That ecological and evolutionary processes can take place on the same time scale is a recent insight. Today we also know that they are directly linked to each other. In the lake Tåkern, in year 2000, there was a structural change when phytoplankton declined and submerged vegetation, mainly stoneworts began to spread. This led to evolutionary changes in the aquatic sowbug, Asellus aquaticus which had previously been limited to the reed, most likely feeding on detritus. But then, sowbugs could exploit the new habitat in stoneworts and a new food resource in terms of periphyton.

The purpose of this thesis is to make a comparative literary study of ten Laboratory experiments with different kind of sources for query expansion terms. The experiments are grouped according to categories of term sources, which are: search results, collection dependent knowledge structures, collection independent knowledge structures and one that combines the two last mentioned sources into one. To enable a comparison all other variables were held as constant as possible. There is the improvement measured in mean average precision, which is used to measure the various sources potential. The result from the study shows a strong connection between the kind of source for the expansion term and improvement of the result.

Every day we make numerous decisions. Some are better than others. Intuitive decisions usually results in less good decisions when we do not reason about our choices. Research has been interested about the process that is behind how we make good decisions. Decisions we face every day, such as when we shop, determined using various mental shortcuts that we use unconsciously.

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.

The purpose with this report was to compare three commonly occurring methods for measuring plant available nitrogen in soils. The methods extraction, incubation and Plant root simulator (PRS) probe - an ion exchange membrane (Western Ag Innovations, Inc., Saskatoon, Canada) method were used and comparison between these methods were conducted. A full factorial experiment were set up in northern Finland with the treatments excluding herbivores, warming and fertilization to see how the inorganic nitrogen content in the soil was effected by the treatments. Soil cores were taken and from them a subsample was incubated for 18 days and thereafter analyzed for inorganic N in Laboratory. PRS- probes were in the ground for 1 month.

Flow measurement is one of the greatest challenges in order to calculate efficiency in hydropower. Most hydropower plants in Sweden use differential pressure methods for flow measurement. These methods are dependent on constant conditions in the waterways. A change in these conditions, like turbine improvements, prevents differential pressure methods to verify efficiency improvements. Since efficiency improvements can?t be verified by one measurement system, another method, which isn?t affected by changing conditions, can be used.

To be able to evaluate different radio waveforms in a Laboratory environment FOI in Linköping has developed an experimental system for radio communication called Rasmus. The system consists of a transmitter, a channel emulator and a receiver. The transmitter modulates a digital signal to a desired analogue waveform. The channel emulator is used to simulate a real radio channel. The channel emulator distorts the signal by splitting it up in several propagation paths.

SammanfattningLaborationer i naturvetenskapliga ämnen är en naturlig del av undervisningen. Syftet med den här uppsatsen är att ta reda på om man tar bort en möjlighet till inlärning och förståelse för eleverna om laborationer inte används i undervisningen. Vidare ville jag undersöka om lärare och elever anser att laborationer utvecklar förståelsen av naturvetenskap, dessutom om eleverna förstår syftena med laborationerna.Undersökningen utfördes genom att kvalitativa intervjuer gjordes med fyra lärare och sex elever i en gymnasieskola. Resultatet visar att lärarna har olika åsikter om laborationens betydelse för förståelsen av ämnet. Däremot anser eleverna att laborationer utvecklar deras förståelse för naturkunskap.

By examine plastic craniums from eight different hominids I wanted to find morfological characteristics that agreed with those of modern humans. The species that were selected had a plastic casting of its cranium in the Laboratory at Gotland University. My focus was on species from the family Australopithecius and Homo and only working with their craniums. And this because the cranium and the theeth shows the most visible morfological characteristics between the different hominids. I also wanted,in a small part of the essay, to write about the differences in now living primates and humans skulls.Except from analysing the plastic castings I also studied surveys written by other scientist on the same subject.

When drivers overnight in the truck lots of electric energy is consumed by heaters, fans, lights and other extra equipment. If the engine is not running, this energy is taken from the lead/acid batteries of the truck which then needs to be recharged during operating hours. The fact that the charge acceptance of the lead/acid batteries is dependent on the temperature makes it hard to fully recharge the batteries at lower temperatures. A negative charge balance can lead to starting problems within a few days use in cold climate.In this thesis work, the effects of different battery charging concept are evaluated on the most common Scania battery (175Ah). A battery model is implemented in Matlab and some simulations of charging are made.

The thesis aims at, from a user perspective, examining how a group of industrial researchers understand the information seeking in their every day work. A qualitative method is employed. The empirical material consists of open-ended interviews with in all ten researchers. All of them work at the Swiss-Swedish Technology Company ABB's research Laboratory in Västerås. The thesis is based on the opinion that the scientific knowledge production has become commercialised and that the scientific communication is going through certain changes.

During my practical training period I observed that many of the students have a negative attitude against mathematics. I also observed that these students have a difficulty reaching the goals in the subject. In my opinion there are different factors that can be the reason to why these students experiences mathematics as a difficult subject in school. This is the reason why I wanted to find out which factors that lies behind the difficulties and how the pedagogues work to support these students. It is also significant that every single student get their rights to develop a positive attitude against mathematics and that the pedagogue supports the students in their development.The point with this degree project is to find out, with the help of three pedagogues, which factors that could lead to difficulties in mathematics with students.

Company X develops a Laboratory information system (LIS) called System Y. The informationsystem has a two-tier database architecture consisting of a production database and a historicaldatabase. A database constitutes the backbone of a IS, which makes the design of the databasevery important. A poorly designed database can cause major problems within an organization.The two databases in System Y are poorly modeled, particularly the historical database. Thecause of the poor modeling was unclear concepts.

Lattelement AB in Ornskoldsvik is one of the leading companies in Sweden in composite elements in walls, floors and roofs in particular. The company supplies elements to buildings located with a wide geographical variation, which means that the products are subjected to very different climate with regard to snow, wind and humidity. This places high demands and requires the elements to withstand large variable loads.The elements are made of lightweight beams with flanges of structural timber and beam webs made of OSB. These are bound together by nogging pieces with the same kind of structure. On top of the beams a nailed and glued plywood is added to absorb compressive forces and on the underside of the element a sheet of steel is added for tensile absorption.These elements are then attached to the building framework in different ways depending on the particular element height, loads and the structual supporting material of the frame work.

The female dog has a unique reproductive endocrinology, with high levels of progesterone throughout the 70-day long luteal phase. In this project, markers of glucose metabolism were studied and compared from the aspects of breed group and time in oestral cycle. The parameters studied were: glucose, insulin, progesterone, fructosamine and the newly introduced analysis of HbA1c. Hba1c was also further evaluated and discussed as a diagnostic tool in canine medicine.No differences in terms of glucose markers were found between a group of purebreed dogs of various breeds compared to a group of dogs with high risk of dioestrus diabetes, namely the Norwegian and Swedish elkhounds.No differences were found between the two sample occasions, anoestrus and dioestrus, concluding that there is no need for relating test results to the time of the oestrous cycle in middle-aged intact female dogs.There were statistically significant higher values of all glucose markers in diabetic dogs than in non-diabetic dogs. When it came to HbA1c, however, there was a larger overlap between the two groups, compared to fructosamine.