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681 Uppsatser om Soil moisture gradient - Sida 14 av 46
Fuktkvotens inverkan på oljeupptag och pigmentinträngning i tall (Pinus sylvestris L.) och gran (Picea abies L. Karst) vid impregnering med Linotechmetoden :
Wood has always been an important material for people, and it is used for many applications. As for example, fuel for cooking and heating houses, construction materials and for constructing means of transport. Since wood also is a material that with time biologically degrades due to activity by micro organisms and wood fungi it is important to find ways to protect and further lengthen the life span of the material when in service. One method is to decrease the amount of water in the material by impregnation with an hydrophobic oil. The Linotech method which uses only pure linseed oil is one such possible method.
The aim of this study was to investigate the possibility to at the same time impregnate and stain/colour wood samples of pine and spruce by using the Linotech method.
Kortsiktig fosforeffekt av avloppsslam : krukförsök i växthus där järn-, aluminium- respektive kalkfällt slam använts som fosforgödselmedel
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.
Varierad kaliumgödsling i potatis : en fältstudie i Hedemora
Variation in tuber quality within a single field was one of the motives for a pilot study
in Halland, in south-western Sweden conducted during 2002. Quality problems in potatoes have been increasing due to the aggregation of several small fields with different land use history into larger farm units, which are heterogeneous in soil properties and fertility. The study in Halland indicated that both the uniformity and the mean size of tubers may increase from site-specific K fertilization, whereas total yields may be unaffected. The results from this pilot-study with site-specific fertilization showed that tubers reached a more uniform quality and gave a more uniform mean size, while the total yield wasn't affected at all.
Site-specific K-fertilization has been applied for some years in Halland with good
results. The aim of this study was to test this technique in another potato growing
area.
Förändring av nitratläckage och växtproduktion från låglänt jordbruksmark vid en ny reglering av vattennivån i Mälaren
The water level of Lake Mälaren has been regulated since the 1940?s. A recentinvestigation suggests that the current regulation needs to be adjusted in order toprevent a decline in water level, salt water from infiltrating from Lake Saltsjön,and risk of floodings. In addition to these preventions, the new regulation couldpotentially effect the natural environment and agriculture practices in the lowlands that surround the lake. The new regulation proposal calls for an increase invariations in Mälaren?s water level during seasons, while the annual mean waterlevel will remain the same.
Problem i högt fuktbelastade byggnader : Riskbedömning med hjälp av WUFI
Många av Sveriges badhus byggda i slutet av 1900-talet börjar idag visa tecken på kraftiga fuktskador på grund av extrema inomhusklimat. Denna rapport förklarar den allmänna problematiken kring högt fuktbelastade byggnader och berör det fuktskadade badhuset Aquarena i Katrineholm. Extrem noggrannhet krävs vid montering av ångspärr i en konstruktion, speciellt vid högt invändigt fukttillskott. Optimal placering av fuktspärren i konstruktionens varmare del innebär att fukt aldrig tillåts kondensera och därmed minimeras risken för fuktskador och negativa konsekvenser. Verkligheten visar också att om kunskaper om fukt och fuktskador prioriteras redan i ett tidigt stadium under projektering kan många hundratusentals kronor sparas. Beräkningar av fukttransport har gjorts för tidigare ytterväggskonstruktion i Aquarena (den som drabbats av skador) och nybyggd ytterväggskonstruktion (nyframtagen till återuppbyggnaden) i datorprogrammet WUFI Pro 4.2 och analyserats i WUFI Bio 3.0.
Systemanalys av skogsbränsletransporter :
At the end of 70s and the beginning of 80s, 18 terminals was built and used for chipping wood residue from clear cuttings. Most of the terminals was terminated before the 2000s but with the high oil- and energy prices that we can see today there might be a place for these terminals again. The goal with the study was to analyze and compare economical differences between 5 different logistical systems, collected data was used with a set of formulas. The systems include long range transport of slash, chips and bundles. Three of the systems include transport by lorry to industry the last two includes a terminal with access to train transport.
Torkning av vallfrö :
In Sweden, grass is the single largest crop grown. Nearly 1 000 000 Ha grows on the
fields, this is primarily used as feed for livestock. To get a good seed, you need to
handle the crop carefully from planting to delivery. The part that I have been
interested in, is how to dry the harvested seed with out destroying the growth in the
small seed. This is very easily done if you aren?t careful during the drying period.
