District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

AbstractThe future of ethanol is depending on good solutions for the production. ENA energy power plant produces electrical power and district heating by heating biofuel. By building an integrated bioenergy plant surplus steam could be used to produce ethanol as fuel to vehicle.This would mean that ethanol is produced renewable energy and the energy for the process derives from the surplus of power.  ENA energy, MDH (the University of Mälardalen) and the energy authority has initiated a research project were different bioenergy combinations integrate with existing power plant.  As a part of the project which size an integrated factory should be to gain the best efficiency for the plant was investigated. Consideration will be taken to the cost of the production in order to be competitive to the price of imported ethanol.  Etanolens framtid vilar på bra lösningar för framställning.  I ENA energi kraftverk i Enköping produceras el och fjärrvärme genom eldning av biobränsle.  Genom att bygga ett integrerat bioenergikraftverk där skulle man kunna använda överskottsånga till att framställa etanol som fordonsbränsle.

Small hydropower plants have been an important source for electricity for many years. During the 70?s the general thought was that nuclear was the future. Around 2000 small waterpower plants were shut down. It wasn?t profitable to invest in.

This has been a thesis work for an bachelor degree at Umeå university. The work has been done at LKAB?s facilities in Kiruna and its main purpose has been to investigate and construct some conceptual designs for replacing a screen with magnetic separation in KA3 concentrator plant. First all information available about magnetic separation was gathered and studies of magnetic separation at the sorting plant and studies of the plant KA3 was conducted. Companies that manufacture magnetic separators were contacted.

The aim with this work has been to examine the climate changes and what these has meant, and will mean during the present century, for plants that have not been hardy in Sweden. A lot of new species can probably be grown today in Sweden's most southern parts, due to an increase in the average annual temperature by 1?C. There is a need of information about these new species and their hardiness. The insufficient information about the subject has been the background to this work.

This is a report written for an examination project C-level, on the subject of energy. The examination project is a product of the FVB Sweden AB (district heating bureau). It started with a meeting with Stefan Jonsson FVB Sweden AB, were he explained the content of the project, and from this a presentation of the problem was made. The problem that needed to be solved was how they could control the valves in the system to provide heating to everyone in the system. The valves are often oversized so the pump in the heating plant would have to be enormous to be able to provide enough flow to be sufficient, if everyone in the system had there valves fully opened. I came up with two solutions to the problem, one was a wireless network that could keep track of the valves and the other solution was an extra sensor that was placed on the radiator.

The main purpose of this thesis has been to find a way to evaluate the soil parameters for the Total sounding method (TS), such as the inner friction angles and settlement modules. This study only includes an analysis of soil profiles from the Stockholm region. The chosen location for the study is a proposed residential area east of Igelstaviken in Södertälje. Presently, the subject plot is located in a residential area and is also adjacent to a school area.Total sounding is originally a Norwegian soil testing method. The differences between the sounding methods (weight-, ram-, CPT-sounding) are for instance how the sound is driven into the ground and what kind of parameters that are registered.

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.

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 thesis work was made for Södra Cell Mörrums bruk in Blekinge. The purpose of the work was to develop a computer model in the simulation program Extend for the removal and balance of organic oxygen consuming substances, measured as COD (Chemical Oxygen Demand), in the new biological treatment plant in the mill. The plant produces two different pulp products, TCF- (Totally Chlorine Free) pulp and ECF- (Elementary Chlorine Free) pulp, for sale. The different bleaching procedures affect the characteristic of the wastewater and thus the effectiveness of the biological treatment plant.In the model that was developed the COD in the wastewater was divided into five different COD-fractions: soluble easily degradable (SS), soluble hardly degradable (SR), soluble inert (SI), particulate inert (XI) and particulate biomass (XB). To create the model FlowMac? was used as a base.

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 master thesis has been performed at Solvina in Gothenburg for Skellefteå Kraftand Vattenfall Eldistribution. The aim of it is to investigate the consequences of theinstallation of a wind power plant on the mountain Uljabuouda in the vicinity ofArjeplog. Especially the impacts on voltage and transient stability are examined.Furthermore, the amount of extra strain on the voltage regulation equipment and theneeds for increased regulation capabilities are looked into.The wind power plant is planned to be built by Skellefteå Kraft and connected to a130 kV grid owned by Vattenfall Eldistribution. The work comprehends the followingmain parts:- Theoretical studies aimed at wind turbines and power system stability issues.- Modelling of the type of wind turbines assumed to be built on Uljabuouda.- Simulations of different operation cases and analysis of the simulation results.The results from the simulations show that, as far as voltage stability and extraworkload on tap-changers are concerned, the wind power plant does not, in anysignificant manner, worsen the present conditions. The problem of overloading theline between Arvidsjaur and Vargfors is also minor.

The species in the genus bumblebees (Bombus) are important pollinators. In the world there are 250 bumblebee species and there are 34 species in Norway. The purpose of this study is 1) to assess changes in the species composition of bumblebees in twenty different places in Norway that have been inventoried first one time between 1939-1960 and the second time in 2012, and 2) to relate species richness and distributions to current landscape composition with the aid of orthophotos. In this study, I have used regression analyzes on the different bumblebee species that were present or absent at the inventory, using the premises of the following variables: low or high altitude, latitude, longitude and seven different types of land use (farmland, building/plots, open land/pasture, forest, wetland and open or snow-covered ground above the tree line) to see if there was any relationship between each species and the different variables. I have not analyzed what the landscape looked like at the first inventories and therefore we cannot say whether it has changed and if that is why species number has decreased. This would be interesting to study further and to see if there is any relationship between landscape changes and bumblebee?s species decline.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

Gastric and intestinal disorders are common and costly human health problems worldwide. Helicobacter pylori are a gram-negative, pathogen bacteria and the most common cause of duodenal and gastric ulcer in the stomach the intestinal mucosa. Prolonged infection and colonization can lead to chronic gastritis and stomach cancer. H. pylori are present in the gastric and intestinal mucosa of half of the world population and a relation between infection and low socioeconomic status has been shown.