ is a certification system that works to reduce the flow of hazardous substances to Swedish treatment plants and to create a sustainable nutrient recycling. According to REVAQ, the yearly accumulating rate of metals should not exceed 0.2% in soil per year. Silver and bismuth are two metals that do not fulfill this requirement. The silver concentration in sludge decreased during the last decade, however the last few years, it has leveled off.
Trafikverkets effektstyrningssystem - EFS 132 kV : Bidraget till minskade förluster
The technological legacy from the early electrification of the Swedish railroads has resulted in a power grid with a lower grid frequency than the national power grid from which it is fed. Energy transfer between these power grids with different frequencies requires substations, adapting the grid frequency for the rail road power grid. For this purpose, a feeding power grid has been built, stretching across the country from Boden in the north to Tälle/Häggvik in the south.Power transfer in the Swedish power grid results in voltage angle differences which increase with increasing loads and transfer distance. These voltage angle differences are transferred from the power feeding substations to the rail road power grid, will in some extent cause loss of energy due to unwanted power flows from north to south.To minimize the losses due to this phenomenon, a power management system called EFS 132 kV has been developed and implemented. The system minimizes the unwanted power flows and controls the desired power flow for a good distribution of loads between the power feeding substations.This thesis investigates the extent of the transmission losses avoided due to the EFS 132 kV that coordinates the idling angles to a common reference point.The results indicate that EFS 132 kV affects the power flow, especially between the northern substations through an improved load distribution.
Scanias Produktionssystem - inte bara för produktion : En implementering av Scanias Produktionssystem inom teknikorganisationen vid Scania Chassi
This report is the result of a master thesis at Linköping University - Institute of Technology and Uppsala University at the request of the chassi workshop at Scania CV AB in Södertälje. Since the beginning of the 90's, Scania CV AB has had a close cooperation with Toyota from which, among other things, the Scania Production System (SPS) has evolved. SPS explains Scanias' values, principles and priorities. The Technician department (MST) at Scania Chassi in Södertälje believes that SPS can streamline the technicians work and help them become a more homogeneous group. The purpose of this master thesis is to initiate an implementation of SPS within MST through two pilot projects involving both the product and process technicians. The SPS principle Normal Situation - Standardised working method was required to be implemented within one work task each for the two groups of technicians with special attention on the three subprinciples Standardisation, Takt and Balanced flow. The master thesis fulfilled its purpose as the two pilot projects initiated the implementation of SPS within MST and the three sub-principles Standardisation, Takt and Balanced flow were implemented within the two chosen work tasks.
Biokemisk och immunologisk karaktärisering av pepsin-spjälkade mjölkallergener
Milk allergens were digested by allowing them to flow through a chromatography column, where pepsin was conjugated to the stationary phase of the column. The allergen fragments were then characterized both biochemically, by using SDS-PAGE and gel permeation chromatography, and immunologically, by examining their reactivity to IgE and monoclonal antibodies..
Hälsoeffekter från trafikbuller vid Bäckegatan
The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.
EN MILJ?STUDIE OM DE GEOKEMISKA F?RH?LLANDENA I SK?RHAMN, SVENSKA V?STKUSTEN
The following study aims to investigate the environmental conditions of the harbor of Sk?rhamn, a small fishing community on the west coast of Sweden. The interest to do so rose as a newly built apartment residence failed to connect the sewage pipes of 18 apartments, causing the untreated sewage running into the sea. The parameters accounted for are the C/N ratio, total organic carbon (TOC) as well as total nitrogen present (TN) and ?13C in the top ten centimeters of a sediment core retrieved in the Sk?rhamn harbour.
Påverkan på energianvändning och termisk komfort vid reglerinstabilitet
The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.
Matting of Natural Image Sequences using Bayesian Statistics
The problem of separating a non-rectangular foreground image from a background image is a classical problem in image processing and analysis, known as matting or keying. A common example is a film frame where an actor is extracted from the background to later be placed on a different background. Compositing of these objects against a new background is one of the most common operations in the creation of visual effects. When the original background is of non-constant color the matting becomes an under determined problem, for which a unique solution cannot be found. This thesis describes a framework for computing mattes from images with backgrounds of non-constant color, using Bayesian statistics.