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505 Uppsatser om Surface runoff - Sida 1 av 34

Sammanvägda avrinningskoefficienter i rationella metoden : en jämförelse mellan idag och 1970-talet

Storm water is rain and melted snow that runs off, primarily from impervious surfaces.Future storm water management is facing the challenges of increased precipitation, asclimate changes, and increased areas of impervious surfaces due to the expansion anddensification of the cities. Impervious surfaces reduce the potential for water to infiltratein the ground leading to increased Surface runoff and higher peak discharge.The runoff coefficient is closely related to the percentage of impervious surfaces andrepresents the maximum percentage of a catchment that can contribute to runoff. In thisstudy, the objective was to evaluate the weighted runoff coefficient for three differenturban types; apartment buildings, townhouses and residential areas and a comparisonbetween today and the 1970`s was made.The runoff coefficient was determined by manual mapping of the different surface typesin each area based on data in the form of orthophotos and aerial photographs. The surfacetypes that were mapped were asphalt, permeable areas, tiles, sand/gravel and roof.Tiles and sand/gravel were the most difficult surface types to map. In order to see towhat extent these categories influenced the weighted runoff coefficient a sensitivityanalysis was carried out and the runoff coefficient based on surface type was changed indifferent scenarios.The results of the sensitivity analysis showed that the surface types tiles and sand/gravelhad little impact on the weighted runoff coefficient which in mainly due to the fact thatthe percentage of these surfaces types of the total area is small.The result of the study showed that the largest change in the runoff coefficient occurredin residential areas where the increase in the percentage of impervious surfaces causedby new roofs in the form of porches and garages and from paved or tiled driveways.

Identifiering av områden med risk för fosforförluster genom ytavrinning : metodutveckling med GIS

The eutrophication of lakes and seas with the algal bloom and deficiency inoxygen that follow, has been given priority by the Swedish government as oneof 16 environmental objectives. The purpose of this project was to develop a toolbased on a simple model, limited amount of data and geographic informationsystem (GIS) to identify areas with risk for phosphorus losses due to surfacerunoff. This tool can act as a decision support to decide where appropriatemeasures should be applied with the aim of reducing phosphorus losses and bythat the eutrophication.The method that has been used is a combination of two models, one calculatingthe potential erosion while the other one identifies areas of erosion (net erosion)or deposition. This ability is of great importance because potential erosionshould be calculated on areas with net erosion. Areas with high potential erosionhave an increased risk for phosphorus losses due to Surface runoff.The potential erosion was calculated based on factors which describe how topography(LS), land use (C), soil type (K) and precipitation (R) effect the erosion.All of them have been modified to a greater or lesser extent.

Metoder att förhindra nedisning av vindkraftverksblad

ABSTRACTMany wind turbines have problems with icing and there is still no effective method to de-ice without stoppage of production and power loss. Here I therefore consider other methods than those available today, and particularly, I consider how these methods could be applied to wind turbines of the company Oxel. A surface where the water droplets do not attach might be the basis for a useful method. If no water attaches, no ice could form. To accomplish this a hydrophobic surface is nessesary, for example wax.

Bestämning av dagvattenflöden i Knivstaåns avrinningsområde

The purpose of the thesis was to map the hydraulic load on the Knivsta river from stormwater runoff, and build a platform for further studies of pollution loads on the rivers ecosystems. New residential areas are planned to be built in Knivsta municipality and it will have an impact on stormwater flows to Knivsta river. To examine the impact this will have, simulations were made in the area as it stands today and after expansion work. The work includes calculation of flows from the populated areas but also from the catchment area around it consisting of woodlands and fields. Because of expected climatic changes which may affect rainfall, the simulations have been performed with different return periods for rainfall data.

Val av värme- och ytbehandling

Atlas Copco Tools develops and manufactures handheld industrial tools. Heat and surface treatments are used to provide the tools with certain properties. There are no routines for the choice of treatment or for how to specify treatment on drawings. Production documents that are sent for production abroad may not be clear enough. Some treatments are known as trademarks and there are no instructions for how to specify these on drawings and in CAD-models.The purpose of this master thesis work is to create recommendations for the procedure of choosing heat and surface treatment.

