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763 Uppsatser om Soil carbon - Sida 23 av 51
Möjligheter till ökat utnyttjande av fosfor genom grödan med mineralgödselmedel
The objective of this thesis is to explore opportunities to enhance the phosphorus use efficiencyof inorganic fertilizers in crop production, with techniques available today and in thefuture. Phosphorus is a finite resource of declining quality; therefore a phosphorus use efficiencyin crop production of only 15-30 % is unacceptable. The main reason for low efficiencyis the retention by Ca and Mg in calcareous soils and Fe and Al in non-calcareoussoils. Due to the low mobility of phosphorus, plant uptake is mainly dependent on root growthrather than diffusion. Therefore, measurements need to be taken that benefit contact betweenroot and fertilizer, before fertilizer phosphorus becomes unavailable to the plant.
Miljöarkeologi i Umeå stads hamn och slagfältsarkeologi på Krutbrånet : Två fallstudier inom historisk arkeologi i Umeås 1800-tal
This master thesis deals with two case studies in environmental archaeology and battlefield archaeology focusing on two major events in the late history of the Swedish coastal town Umeå and its nearby village Sävar. Established in the early 1600's, Umeå was known for its export of timber and import of cereals. The town has suffered from numerous fires, the fire in 1888 being the most devastating. Few written records of the town remain from before the 1900's. The latest war in Sweden's history is documented in historical sources and took place at Krutbrånet, Sävar where the Swedish troops suffered defeat against the russian forces in 1809.
Undersökningsmetodik för klorerade lösningsmedel i marken
Chlorinated solvent are volatile organic substances that can be harmful for humans and for the environment. Examples of common chlorinated solvents are perchloroethene, PCE, and trichloroethene, TCE. Chlorinated solvents appear as contaminants in soils primarily where they have been used as washing fluids in dry-cleaning facilities or as degreasers in metal industries. Chlorinated solvents are DNAPLs (dense non-aqueous phase liquids), which means that they are not easily dissolved in water and that they sink to the bottom of the aquifer. Adsorption to soils is low so chlorinated solvents are mobile in soils.
Ett kandidatexamensarbete inom lättviktskonstruktioner .
Due to recent legal enactments regarding carbon dioxide emissions, the car industry is facing higher demands. An effective way of reducing these emissions is to minimize the weight of the vehicle. This thesis constitutes a feasibility study on whether or not it is applicable for the car industry to utilize an inner floor structure comprising composite materials. The principal was the projectSåNätt, in which the main participant was Volvo Cars Corp. In consultation with a reference group, consisting of delegates from the industry and KTH, a specification of requirements was produced.
Förekomst av törskate (Cronartium flaccidum, Peridermium pini) på tall (Pinus sylvestris) i relation till markfuktighet och fältskikt : en studie om 2000-talets törskateepidemi i norra Sverige
Resin-top disease is a rust fungi that occurs both as a host alternating form, Cronartium flaccidum G. Winter., and as a non-host alternating form, Peridermium pini Pers. The host alternating form can use a variety of hosts but the most commonly used species in the boreal forest is Melampyrum sylvaticum. In Scandinavia the Resin-top disease infect Scots pine, Pinus sylvestris L. The fungus infects the needles through the stomata and then grows through the branch to the stem where it strangulates the vessels transporting water and nutrition to the treetop, which kills the top.
Inventering av Maskinisten 6 och Valhall 2 på LEAX fastigheter i Köping enligt MIFO fas 1
This study is a degree project in environmental engineering at Mälardalens university. Its purpose has been to perform a risk assessment on whether or not any contaminations are present in the soil at two properties in Köping. The assessment was to be done accordingly to a method that has been set up by The Swedish Environmental Protection Agency (Naturvårdsverket). The method for investigation of contaminated sites is called MIFO. MIFO consists of two stages.
Livscykelanalys: Pelletspanna från kvänum energi
This study will identify the environmental impact in terms of carbon dioxide for a boiler house on behalf of Kvänum energi. The boiler central consists of a main building, which in turn contains multiple components such as boilers, pipes, etc, the boiler central uses pellets fuel. It also includes a silo and an ash container. The total weight of the boiler is about 63 tons. Each boiler has an output of 600 kW; the central includes three boilers with room for a fourth if necessary.
Short-term responses of the field layer vegetation in a south Swedish deciduous forest after establishment of wild boars (Sus scrofa)
Inside the south Swedish national park Dalby Söderskog, wild boars (Sus scrofa L.) have been visiting since 2010. The presence of wild boars has earlier been proven to
impact both soil and vegetation characteristics, both positively and negatively. Still, there is a lack of knowledge regarding the rooting effect on the vegetation in
deciduous forest within the native range. In this study, I have compared the field vegetation collected before and after the invasion of wild boars in 74 permanent experimental plots. More specifically, the study aimed to qualify the effect of wild boar rooting on cover ratio, species richness and species composition in a temperate
deciduous forest.
Hållbara uppvärmningsalternativ för Grinda Wärdshus : En studie om uppvärmning med pellets och flis
This report is a bachelor's thesis of two students from the Energy and Environment degree at KTH Stockholm. Grinda is an island situated Stockholm archipelago. Skärgårdsstiftelsen is landowners and manages the area. Grinda Wärdshus, a guest house located in the island, currently uses an oil-fired boiler as a heating system. The aim of this thesis is to investigate whether wood chips or pellets is, from a sustainability standpoint, a suitable heating method for the guest house.
