Today most ice rinks in Sweden use secondary refrigeration systems with a solution of calcium chloride and water as secondary refrigerant. Due to the large amount of energy such a system uses more efficient systems would be desired.An earlier study concluded in the possibilities of using carbon dioxide as secondary refrigerant with copper tubes as the loops in the ice rink. Since then 3 ice rink refrigeration systems has been built with carbon dioxide in copper tubes. Excluding the ones being direct involved in those projects there is still very little knowledge about how these system works. This study has been made primarily with the aim of adding to the knowledge concerning availability and cost and secondary to look at possibilities for improvement.A comparison between systems with carbon dioxide, calcium chloride respective ammonium solved in water has been made by using Decision Matrix.

Environmental destruction is a growing problem in our world. Almost every day there are new reports concerning that we have to do something about the greenhouse gasses. Simultaneously is the human constantly more eager to have a life with higher standards and therefore uses more energy. The environment is a question that is highly up-to-date and more people try to find solutions on how to save our planet. One way to decrease the energy demand is to build passive houses, where the houses don?t have any active heating.

The harbour in Arvika is closed down and the industry that has been established in the area is now beeing wound up. A deepened comprehensive plan for the area is under progress in the municipality. The intentions are for instance that the harbour should be integrated with the city and that Arvika is facing a lake should be more apparent from the city center. The harbour should also contribute to a more attractive city. These intentions have hence been the starting point of my undergraduate theses, which has resulted in a proposal on how to develop the harbour. During the process I have analysed the city image, how the area is used today and the public places in the city centre.

Use of lighting is crucial to make public urban places available during dark hours. Landscape architects participate in planning of lighting, but during our education there is very little taught on the subject. Through this study we approach the subject of lighting by looking into lighting methods for urban plant materials during winter. In this thesis we look into ways to emphasize the visible characters and experiences of urban plants during winter season using light. Target audience are landscape architect students and landscape architects without knowledge of lighting. The part of the thesis that describe basic conditions for, and visual characters of plants can be useful to lighting designers without knowledge in this subject. Working methods used were the following: ? Pre-study about light and lighting techniques through literature and dialogues. ? Compiling important visual winter plant characters through photography and literature. ? Outdoor light experiments with plants.

The purpose of the house which is the basis of this report is to be able present itself on the market as a relatively cheap and at the same time a climate friendly choice. The house is supposed to be able to be built anywhere in Sweden and the rest of Scandinavia in a short period of time. This puts demand on what kind of heating system the house can have, since not all places have the geographic advantage of being able to use geothermal or district heating. Therefore the heating system choices will only include those that are not limited by their geographic location. The house will be built in modules which only require the groundwork to be done before the house can be erected. In this report "System solutions for plus or passive-housing" a comprehensive literature search has been conducted as well as a number of calculations.

Syftet med studien är att undersöka varsels effekter för företags effektivitet och produktivitet under lågkonjunktur. Vår studie bygger på intervjuer med både chefer och anställda från företaget Water Jet Sweden AB. Studiens resultat är att personal påverkas av företags beslut om varsel om uppsägning genom att arbeta mindre effektivt. Detta är så för att varslet sänker arbetsmotivationen och tryggheten vilket gör att personalen underpresterar, detta påverkar hela företaget negativt..

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.

Aquaponics is a food production system consisting of a consecutive cultivation of plants and aquatic animals, fish or shellfish, in recirculating water. The plants feed on the nutritious effluents from the fish tank and bacteria converts ammonia from the fish tank into nitrate that is absorbed by the plants. The plants receive nutrition and the fish gain purified water. The environmental impact of the production of fish meal and fish oil used in conventional fish feed includes a large consumption of fossil fuels with subsequent carbon dioxide emission. The aquaponic system can be made environmentally sustainable and self-supporting if supplemented with a vermicompost/vermiculture for the production of worm protein as a fish feed. Vegetable waste from the hydroponic part of the system can be reused as worm feed in the compost and the protein rich worms can be harvested, dried and grinded and brought back to the aquaculture as fish feed. As a first step in this direction, I have investigated the effect of recycling of vegetable waste in vermicomposts on the growth and number of earthworms (this was evaluated after harvesting). The hypotheses were that earthworms can be cultivated in the vegetable waste and that by adding manure to the vermicompost it is possible to obtain a nutrient content adequate to support a continuous worm harvest, in other words create a vermiculture. Eisenia fetida and Dendrobaena veneta were grown in 20 L bins containing peat mixed with either poultry or cattle manure. The proportions were 70% peat and 30 % manure. Discarded plant parts from lettuce cultivation was added to the vermicomposts (35 g per week) and water was supplied with 0.8 L per week.

