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7889 Uppsatser om Time coefficient - Sida 1 av 526
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..
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.
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.
Deltid och kön: En undersökning av deltidsarbetets utveckling under åren 1987-2005
This paper aims at assessing the relationship between female and male part-time employment and the business cycle in Sweden during the years 1987?2005 using quarterly time-series data and two alternative indicators of the business cycle. It further aims at determining whether the share of women working part-time has changed over time. Key results include that the relationship between the business cycle and female part-time employment is found to be significant and countercyclical. No significant effect is however found for men.
Utvärdering av Transportstyrelsens flygtrafiksmodeller
The Swedish Transport Agency has for a long time collected data on a monthly basis for different variables that are used to make predictions, short projections as well as longer projections. They have used SAS for producing statistical models in air transport. The model with the largest value of coefficient of determination is the method that has been used for a long time. The Swedish Transport Agency felt it was time for an evaluation of their models and methods of how projections is estimated, they would also explore the possibilities to use different, completely new models for forecasting air travel. This Bachelor thesis examines how the Holt-Winters method does compare with SARIMA, error terms such as RMSE, MAPE, R2, AIC and BIC will be compared between the methods. The results which have been produced showing that there may be a risk that the Holt-Winters models adepts a bit too well in a few variables in which Holt-Winters method has been adapted.
Priset på åkermark : påverkande faktorer
The price of farmland has risen sharply in the last 20 years. This has led to discussions about what creates the value of farmland. The aim in this study was to try and find what factors are affecting the price on farmland. The area that is studied is the counties around Mälardalen during the period 2005 to 2009.The method chosen to achieve the objective is the hedonic price model. The variables are chosen after a preliminary study where a literature search has been made and a number of interviews with people in the industry.
Irrigation scheduling for efficient water use in dry climates
In this report the importance of irrigation scheduling in dry climate is shown, how it can save water and energy; how this method can improve crop yield by supplying the right amount of water at the right time. It is shown how irrigation scheduling and irri-gation technology together increase the irrigation efficiency..
Marknadens värdering av redovisningskvalitet
The purpose of this thesis was to investigate whether accounting quality is a priced factor by investors. The event studied is the release of year-end result and the release of the annual report. To assess accounting quality a sample of 30 companies listed on the Stockholm Stock Exchange during 2003 to 2007 are studied. We assess accounting quality by the absolute size of discretionary accruals using the modified Jones model developed by Dechow et al. (1995).
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.
Scintigrafisk undersökning av esofagusmotilitet hos häst :
Scintigraphic examination of the esophagus has for some time been the method of choice for the study of motility dysfunction in humans. The method has not yet been described for horses hence the lack of reference values for passage time for a bolus through the esophagus in healthy subjects. The purposes of this study were to measure passage velocity and time for a bolus to pass through the esophagus in healthy subjects, as well as to evaluate the reproducibility of the method. Eight warm-blooded trotters were used in the study. The horses were sedated with a low dose of Acepromazine prior to onset of the study.
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.
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).
Claw and leg lesions in preweaning piglets : a comparative study of piglets reared on structured polyurethane coating and piglets reared on concrete floors
Floor surface in pig facilities can have an impact on animal welfare and pig health, as it can cause the pig physical damage and thereby increased risk of infectious diseases and lameness. The development of pig housing systems has resulted in a decreased use of bedding. It seems hard to find the optimal floor in farrowing pens, as it must suit both the sow and piglets. The floor friction needs to be adequate to avoid slips and at the same time should the floor be non-abrasive. Abrasions and lesions caused by the floor are not only causing the animal suffering, but are also negative from an economical aspect.