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3126 Uppsatser om Wind power plants - Sida 11 av 209
Primärenergianvändning av passivhus i Sverige : Med fokus på Kvarteret Trettondagen
The building sector accounted for around a fourth of the total energy usage in Sweden in year 2010 (Energimyndigheten, 2012). Therefore it has become very interesting to achieve a lower energy usage in residential buildings. One way to achieve that is to build so called passive houses. By being very well insulated and have low leakage through the walls, they can reduce the energy usage for heating with a substantial amount. The first passive house was built during the 90?s in Germany; and in Sweden the first passive house was built in Gothenburg 2001.
Ljusets betydelse för rotknoppars groningsvillighet i åkermolke (Sonchus arvensis L.)
This study is about how changed light conditions induce dormancy in plants. It is divided in two parts. First a literature study where quantification of light, the concept dormancy, photoperiod and light quality are discussed. Second an experimental part, where the importance of light for sprouting capacity in root buds of perennial sow thistle (Sonchus arvensis L.) is investigated.In the science in how flowering in plants are induced the concepts short day/long day plants and light dominant/dark dominant are well-established. These concepts can also be applied to how light induce dormancy in plants.
Produktutveckling och prestandatest av ett vattenvärmedrivet torkskåp : Jämförelse mellan tre utvecklade versioner av ett vattenvärmedrivet torkskåp
AbstractElectricity consumption is a globally increasing problem caused by the high share of electricity produced in coal power plants. These contribute to high carbon emissions when only about 1/3 of the heat generate electricity and the remaining 2/3 of the heat cools off. Combined heat and power plants (CHP) have high efficiency because they use the residual heat for domestic heating. The CHP plant often use fuels from renewable resources, giving them a lower carbon footprint, but are also depending on the heat demand. If electric powered products such as drying cabinets convert to heat powered products more environmentally friendly electricity will be produced by CHP plants, which can supplant electricity, produced from coal power plants and reduce carbon emissions.
Projektet att etablera vindkraft : möjligheter och risker med ett förnybart energisystem
This thesis describes the processes of establishing wind farms in Sweden. The workcontains a thorough literature review regarding both the establishing process andproject management, including complex project theory. The main part consists of theexecution of 15 interviews with organizations involved in wind farm establishment.The result of these interviews laid the foundation for a process description identifyingdifferent steps and activities in these types of projects. The outcome was thencompiled in a project model, which includes five phases and four processes.When analyzing the project of establishing wind farms from the theory of complexprojects one discovers that the amount of different requirements and stakeholdersnecessitates a systematical and dynamical project structure. Since projects are in needof different types of competences there are also many consultants and contractorsinvolved.
Framtidens energilagring : en studie av befintliga samt potentiella metoder fo?r lagring av fo?rnybar el pa? ett ha?llbart sa?tt
In today?s society there is an increasing demand for renewable energy sources such as sun and wind power. These sources are intermittent, and energy storage is therefore needed to ensure a constant power supply. This report compares pumped hydro energy storage (PHES), compressed air energy storage (CAES), flywheels, batteries, super magnetic energy storage (SMES) and hydrogen energy storage.The opportunities for further development are limited for PHES and CAES in comparison with the other technologies. Lithium-ion batteries and hydrogen energy storage are considered to have the most potential in the future.
Makt i klassrummet : En maktanalys av relationen mellan lärare och elev
This essay is about power in the classroom. It is about the power dimension of the student-teacher relationships that arise in that space. The overall aim has been to investigate which categories are fruitful in a power analysis of these relationships. My aim has therefore been to develop power categories and to use them to identify and to categorise cases of power interaction that take place between those particular actors in that particular setting.In order to gather material for my study I have both read literature that approaches the study of the student-teacher relationships from a power perspective and done a series of observations in a high school.My theoretical frame comprises a concept of power and a series of power categories. These categories include strength, authority, inducement, coercion, violence, resistance as well as to possess power, to have power, to exert power, the scope of power and the base of power.
KORTSIKTIG PRODUKTIONSPLANERING I MINDRE FJÄRRVÄRMESYSTEM : En studie vid Strängnäs Energi AB
District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.
Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik
Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.
