Drinking water from drilled wells has a high content of iron and other minerals in many places in Sweden. Questions about the association between the quality of drinking water and the health of dairy cows are regulary asked both by advisers and dairy farmers. There are so far not many studies published about the relevance for high iron content in water and dairy cow health and production. Therefore, the aim of this study was to investigate if there is a connection between the iron content in water and the health of dairy cows. Initially a literature study was made about iron and it´s function in ruminants.

Swedish biogas is currently produced mainly by anaerobic digestion of sewage sludgeat sewage treatment plants, landfills and anaerobic digestion of household or industrialwaste. Also cattle ma-nure from farms can be used to produce biogas. Upgradingbiogas represents an increase in methane concentration from about 65 % to about 97%. In addition, particles and contaminants must be sepa-rated from the upgradedbiogas. There are various methods for upgrading and this report compares sixdifferent methods with respect to environment and economy: water scrubber,Biosling, cryo technology, chemical absorption, Pressure Swing Adsorption (PSA) andmembrane separation.According to the used ORWARE model, chemical adsorption with amine has the leastenvironmen-tal impact (methane emissions) and the lowest costs.

During the last few years the presence of high arsenic (As) concentrations in ground water has been of major concern both internationally and in Sweden. Much evidence has been reported about toxic effects caused by arsenic. The carcinogenic effects and the possibility to measure the toxic impacts at low concentrations made the World Health Organisation (WHO) to reduce the guideline value from 50 to 10 ?g l-1 in 1993. In Sweden the corresponding reduction was implemented in 2003. Several surveys in Sweden have shown that high arsenic concentrations may occur in ground water.

This master thesis was conducted in order to investigate the effects of the browsing species Yeheb on animal tissues in Swedish landrace goats and to make a literature review in order to increase the knowledge of the importance of this plant for livestock production in Somalia. The evergreen Yeheb bush is a very important feeding source for grazing and browsing animals in Somalia during the dry period. Yeheb contains cordeauxiaquinone that stains the bones of the animals red/pink, which has been an increasing problem when exporting meat to foreign countries. In an experiment, two goats were fed dry and fresh leaves from the Yeheb bush for one and two months, respectively. The goats did not feed the intended amount of dry leaves, since the supply and palatability was not as high as estimated.

This master thesis reviews advances in detection and diagnosis of static friction (stiction) in control valves. Control valves suffering from stiction results in oscillating control loops which in turn decreases both the process stability and reliability. Perstorp AB sees a necessity to automatically detect stiction in valves before the effects of the malfunctioning valves have become too severe. This thesis presents an introduction to maintenance, control loops and how stiction in valves can affect performance of control loops.A selection of methods presented in the literature are introduced and examined using normal operating data from the site in Perstorp. Common for all selected methods is their intuitive ideas and that they are based on normal operating data and minimum amount of process knowledge.

Livestock animals affect their environment in a number of different ways, mostly through grazing and trampling. This study focused on the effects of Gotland pony grazing on forest structure and diversity, and the impact on ground cover. To compare the fenced and grazed area with a reference area outside the enclosure a number of transects were used. The study showed that there was no significant difference in height structure and diversity between the compared sites; however, there were a significantly higher proportion of damaged trees inside the enclosure. The ground cover variables showed a higher amount of bare soil, plant litter and wood-rush (Luzula sp.) inside the enclosure whilst grass was more frequent in the reference area.

A real option model is developed to examine the crucial factors affecting the agricultural firms? decision to quit the production and rent out the land to a company building a PV power plant. The public policies in support of investments in renewable energies have created the conditions for a market regarding investments in PV installations in agricultural areas.The decision to switch offers to the agricultural firm and to society several economical, social and environmental benefits, representing sustainability. However, PV installations in agricultural areas require the allocation of a certain land area. By assigning a part of land to PV installations, thereby the area of land allocated to agricultural production decreases.

Fuel pellets are a refined bio fuel mostly consisting of residues from sawmills and wood industry. At Rindi Västerdala AB's combined bio energy plant in Vansbro fuel pellets are produced, while the waste heat from the process is used for district heating. The pellets are produced from sawdust, wood shavings and dry wood chips that is dried, milled and pressed into small cylindrical rods. The advantage of refining the wood material in this manner is that the energy value is greater per unit volume and unit weight, thereby the cost of transportation per energy unit is reduced. Also, less storage space is needed.Pellet manufacturing is a complex process since many parameters affects the final results.

