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497 Uppsatser om Surface textures - Sida 7 av 34

Energianvändning för markkonstruktioner förlagda med ytvärme : En teknisk och ekonomisk utredning av fördelarna med att isolera under värmerören

The need for snow-free surfaces at squares, bus stops, platforms, car parks and sports facilities increases and at the same time energy price rise and the environment is becoming a hotter issue. The construction of the ground heating systems often lack thermal insulation under the heating pipes, which means that the heat from the pipes not only warm up the soil surface but also heats the surrounding soil. The insulation also has more features, by insulating the risk of frost damage is minimized. The goal of this report is to demonstrate the large heat loss and energy costs in the absence of insulation under the heating system.The report begins with a scientific way to study and treating the soil heating system uses, and the theory involved. Furthermore it also deals with different routing principles of heat pipes depending on the facility.All calculations are made with so called finite element method (FEM), in COMSOL Multiphysics 3,5a, where models are created with different conditions.

Övertoner i elnät vid Skellefteå lasarett : Harmonics in power grids at Skellefteå Hospital

The goal of this paper is to find out how solar cells can improve energy efficiency on-board M/S Sydfart. The paper is based on a number of energy measurements on board the M/S Sydfart. The solar surface is calculated by measuring the available space for installing solar panels. Global radiation data is taken from STRÅNG's database, the data is then used to calculate the theoretical power produced by the solar cells. Energy efficiency is analysed in two ways.

Områdesinbäddning för ODE

This paper gives an introduction to the theory of minimal surfaces. It is in- tended for undergraduate students with some basic knowledge of differential geometry and complex analysis.After defining the concept of minimal surface and giving a brief histo- rical survey, we look at some well-known minimal surfaces and a few of their characteristic properties. The connection between minimal surfaces and harmonic functions is discussed and the Weierstrass-Enneper represen- tation formulas are introduced. We also present Bjo?rling?s problem and give some examples. .

Geokemin inom osorterade cirklar : Analys av tungmetallers distribution inom jordprofiler tagna från Abiskoområdet, nordvästra Sverige

The Arctic region appears as a pristine remote environment, yet there is increasing evidence that it is greatly impacted by pollution such as lead (Pb) and mercury (Hg). In this environment deposition of Hg has increased threefold since the last industrial revolution. In this study five cryosolic soil profiles within non-sorted circles (NSC) in the Abisko region, northwest of Sweden, has been analyzed to improve our understanding regarding how pollutants are distributed within such type of soil. The soil samples have been analyzed with the use of X-ray fluorescence analysis (XRF), for the measurements of the total concentrations of e.g. lead (Pb) and zirconium (Zr).

Flerskiktat papper : en sammanställning av historia, teknik och forskningsresultat

Until the beginning of the 1900:th century the paper making process was handicraft. The paper machines that have been developed since then are as impressing in size as fascinating when it comes to the technique. The process has always been improved to give a better paper for lower costs, with as short manufacture time as possible. Stratified forming has been a reality since 1830. From the beginning it was applied to board and paperboard.

Införande av mjuka golv för mjölkkor : en fallstudie

Soft rubber flooring have gained in popularity over the last years. Rubber flooring al-lows cow to move more freely without slipping and improves claw and leg health. The purpose of this study was to investigate the influence of a stepwise introduktion of soft flooring on cow`s placement in cow houses with robotic milking. A case study was carried out in a herd in northern Sweden with 41 cows. Observations were made every 15 minutes between 09.00 and 16.00 concering cow placement in cu-bicles, in cubicle alley, in feeding alley and in feeding alley with the head through feed-ing gate. One observation period was carried out per flooring alternativ: 1) all concrete slatted floor, 2) rubber slatted floor in feeding alley and concrete slatted floor in cubicle alley and 3) rubber slatted floors in feeding alley and solid rubber floors in cubicle alley. The study showed that 6 %-units fewer cows lay in the cubicles when the feeding alley surface was slatted rubber.

Energieffektivisering ombord M/S Sydfart : Med hjälp av solceller

The goal of this paper is to find out how solar cells can improve energy efficiency on-board M/S Sydfart. The paper is based on a number of energy measurements on board the M/S Sydfart. The solar surface is calculated by measuring the available space for installing solar panels. Global radiation data is taken from STRÅNG's database, the data is then used to calculate the theoretical power produced by the solar cells. Energy efficiency is analysed in two ways.

