This master?s thesis is a remote sensing study of an area-based method used to detect forest in need of thinning by use of laser data and field samples. Only pine-dominated forest has been included in the study and height limits were set to match empirical restrictions. The study area was in the municipality of Älvsbyn (Latitude 65° 40´ N, Longitude 21° 00´ E), in northern Sweden.The Swedish authority Lantmäteriet is currently laser scanning most parts of Sweden, providing new opportunities and applications. The primary aim of the national laser scanning is to create a new elevation model, useful in consequence analysis of climate changes.

In this literature review the characteristics of two free-floating macrophytes, water hyacinth   (Eichhornia crassipes) and duckweed (Lemna sp.), and two microalgae, Chlorella and Scenedesmus, have been examined regarding their suitability as efficient nutrient removers in the treatment of wastewater with high levels of nutrients and suspended solids from a biogas plant in Loudden. The needs required for the plants to be able to grow in wastewater and the amounts of biomass they can produce have also been studied. The results show that Chlorella is capable of a very high uptake of nutrients in photobioreactors with high nutrient loadings. With an ammonia uptake maximum value at 10900mg/m2/d Chlorella outshines the other organisms in this study. The test organism that performed the closest to Chlorella in terms of nitrogen uptake was water hyacinth with an uptake about 1602mg/m2/d.

In today?s society there is an increasing demand for renewable energy sources such as sun and wind power. These sources are intermittent, and energy storage is therefore needed to ensure a constant power supply. This report compares pumped hydro energy storage (PHES), compressed air energy storage (CAES), flywheels, batteries, super magnetic energy storage (SMES) and hydrogen energy storage.The opportunities for further development are limited for PHES and CAES in comparison with the other technologies. Lithium-ion batteries and hydrogen energy storage are considered to have the most potential in the future.

Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication  due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences  that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin.  The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.

Predation is one of many factors that form the structure of the macroinvertebrate community in lakes, wetlands and watercourses. Earlier studies lack an examination concerning how fish- and waterfowl predation affect macroinvertebrates during shorter periods in the spring. I performed an exclosure study in the shallow eutrophic Lake Tåkern which is located in the western part of Östergötland County, Sweden. The experiment was performed during a three week period (1-21 April 2012) when the water temperature was low and the density of migrating diving ducks was high. The experimental cages used included three out of four different treatments; general predation (open cages), bird exclusion (net with mesh size 90*45mm) and no predation (net with mesh size 1*1mm).

Cannibalism can have major influence on fish population dynamics. A prerequisite for cannibalism is that the cannibal and the potential victim meet, and besides density effects, the encounter rate between cannibals and their victims is therefore also largely dependent on habitat use and habitat heterogeneity. In this study I quantified and compared the potential for cannibalism in stream-dwelling European grayling populations in three rivers in Jämtland by means of habitat classifications. I also analyzed population dynamic consequences of varying the potential for cannibalism in terms of intensity, using a physiological structured population model. Findings based on habitat characteristics were that the potential for cannibalism is in general not favourable in these types of streams.

Urban density is not new, but rather one side of the continous processes of change underway in the city. During the urbanizing boom of the industrialization, when the cities grew bigger, the first spaces to be built on were vacant and planted areas in the interior of the district. The gardens that once were there were replaced by yardhouses. The idea of urban density is that a dense city means less distance between residential areas and workplaces, resulting in fewer shipments and travelers, which ultimately leads to lower energy consumption and lower emissions. Urban density may lead to shorter distances, but not necessarily. In the wake of urban density the greenstructures of the city is shattered. The possibilities for green areas to contribute to the health of the city and its inhabitants is dramatically reduced.

SammanfattningSyfte och frågeställningar Syftet med denna uppsats var att undersöka hurvida en LCHF (Low Carb High Fat) kost skulle kunna vara en hälsosam livsstil utifrån hur den påverkar olika hälsomarkörer hos normalviktiga personer där en viktminskning ej har eftersträvats. Frågeställningen var följande: Hur påverkar en LCHF-kost med maximalt 30 gram kolhydrater per dag under 3 veckor normalviktiga kvinnors BMR (Basal Metabolic Rate), blodlipider, blodglukos, blodtryck, kroppssammansättning, midje- och höftmått samt deras kroppsvikt?Metod En experimentell studie har genomförts på 8 normalviktiga kvinnor mellan 20 och 35 år. Samtliga försökspersoners BMR, blodlipider, blodglukos, blodtryck, kroppssammansättning, midje- och höftmått samt kroppsvikt mättes vid normala levnadsförhållanden innan studiens start samt efter 3 veckor av en strikt LCHF-kost med endast 30 gram kolhydrater per dag.Resultat BMR sänktes i genomsnitt med 4,4% vilket var signifikant (P<0,05). HDL (High-density lipoproteins), LDL (Low-density lipoproteins) samt totalkolesterol höjdes signifikant (P<0,01) med 21%, 25% respektive 22%.

The cat has evolutionary become an obligate carnivore. Today it is common to feed the cat a dry food. Studies have shown that the dry formula can have negative consequences for the cat. A literature study where conducted to investigate whether the cats origin makes it incapable to compensate for the changes a dry food entails. The impact and implications regarding water intake, energy intake and blood glucose concentration when feeding the cat dry food where examined.

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.

This master thesis project is a part of a project called ?Järboprojektet? at the regional board of forestry, the district of Gästrikland. The project will give answers to questions regarding if an analysis of satellite images can be used to contact and inform landowners of the located areas where precommercial thinning is useful. The whole project is a part of the National Board of Forestrys IT-stake where the analysis of satellite images will, at the latitudes possible, be adapted to each district in purpose to identify these areas in need of precommercial thinning. This master thesis project is based on a field inventory of identified objects where precommercial thinning is useful.

Genomic selection (GS) is used for selection of breeding animals of dairy cattle. GS is though not as extensively used within the beef industry. One reason for that is the low accuracy (rTI) of the breeding value that is of great importance for the final genetic gain. Causes to the low accuracy are high effective population size, a small reference population and a genetically differentiated population. There is however a market for genomic selection with High density (HD) tests for beef cattle.

At the Skoghall pappermill, sulphatepaper pulp is produced in a continuous digester originally from 1969. To be able to maintain a high level of production there is a need for a process with few disturbances. Variations in how well the wooden chips are packed in the digester is one form of disturbance. Today there are no available measurements on how well the chips are packed. Instead this is regarded as being constant.

In 1994 the EU directive of packaging waste was adopted. The result was that all EU member states developed different systems to manage packaging waste and recycling. This paper examines the various systems and the factors that affect the level of recycling. This is done by a cross-sectional study between countries. The results of my study suggest that take-back system generates less recycling than other systems, the mandatory deposit system can affect the recycling in a positive way.

The purpose of this study is to examine some factors that make a human grouse hunter to prolong and increase its hunting effort. The theory of optimal foraging is used for explaining their behavior.The data of this study is collected from a web-based inquiry from 2007 answered by grouse hunters in Sweden. The method that has been used is mainly bivariate statistics and logistic regression analysis.Key findings shows that an experienced grouse hunter has more than 5 times the chance of prolonging hunting effort when grouse density is high, compared to a beginner grouse hunter. On the same time experienced grouse hunters also stop hunting in advance when grouse density is low to a larger extent than inexperienced hunters. Other factors of importance for prolonging the hunting effort for a day are age and the travel distance to the hunting area.