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132 Uppsatser om Runoff coefficient - Sida 1 av 9
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.
Inverkan av Kiselhalten på Värmeutvidgningskoefficienten hos Aluminiumlegeringar
The purpose of this report is to document the experiments carried out, methods used and results gained during research into how the silicon content of an aluminium alloy affects the coefficient of thermal expansion (CTE).The goal of this paper is to better understand and to find a relation between silicon content and the coefficient of thermal expansion.Experiments were carried out using carefully prepared samples of Al Si alloys (0, 7, 10 and 20% Si content). Using these alloys, the CTE could be measured using a dilatometer.Comparative analysis carried out could map the effects of silicon content on the coefficient of thermal expansion and an equation was created. Using simple graphs and the rule of mixture method, the authors were able to build a simple tool for calculating the CTE of specific aluminum silicon alloys..
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.
Genetisk studie av inavel och fertilitet hos hund :
Inbreeding, the mating of related individuals, has been the one dominating breeding strategy for dog breeders during the last 200 years. However, its negative effects on fer-tility and other fitness traits, a phenomenon called inbreeding depression, have been ignored in the quest of perfect unity in conformation or performance. The purpose of this study was to test the hypotheses that litter size is reduced as a consequence of in-breeding, affected by both the inbreeding coefficient of the dam and the litter and that a rapid increase in the inbreeding coefficient affects litter size more than a slower rate.
Data were collected from the Swedish Kennel Club registry of origin. Breeds included in the study were the Bernese Mountain Dog, the Cocker Spaniel, the Golden Retriever, the Rottweiler and the West Highland White Terrier.
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.
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.
Frånluftsvärmepumpens möjligheter i flerbostadshus
If a building is heated by a heat pump, it is of high importance that the heat pump has a high coefficient of performance. An exhaust air heat pump extracts heat from the building?s exhaust air. The air has a relatively high and constant temperature all year around, leading to a high seasonal coefficient of performance. This thesis examines whether it is profitable to complement an exhaust ventilation system with an exhaust air heat pump in an apartment block that already has geothermal heat pump, district heating, oil- or biofuel heated system.
Det redovisade resultatets värderelevans - före och efter IFRS
This thesis aims to investigate if there are any differences in the value relevance of yearly earnings announcements before (2000-2004) and after (2005-2009) IFRS were implemented for listed companies in the European Union. To assess the value relevance of earnings, an earnings response coefficient (ERC) is estimated using a linear OLS-regression model. The regression model uses accounting earnings per share as the explaining variable, with the corresponding return starting from (but not including) the previous year's earnings announcement date, ending at (and including) the current earnings announcement date, as the dependent variable. This study finds that there is no statistically significant difference between the estimated ERCs for the two periods. Although no statistically significant difference is found, data shows that the R2-values, which measure the explanatory power of the regressions, are higher for the period before IFRS.
Passivhus vid polcirkeln : Fungerar det?
This report is the product of the course AF101X, a bachelors degree in Samhällsbyggnad atKTH. The task of the course is to design a small house at a given location and also implement adeepening study. The house in this report is located in Kiruna in the north of Sweden, where theclimate is much colder than in the rest of the country.The deepening study of this report is to evaluates how realistic passive housing north of thePolar Circle is based on those facts. The house will to some extent be designed to fit the passivehousing standard.
Utveckling av en HBV/PULS-model med sammanfogade markfuktighets- och responsrutiner
Soil properties affect the chemical composition of soil water. When studying transport of chemical substances through a basin, it is therefore important to know from which soil layer the main part of the runoff is generated. The aim of this study is to develop an HBV/PULSE model with merged soil moisture and response routines, which generates good approximations of groundwater levels. It should be possible to extend the model to simulate transport of substances and take into account which soil layer the groundwater level is currently in. The hydrological version of HBV/PULSE is used since there is no need to account for pH or alcalinity at this stage.
