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5068 Uppsatser om Electric power production - Sida 48 av 338
Evaluating six crop mixes used for game fields in southwest Sweden : biomass production, fallow deer preference and species diversity
Game fields are one way to divert animals away from sensitive areas, create shelter and forage, and also to increase the biological diversity. In this study I investigated how the plant composition in six different crop mixes used for game fields affected the biomass production, biomass consumption and biological diversity at the Koberg estate in southwestern Sweden. Six experimental fields were used and each field contained six plots, approximately 1500 m2 each, that was sown with a different crop mix. The crop mixes ranged from a pure grass mix (A), 70 % grass and 30 % leguminous plants (B), 53 % grass, 21 % leguminous plants and 26 % other herbs (C), 100 % leguminous plants (D) to the most complex mixes constituting of 91 % leguminous plants and 9 % other herbs (E) and 87 % leguminous plants and 13 % other herbs (F). The fields were cut weekly during the summer in 2010, to estimate weekly biomass production.
Grovfoder för dikor
This literature review examines different forages which are well suited for suckle cow production in Sweden today. They should also be possible to cultivate in Sweden under the current circumstances. Crops suitable for grazing in Swedish climate but not used in Sweden today, but which may be relevant for Swedish conditions are also mentioned. In Sweden today, mainly grass silage, straw and hay are used as forage, but also wholecrop silage is used to some extent. However, concentrates are not used to a greater extent, since it contains too much energy.
Uljabuouda vindkraftpark turbinmodellering och stabilitetsanalys
This master thesis has been performed at Solvina in Gothenburg for Skellefteå Kraftand Vattenfall Eldistribution. The aim of it is to investigate the consequences of theinstallation of a wind power plant on the mountain Uljabuouda in the vicinity ofArjeplog. Especially the impacts on voltage and transient stability are examined.Furthermore, the amount of extra strain on the voltage regulation equipment and theneeds for increased regulation capabilities are looked into.The wind power plant is planned to be built by Skellefteå Kraft and connected to a130 kV grid owned by Vattenfall Eldistribution. The work comprehends the followingmain parts:- Theoretical studies aimed at wind turbines and power system stability issues.- Modelling of the type of wind turbines assumed to be built on Uljabuouda.- Simulations of different operation cases and analysis of the simulation results.The results from the simulations show that, as far as voltage stability and extraworkload on tap-changers are concerned, the wind power plant does not, in anysignificant manner, worsen the present conditions. The problem of overloading theline between Arvidsjaur and Vargfors is also minor.
Utvärdering av konsekvenserna för nätanslutning av vindkraftparker i Sverige vid införandet av nätkoden Requirements for Generators
Grid codes are becoming more demanding on power generating units due to the factthat the complexity of the power grid is increasing. The penetration of wind powerhas grown over the last years and it is clear that wind farms need to be addressedwith the same type of grid codes as conventional generation units. There is howeveran undeniable difference between the technology in conventional synchronousgeneration units, and the asynchronous generation units in wind farms.This thesis has reviewed the current grid code in Sweden and compared it to the newcode proposed by ENTSO-E, ?the Requirements for Generators?, in the aspect ofwind farms with an installed power of 30 MW or more. The comparison has beencomplemented by an analysis of how wind farms of two different technologies(Doubly fed induction generators and full power converters) can meet therequirements and technical proposals have been given on how to be able to meetcompliance with the new grid codes.The Requirements for Generators contains many non-exhaustive and optionalrequirements, because of this it has been difficult to, at this stage, exactly point outthe technical impact on the grid connection of future wind farms in Sweden.
Flygteknik : Konceptstudie av ett obemannat flygplan
Unmanned aerial vehicles (UAV?s) are nowadays greatly appreciated. The advantage over manned airplanes are great since UAV?s can be much smaller and therefore lighter. The goal of this project is to evaluate the performance of an environmentally friendly UAV using only lithium-ion batteries.
Tidssynkroniserade mätningar i vattenkraftstationer
Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP.
Vad det nu hette...Jämställdhet...? : Ett utredningsarbete på en klinik
The aim of this investigation work " What was it called...Equality...? is to study a clinics current gender equailty plan from a gender approach and by a field survey see if, and in that case, how it can be improved. A connection between existing gender norms and gender power strukctures is applied in the results of this survey in order to illustrate their significance from an individual as well as a structural perspektive.The survey has been carried through by a field survey as well as a discourse analysis as method. Yvonne Hirdmans gender power system is on of the main theoretical points of departure.The results that I have achieved in this essay is that gender can be looked at in different ways within the labour market where women have the main responsibility over the family and are considered more nursing then men. Men on the other hand are thinking of their carriers and have higher salary requirements.
Att möta vampyren : Hur kan Twilight behandlas i skolan?