Rapporten innefattar en jämförande studie mellan olika typer av membran och beläggningar.Främst sker en jämförelse mellan materialens förmåga att andas. Vattentäthet testas på nyamaterial och efter olika sorters nötning så som martindale, flexing och tvätt för att få en ökadförståelse för materialen. Verktyget som används i studien för att mätaånggenomsläppligheten är hudmodellen. Resultatet presenteras med ett Ret-värde vilket är enförkortning på Evaporative resistance of a textile. Metoden används för att på ett bra sättsimulera hur huden svettas.Projektet har utförts på Swerea IVF som är ett forskningsinstitut beläget i Mölndal.Hudmodellen är en av de senaste stora investeringarna på Swereas textil och plast avdelning.Resultatet av studien visar att laminat andas bättre än beläggningar, dock har bärarmaterialetstor inverkan på resultaten.

The project is a thesis which intends to strengthen the form language and increase the user friendliness of an International Moth. This is a single handed dinghy with only one sail. It sails on two hydrofoils and receives a very high speed compared to its size, and are therefore often referred to as ?the Formula One on water ?. The result is a new concept where the aerodynamic forces have been used to stabilize the boat and relieve the hydrofoils.

Grassland is a great part of Swedish agriculture and there is a demand of what the grassland yield is in practice. To be able to control the economic of the milkproduction it is important for the farmer to know how big quantities of pasture there is to use during the year.The work is based on interviews of 22 farmers from southern part of Sweden. Their area of grassland fluctuate between 16 up to 360 hectares. The questionnaire content 32 questions.The most common way to weight the green plant material is to drive over a scale, and to measure the dry extract with your own gauge. It takes in average two minutes toweight one load of green plant material.

No previous studies have been conducted on elementary school in Sweden about children`s thoughts about the first animals on earth. The work takes up the children`s ideas of the first animals and the difference between girls and boys knowledge. The purpose of this work was to determine if student`s views are consistent with the science know today. In the interview, five girls and five boys participated. Mankind is asking where it all began, today we know that the first life arose for 4 billion years ago and it was from the water.

In this project a LC-MS-method for the analysis of gamma-hydroxybutyrate, gamma-butyrolactone, 1,4-butanediol, amphetamine and methadone was developed.Initially, the efficiency of the ionisation of the analytes was evaluated with respect to the ionisation technique (ESI, APCI and APPI) and the composition of the mobile phase. In the next step a number of different columns was tested in order to find the one with the greatest potential for separation of the substances in question. Using the selected column, the separation was optimised by means of experimental design and the software The Unscrambler 7.8. The parameters studied were the flow rate, the column temperature and the mobile phase composition. The response variables were the resolution between the target compounds and the retention time of the last eluting compound.These experiments showed that, in order to obtain the best ionisation, the mobile phase should consist of 5 mM formic acid in water and acetonitrile.

Abstract (in English)The task for the diploma work was to develop methods for measuring of moisture content by the Karl Fischer method, in jam, jelly sweets, and fudge.The start premises was a for the company whole new equipment, which should be started up. Then programs should be developed for different kind of samples.In the task it was as well included to develop methods for dissolving the different kind of samples, since the Karl Fischer method demands completely dissolved sample material..

The objective of this work was to compare the environmentally gentle soil scarification technique Huminmix (with possibilities to do track-grinding/HMMspår, long-scraping/HMMlångfläck and mounding/HMMhög) with conventional disc trencher, concerning seedling establishment and growth of direct seeded and planted Scots pine seedlings. Inventories were made during June and July 2005, in 34 seeded and 6 planted stands from 2000 ? 2004 (1- 5 years old) of lichen- and myrtillus/vaccinum-type in Holmen Skog AB´s district Norsjö in Västerbotten. The Huminmix-technique had been used for HMMspår in the seeded stands and for HMMhög in the planted stands (HMMlångfläck has been used from the year 2006 for direct seeding). The studied stands had been seeded with the same amount of seeds according to stand data.