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985 Uppsatser om Aquatic plant planting in wetlands - Sida 48 av 66
Temperaturens och den fotosyntetiskt aktiva strålningens effekt på avgång och inlagring av kol på en dikad torvjord
The decomposition of organic carbon in drained peat soils is a major source of carbon di-oxide in Sweden. A big part of these drained peat soils are used in agriculture and it is a big challenge to slow down their decomposition. It has earlier been thought that less tilling and higher water table levels would decrease the activity of soil microbes and thereby the decomposition, but recent experiments has showed that this has little or no effect.
In this bachelor thesis a field experiment was made on drained peat soil with ley, outside Björklinge, Uppsala municipality, Sweden. The experiment was carried out in May 2011. The objective was to develop a method to examine how the net exchange of carbon diox-ide from plant covered peat soil is affected by temperature and photosynthetically active radiation (PAR).
Flödesmätning i vattenkraftverk : Studie av alternativa mätmetoder
Flow measurement is one of the greatest challenges in order to calculate efficiency in hydropower. Most hydropower plants in Sweden use differential pressure methods for flow measurement. These methods are dependent on constant conditions in the waterways. A change in these conditions, like turbine improvements, prevents differential pressure methods to verify efficiency improvements. Since efficiency improvements can?t be verified by one measurement system, another method, which isn?t affected by changing conditions, can be used.
Energisystem med utnyttjande av restprodukter för gödsling av Salixodling för energiproduktion : studier av kretslopprojektet i Enköping och dess applicering på en kommun i Ryssland.
The purpose of this work is to study a circulation project in Enköping municipality, where the society?s rest products are used to make beneficial products. In Enköping the rest products from waste treatment plants and private sewers are used to fertilize and irrigate Salix plantations that later are harvested and burned at the local combined heating and power plant, ENA Energy AB, to produce electricity and heat. Possibilities to apply this kind of project ona municipality in Russia are also explored.Guryevsk municipality in Kaliningrad region was chosen since there is a need to improve energy systems and reduce emissions to water and air. This municipality strives to become environmentally friendly.
Restvärmeåteranvändning från absorptionsvärmepumpar : en kartläggning av möjligheter och begränsningar vid Vattenfall Värme Uppsala Block 5
Vattenfall district Heating power plant in Uppsala produces district cooling with absorption heat pumps which leads to a large amount of waste heat that has to be cooled with evaporative cooling towers. The Environmental Court has ordered Vattenfall to survey the possibilities to recover the heat, which is the focus of this thesis.The study begins with an overview of the system, and conditions and limitations for waste heat recovery is examined. In the next step alternatives to recycle the heat is evaluated, either by direct recovering or by upgrading.First, the technical possibility of each alternative is discussed, and then the operation time and the amount of recovered heat is calculated. Those alternatives which are possible are brought further to an economic analysis.The cost of investment for each alternative constitutes the basis for a present value analysis. The results are put together in a table where the total amount of recovered heat is compared with the present value for the different alternatives.
Etablering av höstvete med reducerad jordbearbetning :
The payment for produced grain is constantly going down in price. It is important for farmers to become more effective in cultivating more land in a shorter time perspective. At the same time we have to calculate with the risk of getting lowered subsidies from the EU. This is why I would like to find out the possibilities for establishing winter wheat without ploughing.
I hope to find a difference in the number of plants due to different soil preparations. With this experiment I expect to find out whether I can establish winter wheat at a lower cost, with the same numbers of plants per square meter.
Individual identification in pigs using microchips
Individual identification of pigs could be used in commercial herds for production monitoring, disease monitoring and breeding evaluation. This study investigates the possibility of using microchips designed for dogs and cats to identify individual pigs from birth, through rearing to carcass at the slaughter plant. Two different sizes of microchips, and two different ages of the pigs at injection were tested. Castrates and gilts from ten litters were evenly distributed between chip sizes and injection ages. All pigs were identity marked with both electronic ear tags and injected with microchips.
Spridningsmönster och potentiella spridningsytor hos invasionsarten stor bockrot (Pimpinella major) i Tullgarns naturvårdsområde : ett framtida problem för områdets diversitet?
An organism that is transferred from one place to another, causing major problems to the native species is termed invasive. Its natural dispersal across barriers may have been prevented but as man has turned able to rapidly travel all over the world organisms are brought to sites where they were never before observed. Adding the increasing global warming organisms may find it necessary to move around even further. This might cause major disturbance to the biological diversity, and hybridization and homogenization is one of many scenarios that could disturb the native diversity. In Sweden more that 2/3 of all alien plant species have been introduced to disturbed areas and the major introduction mechanism is gardening.
