An investigation of the heat impact of laser cutting on the material properties when producing tensile and impact test specimens of different steel types of varying thickness has been performed. The purpose of the thesis project was to provide recommendations regarding how much material that needs to be milled from the laser cut edge before tensile and impact tests. The study has been performed partly by investigating the test specimens by heat camera when the specimens were cut in the laser cutting line and partly by performing hardness tests, investigation by microscopy, and tolerance and roughness measurements and tensile tests of the laser cut material and material produced in the traditional multi operation machine. The results show that the heat affected zone in the thicker materials is greater than previously thought of, and that the currently used recommendation has to be adjusted. The study clearly shows that the thicker the material, the greater the heat affected zone, independently of the steel type, since the thicker material takes longer time to cut.

Huvudfrågan i arbetet är hur produktivitet och säkerhet kombineras i de säkerhetslösningar som existerar idag samt huruvida högre säkerhet leder till ökad komplexitet. Det tillvägagångssätt som använts består av en lastmätning av Secure Socket Layer (SSL), och Pretty Good Privacy (PGP), samt en teoretisk jämförelse av säkerhetslösningarna PGP, SSL och Secure Electronic Transaction (SET). Detta innebär att PGP som har jämförelsevis hög säkerhet när det kommer till kryptering även är den säkerhetslösning är mest resurskrävande. SSL däremot är mindre säkert med betydligt lägre resursanvändning. Generellt kan man med facit i hand säga att den lösning som är säkrast även är den mest komplexa.

Calculated and measured energy in residential buildings is going to differ. The reason to this may be due to many factors. In this study there is a study on how these factors affect the energy use in a building. To get an insight in what defines energy, there is first a description of energy supply both worldwide and used in Sweden, followed by a description of the energy balance. In this study energy will be studied in residential buildings only.

The austenitic stainless steel 316L has been compared to duplex stainless steels to be able to highlight a choice of material for manufacturing of spare tanks used for cooling water at nuclear power stations on the Swedish west coast. In this report 316L and the duplex stainless steels 2205, 2304 and LDX 2404 have been compared according to corrosion resistance, strength, manufacturing aspects and prices. The steels arranged by increasing corrosion resistance: 316L < 2304 < LDX 2404 < 2205. The steels arranged by increasing strength (considering the thickness of the plates needed for construction): 316L < 2304 < LDX 2404 and 2205. The steels arranged by increasing price/tank: 2304 < LDX 2404 < 2205 < 316L.

This thesis describes a system for dealing with free surface fluid simulations, and the components needed in order to construct such a system. It builds upon recent research, but in a computer graphics context the amount of available literature is limited and difficult to implement. Because of this, the text aims at providing a solid foundation of the mathematics needed, at explaining in greater detail the steps needed to solve the problem, and lastly at improving some aspects of the animation process as it has been described in earlier works. The aim of the system itself is to provide visually plausible renditions of animated fluids in three dimensions in a manner that allows it to be usable in a visual effects production context. The novel features described include a generalized interaction layer providing greater control to artists, a new way of dealing with moving objects that interact with the fluid and a method for adding source and drain capabilities..

Transformation of inorganic mercury (Hg) to methyl mercury (MeHg) is a biotic process that is proposed to be conducted primarily by sulphate reducing bacteria (SRB). The formation of MeHg is of great interest because it is the mercury species that biomagnifies to the greatest extent in the aquatic food webs; about 90 % of all Hg in fish is MeHg. Our understanding of factors involved in the production of MeHg is very important for making a reliable risk assessment. The purposes of this study were to investigate the different factors that control the solubility of Hg and the production of MeHg in a contaminated lake sediment. The lake Ala-Lombolo, Kiruna municipality, is well-known to be contaminated by mercury from different sources. Sediment cores were sampled at three different locations (N, SW and SE) in the lake and divided in three different layers; 0-5, 5-10 and 10-15 cm.

This is a master degree thesis at Royal Institute of Technology (KTH) betweenÅngpanneföreningen and Programma. KTH is the examiner, Programma is the client andÅngpanneföreningen is mentor for this project.Programma has a product called TM1800 that has problems with EMC; the problem is thatthis product does only pass the CE-check with a small safety margin. This problem can besolved by reducing the radiation from the electric components in the product or by reducing offix base frame. In this degree thesis the focus is only on mechanical redesign.The main problems right now depends on the long distance between the screws, there is anisolating layer on most of the parts and the forces between the joints are too small. The mainfocus is to solve these three problems.The best solutions are when the whole base frame is more or less redesigned instead of onlyredesigning some of the connection points.

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.

As a guitarbuilder it is an advantage if you can control and understand what is creating the character of the tone. To approach this vast jungle of variables that controls the tone in a guitar, I built two guitars and in one, guitar 2, reduced the thickness of soundboard, back and sides.The purpose was to compare the guitars and establish if there was a significant difference and what it was, in the guitars ability to produce sound. The thought was also to try the thesis: loud but short, long but moderate tone. Also if a lighter built guitar has an advantage in producing a loud but short ton and vice versa.The instruments has been examined by five guitarist, one guitarbuilder and a professor in Speech, music and hearing at KTH in Stockholm.The relative obvious conclusion is that guitar 2 is a bit louder and has a clearer base and treble but the more part of the guitarists fancied guitar 1 better. This one has got more mass fore the tone to stay alive with.

Coastal areas are popular for housing, both for permanent living and holiday houses. At the same time, thin sediments and small storage capacity in the bedrock makes the ground water resources limited. The limited ground water resources combined with too large withdrawals of ground water makes salt water intrusion a problem in many coastal areas. This study examine the risk of salt water intrusion in drinking water supplying wells on the island Södra Finnö in S:t Anna archipelago, Östergötland, Sweden. A calculation of the relation between ground water recharge and withdrawal is obtained to analyze the ground water balance in the area.

An investigation of the heat impact of laser cutting on the material properties when producing tensile and impact test specimens of different steel types of varying thickness has been performed. The purpose of the thesis project was to provide recommendations regarding how much material that needs to be milled from the laser cut edge before tensile and impact tests. The study has been performed partly by investigating the test specimens by heat camera when the specimens were cut in the laser cutting line and partly by performing hardness tests, investigation by microscopy, and tolerance and roughness measurements and tensile tests of the laser cut material and material produced in the traditional multi operation machine. The results show that the heat affected zone in the thicker materials is greater than previously thought of, and that the currently used recommendation has to be adjusted. The study clearly shows that the thicker the material, the greater the heat affected zone, independently of the steel type, since the thicker material takes longer time to cut.

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.

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.

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.

The purpose of this thesis work is to evaluate how the physical behaviour of a pipe bend is affected by the pipe bending procedure. Effects such as initial ovalization, thinning, thickening and plastic hardening from the bending procedure are examined and the mechanical properties of pipe bends containing these effects are investigated.This has been evaluated by creating a detailed Finite Element model of a pipe that is being bent. Then the differences compared to a bent tube in a virgin state, so called Elbow elements and an analytical in-house program have been evaluated. The virgin state refers to a model of a pipe that is bent from the beginning, thus having a homogeneous thickness and not containing any plastic hardening. The Elbow element is a calculationally cheap element, specially developed for accurate calculations of pipe bends in an initially virgin state.The goal with the thesis work is to get a better picture of what happens to a pipe as it is being bent, how this affects the mechanical properties and to evaluate the possibility to develop an easy method for taking these effects into account when using the Elbow element.This report describes the layout of the work and how the detailed FE-model has been constructed.