Svensklärares arbete : om villkor för gymnasieskolans svenskämne

The aim of this didactic study is to understand the terms of work, education and teaching of Swedish in a period round 2000. The research questions focus on how teachers at upper secondary school in conversations describe and construct their work, values in society and school, structures of power and relation to time. With the help of tools related to story and storytelling, and by connecting the empirical material to a late modern society, I caninterpret and understand the description of their work. With the help of Pierre Bourdieu’s theory I can see how values, power and relation to time are expressed in different ways when teachers of Swedish talk about their work and education.The results show that when teacher talk about work in school is it related to ideals in a global economy. Decentralization and individualization get new meanings when those words are placed in school environment and activity. Effectiveness, flexibility and individualization are words related to economy and they seem to have an effect on education and subjects of Swedish. I can also understand teachers’ work when it is related to power and values on the educational field. I can see how a diffuse power acts on the field and how harmony is a dominant value and a term that influences teachers’ work. New terms also form new identities related to teaching. New terms form new subjects of Swedish that in time and practice will form newhabitus connected to subjects. I call it ämneskonceptionella habitus.

Tribology in Metal Working

This thesis focuses on the tribological performance of tool surfaces in two steel working operations, namely wire drawing and hot rolling. In all forming operations dimensions and surface finish of the products are of utmost importance. Forming basically includes three parts – forming conditions excluded – that may be changed; work material, tool and (possibly) lubricant. In the interface between work material and tool, the conditions are very aggressive with – generally or locally – high temperatures and pressures. The surfaces will be worn in various ways and this will change the conditions in the process. Consequently, the surface finish as well as the dimensions of the formed product may change and in the end, the product will not fulfil the requirements of the customer. Therefore, research and development in regard to wear, and consequently tribology, of the forming tools is of great interest. The investigations of wire drawing dies focus on coating adhesion/cohesion, surface characteristics and material transfer onto the coated steel both in laboratory scale as well as in the wire drawing process. Results show that it in wire drawing is possible to enhance the tribological performance of drawing dies by using a lubricant together with a steel substrate coated by a polished, dual-layer coating containing both hard and friction-lowering layers. The investigations of hot rolling work rolls focus on microstructure and hardness as well as cracking- and surface characteristics in both laboratory scale and in the hot strip mill. Results show that an ideal hot work roll material should be made up of a matrix with high hardness and a large amount of complex, hard carbides evenly distributed in the microstructure. The surface failure mechanisms of work rolls are very complex involving plastic deformation, abrasive wear, adhesive wear, mechanical and thermal induced cracking, material transfer and oxidation. This knowledge may be used to develop new tools with higher wear resistance giving better performance, lower costs and lower environmental impact.

Dynamic whole system testing of combined renewable heating systems : the current state of the art

Objective: For the evaluation of the energetic performance of combined renewable heating systems that supply space heat and domestic hot water for single family houses, dynamic behaviour, component interactions, and control of the system play a crucial role and should be included in test methods. Methods: New dynamic whole system test methods were developed based on “hardware in the loop” concepts. Three similar approaches are described and their differences are discussed. The methods were applied for testing solar thermal systems in combination with fossil fuel boilers (heating oil and natural gas), biomass boilers, and/or heat pumps. Results: All three methods were able to show the performance of combined heating systems under transient operating conditions. The methods often detected unexpected behaviour of the tested system that cannot be detected based on steady state performance tests that are usually applied to single components. Conclusion: Further work will be needed to harmonize the different test methods in order to reach comparable results between the different laboratories. Practice implications: A harmonized approach for whole system tests may lead to new test standards and improve the accuracy of performance prediction as well as reduce the need for field tests.