Sök:

Sökresultat:

1020 Uppsatser om Soil parameters - Sida 47 av 68

Do retention trees affect the composition of ectomycorrhizal fungi? : a comparison between clear-cuts areas with and without retention trees in pine forests

Under det senaste årshundradet har de svenska skogarna genomgått en omfattande förvandling, från mer eller mindre naturligt dynamiska till hårt brukade skogar bestående av monokulturer av tall eller gran. Denna förändring har lett till en minskning av den biologiska mångfalden, att många arter som är beroende av skog har minskat radikalt och hotas av utrotning. Som ett försök att främja variation, biologisk mångfald i allmänhet och förhindra minskningen av rödlistade skogsarter introducerades i början av 90-talet en viss naturvårdshänsyn i brukade skogar. I den här studien utvärderas den påverkan som kalavverkning har och den betydelse hänsynsträd har på artsammansättningen och förekomsten av ektomykorrhizasvampar (EMF) under de första 20 åren efter kalavverkning. Studien utfördes genom extrahering och identifiering av svamp-DNA från jordprover tagna på kalavverkade ytor, nära hänsynsträd och i gammal skog i ett begränsat geografiskt område i norra Sverige.

Genetic study of cryptorchidism in Swedish Icelandic and Standardbred horses

Samodling är en odlingsmetod som kan användas för att förbättra dagens odlingssystem. Metoden innebär att två eller flera kulturer odlas tillsammans under en större del av växtsäsongen. Samodling kan användas på flera olika sätt för att förbättra odlingsförhållandena för antingen huvudgrödan eller hela odlingen. Den har en bevisad effekt på olika skadegörare och kan minska angreppen i odlingen. Samodling kan även användas för att minska ogrässpridningen, förbättra mikroklimatet, samt öka antalet maskar och naturliga fiender i odlingen.

Marknaden för skogsvårdstjänster : en undersökning bland privata markägare inom en region i Värmland

This work broadly illuminates the conditions for increasing the commissions of forestry services within the whole, or parts of, the western regions of Stora Enso?s operating area. Through a questionnaire, a survey was made examining whether the owners of the forests themselves do the forestry on their woodlands. This foremost concerns the pre-commercial thinning, but also planting and soil scarification. The survey also shows who are buying the most part of their forestry services and who are carrying it out themselves.

Vattensork och åkersork - skadegörare i svensk fruktodling

There are two species of voles that cause damage in Swedish fruit production: the water vole (Arvicola terrestris) and the field vole (Microtus agrestis). Both species make the most damage during the winter season. The water vole makes subterranean burrows and cause serious damage by gnawing on the tree roots. The field vole seldom makes burrows and gnaws the bark at the base of the tree trunk. In recent years there have been several reports about increasing vole damage.

Modellbaserad temperaturregleringav partikelfiltrets regenereringsprocess

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Försöksmetod för automatisering av kvalitetssäkring av SKB

Within all industries, there is a change in working time required; this also includes the construction sector. However, the way construction sectors are differentiated is by not having been given the opportunity to be practiced or tested.  The aim of this thesis that we have done in collaboration with the Concrete Industry was to investigate the possibility of developing an automated method for quality assurance of SKB at the site. The idea is to make the O-funnel to be more utilized and therefore ensuring that the appropriate concrete quality is provided which eventually would lead to a better development in the production process.The project has involved theoretical work and laboratory experiments. The theoretical work gave us a good foundation at the beginning of the project. After gathering the information and material, the laboratory experiments began by SCC in their laboratory in Hammarby. The collected data from the various laboratory tests formed the foundation for trying to relate measurements for consistency of SCC with each other and therefore find out how measurements from O-funnel varies with different concrete mixtures.

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.

ICC-profilers funktionalitet vid byte av tryckfärgskvalitet

This degree theme work aims to evaluate the present ICC-profile and printing ink of Dalarnas Tidningar AB. The companyhas changed printing ink quality and wants to evaluate how the present ICC-profile work with the new printingink. Four different ICC-profiles were included in the comparison.One test printing was accomplished with two different separations. Two new ICC-profile was created, as a comparingmaterial. An densitometer was used to measure the technical parameters of the printing.