Fosforläckage från växtodling - orsaker och ågärder :

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

Blästring av trä : Ett materialbibliotek av blästrade och ytbehandladeträytor

In my thesis I have sand blasted different type of woods - ring-porous and diffuseporous deciduous tree species and conifers - to show different results depending on the species, the direction of the grain and the effects of surface treatment of a blasted surface.The results of my tests were sometimes unexpected, such as that the sand from blasting almost completely disappeared, that all wood surfaces after blasting exhibited a much lighter or paler surface than before and that the diffuse-porous tree species showed differences in hardness between the beginning and end of annual rings.By creating a library of different kinds of wood and sandblasted surface treatment, I have created a reference bank that I will be able to use me in the manufacturing of interiors, furniture and other objects..

Time Machine Computing for Media Improvisation

C3LOOPS is an application for DJs and VJs based on surface interaction. A system is said to be based on surface interaction if it presents content on a two dimensional, endless surface that a user navigates through zoom, pan and incremental text filtering where processing is tightly coupled with the content without breaking the workflow. C3LOOPS is designed to encourage improvisation and collaboration. During improvisation changes occur rapidly. Allowing navigation through time as well as the two spatial dimensions of an interaction surface the possibility of unlimited undo operations opens up.

Utveckling och produktion av system fo?r ma?tning samt loggning av temperatur i roterande elektriska maskiner

The purpose of this thesis has been todesign an electric circuit that measurestemperature in three different ways. Asoftware was also designed to record andanalyse the measurments. The result of thecircuit was a PCB with inputs for 42sensors of both surface and non-surfacemeasurments. These all have a maximumerror of ±3°C..

Bioorganisk fastfas syntes för att skapa intelligenta ytor

This thesis investigates three different surface modifications, and the route to design and synthesize them. The thesis is therefore divided into three sub- projects. (i.) Design and synthesis of a peptide which secondary structure could be controlled by a negatively charged surface. (ii.) Design and synthesis of a cyclic peptide, that would self-organize prior to surface interaction, using the type I anti-freeze protein of a winter flounder as template. (iii.) The use of solid-phase synthesis to make the synthesis of SAM-molecules easier..

Great design experiences don?t happen by accident - En kvalitativ studie om design av upplevelser i Surface-computing system

Användarupplevelser är en gren inom användbarhetsområdet som på senare år kommit att studeras alltmer. Orsaken till detta är att ny teknik medför andra krav på produkter än att produkter som sådana ska vara lätthanterliga. Produkten kan likväl ha som syfte att vara rolig att använda sig av.Studiens syfte var att studera användarupplevelser beträffande Surface-computing teknologi.Företaget Interactive Institutes innovativa Surface-computing produkt Virtual Autopsy Table fick exemplifiera Surface-computing teknologi i publika miljöer. Genom att använda denna uppmärksammade produkt som underlag är syftet att undersöka vilka designmoment som kan anses vara kritiska för upplevelsebaserad design. Studiens frågeställning blev:Vilka riktlinjer kan tas fram för att vägleda en designprocess att bli mer fokuserad påanvändarupplevelser vad gäller Surface-computing system?Med utgångspunkt från studiens datamaterial, så var en del av studiens syfte att ta fram riktlinjer.

På ytan av interaktionsdesign : En undersökning om hur designen på en Microsoft Surface SUR40 applikation kan förbättras för flera användare

The purpose of this thesis is to examine and analyze how to improve the design of a Microsoft Surface SUR40 application. The application in focus was an interactive product browser developed by the company Spree, our external client. Spree is a multi-touch software provider, established in September 2010 and they expressed a need for suggestions for how to improve this application. Our work aimed at revealing how to make the application more suitable for several users and make it easier for them to interact simultaneously on the surface. From a qualitative standpoint we have examined how 17 users experienced the application.

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.

Markavvattningsföretagens geografi och konsekvenser i Trosaåns avrinningsområde

Agricultural drainage is widely used to manage the amount of water in the ground in order to improve conditions for cultivation. However the effects of drainage companies on water regimes are considerable leading to runoff changes such as altered stream flows, peak flows and water levels. In a greater extent this could imply an increased risk for floods along affected watercourses. This study analyzes the extension of agricultural drainage within the drainage basin of Trosaån in Sweden by ArcGIS mapping. In a statistical analysis, historical variation in streamflow in relation to mean precipitation and mean temperature are investigated for the study area.

New Generation Surface treatment for tools : A preliminary study

The surface finishing technique called black oxidation is currently being used on thetool holders made of low alloyed tool steel produced by Sandvik Coromant. Blackoxidation isn?t considered a sufficient technique because it doesn?t make the toolholders look like the quality products that they actually are. The reasoning behind thisis that the tool holders can show signs of corrosion after prolonged storing times orin countries with high humidity and temperature. The corrosion doesn?t decrease thetool holders performance, but the customers might believe otherwise.

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