
Sökresultat:
3803 Uppsatser om Nyckelord: Mixing-layer - Sida 8 av 254
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.
?Anorna hafva mer välde i contradans än växelbref? : Sällskapsdans och klassamhällets ankomst vid slutet av 1700-talet
The purpose of this paper is to examine how the arrival of class society is expressed in the social dance of high society during the second half of the eighteenth century. The study is based on the idea that culture and society develope in interaction; that changes in the economic, political and social life determine the cultural expressions as well. What I wish to examine is whether cultural themes from the developing bourgeois culture ? individualism, to be precise ? is expressed in the social dance during the second half of the eigthteenth century. // The study shows that public balls definitely gave people a chance to show off on the dance floor in spite of social rank.
Lilaköttig taggsvamp, Sárcodon fuligíneovioláceus : miljökrav i Sverige och en analys av vad som styr artens etablering
Burnt Spine-cap Sárcodon fuligíneovioláceus are one the most endangered
mycorrhizal fungal species in Europe. They have their main distribution in Sweden. It
form mycorrhiza with pine and dependent on limestone, which makes it connected to
a rare environment. It has therefore been important to study the ecology of it further
and to recognise the requirement it has on the environment more accurate and what it
need to establish in a new area. In this study, 31 of 34 known sites in Sweden was
visited and studied in field and their history analysed through aerial photographs.
Jordtäckta hus : Energiberäkningar och kostnadskalkyler på ett jordtäckt hus i Malmö
With rising energy prices and the threat of climate change, energy costs and energy savings havebecome a central and important part in building. Therefore it is interesting to explore different andnon-conventional methods of energy conservation. Building Earth sheltered houses is such a method.Earth provides good insulation and provides the ability to both reduce the total heating needs and toreduce the maximum power demand. The aim of this study was to construct a house in Malmö and seeif Earth sheltered houses can be a cost effective alternative for the construction of sustainable andenergy-efficient houses.Previous studies have shown that Earth sheltered houses have reduced their power requirement with upto 25% and their use of energy with 10%. Numerical calculations in Comsol Multiphysic 4.2, wasperformed on a house with different degrees of earth covering.
Inneluftsventileradekryprumsgrunder : en utvärdering av två tillverkare
This Diploma work investigates internal air ventilated crawl-space in respect to construction and damp. The Diploma work assumes from a general description of crawl-space and general dump problems in ground construction. An internal air ventilated crawl-space is a construction where you take the ventilation air from the building and bring it down to the crawl-space and lets the air circulate before it passes through a retaining aggregate on the way out from the crawl-space. In this matter you get a worm space under the building and a lot less dump problems in form of · Ground damp · Build damp The ground dump reduces through draining around the building, different layer of gravel between the ground and the building and ventilation of the crawl- space. The build dump reduces through ventilation of the crawl-space as fast as possible.
OLED : Evaluation and clarification of the new Organic Light Emitting Display technology
Organic Light Emitting Displays (OLEDs) are a new type of thin emissive displays predicted to possess superior properties to existing techniques e.g. Liquid Crystal Display (LCD). The main advantages are low power consumption and a thin display structure. This report contains an explanation of the emissive OLED technology, its functionality and the physics of the organic layer structure in an OLED. The technology is described with respect to the two classes of organic materials used in displays, small molecules and conjugated polymers.
Den preanalytiska fasen ? Hur viktigt är det att blanda serumrören?
Bakgrund: Cirka 2/3 av alla preanalytiska fel uppkommer i den preanalytiska fasen, där blandning av provrör direkt efter provtagningen är en av faktorerna. Studiens syfte var att jämföra analysresultaten för glukos, laktatdehydrogenas samt kalium i serum från blandade rör med oblandade rör. Studiens syfte var även att undersöka hållbarheten på dessa tre analyter i rumstemperatur (25 °C) under sju dagar.Metod: 100 blandade och 100 oblandade serumrör med gel, från 100 patienter, analyserades på Architect ci2800. Analysresultaten jämfördes statistiskt med parat t-test. Alla serumrör förvarades i rumstemperatur under sju dagar och de tre analyterna analyserades dagligen.
