Rwanda is one of the poorest countries in the world and about 70-80 % of the population lives in rural areas. The land is strongly affected by land erosion which makes it difficult for the agriculture and food production. Agroforestry is a system where tree plantation is combined with livestock- and crop production. The system provides soil fertilization and binds the soil together. Some of the trees used in agroforestry systems are also used as fodder.

This master thesis was made to validate hydropower models of a turbine governor,Kaplan turbine and a Francis turbine in the power system simulator ARISTO atSvenska Kraftnät. The validation was made in three steps. The first step was to makesure the models was implement correctly in the simulator. The second was tocompare the simulation results from the Kaplan turbine model to data from a realhydropower plant. The comparison was made to see how the models could generatesimulation result that was similar to the reference power station.

The combustion engines in today?s vehicles are getting more and more advanced and there are increasing demands on that the engines should operate during optimal conditions. Examples of internal combustion engine parameters which may be carefully controlled are the rate between fuel and air, that this gas mixture is homogenous enough and that it is ignited at the correct moment. Moreover, the requirements of these parameters vary depending on, among other, engine speed and load. To meet these requirements in all occurring operation conditions, it is required that many subsystems work together.

The prevailing food and energy crisis of the world, due to the declining reserves of fossil energy and a never ending rise of consumption, forces us to look into new fields to supply our energy demand. The boom of bio energy is criticized, as food crops are used to provide biodiesel and ethanol and the volumes are ridiculously small to supply world demand. Algae are one of the world?s oldest life forms and exist in many different phyla, providing a great variety to choose from, for different purposes. Cultivating microalgae offer a way to produce energy at great volumes without competing with food production and at the same time the algae offer a way to use our expensive nutrients in a more efficient way, besides this the algae are carbon dioxide neutral since their carbon source can be supplied by the atmosphere and the additional energy required can be supplied by algal oil or other renewable sources.

Fungi are everywhere around us and recently, there has been an increased interest in their role and importance in the forest. The fungi have several strategies to acquire energy and nutrition; one example is a mutual symbiosis with trees and plants - another being dissolving organic materials. Attempts have been made to better understand the circulation of nutrition in coniferous forests, and how fungi cooperate. Trees and plants have adapted with mycorrhizae and are now interdependent which is important to consider in forestry. A great number of fungi depend on dead wood and old trees to set fruiting bodies and spread further. These fungi also create environments for other species, such as birds and insects. The vegetation of a forest is determined by a series of factors; tree species, how old the forest is, soil type, as well as the ability of the fungal spores to spread and establish. Furthermore, in determining vegetation, the fungi?s ability to compete in the soil matters. These factors are nearly unexplored. Researching fungi knowledge and interest, a survey was distributed to five groups of people. The groups included forest owners, high school teachers, high school students, senior citizens, and a fifth group - ?o he ? - consisting of people of mixed ages and backgrounds.

This report deals with the performance of a batch flow treatment of landfillleachate compared with a continuous flow system. The parameters in focus were total Kjeldahl nitrogen (TKN), BOD5 and COD. The pilot-scale experiment used eight barrels with a volume of 150 liters. Each barrel was constructed differently concerning its flow, its bed material grain size and its presence of plants or not. Four of the barrels worked in batch mode, thus four in continuous flow mode.

To plan and build a garden in Dubai has other conditions and challenges than what you experience in Sweden. The heat, wind and lack of water makes the need for durable plants, a good design and landscaping important if you want to have the opportunity to use your garden during most of the year. The soil is poor of nutrients, alkaline and sometimes saline, witch makes supplying the soil with organic material and various fertilizers necessary if you want to be able to plant a bigger range of plant material in your garden. Another important part is to provide your garden with a good irrigation system that should be put into the ground before planting so that the plants are given a more even irrigation. It?s relatively green scenery you meet and to me it?s in a way surprising since the country with its climate is rather harsh for the purpose of supporting plant life.