This essay discusses how popular literature in general and Stephanie Meyer?s Twilight-series in particular can be useful in the classroom, despite, or rather, thanks to, its inherent problems concerning gender roles, relationships and the power systems within them. The essay takes a reader and teacher centered approach in describing both the problems of Twilight and the ways these problems can be worked with in the context of the school subject Swedish in upper secondary school. It makes an inventory of Twilight?s problematic aspects, and attempts to use them in conjunction with the governing documents of the Swedish school system.
Aktivt system för tidvattenreglering av Lysekilsprojektets vågkraftsteknik
This report investigates a possible solution to the problem with adapting wave powerplants to work in countries with tidal water. The wire connecting the buoy at the surface with the generator at the bottom needs to adjust to the varying water depth. Our solution to this problem is to attach the wire to a jack which is then placed inside the buoy. The jack is then powered by an electric engine. The report discuss what forces the buoy will be exposed to and then the structural integrity of the design is evaluated through simulations.
Fodder to ruminants within agroforestry systems in Rwanda - species and management
Rwanda is one of the poorest countries in the world and about 70-80 % of the population lives in rural areas. The land is strongly affected by land erosion which makes it difficult for the agriculture and food production. Agroforestry is a system where tree plantation is combined with livestock- and crop production. The system provides soil fertilization and binds the soil together. Some of the trees used in agroforestry systems are also used as fodder.
Small-worlds och rich-clubs bland bloggar : En nätverksanalys av den svenska bloggosfären under FRA-debatten 2008
Purpose/Aim: To find power structures within the blog network.Material/Method: Using keywords to find all available blog posts about the National Defence Radio Establishment from the blog search engine Twingly, and thereafter using the same blog search engine to find inlinks from other blogs, to those posts. The data is set into the context of the small-world networks models of Duncan J. Watts and rich-club models of Sergi Valverde och Ricard V. Sole.Main results: 5183 unique blogs have written about the subject in 22779 blog posts to which 28128 inlinks from other blogposts are made. Just over one fifth of the blogs are linkted to each other in one big network, where the remaining blogs stand without any ingoing or outgoing links.
Ikeas retuscherade kvinnor : En kvalitativ studie av Ikeas val att retuschera kvinnor i den Saudiska Ikea-katalogen
On the first of October 2012 the media reported that the women in the Ikea cataloguehad been airbrushed in the Saudi edition. Initially the blame was put on either theSaudi government the Islamic culture or the Saudi franchise. In the end it wasrevealed that the Swedish company Inter Ikea Systems had the full responsibility forIkeas actions and therefore was the culprit behind the airbrushing. On whoseinitiative or why the airbrushing was done the media never found out. These areanswers only Ikea has, although they remain unresponsive to these questionsthroughout the news portrayal.This study methodology uses a qualitative content analysis as framework to furtherinvestigate the news media with support of theoretical perspectives such as mediatheory, power relations and cultural differences.
Den bortglömda krisen ? en kritisk diskursanalys på nyhetsrapporteringen av Centralafrikanska republiken
Central African Republic has partly been portrayed in the media as a forgotten crisis, but also as something that is completely natural for how it is in Africa. The society has perceptions about Africa, which has been reproduced and reconstructed in the selected articles. The discourses in particular have appeared in articles are discourses about: us and them, the confidence in experts, social representations especially (emotional roots), ideological inequities and power relations between different parties..
Journalistik 2.0 : Om journalistens upplevelse av medborgarnas inverkan på tidningarnas innehåll
Title: Journalism 2.0: About the journalist's perspective on citizen participation and its influenceon the news content.Purpose: The aim with this study was to examine whether, and if so how, professional journalists experience that the production of news has changed as the media development has progressed and the citizens opportunities for active participation in this process has potentially expanded.Research questions:Does professional journalists experience that the opportunities for citizen participation in the news making-process has changed with the spread and accessibility of new media- if so, in what ways?Wheatear professional journalists experience that the relationship between themselves and their news sources has changes with the spread and accessibility of new media?What consequences can an empowerment from citizens have on the production of news and on the professional role of the journalist?Theory: This essay is based on theories about convergence, gatekeeping, agenda building, participatory journalism, news sources and the journalistic profession.Method: The survey is based on ten qualitative interviews with ten professional journalists, eight reporters and two web editors from the newspapers NWT and VF.Results: The results of this survey shows that the citizens? opportunities in influencing the production of news has partly changed. The journalists do not experience that citizen participation affects their professional role. Citizens have always had an impact on the production of news but new technology offers citizens and journalists new channels that facilitate the communication and interaction. The gatekeeping process is protecting the decision-making role of the journalist, which restrains citizen participation.
Sammanställning och produktion av ritningsunderlag till båt
Hanterbara båtar is a new company who builds alumina boats customized for people in wheelchairs. Due to the fact that the company only built two boats yet, the production documentation is not complete. The drawing that does exist is not in an exact standard which makes production planning harder.The purpose of this work has been to make the production of the boat easier and simplify further development and modification. Product development in the form of optimizing details is also one of the main purpose of this work.This is all done by making a 3D-assembly of all the existing drawings. After this is done new drawings will be made and added to the main assembly.