Undersökning av tidstrender i registerdata. Lungcancerregistret ROC.

This paper gives an introduction to the theory of minimal surfaces. It is in- tended for undergraduate students with some basic knowledge of differential geometry and complex analysis.After defining the concept of minimal surface and giving a brief histo- rical survey, we look at some well-known minimal surfaces and a few of their characteristic properties. The connection between minimal surfaces and harmonic functions is discussed and the Weierstrass-Enneper represen- tation formulas are introduced. We also present Bjo?rling?s problem and give some examples. .

Basal prediktionsmodell för graviditet vid in-vitrofertilisering

This paper gives an introduction to the theory of minimal surfaces. It is in- tended for undergraduate students with some basic knowledge of differential geometry and complex analysis.After defining the concept of minimal surface and giving a brief histo- rical survey, we look at some well-known minimal surfaces and a few of their characteristic properties. The connection between minimal surfaces and harmonic functions is discussed and the Weierstrass-Enneper represen- tation formulas are introduced. We also present Bjo?rling?s problem and give some examples. .

MCNP-modell för beräkning av neutrondos och DPA på reaktortanken vid Ringhals 2

In this report an MCNP (Monte Carlo N-Particle) model is described for the reactor vessel at Ringhals 2. The model is validated against the specific activity in neutron dosimeters, extracted in 1977, 1984 and 1994. The validation showed that the calculations of the model are within the requirements of a maximum of 20 percent uncertainty for every neutron dosimeter except one, extracted after the first cycle. The uncertainty of this cycle was mostly due to the operation data rather than to the MCNP model.The model has been used to investigate various questions concerning radiation damage. The reliability of the traditional measure of radiation damage, fast neutron flux (En > 1MeV) has been evaluated.  This has been done by taking the ratio for this and another measure of radiation damage, DPA (Displacement Per Atom), for various positions and layers.

Utvärdering av en ny typ av lagerinbyggnad för traktionsmotorer

The thesis evaluates a new kind of bearing arrangement in a traction motor that ABB hasdeveloped. Since the arrangement is designed in a new and innovative way it needs to beevaluated to see if it is safe to use. In today?s traction motors, bearings with a big internalclearance (C4-clearance) are used. The basic idea of the new arrangement is to reduce the fitsbetween the bearing and shaft/house.

Minimalytor och Björlings problem

This paper gives an introduction to the theory of minimal surfaces. It is in- tended for undergraduate students with some basic knowledge of differential geometry and complex analysis.After defining the concept of minimal surface and giving a brief histo- rical survey, we look at some well-known minimal surfaces and a few of their characteristic properties. The connection between minimal surfaces and harmonic functions is discussed and the Weierstrass-Enneper represen- tation formulas are introduced. We also present Bjo?rling?s problem and give some examples. .

Att existera i ögonblicket -Töj, en textil sittmöbel

This project started with an exploration of geometric shapes and textile materials. It resulted in a chair made out of textile bands with different elasticity. The surface for sitting is flat when the chair is not used, and changes in the moment you sit down and gets a new shape. A piece of furniture that adapts to each individual. The chair emphasizes the important relationship between human and product as the person using it becomes a part of the chair for a moment..

Den bäcknära zonen vid små skogliga vattendrag i Värmland : generell beskrivning, förekomst av traktorspår samt kvicksilverhalter i körpåverkat ytvatten

Forest streams and the associated riparian zones are sensitive to disturbances and changes that occur within these riparian areas. Particularly sensitive are small streams of low order, which will have large impacts down-stream. The disturbances that occur in the riparian zones are reflected quickly in the stream. Driving with forestry machines in the riparian zone will have detrimental effects to the soil and water. Driving the machines will lead to changes in the mineral soil composition, resulting in the reduction of porosity, less infiltration, compaction, and an increased bulk density.

Prediktionsmodeller vid in vitro-fertilisering då ett embryo återförs

This paper gives an introduction to the theory of minimal surfaces. It is in- tended for undergraduate students with some basic knowledge of differential geometry and complex analysis.After defining the concept of minimal surface and giving a brief histo- rical survey, we look at some well-known minimal surfaces and a few of their characteristic properties. The connection between minimal surfaces and harmonic functions is discussed and the Weierstrass-Enneper represen- tation formulas are introduced. We also present Bjo?rling?s problem and give some examples. .

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