The rainforests of the world are important not only to the countries in which they grow but to the world as a whole. They influence oxygen and water circulation as well as carbon sequestration which in turn affect global radiation and global warming. The forest also have great value and in Malaysia as in many other tropical countries large volumes are harvested which leaves great areas of degraded forest with little growth and biological diversity. Due to their low financial value these forests are often transformed and used for other purposes than forestry such as oil palm plantations. The trees are often transported out of the forest using large bulldozers. They are heavy which causes compaction of the forest floor and during transport the top soil layers are moved to improve mobility.

The farm management system controlled traffic farming (CTF) aims to reduce soil compaction by restricting the field traffic from agricultural machinery to permanent traffic lanes. Literature and empirical findings show that soil compaction and field traffic from heavy machinery may affect crop growth negatively, reducing crop yields. If grass-clover leys are subject to heavy field traffic the botanic composition might be altered, providing a lower clover content in the forage. Clover as a silage feed is rich in protein providing good conditions for high yielding dairy cows. Grass-clover silage production is generally associated with intensive field traffic.

This report describes the construction of a climate-cabinet for testing of HV-cards (High Voltage) produced at VG Scienta. The main part of the report describes all the different components of the cabinet. The most important parts are a PID regulator from Eurotherm model 2408, a solid state contactor (SSC), a thermocouple, a finned resistor from DBK and different fans. The report even includes the connection between components by cable wiring, isolation, grounding, fuses and shaping of metal goods.As the cabinet also communicates with a computer, the report includes the solution of the data communication using the software iTools from Eurotherm. The communication part includes information about a converter that converts EIA422 to USB.The cabinet was produced at a company, called VG Scienta, in Uppsala during the spring 2010.

The mining company LKAB extracts iron ore in three areas in the north of Sweden, Kiruna, Malmberget and Svappavaara. The iron ore is refined and in the pelletizing plants the material is rolled to finished pellet product. The different steps of pelletizing plants causes among other things emissions to the air. It occurs occasionally stops in the production and the emissions are vented via an emergency chimney without purification. The aim for this work is to look into how LKAB may improve their monitoring of air emissions and control of ambient air quality and the analysis methods which are suitable for measuring.

Pulsatilla vernalis is one of several endangered plant species that benefit from wildfires and small scale disturbance events that repel competing vegetation and create open patches in the vegetation cover. Previous studies argue that Pulsatilla vernalis is decreasing in numbers due to vegetation changes associated with the decrease in wildfires, forest grazing and changes in forest management. In this study, 17 populations of P. vernalis were inventoried in order to examine if soil and/or vegetation structures affect the population structure of P. vernalis (i.e.

During 40 years of industrial production, from the end of the 1890?s until the end of 1930?s, coal and wood distillation products were manufactured in AB Carbo?s tar factory along the River Gimån in Grötingen, in the county of Jämtland, Sweden. In accordance with the Swedish Environmental Protection Agency?s Methods for Inventories of contaminated sites, MIFO, the site in Grötingen has been identified as a potentially contaminated site. In order to determine whether toxic substances pose a threat to human health and ecological systems in the area, there was a need to investigate the presence of contaminants, their levels and potential for migration.

This thesis describes redesign and adaption of a products housing. In order to make it more economical to produce at a lower production volume. The thesis is based upon a prototype that a previous student developed for injection moulding. The goal is to find alternative manufacturing methods, but also to identify parameters that affect the cost of the injection moulding tool.The housing must be tough in order to protect the circuit board inside. But at the same time it must allow sound, light an electrical communication to pass through.

The purpose of this report is to increase the awareness about the problem that occur when the waste hierarchy is applied to management of contaminated land. The work with remediation of contaminated land in Sweden is part of the efforts towards reaching the national environmental objectives. Therefore a subsidiary aim is to analyze how this influences the prospects of reaching the objectives. The work consists of two parts; a case study and a comparative literature study that focus on England, the Netherlands and Sweden. The case study is intended to provide a practical perspective through a comparison of the climate impact from two methods.