Sökresultat:
1781 Uppsatser om Amount blocking - Sida 13 av 119
Effekt av olika kvävegödselmedel på utvecklingen av klumprotsjuka i salladskål (Brassica rapa ssp. pekinensis)
The price trend on rapeseed the latest years has led to an increasing interest to grow the crop among many farmers in Sweden. The price trend has resulted in more than a doubling of the oilseed area since the early 2000s. For many farmers it is an advantage to increase cultivation of rapeseed because of the high proportion of cereals in the crop rotation on many farms, but it is not just benefits. The risk of the fields being infected by clubroot increases within frequent rapeseed cultivation and it often leads to subtantial economic losses. Clubroot is caused by Plasmodiophora brassicae that is a soilborne pathogen in genus Protozoa and its resting spores can be found in the soil for up to 18 years.
Effekten av kvävegödsling på gasproduktionen vintertid i boreala sjöar
To investigate effects of nitrogen on in-lake CO2 and CH4 production during winter, three pair of lakes was subject for a fertilizing experiment in which one lake in each pair was fertilized with nitric acid (HNO3) directly into the water column in the summer of 2012. The lakes in each pair are assumed to be morphologically, hydrologically and biologically similar, that is, the non-fertilized lakes are considered references. The pairs do differ in one major way by being progressively less humic, going from around 25 mg/l to 10 mg/l DOC. Sampling and analysis was carried out at the end of the frozen period in 2013. Results show a significantly higher concentration of both CO2 (p<0,001) and CH4 (?=0,1, p=0,053) between impact and reference sites in the two less humic pairs.
Forsmark 3 ?Ett Framtida Biobränslekraftverk?
Recent turmoil surrounding nuclear power as an energy source, especially since the accidentat Fukushima, has largely contributed to the debate of whether or not nuclear power should beused as an energy source. This study has examined the economic feasibility of replacingForsmark?s 3rd nuclear reactor with a bio fueled power plant, and find out how this could bedone.The power generation that has to be replaced is equal to 1170 MWe. To replace this, 6 largescaleCFB-boilers, each providing over 200 MWe, were necessary. In addition to this, eachboiler required their respective turbine sets, comprising one high-pressure-, and one lowpressureturbine with intermediate reheating capacities.Based on this, a rankine-cycle was modeled using the software EES, to be able to calculatethe total heat required in the power plant.
Självförsörjande elgenerering : Kan Orust bli självförsörjande på förnybar el?
Orust Kretsloppsakademi is a nonprofit organisation, with a goal of annually generate the same amount of electrical energy that is consumed. Orust is an island on the west coast of Sweden, north of Gothenburg. The population of 15 000 reaches 40 000 during summer, due to the large amount of vacationer. The total electricity demand is 174 GWh a year with a maximum power need of 32 MW. This report presents an analysis for the plausibility of their plan and from a power system stability perspective, the effects on the electrical grid.The conclusion is that the restraints for development of power generation from wind, solar and wave generation, are the power systems capability to transfer power, primarily in the transformers of the grid.
Raä 977 - En lokal och tre aktivitetsytor. : En tvärvetenskaplig undersökning av Raä 977 vid Vojmsjön i Vilhelmina socken
This candidate thesis concerns the ?all but forgotten? material from the bronze age site named ?Raä 977, Hansbo 1:3, Vojmsjön, Vilhelmina?. During 1975-76, an archaeological dig was carried out by Västerbottens museum led by Ulla Walukiewich in an attempt to preserve the information the site held, before it was destroyed by the erosion brought on by the recently regulated sea ?Vojm? (Vojmsjön). The archaeological dig yielded a stunning amount of finds, samples and information previously unknown.