Grovkrossning av stubbar : en produktivitetsstudie
The Swedish parliament has decided that Sweden should increase its usage of renewable fuel sources to a level of 50% of the total energy consumption in Sweden by the year 2020. One way to reach that goal may be to increase the usage of stumps as a bio-fuel. In Sweden stump harvesting is possible on about 5-10% of the total harvested area and thus contribute with 1,3 - 2,6 TWh per year. An increase stump harvest doesn't come without its drawbacks for the environment. When harvesting stumps a tracked excavator is used to pry the stumps from the ground and then cut the stumps into smaller pieces.
GIS och statistik vid dräneringsområdesvis kväveläckagebeskrivning i Halland
The last decades have shown increased nitrogen leeching from soil to water recipients. This is inSweden mainly due to over-manuring of agriculture land, effectivization of drainage systems and thedeclining extent of wetlands. The accumulated amount of nitrogen in water doesn?t only make itunsuitable for use by humans and cattle, but also decreases the biological diversity as well as negativelyaffect tourism and fish industry. In the most severe cases shallow maritime grounds can be completelydepleted of oxygen due to decomposition of the increased amount algae and plankton growth.This study have the aim to describe and quantify the nitrogen leeching from the Genevad drainagebasin, located in southern Halland, Sweden.
Utveckling av ett användbart IT-stöd : för att stödja operativa arbetsrutiner
Nuclear power production carries potential risks both for the environment and for the work force. Different safety measures are employed and they stem from local rules as well as from regulatory authorities. This work describes the development of a safety promoting tool at Forsmark Power Plant, one of Sweden?s three Nuclear power plants. We describe the development of a computer based system for Pre-Job Briefing and Post-Job Debriefing.
En jämförelse mellan får- och nötkreatursbetade hagmarker med avseende på populationsstorlek samt artsammansättning hos dagfjärilar och örter
Many of Europe?s day-living butterflies have shown decreasing populations during the last decades and many species are threatened. Many butterflies are dependent on managed semi-natural grasslands because of their richness in nectar sources and host plants for the butterfly larva. Swedish pastures are mostly managed through grazing. The number of cattle in Sweden have been decreasing while the number of sheep in the country increased by 30%.
Markberedning i blockrik terräng : en jämförelse mellan grävmaskin och harv
Runt 70 % av skogsföryngringen i Sverige utförs genom plantering efter maskinell markberedning. På de flesta marker uppnås tillräckligt antal godkända planteringspunkter men vid riklig förekomst av block som hindrar eller stör markberedningsaggregatet blir det problem. En annan komplikation i samband med markberedning på blockrik mark är att där till följd av tidigare brukningshistorik och ålder ofta finns rikligt med död ved i form av lågor. Vid markberedning ska hänsyn tas till att dessa inte skadas, eftersom död ved är viktig för den biologiska mångfalden.
Huvudsyftet med denna studie var att jämföra resultatet av markberedning med grävmaskin respektive harv på blockrik mark, vad gäller planteringspunkter och skador på lågor. Även användbara planteringspunkter innan utförd markberedning samt skador på lågor orsakade av maskiner i samband med avverkningen studerades.
Kunskapsläge och attityder till vildsvin (Sus scrofa) och dess förvaltning i Sverige
The wild boar (Sus scrofa) is since its recent establishment and increasing density a controversial species in Sweden. But the attitudes towards the wild boar are poorly documented so far. To improve this knowledge, a questionnaire was sent out to chosen people (n=400) connected to the management and/or land use activities.
The study got 162 replies (reply frequency 40,5%) and the results show varying attitude trends among organizations and individuals, with some aspects coherent within groups and some not. Farmers and their organization showed the most negative attitudes towards wild boars, which was expected due to the practical and economic problems they suffer from this species. People involved with forestry were more positive to wild boars, probably because the species does not affect forest growth etc severely, and may even promote plant establishment by the rooting.
Installation av la?glutande fingaller fo?r fra?mjande av ekologisk funktion i vattenkraftverk : En fallstudie av ett kraftverk i Umea?lven
The purpose of this bachelor degree thesis is to analyze technical issues associated with an implementation of a low sloping trash rack with narrow spacing. A hydropower plant in Umea?lven was used as a case study. The basis for the study was a model where trash racks were dimensioned for inclinations between 25 and 45 degrees. Corresponding head loss, durability and water speed through the rack were then determined for each inclination.
Inventering och karakterisering av brännbart avfall i
Norrköpingsregionen
The purpose of this study has been to make an inventory of combustible waste in the region around Norrköping and to investigate the composition of domestic waste, industrial waste and two different types of sludge. The work was performed at the request of Norrköping Miljö & Energi, due to the planning of an incineration plant. The inventory of the waste was performed through inspection of environmental impact reports, from waste disposal plants in a number of local government areas in the region. The quantities were also compared to another inventory, carried out in a different way. The characterisation of the wastes was compared to the fuel specification determined by Norrköping Miljö & Energi.