Voltage sag indices are a way of quantifying the performance of the power supply, as far as voltage sags are concerned. Indices can be defined for individual events, for individual sites, and for a whole system. A standard method for single-event methods is part of IEC standard 61000-4-30.This thesis emphasizes the importance of voltage sag indices and different methods for calculating three-phase voltage sag characteristics. Three-phase events measured in a medium network voltage over period of one month were analyzed, results examined and statistically evaluated. An algorithm for calculating voltage sag characteristics and indices was created in Matlab.

Miljonprogram is a Swedish building program from 1964 to 1975. During that time about a million homes were constructed. Now, almost 50 years later, they are in desperate need of renovation. In order to fulfil the Swedish environmental objective to decrease energy consumption 50 per cent until 2050, considerable housing stock built under the Miljonprogram has to be renovated.Focus in this thesis is on the building services and theirs profitability that can decrease energy consumption in households build during the Miljonprogram. Building construction is not considered in this report.

The purpose of this essay is to illustrate how the position of power / exercise of power are perceived in today's schools from the teacher's perspective. I have examined how students' freedom and democracy education interpreted in real life, and how this affects both teacher and student learning approaches. I would also highlight the need to set standards for children's psychological development related to the consequences will be. I have chosen to perform a qualitative research through individual interviews with five participating teachers from different experiences in different type of school. I have used the hermeneutic method of analysis to analyze the material.

The rising demand for electricity and heat raises a big challange for the society and engineers. Many products have been introduced to the market to supply more energy to the energy systems. Absolicon AB is a Swedish company that develops and markets a combined heat and power generating product. The product, Absolicon X10, uses a parabolic trough to concentrate the radiation of the sun onto a receiver. The receiveris equipped with mono crystalline solar cells and is cooled by a circulating liquid media.

Skiascopy, also called retinoscopy, is a method for determining the refractive power of the eye. There are only a few, old studies made on equine refraction. The aim of this study was to investigate the refractive power in a population of Swedish horses. The study consists of a review of relevant studies done on animals and an experimental part where the refractive power of 93 horses of different age, breed and usage was examined. A pilot study of 12 horses was performed regarding the importance of cycloplegia when doing skiascopy on horses. The results of the pilot study show no significant difference in the skiascopy results between the group before and after cycloplegia were induced. Consequently, there is no need of inducing cycloplegia before doing skiascopy in adult horses. The study shows that horses usually were emmetropic (normally sighted) with minor deviations toward myopia or hyperopia.

During the last decades the fertility of dairy cows has declined in the same rate as the milk yield has increased. This is a result of the negative genetic correlation between milk yield and fertility, failure to show estrous signs and metabolic problems in the cow. The purpose of this review was to investigate the function of metabolites and hormones as markers for disturbances in fertility, health and production in the dairy cow. There are several metabolites that are suggested to indicate the cow?s energy balance.

In connection with the property crises in many countries, caused by the financial crises, people are now more aware of the risks involved in poor property-investments. The unusually cold winters along with extreme prices of electricity in Sweden in recent years has also contributed to increased interest in energy-efficient buildings.The process of developing a modern family home in Kiruna, Sweden is presented the first part of this paper. The house has been designed to withstand very high stresses from snow, low energy consumption as well as a high standard of living comfort. Aspects of the house covered here involves everything from construction, heating and ventilation to sanitation. Each of these areas is presented based on their underlying, scientific methods or theories.

The climate changes that are occuring in the world have resulted in that the EU callingfor a 20 % reduction in energy consumption to the year 2020, to reach that goal theEU want the public sector to go forth as a good example. Västfastigheter owns andmanage the hospital buildings in the Västra Götaland region. To be able to reducetheir energy usage Västfastigheter has hired several consulting firms to chart out theenergy consumption on each hospital building. The biggest energy savings potentialhave been calculated and what the cost will be to perform each action. The energyaudit have been completed and stand as the decision basis for Västfastigheter?s choiceon which action packages that should be implemented.