Skolan i universum - att förklara det ofattbara : Astronomiundervisningen i skolan på 1900-talet
This is a study in how astronomy has been taught and is being taught in Swedish schools from 1905 to this date with an emphasis on the latest 30 years. It concerns the regulations and methodical recommendations/curricula for Swedish junior high school/Swedish Comprehensive school for the years 1905, 1933, 1955, 1958, 1962, 1969, 1980 and 1994. The matter of integrating astronomy with other subjects and different methodical approaches is also considered. The problem with textbooks written only for one subject when the teacher tries to integrate subjects is emphasised.Physics textbook analysis shows that astronomy teaching has over the years developed, from being based on observations, to become more and more theoretical. It also shows that the amount of practical exercises has been fairly constant in physics textbooks during the seventies end eighties but now in the nineties varies a lot from textbook to textbook. The amount of liberty the textbook gives the pupil in finding knowledge and answers himself in the practical parts of astronomy was at its lowest during the seventies.
Implementering av en PSS i Trängslets kraftstation
The purpose of this master thesis is to implement and validate a Power System Stabilizer (PSS) to a generator at Trängslet hydropower station in Dalarna, Sweden. Problems with local rotor oscillations can occur at the hydropower station when power is transferred on a new power line (130 kV) from Northern to Southern part of Dalarna. To ensure good operation properties on this power line Fortum Generation AB and Fortum Distribution AB wants to activate a PSS on a generator.There have been investigations in which situations and what equipment that contributes to rotor oscillations. When this is known the PSS is tuned to damp these oscillations by choosing a good set of parameters. The most important parameters for good performance are to choose amount of gain and phase compensation.
Rening av avloppsvatten efter skärprocess
ABB I-R Waterjet Systems combines the robotics and motion expertise of ABB Flexible Automation with high-pressure intensifier/pumping technology from Ingersoll-Rand to provide and continue to develop innovative waterjet cutting systems for global markets. The purpose of this assignment is to develop a process water purifier. The purifier should be applicable as an option to ABB I-R?s production cell Cutting-Box. At first hand the process water should be purified well enough to let out in the municipal sewage system, but the ultimate solution is purifying the process water to the range that recycling is possible.
Miljöarbete inom den civila luftfarten
The main environmental problem for aviation is the great amount of exhaust gases, mainly nitrogen oxides, carbon monoxide, carbon dioxide and hydrocarbons - mostly "greenhouse gases" leading to climate changes. I decided to sort out what is being done to decrease these problems and what regulations there are concerning air pollution by the means of searching the internet and using publications from aviation authorities for current figures. I chose to scrutinize authorities on political, authority and company level, resulting in summarizing the work of UN and EU respectively, ICAO (International Civil Aviation Organization), JAA (Joint Aviation Authorities) and LFV (Swedish Civil Aviation Authority), and finally SAS, representing the airline companies. Conclusion that I have drawn are thatthere are regulations for air pollution, written down in ICAO's Annex 16, that are to be followed. Secondly, LFV are environmentally controlling their nineteen airports and since economy is an important reason for not giving priority to environmental issues in aviation emission charge and noise charge are added to the landing fees.
Hållbarhetsaspekter på tillvaratagande av spillvärme i borrhålslager- ur ett företags- och samhällsperspektiv
The objective of this study is to examine the sustainability of recovering industrial wasteheat from several heat sources in a foundry constructed in a plant belonging to ITT Waterand Wastewater in Emmaboda, Sweden. A triple bottom line perspective will be appliedto achieve this objective. The triple bottom line approach takes into account ecologicaland social performance in addition to financial performance. The technology forrecovering the waste heat is a Borehole Thermal Energy Storage (BTES) which is aconstruction consisting of 140 vertical boreholes, 150 meters deep with an internal spaceof four meters.The calculated amount of energy for storage is approximately 3800 MWh annually. Ofthis amount 2500 MWh are expected to be utilized, while storage losses accounts for theremaining part.
Betydelsen av skogsbruksplaner som verktyg vid anskaffning av virke
Forest management plans have been sold to private forest owners by wood supplying companies for a long time. These plans are considered to be effi-cient tools to identify measures and wood volumes, and are simply a starting point for discussions between private forest owners and round wood pur-chasers. However, large variations are observed between different purchas-ers, in their usage of the plans.