Gaffelbandsskador : en retrospektiv studie av konservativt behandlade hästar

Suspensory ligament injuries are a common cause of lameness among sport horses. These injuries are expensive due to slow healing, extensive convalescence and high risk of recurrence. The prognosis has been reported to be everything from good to guarded depending on the size of the lesion and the location within the suspensory ligament. The purpose of this study was to determine how different factors such as age, use, and location of the lesion are associated with the final outcome after a suspensory ligament injury. Material: Hospital records of 27 horses treated for suspensory ligament injuries at SLU equine hospital in Skara, Sweden, between January 2002 and July 2003 were examined retrospectively.

Påverkan från den förväntade klimatförändringen på tillväxten i norra Sveriges skogar : En litteraturanalys

This is a literature review of how the climate change affects the forest growth innorthern Sweden. The temperature will rise about 5 °C with the largest increase in thewinter season (December - February) and the CO2level in the atmosphere is expected tobe doubled. Precipitation patterns will change and increase with 25-35 % and theprecipitation will be in form of rain rather than snow. Today the forests in northernSweden are entirely dominated by coniferous stands. This may shift with the climatechange and results in a larger number of deciduous trees, preferably birch will becomestronger and grow better and faster.

Sjuksköterskans arbete på en akutmottagning,sett ur ett omvårdnadsperspektiv : en litteraturstudie

Aim: The aim of this study was to describe the nurse?s work at an emergency department trough a perspective of caring.Method: A literature review has been made of twelve studies published between the years of 2002 ? 2012. The focus of all the studies was on Swedish emergency departments.  Results: The researchers found four themes that they choose to use as a way of describing the nurses work in the emergency room as detailed as possible. These themes were: ?The emergency room?, ?the nurse?s job assignments at an emergency department?, ?the patient?s experiences? and ?lifeworld and communication?.

Förutsättningar för småskalig solelproduktion i Australien

The study aims to investigate the feasibility of small-scale electricity production with solar electricity systems, also known as PV (photovoltaic) systems, in Australia. Due to the global warming, sustainable energy has in recent years become an increasingly important issue, both internationally and in Australia. With one of the largest dependencies on fossil energy sources in the world, the country's abundant solar radiation is a possible solution to this issue.Both the technical and the economic feasibility of small-scale PV systems were investigated. On the technological side, the electricity generation, distribution and consumption systems were studied. On the economical side, the parameters that drive the profitability of a PV investment were investigated.

Itrakonazol till häst : en farmakokinetisk möjlighet?

Itraconazole is a third generation azol, a fungicide which acts by inhibiting ergerosterol synthesis in the fungal cell membrane, and thereby disturbing fungal regeneration. It has proven to be less toxic, to have a broader spectrum of activity and to be more potent than its predecessor ketoconazole. Itraconazole is only available in therapheutics approved for human use. Pharmacokinetic studies has been performed in humans, dogs, cats and laboratory animals. Although itraconazole has been used tentatively with good effect against fungal infections in horses, no pharmacokinetic studies have yet been done.

Konstruktion av sök/räddningsrobot

Volvo Human Monitoring (VHM) is an ongoing project at Volvo Cars where they measure, amongst other parameters, inhalation and exhalation through a device called Respiratory Inductance Plethysmograph (RIP), on drivers. RIP measures changes in the cross-sectional area of the chest and abdomen. When the driver is in motion, such as when she is turning the vehicle, the cross-sectional area changes and noise in the RIP signal may arise.The noise results in a large number of manual adjustments in the analysis of the RIP signal, which is very time consuming and the validity of the device for measuring inhalation and exhalation is questioned.The purpose of this study was to improve the efficiency of the analysis of the RIP signal. The goal was to create a new data processing tool in Matlab that automatically detects inhalation and exhalation from a RIP signal with higher validity compared to the previous data processing tool.In this study, nine tests were performed on drivers while they were driving in different scenarios such as highway, country road and in city traffic. Inhalation and exhalation was measured using a RIP, a pneumotachograph with a tightly sealed facemask and a thermocouple placed between the nose and mouth, which was used as reference to the RIP.The result of this study was a data processing tool that automatically detects inhalation and exhalation with higher validity compared to the previous data processing tool.

Nya träd för stadsmiljö

Trees in urban environment are exposed to extreme conditions, foremost the ones that grow in the hard packed soil along our streets. They are also exposed to damaging insects and fungal diseases both local and new ones spreading from South Europe. The global warming with warmer temperatures provides a longer growing season, making it easier for insects and fungus to establish a habitat. Based on these facts new tree species need to be available for future urban plantings.To determine what these trees would be an interview study began. Six people were selected who have experience in the field of urban environment planting.

<- Föregående sida 47 Nästa sida ->