This Master Thesis discusses the development of bids for regulation power with consideration of change of discharge. The study was initiated by Vattenfall PD and is a limited part of a substantial development project at the same division. The background of the project is the new demands from SvK, which among other things includes more detailed regulation bids. As from the 1st of November 2008, the regulation bids are supposed to be calculated regarding each specific regulation object, something that is defined by SvK. These new demands changes Vattenfall?s conditions and will increase the need for detailed knowledge about available regulation power and costs for regulation.In this study a strategy for regulation bids was developed.

This thesis concerns to investigate renovations of existing buildings aiming at enabling energy efficiency, from a conservation and restoration perspective. This includes performing case studies of three projects in the Gothenburg area where renovations has been done and an analysis of directives raised by the EU and later implemented by the Swedish National Board of Housing, Building and Planning, Boverket. In addition to these, regulations enforced by the Swedish law, related to the topic, have been considered.The investigated projects in this case were the housing cooperative Välten in Brämaregården, the Solar Buildings in Järnbrott and Gårdsten as well as Katjas Gata 119 at Backa Röd. In order to measure and compare the results of these projects a comparison between the pre- and post-restoration energy consumption have been performed. To capture additional perspectives the grading system Operation Kungsörn has been applied.Regarding the comparison of energy consumption the renovation of Katjas Gata 119 was found preferable but showed in my view lacking attention to the cultural heritage of the area.

VAV (Variable Air Volume) system has been studied in a newly constructed office-building. The goal for the study has been to evaluate how the ventilations system work in practice, if adjustments can be made to achieve an more energy efficient system and to evaluate if other alternative ventilation systems is to be preferred in the further.The degree project has been executed at Helenius Engineering Firm who is working with the environment, media systems, HVAC and energy in buildings. The building that has been studied is owned and operated by Akademiska hus.Literature studies, visits at site, inventory, review of system documentation, energy analyses, interviews, key figures, LCC, sand energy- and indoor climate simulations has been made to study the building. Where appropriate some tools from Six Sigma have also been used.How to achieve an energy efficient system and a pleasant indoor climate is studied with human health and well-being as base for the indoor climate requirements. Technical support systems such as ventilation systems have to be designed so that an acceptable indoor climate can be achieved.

NCC ROADS Sweden east is a part of the NCC Corporation. The company mainly produces aggregates, asphalt and concrete. They have taken the environmental issues seriously and been working with that since the middle of the nineties. When manufacturing asphalt large a quantity of fossil energy is needed. The company is now about to make further progresses by manufacturing environmental friendly asphalt (?green asphalt?) with using bio-energy.

To achieve the Government's milestones for 2018, which means that 50 % of food waste shall be separated from household waste and undergo biological treatment (composting or anaerobic digestion).   Hultsfred, Högsby and Vimmerby are three adjacent municipalities of Kalmar, county Småland. During 2012 and 2013 analyzes were performed on their household waste to determine its composition. The household waste is currently collected in one fraction. The work, examines how much food waste the household waste contains. From the amount of food waste, the biogas potential is examined - how much food waste biogas generates and how much energy it corresponds to.   Food waste is broken down by microorganisms under anaerobic conditions (anaerobic digestion) in a biogas plant.

The climate changes that are occuring in the world have resulted in that the EU callingfor a 20 % reduction in energy consumption to the year 2020, to reach that goal theEU want the public sector to go forth as a good example. Västfastigheter owns andmanage the hospital buildings in the Västra Götaland region. To be able to reducetheir energy usage Västfastigheter has hired several consulting firms to chart out theenergy consumption on each hospital building. The biggest energy savings potentialhave been calculated and what the cost will be to perform each action. The energyaudit have been completed and stand as the decision basis for Västfastigheter?s choiceon which action packages that should be implemented.

Energy issues are constantly increasing attention in today's society. People's impact on Earth isentered in more contexts. Many discussions are about how the entire social structure needs to bestreamlined in order to achieve sustainability. The residential and service sector accounts for 39 % oftoday's total energy consumption in Sweden and the increasing electricity prices have made buyersmore interested in energy issues.There are many buildings in need of refurbishment today, including all the apartments that werebuilt in the 1970s to reduce the housing shortage at the time. 650 000 apartments of one millionapartments were built during the so-called the one million program and is currently in need ofrefurbishment.