Because of new emission and on board diagnostics legislations, heavy truck manufacturers are facing new challenges when it comes to improving the engines and the control software. Accurate and real time executable engine models are essential in this work. One successful way of lowering the NOx emissions is to use Exhaust Gas Recirculation (EGR). The objective of this thesis is to create a mean value model for Scania's next generation EGR system consisting of a poppet valve and a two stage cooler. The model will be used to extend an existing mean value engine model.

The purpose of this paper is to create an understanding of the negotiation process behind the decision of who will stay at home with a sick child and to develop the knowledge of the mechanisms considered to affect the negotiation process, in particular, the mechanisms likely to contribute to an uneven use of care leave. In the study six interviews were conducted with three sets of parents. These interviews were then analysed with Janet Finch?s (1989) definition of negotiation of family responsibilities. The study finds that the negotiation on care leave is a result of the negotiation of the shared view of reality.

The aim of the study was to examine the retinal ON- and OFF-pathways of the canine electroretinogram (ERG). The ON- and OFF-pathways are used to distinguish objects from their backgrounds. A dark object is discernible from a lighter background using the OFFpathway and the ON-pathway is used to descry a light object upon a darker background. This study shows that the dog ERG has both ON- and OFF-responses and that these responses can be separated by prolonging the flash duration over 50 ms. The dog OFF-response waveform was more similar to the cat OFF-response than the human OFF-response (Frishman, 2006; Zrenner and Gouras, 1979). In this study six female three-year-old Beagle dogs were included. Both background and flash stimuli were provided by LEDs (light emitting diodes) with a wavelength of 470 nm, a wavelength that is absorbed almost as effectively by the canine M/L-cones as by the S-cones. These stimuli gave ERGs with both ON- and OFF-responses.

Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.

Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.

Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP.

To save energy it?s popular to build houses with low energy loss. In these houses the walls are keeping a lower temperature in the external side which leads to a higher relative humidity. In addition more material, such as wood studs, are used which means that there is more moisture to dry. More moisture in combination with higher relative humidity may pose a higher risk of microbial growth.

Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.

The aim of this masters thesis is to examine query expansion. Query expansion is the process of adding new terms to a query to improve the retrieval effectiveness. In this study the baseline query was expanded in five different modes. The first expansion strategy was formulated by the inflected terms as the system does not allow truncation, I have inflected the terms, e. g.

Alzheimer's disease is the most common form of dementia. The individual who fall ill can be in an age between 40-65 years old. When dementia affects individuals at this age, many relatives take their responsibility for taking care of them at home for a long time.The aim of this study was to illustrate emotions relatives experienced when a close family member's suffering from Alzheimer's disease. The study was intended to show relatives emotions, and therefor four self-biographies were chosen to read. The method used to analyze was a narrative literature review.

The world is currently facing a huge severe challenge in handling the issue of climate change. One of the ways to lower the green house gas emissions, which is seen as one of the main contributor to the climate crisis, is to use renewable technologies such as for example photovoltaic (PV) systems. PV-systems are also suitable for so called micro production, small scale energy production facilities, since it can be placed on practically any rooftop with the right solar conditions. In Sweden the usage of PV-systems has not yet gotten any wider spreading, even though the solar radiation conditions are very similar to countries that produce a lot of solar energy, as for example Germany. The aim of this paper is to describe non-adopter perceptions of PV-systems. The study holds a qualitative approach using deep interviews for data collection.

Difficult calvings and stillbirths are problems in Swedish dairy production that result in large expenses for the farmers and welfare issues concerning the animals. A common opinion is that the live weight of SRB and SLB is increasing, and whether increased weights have caused the increase in calving problems has been discussed. The aim of this study was to investigate the relationship between the relative birth weight (calf/cow) and calving difficulty and stillbirth, respectively. The importance of breed and parity for the relative weight has been investigated, and comparisons with previous studies have been made to evaluate whether the relative weight has changed over the last decades or not. The study was based on 807 calvings, registered during the period 1993-2003 in the experimental dairy herd of the Swedish University of Agricultural Sciences (Jälla).

Background: The difference between the market value and the book value of the companies has dramatically increased. One explanation is that the inflow of capital on the market has increased. Another explanation is that companies have a larger share of intellectual capital. The question is how this has influenced the company-valuator's use of valuation-models? Purpose: The purpose of this study is to find out what relevance the substance valuation model has, the DCF-model has, and also discover new valuation-models, among company-valuators.

This Masters thesis deals with query expansion in an online library catalogue. The aim of the study was to compare the retrieval effectiveness of four different query types when applied to the online library catalogue of the University College of Borås. The query types were: an initial query, the initial query with right hand truncation, the initial query expanded with synonyms and finally the initial query expanded with synonyms and right hand truncation. 24 topics were formulated, and four queries for each topic were constructed. The records retrieved by the searches were judged with regard to topicality, and were judged to be non-relevant, partially relevant or relevant.

Purpose: This study examines pedagogues? thoughts about children?s understanding of death, and their reactions to the death of a relative. The aim is also to examine pedagogues? thoughts about their part in supporting bereaved children, and how they wish to do so. Method: Seven pedagogues, who work with six to nine year old children, were interviewed.