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.

In this report a study is carried out with the aim to identify added values of EPC projects implemented in schools in order to increase the interest of EPC projects on the market. The report examines how the planned maintenance, supervision, maintenance and corrective maintenance is affected, how insurance premiums and terms are affected, the indoor environment and how the tasks of the operating staff is changing. A literature study of energy savings, energy use in schools, maintenance and insurance as well as how energy efficiency improvements are related to the Swedish environmental objectives has been made. Visits were carried out in Ludvika, interviews were also carried out with operation technicians and local strategists in Ludvika as well as employees of insurance companies.Schools often have neglected maintenance and problems with ventilation and indoor environment. Schools also have a large energy saving potential due to their low utilization, mainly because they are empty parts of the year.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

Purpose/Aim: The purpose of this study is to examine how the advertisements of houses in the newspaper of Dagens Nyheter, have developed in layout, by text and image, during the last fifty years and to examine what part of the home is highlighted, as evident values of lifestyle.Material/Method: By examining twenty advertisements from the newspapers every decade during the period of 1958-2008, the layout and lifestyle will be described and analyzed by a quantative and qualitive (discourse) method.Main results: The advertisements has changed in many ways. The layout has drastically developed to a more personal layout of the estate agents and the trends of lifestyle have had an impact on how the agents have created the text in the advertisments to entice customers..

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

There is always a need for more effective ways to store energy in order to reduce the human impact on the environment. One step on the way can be the use of flywheels as kinetic energy storage devices. Low frictional losses are essential for a flywheel to be effective. To minimize these losses active magnetic bearings (AMB) can be used to keep the shaft centered instead of the more conventional ball-bearings. AMBs use actuators and a fast control system that needs correct and noise-free measurement data of the shaft position and the current in the actuators to work properly.This thesis explains the process of constructing power electronics and a current measurement system for active magnetic bearings (AMB).

The aim of this study was to investigate whether a dietary change, physical activity or a combination of both gave the best result when treating obesity, concerning weight loss and BMI. Excessive weight and obesity are today a big health-issue and it is estimated that 10 % of the men and 12 % of the women in Sweden have a BMI over 30, i.e. are suffering from obesity. The corresponding number for children is 3 %. No one can say for sure what causes obesity but there are many theories.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

Byggandet av passivhus har ökat kraftigt under 2000-talet i Sverige. Dock har det inteutformats och byggts några studentbostäder i passivhus form ännu. Denna studie går ut påatt försöka utforma studentbostäder som uppfyller de svenska kraven för passivhus. Genomatt välja ut lämpligt material och komponenter, t ex. väggtyper, platta på mark ochfönstertyper redovisas olika beräkningar för energiförbrukning.I metoden till beräkningarna som genomfördes, där resultaten hamnar i jämförelse medvarandra, användes VIP-energy samt PHPP.

"Ekskolan" is a monumental school placed in the middle of the new town area "Mariehäll" in Stockholm, Sweden. 600 pupils between preeschool until year 5 will use the school and its big schoolyard between the townsquare and the public park.The school will be built in massiv wood, both for human reasons with a environment of good, healthy and suitable material for the people and the school activity.The school is seperated in 3 volymes that organises different years; house B and C, and the common facilities: house A. The scool has a cultural profile with rooms for creative activites, documentation and exhibition.To mark the border to the public places that surround the scool and to meet the inclined topography, the schoolhouses will stand on a terrace. The terrace creates rooms between the houses that can be used to utdoor teaching. Likewise, the terrace creates a opened sightline between the public rooms and all the way down to the river..

Mindre än en timmes solsken på vår planet innehåller mer energi än hela världens energiförbrukning på ett helt år. Ett vanligt villatak i Sverige tar på ett år emot flera gånger mer energi än vad dess behov är. Potentialen för solenergi är mycket stor. Samtidigt använder samhället idag stora mängder energi och det mesta av energin kommer från icke-förnyelsebara källor. Sverige har visserligen en hög andel förnyelsebar energi jämfört med andra länder men ändå är mer än hälften av energin som vi använder icke förnyelsebar.Syftet med den här rapporten är att utveckla ett mer hållbart samhälle genom att använda solenergi.

I denna rapport undersöktes S&P 500 Energy Index genom multipel regressionsanalys. Modellerframställdes genom regression och baserades på data hämtad från börsen. Modellerna angavs iprocentuell ändring respektive absolut ändring. Validitet för varje enskild kovariat testades och en risknivå avgjorde om en kovariat skulle inkluderas i modellen eller inte. Detta ledde till två modeller med bättre kurvanpassning till den givna mängd data över det valda energiindex.

A vulnerable group in society is people with ASD (autism spectrum disorders) or autism. This group seems to increase, mainly due to genetic factors but also environmental problems. Medical research has accelerated in the U.S. and Europe. The biggest problem for people with disabilities is the inability to communicate, both verbally and socially.

Intelligent IT-based solutions, often called Smart Grids, are considered to be the future balancers of renewable energy sources. One area within the Smart Grid concept is called demand response, which is focused on making customers more consumption flexible by making them more active in their consumption. In this thesis the aim is to analyze a business model by investigating the income potential for a demand response solution as well as its market potential. This has been done through literature studies, interviews and development of a computational model.The use of 5000 households with flexible consumption can provide a cost reduction of 17.2% or 2.4 million SEK for a balance responsible party during an average year. If the solution is used to make strategic bids on the regulation markets the study indicates that the largest potential for revenues lies within this strategy.

BIOGAS POTENTIAL IN GRASSES FROM WETLANDSMarvin MartinsThe purpose of this study has been to survey wetlands that are suitable for mowing and to analyze the biogas potential in the harvested grasses. A preformed investigation showed that there are suitable wetlands, which can be harvestable, namely those mowed formerly in traditional haymaking. The practice of traditional haymaking is dying out in Sweden today but there are several good reasons why it should to be reconsidered. Nature- and cultural values are obvious, also the unutilized energy in the grass.The suitable types of wetland that were specifically studied were the productive wetlands; meadow marshes and wet meadows. These wetlands are represented in the Swedish meadow- and pasture inventory database; (TUVA) and the Swedish national wetland inventory (VMI).