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681 Uppsatser om Soil moisture gradient - Sida 13 av 46

Driva tulpaner i näringslösning eller i jord :

The aim with this thesis is to make a comparison between forcing tulips in a hydroponic system and the forcing off tulips that have been planted in soil. The results are mostly based on interviews with six Dutch and one Swedish tulip forcer and the managing director at the Horticultural Research Centre, Proeftuin Zwaagdijke, in the Netherlands. There are benefits and disadvantages with both methods. Tulip bulbs planted in soil seem to get a brighter colour after forcing, compared with those forced ?in water?.

Konstruktion av patientsimulator för anestesimaskiner

A patient simulator for testing anaesthesia machines has been developed at Maquet Critical Care AB, to reduce costly and time-consuming experiments on animals. The device simulates human lungs regarding lung dynamics and volume, uptake of anaesthetic agents and the production of carbon dioxide, heat and moisture. Further demands on the simulator are durability and size; the device shall be compact enough to be moveable.The resulting simulator fulfils the requirements and enables better repeatability and ability to test extreme cases than experiments on animals do.Uptake of the anaesthetic agent is achieved in a active carbon filter and controlled by regulating the flow. The flow is created by a regenerative blower and controlled using a proportional valve. The uptake can be set by the user or by a simple uptake model modified to recursively handle changes in the concentration of anaesthetic agent.Carbon dioxide is fed into the system from a tank by a mass flow regulator.

Spetsbärförmåga hos betongpålar slagna i friktionsjord

The purpose of this study was to build a database for point-bearing piles in dense noncohesive soil, predominantly moraine. Further, the database was analysed and areas with difficult geotechnical conditions was identified.The database includes for point-bearing piles driven to refusal in moraine. Piles with mainly shaft friction have been excluded. Only concrete piles have been included. Geographically the database covers almost all geotechnical conditions of Sweden.

Tillsats av biokol till en svensk sandjord : effekter på lustgasavgång, kväveretention och andel vattenfyllda porer

In a column experiment the effect of three different biochars on nitrous gas emissions, nitrogenretention and water filled pore space (WFPS) were studied in a Swedish sandy soil, classified as aCryopsamment. Ammonium retention was positively correlated, while KCl-extractable ammoniumwas negatively correlated, with the specific area of the biochars. The question was raised whether thenegative correlation between extractable ammonium and biochar specific area reflects the amount ofammonium present in the soil or its extractability from the biochar, and whether methods forextracting soil mineral nitrogen, like KCl-extractions, have to be modified for application on biocharamended soils. There was a tendency of increased nitrate retention and KCl-extractable nitrate withbiochar and KCl-extractable nitrate was positively correlated with the specific area of the biochar. pHwas higher for all biochars compared with control, although the differences were not significant, andWFPS was lowered by biochar addition, significantly in one case.

Att gestalta en socialt hållbar begravningsplats

This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.

Water balance and nitrate leaching from arable land in a changed climate : a model study

This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.

Societetsparken i Norrtälje : nulägesanalys och utvecklingsförslag

The short term effect of phosphorus in sewage sludge was investigated to establish howmuch of this a farmer can grant him- or herself, if using sewage sludge as a phosphorusfertilizer. Possible differences in plant availability between sludge phosphorus precipitatedby iron, aluminum or calcium integrations were studied in a sandy soil at two pH levels.The sludges were analyzed using pot and incubation trials. As the intention was to investigategrowth limitation due to phosphorus deficiency, a soil with low phosphorus supplywas chosen as well as a low phosphorus application rate. Sludge corresponding to 12kg phosphorus per hectare was applied. Treatments fertilized by sludge were compared totreatments where 0, 6 and 12 kg phosphorus per hectare from mineral fertilizer was applied.Every treatment was replicated six times.

Helicobacter spp. i digestionskanalen hos svenska katter : en metodologisk och klinisk studie

Following the accident at the nuclear power plant in Chernobyl in 1986, great volumes of137Cs were distributed over large parts of the former Soviet Union and Europe. Over Scotland,radiocaesium was deposited as wet deposition. Due to the relatively long physical half-life of30 years, there are still measurable activity concentrations in the natural environment. Thisstudy was made on two organic soils, Knockandy Hill and Rora Moss, situated in the easternpart of the central highlands of Scotland. At these two sites, studies on migration and transferbetween soil and plants were conducted.