Metodik för beräkning av anslutna hårdgjorda ytor till spillvattennätet
Sveriges avloppsledningsnät förnyas och utvidgas kontinuerligt. Idag finns ett flertal datorprogram för hydraulisk modellering av flöden och uppdämningsnivåer i spill- och dagvattennät. Modellerna kan även användas som planeringsverktyg för att bedöma effekter av planerade åtgärder samt för uppföljning av utförda åtgärder. Vid uppbyggnaden av en modell krävs beräkningsresultat från en hydrologisk avrinningsmodell som indata. Det största arbetet vid modelluppbyggandet ligger just i beskrivningen av hydrologin.
Akustisk mätning av U-värde
This pre-study investigates the possibility of U-value measurements through an acoustic method. A hypothesis about an acoustic model built on acoustic theories combined with U-value theories is presented to answer the questions:
? Can U-value theory be combined with acoustic theories?
? Can the coefficient of heat be affirmed trough an acoustic measurement?
The idea for this dissertation begun with a logical idea in mathematical similarity, between the coefficient of heat transmission units and sound intensity units.
The U-value theory is based on assumptions such as initial resistance for inner walls and initial resistance for outer walls. The resistance in the material is interpreted through sound intensity theory.
The argument is built upon mass law theory, which means if the frequency or thickness of the material layer doubles it implies an increase of sound reduction by 6 dB.
Validering av Casmo-5M / Simulate-3
The objective of this M. Eng. Diploma work was to validate the new version, CASMO-5M, and compare the results with CASMO-4E, by using the same input in both programs. The tasks that were included in this work was to compare TIP-measures, k-effective curves (warm), k-effective curves (cold), the effect of void on k-effective, the isothermal temperature coefficient (ITC), the moderator temperature coefficient (MTC), damping ratio calculations, internal effect in a fuel bundle of a BA-rod, the speed of BA-out burn, impact of xenon, falling control rod, margins and isotopes.The TIP-measures showed that the differences were small for all reactors, at most, 6% nodal improvement by C5M (Casmo-5M) for Oskarshamn 3. The warm measurements of k-effective showed that C5M had a higher value for all cycles of Oskarshamn 1, 2 and 3 in comparison to C4E (Casmo-4E).
Möjligheter att minska kväveutlakningen genom att anpassa kvävegödslingen till variationer inom stråsädesfält
Due to excess precipitation that cause runoff, all soils in Sweden naturally leaches nitrogen.High leaching from arable land is an environmental problem when the runoff reacheswaters. In the international agreement, Baltic Sea Action Plan, the aim is to reduce therunoff of nutrients. Sweden has agreed to reduce its load of e.g. nitrogen to the Baltic Sea.One of the proposed measures is an increased use of site-specific N-fertilization, which hasbeen shown to increase nitrogen use efficiency and therefore also reduce the nitrogen runoff.Either yields are increased with the same total amount of nitrogen, or the total quantityof nitrogen is reduced with preserved yield levels, which is profitable for the farmers.The dynamics of nitrogen leaching differs between top dressing applications above orbelow the economical optimum. There is a consensus about a difference in the dynamics,but not about its magnitude.
Quantification of Tripeptidyl-peptidase II : Optimisation and evaluation of 3 assays
Abstract Tripeptidyl-peptidase II (TPPII), is present in most eukaryotic cells. It cuts tripeptides from the N-terminus of peptides and is especially important for degrading peptides longer than 15 amino acids. TPPII also tailors long peptides into suitable substrates for the enzymes which transport and produce the peptides that MHC I present. Increased levels of TPPII have also been found in certain cancer cells, thus it is of interest to determine if TPPII could be used as a tumour marker.The aim of this study was to optimise and evaluate 3 different methods for quantifying TPPII. Western blot, enzyme-linked immunosorbent assay (ELISA) and fluorophore-linked immunosorbent assay (FLISA) protocols were optimised regarding incubation times and antibody dilutions.