Sökresultat:
4212 Uppsatser om Energy Systems - Sida 37 av 281
Analys av systemfaktorers påverkan på tillförlitligheten i distributionsnät
In this master thesis outage statistics covering tree years from two distribution grids are analyzed with the purpose to deduce which factors yield outages. The statistics are extensive therefore allowing in-depth analysis of both customer and system related factors. From this starting point and as a model of explanation energy not supplied is studied as the consequence and the measurement of the inconvenience caused by outages. Different methods for calculating energy not supplied are developed and studied and put in comparison to the method used in Network Performance Assessment Model, which is the Swedish frame work for regulating electricity distribution.Analysis of the outage statistics show a relation between the type category of customer and outages that can be deduced to the variance and the density associated with that customer category. Prioritization of different customer categories is elevated also in this aspect.
Miljöbedömning av olika behandlingsmetoder för organiskt hushållsavfall, slakteriavfall och flytgödsel
Organic material used for biogas production can also undergo other treatments. The emissions and impact from the different treatments are evaluated in this environmental assessment, with a focus on energy and climate. The materials included in the study are organic household waste, slaughterhouse waste and liquid manure. Other than biogas production, the possible treatments for organic household waste and slaughterhouse waste are incineration and composting, and for liquid manure storing and spreading. The analysis is based on data and information from current and relevant literature, and relates to the conditions in the Swedish energy system.
Vindkraftens framtida scenarier
In several countries that have been early in the development of wind farms, there is today a second hand market for the used wind turbines. The European Union (EU) has established a waste hierarchy in order to minimize throwaway mentality. The second hand market is a part of this as the steps are to minimize, reuse, recycle, extract energy and landfill.In order to promote the development of renewable energy, there are energy certificates for the producers that provide it, wind power being one type of renewable energy. After 15 years the energy certificates for a specific wind turbine are no longer paid, and after that there are several different scenarios for the wind turbine. The scenarios investigated in this bachelor?s thesis are export of the wind turbine to countries that are not as far along as Sweden in their development towards renewable energy, selling in Sweden to individuals, and recycling of the wind turbine, as it mostly consists of metals and therefore is recyclable.
Elektrisk skorstenständare
Between 1965 and 1974, the Swedish Parliament decided to build one million dwellings, called Million Program. The million program buildings were erected with new, untried design solutions, in a short range of time, and at low cost. The residential buildings from that time are now greatly in need of renovation. The municipal housing company, Gavlega?rdarna, renovates and improves the energy efficiency at some of it?s apartment buildings in the district Sa?tra, Ga?vle.
Vatten- och avloppssystem i klimatförändringarnas tidevarv : - en studie om VA-situationen i Karlstads kommun, dess sårbarheter och anpassningsförmåga
This report is about the impact climate change has on the water and sewage systems in general, and the situation in the municipality of Karlstad in particular. Which vulnerabilities are linked to water and sewage systems with regard to climate change and extreme weather situations, what are the possibilities to adapt the system to this and what significance does climate adaptation of the water and sewage systems have in relation to sustainable development?To answer these questions I have studied literature on the subject and interviewed several people who work with these types of questions. The answers I have received state that there are a multitude of vulnerabilities linked to the water- and sewage systems, but that there are also many strong interests which strive to take measures and adapt to a changed climate. I have also come to the conclusion that the starting points and views of the possibilities to act differs between the people that I have interviewed, but that theses problems are built into the concept of democracy..
Från alger till biodiesel - Den italienska drömmen?
This project aims to investigate whether algae can be used for biodiesel production in Italy. Algaes are a good option since they are fast growing and do not occupy arable land. The aspects that have been considered are growing, harvesting, which algae strain that is most suitable, extraction of oil, the production of biodiesel and where in Italy this could be possible due to climate. Cost? and energy calculations have been made to investigate if biodiesel produced from algae would be profitable. During the production of biodiesel there are several residues obtained. When the oil has been extracted from the algae, biogas is produced from the residual biomass by anaerobic digestion and then the electricity that can be produced is supplied to the production of biodiesel.
Effekten av olika andelar grovfoder och kraftfoder i foderstaten på mjölkproduktion, välfärd och hälsa hos mjölkkor
Dairy cows transform grass to milk with help from ruminal microorganisms that can digest indigestible fiber in their feed. The digestive system of the cow is adapted to a diet consisting of forage and disorders like acidosis, laminitis and abomasal displacement can occur if the feed contains too much starch. To achieve the highest production possible the cow has to be given a high amount of concentrate or grain as the difference in milk yield is significant, approximately 1000 kg energy corrected milk per cow and year between conventional and organic cows that are fed a lower versus a higher share of forage. If the cow shall be able to eat the same amount of energy from forage as from grain or concentrate the eating- and rumination time gets longer and she might not be able to eat enough, which will result in a lower milk yield and will make it harder for the cow to recover from the negative energy balance that originate from the beginning of the lactation. Fat and in a sense protein content differs also depending on if the cow is given a high or low share of forage..
Myndigheter för hållbar utveckling : En studie av myndigheters miljölednignssystem 2005
Agencies towards Sustainable Development ? A Study of Environmental Management Systems in Governmental Agencies 2005A vision of the Swedish government is to build an ecologically sustainable society. A tool in this effort is to implement environmental management systems (EMS). The aim of the thesis is to present in which phase of the implementation of EMS Swedish governmental agencies are. This will be done by compilation and evaluation of agencies? yearly environmental reports.The thesis is written in co-operation with the Swedish Environmental Protection Agency (Swedish EPA).
Vakuumisolering ? Ekonomiskt försvarbart för småhus?