This master thesis was conducted in order to investigate the effects of the browsing species Yeheb on animal tissues in Swedish landrace goats and to make a literature review in order to increase the knowledge of the importance of this plant for livestock production in Somalia. The evergreen Yeheb bush is a very important feeding source for grazing and browsing animals in Somalia during the dry period. Yeheb contains cordeauxiaquinone that stains the bones of the animals red/pink, which has been an increasing problem when exporting meat to foreign countries. In an experiment, two goats were fed dry and fresh leaves from the Yeheb bush for one and two months, respectively. The goats did not feed the intended amount of dry leaves, since the supply and palatability was not as high as estimated.

Structural rationalizations and regionalization of the agricultural sector in Sweden has lead to unevenness in thedistribution of plant nutrients. Nutrients are lost from crop producing farms as harvest products are sold, whilefarms with animal production often have manure in excess of their needs. In addition to this the retention ofwater and nutrients in naturally occurring wetlands has decreased due to a reduction of wetlands in number andsize in the agricultural landscape. This increases nutrient levels in agricultural run-off and causes eutrophicationas well as nutrient losses from arable soils. One potential solution to both problems would be to store nutrientrichsurface water from agricultural areas and use it for irrigation of agricultural crops.

Volvo Trucks is the second largest manufacturer of heavy trucks, with factories in several countries and with around 21 000 employees. At the plant in Tuve, trucks have been built since 1982 and the activity mainly consists of producing side members and to assemble and packing kits of trucks. In 2005, the factory in Tuve launched the ambition to be the first carbon dioxide neutral vehicle factory in the world. This will be implemented by streamlining and investing in renewable energy. The aim of this degree thesis is to map the usage of energy within production, and also to prepare a method to measure key figures (use of energy per produced unit).

Invasive alien plant species have historically caused major damage to ecosystems and are considered to be amongst the greatest threats to biodiversity globally. The lurking threat of harm to well functioning ecosystems has led to the development of global and regional goals and regulations which seek to stop the spread of invasive species. The Swedish Environmental Protection Agency has proposed a list of species that are specifically harmful to the Swedish flora and fauna, which includes (amongst others) garden lupin. The management of invasive species is however largely dependent on local actions, making municipal public servants key players. This qualitative study uses interviews to investigate how municipal public servants who are responsible for managing invasive alien species view this work.

The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

The aim of this study was to examine the current and historic mercury(Hg) load of the lake Storjuktan due to its recent exposure to a local potential source of Hg in form of the Sulphide mine Blaikengruvan(2006) and an earlier potential sources of Hg-load, the damming of the lake(1960s). Sediments were extracted using a HTH-sampler, freeze-dried, and analyzed for tot-Hg, LOI and activity of 210Pb and compared to samples extracted prior to the opening of the mine(2006). Constant initial concentration (CIC)-dating model was used for dating the samples. Low levels of Hg (100ng/g) were found throughout the lakes sediment. The highest levels of Hg(220ng/g) was detected at a depth of 4-5cm dating back to the mid 1970:s, suggesting that increased levels of atmospheric Hg rather than damming of the lake has caused the increase of Hg.

This thesis work was made to optimize the writing of the construction specificationsat FKA. These construction specifications are created before each plant modificationsthat is started because requirements from the Swedish radiation safety authority(SSM) and internally on Forsmarks nuclear group as constructions / implementationdocumentationThe study was done through seven interviews of two people at three different groupsinvolved in the construction specification and an interview from the group accreditedverification. The four selected groups were selected through an extensive analyticalwork resulted in an elimination matrix where these four groups was considered to bemost involved with the construction specification.The questions asked to these individuals were based on the instructions and sampletext that are described in the construction specification. To ensure the quality of thethesis were to limit itself to the chapters that were considered most relevant toimprove. The analysis revealed a number of points that should be improved, partlyinto the routines when writing the construction specification and when ether sampletext or suggestions should be changed and complemented.