Snabb och säker roaming i WLAN
This thesis investigates how Ericsson AB should do to achieve fast and secure handover when roaming in a WLAN. It also provides a security analysis of the system that the wireless access point is part of. The reason for this is that Ericsson is selling an access point called the ABS 2200 aimed at the public hotspot market. The premise was that they wanted a standardized way of handling the roaming issue. At the outset the 802.11F standard looked like a good alternative (in fact the only standardized alternative).
Symbolisk dekoration : En studie av Järnspiralen som symbol under yngre järnålder.
When the Iron spirals investigated in this paper saw the light again no one looked at them as nothing more than decoration. It was first during the 2011 excavation in Old Uppsala that the symbolism of the items no longer could be ignored. The spirals of Old Uppsala lay along the walls of the great hall, which stood upon one of the human constructed plateaus in the area. The hall had been burned down and then cleared of all lumber. Then the iron spirals had been placed in the positions and then everything was sealed with a layer of clay.A study of the artifact began with the purpose to contextualize and interpret the iron spiral.
Skydd mot yterosion i slänter av finmorän
Slopes in fine till soils are exposed to surface erosion due to rainfall, snowmelt and upland water sources. Large areas of road slopes are therefore covered for surface erosion protection. Preventive methods like ditches and trenches are also being used. Silt tills are particularly troublesome since the water can bring the soil into suspension and cause mudslides. Different methods for erosion protection have been studied in this work, with the emphasis placed on rockfill covering. The need for and the dimensioning of this type of covering has been examined in literature and field studies.
Resurseffektivt bussprotokoll o?ver RS-485
This report describes the design and implementation of a multi-master, packet based protocol for small and tiny microcontrollers where resources are limited. The protocol was named "Tiny Controller Network" or TCN for short. The protocol is meant mainly as a control bus for automation and sensor acquisition applications but due to its flexibility can also be used for other purposes as well. It borrows some of its functionality and design ideas from the well known CAN bus and Modbus but also has a number of major differences like the use of standard hardware and time synchronisation. One of the key aspects during the design was the use of very little system resources and common on-chip hardware peripherals like a UART.
Relining ur ett beställarperspektiv
This report is focusing upon relining from a client?s point of view. Potential buyers are given a presentation of the different methods available today together with a general briefing describing the process. An important part of this report are the interviews that took place with already established customers. Property owners, managers, pipe cleaners, and project managers whom all been in contact with relining have answered the questions given along with their own thoughts and have also given recommendations of other persons to talk to.
Brunnsviken : Utvärdering av åtgärder för förbättrad vattenkvalitet
Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin. The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.
Högfrekventa tryckvariationer under de senaste århundradena
Long time-series of pressure measurements often have high quality because the early instrumentsare more or less the same as the modern ones. A time-series from Lund consisting of three dailymeasurements from 1780-1997 has been homogenised and is therefore suitable for analysingpossible influences of the enhanced greenhouse effect. According to a two-layer model of theatmosphere one finds a shift in the frequency of baroclinic instability due to an increasedtemperature gradient caused by the increasing CO2. Baroclinic instability over the Atlantic Oceanis the main cause for frontal zone production, causing cyclonic activity over the southern part ofScandinavia. Changes to the baroclinic instability would therefore be traceable in the time seriesfrom Lund.
Klostridier och jästsvamp i ensilage ? orsak, verkan och samverkan
Yeast and Clostridia is a problem in silage for farmers as contaminated silage may result in poor animal health and milk quality. Clostridia can produce toxins that, when consumed, acts as neurotoxins, it may also cause blown cheeses if the Clostridia contaminates milk. The purpose of this study was to investigate the cause, effect and interaction of yeasts and Clostridia in silage. Clostridia are microorganisms which are strictly anaerobic and consume carbohydrates and protein in the silage. Yeast is a fungus that is facultative aerobic and feed on carbohydrates in the silage.