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.
Erfarenheter av utedrift med köttdjur i Sverige och Kanada :
Beef cattle wintering outdoors should be provided a shelter, e.g. a type of barn or corresponding. This type of production requires appropriate soil types and secured animal welfare. For example, a clean and dry resting place needs to be provided to the animals. To receive an exemption for buildings the farmer has to have something equivalent that provides an adequate shelter.
Pre-treatment of grain for ethanol production during storage
Ethanol for automotive purposes is an issue much debated and researchers disagree about the benefits of bioethanol. Converting energy-rich crops into ethanol suitable as motor fuel is a complex process and continuous development and improvements of processes and material used are important steps in the work of developing environmental friendly fuels. Grain is usually preserved by drying which consumes a lot of energy. Alternative storage of high-moisture grain in airtight storage systems reduce the energy required to produce bioethanol and studies have also shown that ethanol yields are increased more than 10% in ethanol fermentations of moist grain compared to dry. Airtight storage is often not perfectly airtight so biocontrol agents are necessary in order to preserve the grain.
Askans inverkan på beläggningstendensen i ett biobränsleeldat kraftvärmeverk och växtplatsens påverkan på askegenskaperna :
This report was written by Sofia Ericson and describes the degree thesis with the title: ?Connections between the growing site of bio fuel, the chemical composition of bio fuel ash and the deposit growth in a bio fuel fired boiler.? The purpose of this degree thesis was to avoid melted deposit growth in the bio fuel fired boiler at ENA Kraft in Enköping.
Potassium and sodium are known to lower the melting point of bio fuel ashes and are therefore not wanted in the trees in higher amounts than necessary for the growth. Silicon is also known to be important for the deposit growth but it is not possible to say in general if higher or lower contents of silicon is better. The relation between silicon and other chemical substances is more important than the total amount of silicon.
Försök med olika såmaskiner vid konventionell sådd och direktsådd
In this thesis, two studies with different drills were included. In one of the studies two drills were compared: Väderstad Rapid and Väderstad Spirit. In the other study various drills for direct drilling were compared.
The study with Rapid and Spirit was placed in two locations with different autumn tillage; one on ploughed land in Uppsala and one on cultivated land in Västerås, both with relatively high clay content. Rapid drills have a single disc coulter, while the Spirit drills have a double disc coulter. Various aspects were compared such as aggregate distribution, seed placement, emergence, crop yield and economic outcome.
Hur stor areal äldre skog lämplig för trakthyggesbruk finns det på Gotland 2013?
The degree project at hand investigates how large areas of older forest (80 plus years) suitable for clear cutting there is on the Swedish island of Gotland. Large areas of older forest on Gotland are situated on land with shallow soil depths which are economically uninteresting and often unsuitable for clear cutting forestry. Other forests hold big nature conservation values and should not, or cannot, be used for forestry purposes.
The survey is made as a GIS analysis based on the old but carefully made ?Brief forest inventory? (ÖSI) made in the 1980s and early 1990s. A sample from the inventory is combined with studies of orthophotos, satellite photos and other GIS layers that display estimated soil depth and nature conservation values.
Partly contrary to common belief, the survey shows that there are still large areas of older forest suitable for clear cutting forestry on the island.
Elektrisk skorstenständare
Between 1965 and 1974, the Swedish Parliament decided to build one million dwellings, called Million Program. The million program buildings were erected with new, untried design solutions, in a short range of time, and at low cost. The residential buildings from that time are now greatly in need of renovation. The municipal housing company, Gavlega?rdarna, renovates and improves the energy efficiency at some of it?s apartment buildings in the district Sa?tra, Ga?vle.
Människan i urskogen : vegetationshistoria i Hamra nationalpark under 2500 år
Pollen analysis of a peat core was used to reconstruct the last 2500 years of vegetation history, with focus on the impact of anthropogenic disturbance, in Hamra National Park, central Sweden. In addition, analysis of pollen in soil samples was performed in an attempt to locate ancient cultivation plots in the National Park.
The analysis of the peat core shows a development of the vegetation that can be divided into four stages of different degrees of human impact: A - virgin forest (c. 500 B.C.-A.D. 1300), B - grazed forest (c. A.D.