The purpose of this report is to identify to what extent a forest management plan can promote an increase in the amount of wood which a round wood purchaser can obtain and to find differences in the way of using the plans between different wood purchasers. Furthermore, the purpose is also to ana-lyse if varying owner structures can be underlie variations in the selling of forest management plans.
Qualitative interviews with nine of Stora Enso?s round wood purchasers were performed.
Sveriges potential för elproduktion från takmonterade solceller : Teoretisk, teknisk och ekonomisk analys
The Swedish potential of electricity production from roof mounted solar panels has been determined in three steps: accessing the existing roof top areas, simulating the amount of electricity solar panels can produce on these areas and finally analyzing how large the necessary economical change is to make the solar cells profitable.The total existing amount of roof top areas are 319 square kilometers and the area distribution follows the distribution of people. This leads to an installed power of 47,9 GW which are expected to produce 49,0 TWh electricity per year. If the quality of the electricity is prioritized the highest the power is reduced to 3,7 GW, generating 3,8 TWh yearly, but if the hosting capacity is calculated from Sweden?s total electricity need, the capacity is 42 TWh per year.Today, solar panels are not profitable in Sweden for houses, even though there is a subsidy of 35 % of the investment costs, discounted in 25 years. The profitability is calculated with a cost of capital of 5 %, a price on electricity of 1 SEK/kWh and an investment cost of 20 SEK/Wp.
Hunter demography, trends and correlates of hunting participation in Sweden
The concerning issue of declining number of hunters in North America is also apparent in Europe and Sweden. When the bulk of research found on human dimensions and hunting participation has almost exclusively been done in the United States, this report seeks to add to the needed knowledge on a national level focusing on the causes of hunter declines related to social factors within Sweden. Using hunter data reaching from commune, county to National level, this report describes the correlation between a number of variables and the hunting participation in Sweden.The typical Swedish hunter lives in an area with low population density, the person usually has higher education, the living situation is stable with no recent moving and there is relatively good access to forest land. Persons with weaker connection to the Swedish culture such as foreign citizens, people with foreign background and people born outside ?the Nordic countries? are less likely to start hunt or participate in hunting.A strong relationship was found between the favorite game, moose (Alces alces), and the amount of hunters participating in the hunting.
Flockning och förtjockning i High-Rate-förtjockare ? en jämförelse med konventionell förtjockarteknik och lamellsedimentering.
In the process laboratory of Metso minerals (Sala) AB, continuous tests have been made with a laboratory unit High-Rate thickener. The tests are made in order to compare three methods of thickening techniques of suspended solids. The three techniques are High-Rate thickening, conventional thickening and lamella thickening. The High-Rate and the conventional trials are based on a continuous method, while the lamella thickener is based on batch trials. Because the lamella thickener is based on batch trials and there were some optimization problems with the adding point of the flocculant at the continuous trials, it was not feasible to compare the lamella thickener with the other two thickener types.
Åkerböna i samodling med vårvete som helgrödesensilage till mjölkkor :
The aim of this undergraduate thesis was to formulate advices regarding the use of field beans, cultivated together with spring wheat, as whole-crop silage in feeding to dairy cows. In the thesis, optimal harvest time of the field bean/spring wheat crop, as well as the feeding value and the fermentation quality, was studied.
On the research station at Röbäcksdalen in Umeå field bean/spring wheat (70 % respective 30 % of normal seed rate for the pure crop) and pea/oat (70/30) was grown in field experiments both 2002 and 2003. The following year, 2004, the pea/oat crop was excluded and instead field bean and spring wheat was cultivated in three different mixed ratios (field bean/spring wheat; 100:0, 70:30, 30:70). Every year the crops were harvested at four different development stages and the green forages were used in ensiling experiments.