The number of people in the world and the urbanization increases. This leads to a bigger need of space for the built environment, space that soon doesn?t exist. A large portion of humanity?s energy disposal is used for heating of buildings.
Koalitionsbildning och Fragmentering. En studie av koalitionsbildning i kommuner med fragmenterade partisystem
During the last decades the Swedish local party systems have gone through some considerable changes. The number of parties present in local party systems have increased and in some cases even doubled. This makes coalition building between parties complex and parties will be forced to rethink their coalition strategies and adjust to the new circumstances. Theoretically, coalition building has often been considered and applied to national data and there have been just a few attempts to develop and theoretically explain coalitions on a local level. Thus the aim of this paper is to use different theoretical approaches to local data to test the significance of traditional coalition theories.
Effekten av frukostens glykemiska index på energiintag hos barn och ungdomar
Sahlgrenska Academyat University of GothenburgDepartment of Internal Medicine and Clinical NutritionTitle: The effect of the glycemic index of breakfasts in energy intake inchildren and adolescentsAuthor: Charlotte Olofsson, Cornelia Johansson and Maria NordbeckSupervisor: Fredrik BertzExaminer: Ingrid LarssonProgramme: Dietician study programme, 180/240 ECTSType of paper: Examination paper, 15 hpDate: May 16, 2013Background: The glycemic index (GI) and it´s effect on energy intake is a debated subject.Research has been done whether food with lower GI decreases hunger and lowers energyintake, which could be an effective tool to prevent overweight in children and adolescents.Breakfast eating is successful for maintaining a healthy weight and it´s therefore interesting tosee if the quality of the carbohydrates matters.Objective: To evaluate the scientific evidence regarding the effect of GI of breakfasts inchildren?s and adolescents energy intake.Search strategy: To find relevant articles, a systematic literature search was made in thedatabases PubMed, Scopus and Cochrane. Search terms that were used were: breakfast,breakfast quality, children, glycemic index, energy intake, obesity.Selection criteria: Randomized controlled trials and cohort trials, breakfast eatingindividuals, children and adolescents under 18 years old, reported glycemic index. Outcomemeasurements: Energy intake.Data collection and analysis: Six original articles met the inclusion criteria and werereviewed by the SBU audit template for randomized and controlled studies. There after onearticle was excluded because of very low quality of the study.
Tätskikt i klimatskal : En studie av byggentreprenörers arbetssätt
As energy prices skyrocket and the environmental issues become more frequently debated, interest in energy-efficient buildings has increased sharply in the past decade. Because of this, the interest to achieve high air tightness in building envelopes have once again awakened, due to a good air tightness contributes to lower energy consumption in several ways and to a healthier indoor environment.As the regulations for energy consumption and controls of achieved air tightness has tightened considerably in recent years, the work regarding sheets for air tightness changed significantly for construction contractors. This thesis includes a study that aims to detect what kind of manuals, recommendations or instructions contractors working according, and how a number of randomly selected construction companies in Halland, Sweden, are dealing with the matter of high air tightness of the building envelopes. The study also includes a knowledge inventory of supervisors, site managers and skilled workers, and what their opinions and attitudes are like towards work regarding the sheets of air tightness. The results have been compared with a similar survey dated to 2004, conducted by the SP Technical Research Institute of Sweden in collaboration with Chalmers University of Technology.
Tidsstudie - grovfoderhantering :
Since feeding fodder crops to dairy cows is a heavy and time-consuming but often
disregarded line of work, this study wishes to view the different possibilities that are
currently available to decrease the time to feed and apply this knowledge on an
existing farm. For this purpose, four farms have been studied due to what feeding
systems that are currently used and how long time the feeding required. The occurring
systems are either mobile, i.e. a feed mixer operated by a tractor witch feeds the cattle
via a drivable fodder table, or a stationery mixer, i.e. an electrically powered mixer
which fills an automatic feeder.
Hur hanterar institutioner en miljö med blandade Operativsystem?
The purpose of this thesis is to investigate if there are environments that use some kind of central authentication system within institutions/schools. The hypothesis is that an institution not using a form of central authentication service has more need for maintenance and as such is considered a higher cost for the organization. The gathering of data has been done through interviews with technical personal at Blekinge Tekniska Högskola and Linköpings Universitet. Based on the technical background of the authors, and the system limited to discussing Windows and UNIX operating systems, a discussion and analysis of the systems working today has been done, with emphasize on the hypothesis..
Studie av energianvändningen på Spira förskola: En jämförande studie av faktiskt och simulerad energianvändning samt en parameterstudie av ingående data vid simuleringar av energianvändning
I detta arbete har den faktiska och simulerade energianvändningen på Spira förskola i Luleå undersökts. Den faktiska specifika normalårskorrigerade energianvändningen fastställdes till 121,4 kWh/kvm år. Vid projektering av förskolan uppskattades den specifika energianvändningen med hjälp av simuleringsprogrammet VIP-Energy till 78,5 kWh/m2 år. Därmed översteg den verkliga användningen den simulerade med 54,6 %.En parameterstudie av indata till simuleringsprogramet har också genomförts med avsikt att fastställa den totala förändringen i energianvändning då indata ändras. Följande parametrar har studerats;?Drifttid hos ventilationssystemet?Horisontvinkel?Inomhustemperatur?Klimatzonen?Kvot mellan till- och frånluft?Luftomsättning för ventilationssystemet?Solreflektion från omgivande mark?Temperaturverkningsgrad?Vindhastighet?Vridning av byggnadenNyckeltal som kan användas för att snabbt uppskatta påverkan på den totala energianvändningen har också sammanställts för majoriteten av de studerade parametrarna.