Cisterciensklostrens odlingar i Sverige under medeltiden
The aim of this paperisto find out which plants the Cistercian monks might have cultivated in Sweden during the Middle Ages and which types of plants it would have been practical to grow inside or outside of the Cistercian monastery precinct. Archaeologicaland archaeobotanical studies have been consulted to find out which plants were available in Sweden during the Middle Ages. Examples, mainly from Scandinavia, but also from the continent, are used to show that the monasteries were large institutionsthat had to feed a large number of people and that there would not have been enough space to cultivate everything needed within the monastery precinct.Secondary sources have in the main been used to gather this information, except in the case of the Swedish monastery of Nydala where F-Topo, a database developed by the County Museum of Jönköping,has been used to analyse the amount of land and the types of properties owned by the monastery.The conclusion is that for practical reasons the monks would have cultivated plants that needed to be close at hand, that were rare or delicate, that could not be stored for long periods and that were used in small quantities within the monastery precinct. This would include medicinal plants, herbs for cooking and some vegetables like lettuce, spinach,and similar,that do not keep well. Most other items, grains, cabbages, root vegetables, peas and beans could equally well be cultivated outside the walls.
Projektering för återupptagandeav elproduktion vid småskaligtvattenkraftverk
Due to historically low prices for electricity in Sweden, many small-scale hydropowerplants were closed down. A small-scale power plant has more or less the samemaintenance costs as larger plants, but doesn?t generate as much income. Today?sincreasing price for electricity in combination with a desire for renewable energysources makes small-scale hydropower interesting again.
Design av utomhusträdgård i Dubai :
To plan and build a garden in Dubai has other conditions and challenges than what you experience in Sweden. The heat, wind and lack of water makes the need for durable plants, a good design and landscaping important if you want to have the opportunity to use your garden during most of the year. The soil is poor of nutrients, alkaline and sometimes saline, witch makes supplying the soil with organic material and various fertilizers necessary if you want to be able to plant a bigger range of plant material in your garden. Another important part is to provide your garden with a good irrigation system that should be put into the ground before planting so that the plants are given a more even irrigation.
It?s relatively green scenery you meet and to me it?s in a way surprising since the country with its climate is rather harsh for the purpose of supporting plant life.
What goes up must come down - Modelling economic consequences of wind turbine decommissioning
At the time being there is limited experience within turbine decommissioning in Sweden and the economic effects are unknown. Despite this, there are expectations that revenues generated by sales of materials will cover decommissioning costs. The model developed identifies thirteen parameters that vary between different types of turbines and that affect the economic consequences of decommissioning. The three most important parameters are turbine location, tower material, and the scope of decommissioning. Trends in the wind energy industry show that these three factors are developing in a manner that increases decommissioning costs dramatically.
Olika typer av täckning och samodling och dess påverkan på antalet skadegörare i en Pak choi odling :
The purpose of this report is to examine the possibilities to decrease the number of insects and other pathogens in a crop of pak choi (Brassica rapa), grown with different types of cover and living mulches. Included in the report is a study of literature where amongst others, a summary on the vegetable pak choi and theories of living mulches and different kind of covers are to be found. To examine the amount of predators in the field, traps were used.
During the autumn 2002 the tests were conducted in Alnarp. The pak choi and the living mulches were planted/sawn at the same time, the different covers were also applied at this time. The total experiment was divided into six different treatments (plus control) of which three were with covers and three were with living mulches.
Once a week the number of leaves, the height and damages were read on ten of the plants from each parcel.
Effekten av höghöjdsvistelse på anaerob arbetsförmåga
Syftet med denna studie var att undersöka om vistelse på hög höjd påverkar den anaeroba arbetsförmågan. Sex aktiva universitetsstudenter, fyra män och två kvinnor, deltog frivilligt i studien. Expeditionen till Nepal varade i 40 dagar och under den perioden sov och vandrade försökspersonerna mellan 1400 och 5100 meter över havet. Före och efter expeditionen genomförde försökspersonerna ett anaerobt wingatetest där peak power, average power, minimum power and power drop uppmättes. Resultatet visade en signifikant sänkning av average power efter den genomförda expeditionen på hög höjd, med ett medelvärde på 8.44 ± 0,84 w/kg före expeditionen och 7.81 ± 0,87 w/kg efter expeditionen.
Livscykelkostnader för vindkraft : En jämförelse av fallstudier
I denna rapport har det utförts två fallstudier från två olika vindkraftsanläggningar och med hjälp av en utarbetad modell har livscykelkostnaderna jämförts för de två fallstudierna.Resultatet visade att livscykelkostnaden per producerad kWh sjunker allteftersom den installerade effekten blir högre.Kostnadsmodellen som utarbetats och tillämpats för resultaten har visat sig ha hög verifierbarhet då resultaten har varit jämförbara med litterära studier..