Historiska emissioner av bly och arsenik till luft från Åfors Glasbruk och deras konsekvenser för miljön.
Åfors glasswork was a company which started in 1876 and closed in 2012 due to the bad economical situation in the company. After its closure, the glasswork left behind contaminated soil with different concentrations of heavy metals such as, arsenic from arsenic trioxide, a chemical used to remove bubbles during the melting of glass, and lead oxide, a chemical used in the production of crystal glass. Crystal glass?s production occurred under 1921-1971, but emissions of lead into the air from Åfors glasswork continued until 2011, because of the artist Bertil Valliens? artglas was made in Åfors glasswork from 1970?s and onwards.The aim of this study was to estimate how much lead (Pb) and arsenic (As) that were released by Åfors Glasswork into the atmosphere during the operational period of the glasswork in comparison with how much of lead and arsenic were purchased for the company. Added to the assistance of the data from National Archives the variations in the activities of Åfors glasswork could be shown.
Kvalitetssäkring av markberednings- och planteringsuppföljning hos SCA Skog AB Jämtlands skogsförvaltning :
Quality assurance means to systematically work for better understanding of the customers needs, demands and expectations. The goal for this study was to investigate how quality can be assured in the job follow up that is made by forestry contractors after soil scarification and planting. The study consisted of a description over the current follow up process at SCA forest AB Jämtlands forest administration, analysis of current follow up situation and an investigation of follow up process made by contractors in other line of business.
The first step was a statistical comparison where the own follow up made by contractors were compared with follow up made by SCA them selves over 100 stands. Two soil scarification contractors and two planting contractors carried out the silvicultural measures. The results showed that significant differences between a number of quality factors measured, for example number of approved plants or approved scarification points, average score on stand and number of totally planted plants.
Anlockning och gnag av snytbaggar (Hylobius sp.) : effekt av plantstorlek och behandling med metyljasmonat
Two field experiments were conducted in central Sweden in order to: 1) Determine a relationship between the number of approaching pine weevils (Hylobius sp.) and the number of attacks by pine weevils, in relation to the size of seedlings of Scots pine (Pinus sylvestris). 2) Determine if application of methyljasmonate (MJ) on seedlings of Scots pine will result in higher resistance towards attacks by pine weevils and/or have any effect on the number of approaching pine weevils. The field experiments were designed with two separate parts in close vicinity on the same clear cuttings: a) pitfall traps placed in patches of scarified soil that caught approaching pine weevils at 2.5 cm from the bait, which consisted of different sized seedlings of Scots pine some of which were subjected to application of MJ and b) the same type of seedlings planted out in patches of scarified soil.
The first field experiment was conducted on a 1-year old clear cutting outside Uppsala in east central Sweden and the trapping part of the experiment consisted of 8 blocks with 6 treatments: 1) control, 2) small over-wintered seedling, 3) medium sized seedling, 4) medium sized seedling treated with 0.5 ml 100 mmol MJ 4 days prior to start of experiment, 5) large seedling, 6) vial with 9.5 ml of ?-pinene. The trapping experiment lasted for 6 weeks in the early summer.
Föroreningstransport i grundvatten : En modelljämförelse
This thesis compares different methods for risk assessment of a creosote contaminated site in Vansbro, Dalarna. In a complementary study the importance of using representative data for calibration and validation of stationary groundwater models is discussed. The time dependency between surface water levels and groundwater levels on the site in Vansbro is evaluated by step response analysis. The results show that the groundwater levels reflect only long-term variation in the surface water levels. Hence the use of such long-term means for calibration and validation of the stationary groundwater models is the only theoretically defendable alternative.As a first step in the comparison of risk assessment methods the degree of contamination is evaluated on the basis of generic guideline values for contaminated soils, developed by the Swedish Environmental Protection Agency.
Hackerör på Sydsvenska höglandet : vad skiljer röjningsröseområden från celtic fields, stensträngsområden och bandparcellområden?
From the pre-Roman and Roman Iron Age, a number of different fossil agrarian landscapes can be found in southern Sweden - clearance cairn areas, celtic fields, stone-wall complexes and geometrically laid-out strip fields. With two different comparative analyses, this paper tries to explain some of the differences between clearance cairn systems and the other fossil field systemsThe shape of the early Iron Age agrarian landscape varies between different provinces of southern Sweden. At Gotland, celtic field systems were laid-out before 500 BC. In Småland at the same time, areas with clearance cairns were created. How can the difference be explained? The different physical appearance of clearance cairn areas and celtic fields can be explained by the different ways to handle the ard in till and in sandy soil.
Kartläggning av energiförluster : gällande klimatskal och ventilation för Stora Enso Timbers Pelletsfabrik i Grums
Due to recent legal enactments regarding carbon dioxide emissions, the car industry is facing higher demands. An effective way of reducing these emissions is to minimize the weight of the vehicle. This thesis constitutes a feasibility study on whether or not it is applicable for the car industry to utilize an inner floor structure comprising composite materials. The principal was the projectSåNätt, in which the main participant was Volvo Cars Corp. In consultation with a reference group, consisting of delegates from the industry and KTH, a specification of requirements was produced.