Epiphytic lichen flora in a boreal forest chronosequence

Epifytiska lavar utgör en viktig del av floran i den boreala zonen. Några miljövariabler är kända för att styra artrikedomen och artsammansättningen av epifytiska lavar på beståndsnivå, såsom träddiversitet, beståndsålder, fuktighet och trädens barkstruktur. Skogsbränder utgör den viktigaste störningen i boreala skogar men studier på brandeffekter på epifytiska lavar är mycket få. Detta arbete undersökte artrikedomen, diversiteten och artsammansättningen av epifytiska lavar på basala delar av björkar längs en gradient av 30 skogsbeklädda öar som skiljer sig i storlek och brandhistorik i den norra boreala zonen i Sverige. Målet med studien var att undersöka hur lavfloran påverkades av östorleken och miljövariablerna längs gradienten.

Identifiering av deponerat material i en deponi samt metodikförslag för upprättande av vattenbalans.

Högbytorp is Ragn-Sells? largest waste facility and it is located north of Stockholm. There is an old landfill still in use, but at the end of this year it will be closed. The waste deposited on the landfill can, through decomposition, give rise to a large amount of methane gas, which is an energy rich gas that can be used for heat and electricity production. To receive a relatively large amount of gas, the decomposition requires a high moisture content in the waste.

Föroreningsspridning via ledningsgravar : en fältstudie på Köpmanholmens industriområde

Sewer trenches usually contain material with a higher hydraulic conductivity then the adjacent soil. Thus they can serve as paths of preferential flow in a polluted area. Wastewater from factories can also leak from wastewater pipes and pollute the soil in the sewer trenches.The purpose of this project was to investigate pollutions in sewer trenches and in sewer pipes in the industrial area of Köpmanholmen, 20 km south of Örnsköldsvik in the north of Sweden. To make an estimation concerning the potential of transport of pollutions in sewer trenches, hydrological calculations were performed.Leakage to any greater extent did not seem to be a problem in the area. This is the case both for the concrete and the wooden pipes that have served as factory wastewater pipes.

Klimatskärmens funktion : En jämförande analys av projekterade nybyggnationer i Östra Salabacke, ur ett energi- samt fuktperspektiv

The design of the building envelope affects the energy consumption of a building. As the energy requirements for new buildings are becoming more demanding, the performance of the building envelope must be improved. Energy efficiency and durability are important attributes to consider.This report includes investigations of the building envelope, moisture and passive solar energy. It is based on the analysis of two different buildings with different designs. These buildings stand as reference for two of the companies who are working on a new, climate smart, residential area in Uppsala, Sweden.Studies and analyses on energy consumption and moisture transportation were made.

Kan markfuktighetskartor användas för att hitta skogsmark med hög bonitet? : ett gis-baserat försök med dtw-index och laserskannad övre höjd

The depth-to-water-index (DTW-index) is derived from digital elevation models (DEM) to map soil wetness, in terms of distance from soil surface to the ground water table. The aim of this GIS based study was to investigate the existence of a relationship between DTW-index and forest site productivity (SP). The belief of such an assumed relationship was based on knowledge that the ground water level is related to site properties that can either promote or impede tree growth. Data primarily comprised rasters of the Krycklan catchment in northern Sweden and depicted DTW-index and a laser scanned vegetation height. The 100th height percentile of each pixel in the vegetation raster was assumed to mirror the top-height, letting it act as a relative measure of SP within a delineated area of equal stand age.

Fältdiagnostik - ett verktyg för hållbar odling : Resultat och tillämpning av fältdiagnostiska metoder i planeringsstadiet av en ny trädgårdsblåbärsodling

I det här arbetet undersöks fältdiagnostiska metoder och användbarheten av dess resultat i planeringsstadiet av en ny trädgårdsblåbärsodling. Syftet är att fastställa vilken information som kan erhållas från en jordanalys, penetrometerundersökning och en jordmånsbeskrivning samt vilka rekommendationer från dessa undersökningar som vidare kan härledas till planeringen av en ny trädgårdsblåbärsodling. Som exempel och fallstudie används en bit åkermark i Ockelbo där provmätningarna ägde rum.Resultatet visar att fältundersökningar i kombination med en jordanalys gjord på laboratorium är ett bra verktyg för att utreda en jords grundläggande förutsättningar. Jordanalysen visar hur näringsinnehållet ser ut i jorden samt vilka eventuella näringsbrister eller näringsöverskott som finns. Penetrometerundersökningen informerar om eventuella markpackningar, som utgör eventuella hinder för t.ex.

Texturbestämning genom fält-, pipett- och hydrometermetoder :

Texture is an important soil property and accurate particle size analysis of soil texture is therefore crucial. There are a number of well-established and newly developed methods available for determining soil texture. In order to compare the results of these methods, the differences between them must be determined. The difficulties, problems and differences regarding texture class determination were examined through a study performed on forest soil samples. The study compared different methods (pipette, hydrometer and field methods) and two types of dispersing agents (sodium pyrophosphate and sodium hexametaphosphate (calgon)) commonly used for particle size analysis.

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