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4212 Uppsatser om Energy Systems - Sida 32 av 281

Automatisk trimning av drivsystemreglering från MATLAB

This master thesis covers the development of an automatic tuning process for the existing speed controller for drive systems. The drive systems are resonant two-mass systems where a motor is used to drive a load connected by a shaft. The developed method relies heavily on system identification and the construction of a complete mechanical model of the process. With this approach, the common problem with poor load speed control that derives from measuring only the motor speed can be addressed and solved for a majority of such processes.The automatic tuning method has along with general test functions been implemented in a complete tool for automatic tuning, testing and performance evaluation and reporting for drive systems..

Metabolit- och hormonnivåer som tidiga markörer för fruktsamhet och produktionsstörningar hos mjölkkor

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.

Flödet av elektrisk och elektronisk apparatur i Sverige 1995 - 2011

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.

Webbens klassifikationssystem. En komparativ studie

This thesis deals with subject-based hierarchical search-services on the World Wide Web. The purpose is to investigate how systems of this kind facilitate information retrieval through subject-based information seeking. Its starting point is taken from the study of texts and qualitative analyses of search-services on the World Wide Web. Important aspects and features of the Internet and the World Wide Web are explained as well. Three systems are examined: Mölndals Stadsbiblioteks Länkkatalog, Svesök, and Alta Vista.

Energieffektivisering av befintlig bebyggelse med exempel från Göteborgsområdet

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.

Productivity of integrated harvesting of pulpwood and energy wood in first commercial thinnings

The aim of this study was to quantify the productivity and the costs of different harvesting systems (teams), containing harvesters equipped with accumulating harvester heads and forwarders, in first commercial thinnings were an integrated harvest of pulpwood and energy wood were performed. In the beginning the plan was to study and measure 20 sites before and after harvest. Due to storms during the summer of 2010, complete data could only be obtained from 8 of these 20 sites. Seven of these sites were privately owned and one was owned by UPM, all of the sites had been pre-commercially thinned. The mean stem density before harvest was 2578 stems per ha and the mean stem volume was 0.074 m3solid over bark.On average 1518 stems/ha was harvested.

Driva tulpaner i näringslösning eller i jord :

The aim with this thesis is to make a comparison between forcing tulips in a hydroponic system and the forcing off tulips that have been planted in soil. The results are mostly based on interviews with six Dutch and one Swedish tulip forcer and the managing director at the Horticultural Research Centre, Proeftuin Zwaagdijke, in the Netherlands. There are benefits and disadvantages with both methods. Tulip bulbs planted in soil seem to get a brighter colour after forcing, compared with those forced ?in water?.

Plan för multifunktionella buffertzoner längs Vramsån påMalörten AB : s jordbruksfastigheter

To create multifunctional buffer strips along a watercourse in an economically sustainable way requires consideration of many different factors. In this plan we have selected pollutant reduction as the main purpose of the buffer strip. We have also strived to achieve minimal income loss due to reduced production, increased biological diversity, good game preservation that leads to higher income from hunting, aesthetical satisfaction and possibility to profit from available subsidies. This is done mainly to make landowners/farmers more interested in creating buffer strips along water courses.As sand is the dominant type of soil in the area, the water course is less affected by surface runoff compared to if the soil would be clay or some other finer texture. Game preservation and subsidies have therefore been the main factors when establishing the width of the strip, because these require wider buffer strips in some cases.

Grön asfalt och NCC : rätt tillväxtstrategi för en asfaltproducent?

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.

Biogaspotentialen av matavfall sorterat ur hushållsavfall.

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.

Föroreningskällor till sjön Anten. En kartläggning och kvantifiering av kväve- och fosfortillförsel

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.

Ombyggnation till passivhus

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.

Potential för värmeåtervinning från mjölkkylanläggningar

The present climate discussion has made energy efficiency an interesting topic. Saving energy does not only help the climate but also saves money for the energy consumer. The purpose of this thesis was to examine the potential of heat recovering from milk cooling. Two milk farms, one with voluntary milking system, VMS, and the other with conventional milking system was used to measure interesting temperatures and electricity consumptions. The numbers were used both to do theoretical calculations and to construct a SIMULINK model. To calculate the potential for heat at milk farms theoretical calculations were made in MATLAB using a reference farm with different combinations of heat recovery and pre cooling. The farm was assumed to keep a dwelling house with the annual heat consumption 18165 kWh.

Distribuerade fastighetsautomationssystem : - En implementation av kommunikationsprotokollet BACnet

Building Automation Systems in commercial buildings are often designed and installed by different contractors, using equipment and components from different manufacturers. The lack of an accepted communication standard has resulted in a few different standards. Many manufacturers of building automation systems only support one, a few or none of these standards, while developing proprietary system solutions. Regin, who develop such equipment, are planning to adopt an open communication protocol specially designed for building automation - BACnet. As a step in that direction this thesis was announced with the purpose to investigate the possibility to implement BACnet in one of their products and to gain more knowledge of the BACnet protocol.

Renen och nötkreaturet, en jämförelse mellan två olika typer av idisslare :

The aim of this literature review was to make a comparison between the feeding requirements of Swedish reindeer (Rangifer tarandus tarandus) and meat producing cattle (Bos taurus) within farming. Reindeer are an intermediate feeding type; they have the ability to adapt to short term seasonal changes in food. They avoid eating fibre as much as possible and display highly selective behaviour while foraging. Adaptation to harsh environments with a limited amount of food has made reindeer dependent upon easily digestible food and consequently their digestive systems are less capable of processing plants with high fibre content. Herding is an extensive system which requires a significant amount of land and labour and describes the reindeer industry.

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